Introduction How straight is a straight wire appliance? When this question is asked to the orthodontists, it will produce varied responses. Some clinicians readily accept the straight wire concept and appliance, as being both scientifically sound and clinically acceptable, other clinicians question the concept itself and criticize the appliance but considering all factors preadjusted systems have provided great benefit to orthodontics in all stages of treatment, no matter what the original malocclusion, a rectangular finishing arch wire in a preadjusted system always require some 1 st, 2nd and 3rd order bends to precisely position the teeth. One can not simply place an ideal rectangular arch wire in a straight wire appliance, and assume that ideal positions of each tooth will result. Essentially every patient varies in teeth morphology and bracket positioned. Will require some adjustment in the final rectangular arch wire. The actual amount of finishing and detailing in any given case may be increased by any of the following; 1. Variation in the shape and size of the patients teeth preadjusted to the average measurements used for the preadjusted appliance. 2. Inaccuracies or shortcoming in appliance design relative to its measurement goal. 3. Inaccuracies in appliance placement relative to the design of the appliance. 4. Failure to allow sufficient time for the bracket system to express itself. As in many other aspect of dentistry for e.g. a denture will not be better than a primary impression or an only will not be better than a crown preparation an obturation will not be better than a root canal preparation. If all other factors remain equal in a pure preadjusted system a finishing and detailing will not be better than a bracket placement, so if we consider, a straight wire system purly straight then the effectiveness of the straight wire appliance depends on perfect bracket placement. However practically this axiom is impossible hence I believe that in preadjusted system finishing is the beginning of the end so lots start with the end. The six keys to normal occlusion Andrews discussed six significant characteristics observed in a study of120 casts of non-orthodontic patients with normal occlusion. These constants will be referred to as the six keys to normal occlusion. The six keys to normal occlusion contribute individually and collectively to the total scheme of occlusion and, therefore, are viewed as essential to successful orthodontic treatment. Key I Molar relationship1

The first of the six keys is molar relationship. The non-orthodontic normal models consistently demonstrated that the distal surface of the distobuccal cusp of the upper first permanent molar occlude with the mesial surface of the mesiobuccal cusp of the lower second molar. Therefore, one must question the sufficiency of the traditional description of normal molar relationship. It is possible for the mesiobuccal cusp of the upper first permanent molar to occlude in the groove between the mesial and middle cusps of the lower first permanent molar (as sought by Angle) while leaving a situation unreceptive to normal occlusion. The closer the distal surface of the distobuccal cusp of the upper first permanent molar approaches the mesial surface of the mesiobuccal cusp of the lower second molar, the better the opportunity for normal occlusion. Key II Crown angulation The gingival portion of the long axes of all crowns was more distal than the incisal portion. The crown tip is expressed in degrees, plus or minus. The degree of crown tip is the angle between the long axis of the crown (as viewed from the labial or buccal surface) and a line bearing 90 degree from the occlusal plane. A plus reading is awarded when the gingival portion of the long axis of the crown is distal to the incisal portion. A minus reading is assigned when the gingival portion of the long axis of the crown is mesial to the incisal portion. Normal occlusion is dependent upon proper distal crown tip, especially of the upper anterior teeth since they have the longest crowns. Let us consider that a rectangle occupies a wider space when tipped than when upright . Thus, the degree of tip of incisors, for example, determines the amount of mesiodistal space they consume and, therefore, has a considerable effect on posterior occlusion as well as anterior esthetics. Key III Crown inclination The third key to normal occlusion is crown inclination. Crown inclination is expressed in plus or minus degrees, representing the angle formed by a line which bears 90 degrees to the occlusal plane and a line that is tangent to the bracket site (which is in the middle of the labial or buccal long axis of the clinical crown, as viewed from the mesial or distal. A plus reading is given if the gingival portion of the tangent line (or of the crown) is lingual to the incisal portion. A minus reading is recorded when the gingival portion of the tangent line. Anterior crown inclination Upper and lower anterior crown inclinations are intrieately complementary and significantly affect overbite and posterior occlusion. The upper posterior crowns are forward of their normal position when the upper anterior crowns are insufficiently inclined. Even when the upper posterior teeth are in proper occlusion with the lower posterior teeth, undesirable spaces will result somewhere between the anterior and posterior teeth, if the inclination of the2

anterior crowns is not sufficient. This space, in treated cases, is often incorrectly blamed on tooth size discrepancy. Posterior crown inclination upper The pattern of upper posterior crown inclination was consistent in the nonorthodontics normal models. A minus crown inclination existed in each crown form the upper canine through the upper second molar. Posterior crown inclination The lower posterior crown inclination pattern also was consistent among all the non-orthodontic normal models. A progressively greater minus crown inclination existed from the lower canines through the lower second molars. Key IV Rotations The fourth key to normal occlusion is that the teeth should be free of undesirable rotations. Key V tight contacts The fifth key is that the contact points should be tight (no spaces). Key VI occlusion plane The planes of occlusion found on the non-orthodontic normal models ranged from flat to slight curves of Spee. Intercuspation of teeth is best when the plane of occlusion is relatively flat. Three is a tendency for the plane of occlusion to deepen after treatment. A deep curve of Spee results in a more contained area for the upper teeth, making normal occlusion impossible. Only the upper first premolar is properly intercuspally placed. The remaining upper teeth, anterior and posterior to the first premolar, are progressively in error. A reverse curve of Spee is an extreme of overtreatment, allowing excessive space for each tooth to be intercuspally placed A brief note on three main orthodontic goals. In broad sense, the 3 major goals of orthodontic treatment are; 1. An ideal occlusion which is healthy and functionally satisfactory 2. Ideal facial esthetics 3. Ideal stability of results An ideal occlusion which is healthy and functionally satisfactory.3

There is no evidence, that minor irregularities of teeth or of arch relationship are harmful to the health of dentition, but a normal occlusion to have proper function should have certain property. The term normal implies a situation commonly found in the absence of disease and physiological adaptive range. The end result of the orthodontic treatment to bring about an occlusion which is healthy and functionally satisfactory should have following quality. 1. Stable jaw relationship when the teeth make contact in centric relation. 2. Correlation between centric occlusion and centric relation. 3. The occlusion guidance in various excursion should be on the working rather then on balancing side. 4. Functional stability means that impact of full intercuspidation closure be in the long axis of all posterior teeth. 5. Absence of any occlusal interference between centric relation and centric occlusion. 6. Guiding inclines. They are lingual incline of the buccal cusp of the maxillary posterior and lingual inclines of the maxillary anterior teeth. Buccal inclines of the lingual cusp of the mandibular posterior teeth. The guiding inclines are the planes of occlusal ridges that determine the path of the supporting cusp during normal lateral and protrusive excursions. Aesthetically satisfactory The majority of the patients seek orthodontic treatment for esthetic reasons. A perfect occlusion is generally regarded as esthetically ideal. However esthetic standard cannot be rigidly formulated and not all irregularities of teeth are esthetically unsatisfactory. What is acceptable, depends on the attitude of the patient himself, and on the community in which he lives. For example for some people a mild element of bimaxillary proclination is attractive while for other it is unacceptable and is considered to be a justification for orthodontic treatment. Stability The natural occlusion before orthodontic treatment is stable in planing orthodontic treatment to any change in position of the teeth must be another position of stability. Generally it is impossible to maximize all three goals. In fact, to attempts to achieve an absolutely ideal dental occlusion, one can compromise facial esthetic. However, it may be associated with instability after treatment in the same way effort to achieve the most stable result after orthodontic treatment, may necessitate compromise in both facial esthetic and occlusion. Where as positioning the teeth to produce ideal facial esthetics may result in less than optimal occlusion and stability. One way to deal with this of course is to emphasize one of the goals, at the expense of the others. In the early twentieth century angle solved this problem by focusing solely on the occlusion and declaring that facial esthetics and stability would take care of themselves, unfortunately they did not.4

As important as dental occlusion is it is not the most important consideration for all patients. Some times ideal occlusion must be altered by extraction or otherwise, to gain acceptable esthetic and stability. In general if all of three major goals of orthodontic treatment cannot be reached, those of greatest important to the patients should be favoured. Elimination of lower retention The frequency with which lower retainers are used after treatment to prevent lower incisor or cuspid collapse suggests there is little understanding of how to avoid these post treatment events. However, several steps can be taken during fixed appliance treatment to eliminate the need for retention in the lower dentition. (Raleigh Williams) has introduced six treatment keys which have emerged as essential if lower retention is to be eliminated. First key The incisal edge of the lower incisor should be placed on the A-P line or 1mm in front of it. This is the optimum position for lower incisor stability. It also creates optimum balance of soft tissues in the lower third of the face for all the variations in apical base differences within the normal range. Appliance control is required to achieve optimal position of the lower incisor consistently at the end of treatment. If the lower incisor is advanced too far beyond the A-P line, relapse and crowding will occur. Lower incisors that are overly proclined in treatment beyond one standard deviation can only be maintained in such an untenable position with a fixed retainer. When the retainer is removed, the incisors will move lingually and become crowded. Second key The lower incisor apices should be spread distally to the crowns more than is generally considered appropriate, and the apices of the lower lateral incisors must be spread more than those of the central incisors. When the lower incisor roots are left convergent, or even parallel, the crowns tend to bunch up and a fixed lower retainer is usually needed to prevent post treatment relapse. Third key The apex of the lower cuspid should be positioned distal to the crown. The occlusal plane, rather than the mandibular plane, should be used as a positioning guide. Use of the mandibular plane might indicate that the apex is not sufficiently distal to the crown, when in fact it is if the occlusal plane is used. Such a circumstance could occur when there are highly divergent occlusal and mandibular planes in a steep mandibular plane angle case. This angulation of the lower cuspid is important in creating post treatment incisor stability because it reduces the tendency of the cuspid crown to tip forward into the incisor area. If this happens, the lower incisors crowd up, even if their roots are spread and the incisal edges are on the A-P line or 1mm in front of it. 5Distal

inclination the lower cuspid should be a standard treatment object and is easily accomplished with the Begg or any straightwire technique. Straightwire systems agree within 4-6 of inclination of the lower cuspids to the occlusal plane. Fourth key All four lower incisor apices must be in the same labiolingual plane. Spreading the apices of the lower incisor roots distally causes a strong reciprocal tendency for the crowns to move mesially. Moreover, as the roots are spread, the contact areas between the incisor crowns move upward toward the anatomical contact points, which are small, rounded, and near the incisal edge. Because of the strong mesial pressure, there is a tendency for these contact points to displace each other labiolingually. This results in a reverse movement of the apices linguolabially. The displacement forces are considerably augmented by the increasing width of the lower incisor crown toward the incisal edge and contact point. This means that provision for the additional space must be made during the spreading process. Otherwise, labiolingual apical displacement of the lower incisors will tend to occur, and the degree to which it occurs will affect lower incisor post treatment stability. Fifth key The lower cuspid root apex must be positioned slightly buccal to the crown apex. This is extremely important because of its influence on post treatment stability. All sort of occlusal forces await their chance to exert lingual pressure on the lower cuspid crown. If the apex of the lower cuspid is lingual to the crown at the end of treatment, the forces of occlusion can more easily move the crown lingually toward the space reserved for the lower incisors because of these functional pressures plus a natural tendency for the crown to upright over its root apex. Even if a lower cuspid with abnormal lingual position of the apex were supported for many years with a fixed retainer, the crown would eventually move lingually when the restraint was removed. To torque the lower cuspid apex buccally, a Begg clinician can use a simple auxiliary. An edgewise clinician can place the appropriate torque in the rectangular wire. There is a bewildering range of lower cuspid buccal root torque in straightwire edgewire brackets, from 11O to 47O, a total variation of 18O. Between the lower right and left cuspids, the combined variation can be 36O. Variations in crown slopes to which the variously torqued brackets are attached compound the dilemma. Sixth key The lower incisors should be slenderized as needed after treatment. Lower incisors that have sustained no proximal wear have round, small contact points, which are accentuated if the apices have been spread for stability. Consequently, the slightest amount of continuous mesial pressure can cause various degrees of collapse in the lower incisor segment.

6

Flattening lower incisor contact points by slenderizing or stripping creates flat contact surfaces that help resist labiolingual crown displacement. This treatment also helps eliminate the need for lower incisors retention. If the post treatment dentition displays pressure signs by developing irregularities among the incisors reduction of incisor width by slenderizing can be the answer. Usually only minimal tooth structure has to be removed if the root apices have been adequately spread. Occasionally, more than one slenderizing session may be necessary to bring the tooth mass into harmony with the jaw size and to eliminate the need for lower incisor retention. Some post treatment situations do not seem to have a detrimental effect on lower incisor stability. One is the depth of the overbite, and another is prodigious mandibular growth that carries incisors forward against the upper incisors and tips them out. Experience has shown that neither of these requires the protection of a lower retainer. Proper positioning of maxillary first molars The normal position of the maxillary first permanent molar has been described with some detail concerning its cusp relation, and axial alignment. With these basic factors in mind, the orthodontist needs to deviate from them in a major or minor degree as warranted by the case under treatment. The orientation of the maxillary first permanent molar into normal occlusion, may be simplified by following a few suggestions in appliance therapy. It is necessary to eliminate the supraversion of the mandibular second permanent molar. This may be accomplished in a multiband technique by banding the mandibular second molars and placing its attachment as far occlusally as is possible. When the mandibular second molar is not sufficiently erupted to be banded, an extension may be soldered to the lingual arch and adapted to rest on the occlusal surface of the second molar. This extension may be adjusted to correct the supraversion of the second molar to the first molar. The attachment on the buccal of the maxillary first molar may be placed in such a position that mesial axial inclination will be accomplished with a minimum number of compensating bends in the arch wire. When the band for this tooth is formed parallel with the tips of the buccal cusps, the buccal attachment should be placed on the band at such an angle that its mesial edge is directed toward the incisal. A straight arch wire placed into this attachment will accomplish the mesial axial inclination. When the buccal attachment on the maxillary molar band placed toward the mesial angle of the tooth, the favourable distolingual rotation of the buccal cusps will be accomplished with a minimum number of compensating bends in the arch wire. The suggestions made for treatment therapy to correct the malposition of the maxillary first permanent molar are;7

a. Depressing of the mandibular second molar. b. Placement of buccal attachment to accomplish proper mesial inclination. c. Placement of the buccal attachment to accomplish proper rotation. Factors which should be considered during finishing and detailing problems and remedies; 1. Root paralleling at extraction sites. 2. Correction and over correction of the A-P jaw relationship. 3. Establishing correct tip of the upper and lower anterior teeth. 4. Establishing correct torque of the upper and lower anterior teeth. 5. Correction of vertical relationship. A. B. Excessive overbite Anterior openbite

6. Correction of midline discrepancies. 7. Co-ordinating arch width and arch form. 8. Tooth size discrepancies. 9. Establishing correct posterior crown torque. 10. 11. 12. 13. 14. 15. 16. 17. Establishing marginal ridge relationships and contact points. Checking cephalometric objectives. Maintaining the closure of all spaces. Evaluating facial and profile esthetics. Checking for T.M.J. dysfunctions such as clicking and locking. Checking functional movement. Determining if all habits have been corrected. Correction of rotations and over correction where need.

18. Establishing a relatively flat plane of occlusion Root paralleling at extraction sites8

During space colours with the edgewire appliances. It is usually a goal of treatment to produce bodily tooth movement during space closure, preventing the crowns from tipping together. If proper moment to force ratios have been used. Little if any root paralleling will be necessary as a finishing procedure. On the other hand, it is likely that at least a small amount of tipping will occur in some patients, and some degree of root paralleling is often necessary. With the 018 appliance, the typical finishing archwire is either 017 x .022 or . 017 x .025 steel. These wires are flexible enough to engage narrow brackets even if a moderate degree of tipping has occurred, and the archwire will generate the necessary root paralleling moments. If a greater degree of tipping has occurred, a more flexible full dimension rectangular archwire is needed. To correct more severe tipping, a bets titanium or even a nickel steel archwire to obtain final positioning. With wider .22 x .025 brackets on the canines and premolars and with the use of sliding rather than loop mechanics, there is usually even less need for root paralleling as a finishing procedure than with narrow brackets and closing loop archwires. If teeth do tip even slightly into the extraction space, however, a full dimension steel archwire in a .022 bracket is much too stiff to produce the needed root up righting moment. Even a .019 x .025 steel wire is undesirably stiff. A rectangular beta titanium wire is an excellent choice of root paralleling is needed. A root paralleling moment is a crown separating moment in edgewise just as it is in Begg, and this effect is important to remember. Either the teeth must be tied together at the extraction site, or the entire archwire tied back against the molars (Fig. 21), to prevent the extraction site from reopening during finishing. Occasionally, a severely tipped canine tooth will be encountered, and a longer range of action is needed than can be delivered by even the most flexible continuous archwire. In this situation, there are two options: (1) bending a loop into a rectangular archwire to provide the desired flrxibility or (2) using a auxiliary root uprighting spring. With the .018 appliance, the best choice is usually a box loop in .016 x .022 or .017 x .025 wire. At the same time that the root of the canine tooth is being positioned distally, this loop can also be used to obtain a last bit of space closure. A similar box loop archwire can be used with the .022 appliance, made from .018 x . 025 wire (the smallest size that will not twist in an .022 bracket). The alternative is to by pass the tipped canine with a rectangular base arch and use an auxiliary root uprighting spring extending from the auxiliary tube on the first molar and tied into the canine bracket. In .022 edgewise, this is the preferred approach. Another method which has been introduced by L. Colin Ress for paralleling at Extraction Sites is as follows: If extraction space has been closed too fast, the crowns of the canines and first premolars tend to tip toward each other. With inaccurate bracket placement, paralleling the roots becomes even more difficult. In such a case, make a gable bend directly over the extraction site with a Tweed loop forming plier. Use figure eight metal ligatures on the adjacent teeth to counteract the crown separating tendency of the bend and consequent reopening of the extraction site. To enhance 9

the root paralleling action of the gable bend, place another bends mesial to the premolar and distal to the canine. After the roots are parallel in three or four months, place the archwire under the canine and premolar brackets to level the arch. New brackets can then be bonded. If a bracket has been bonded slightly too far incisally on one tooth compared to adjacent teeth, place bends on either side of the tooth. These will exert a purely extrusive force on that tooth and an insignificant intrusive force with distal root tip on the adjacent teeth. Even if the arch has been levelled, the mesial marginal ridge of the first bicuspid may be more gingival than the distal marginal ridge, causing excessive distal root tip. Make identical clockwise bends, directed toward the tooth to be moved, with the rounded tip of a jarabak plier on either side of the tooth. This will result in a pure tipping movement of the first bicuspid, along with a slight extrusive and mesial root tipping effect on the second bicuspid and a slight intrusive and mesial root tipping effect on the cuspid. Correction and over correction of the A-P jaw relationship Considerations of anteroposterior skeletal and dental corrections are, for the most part, not specific to preadjusted systems. The tip and torque built into the anterior brackets of these appliances create a greater demand for anchorage, particularly in the upper arch, but the total anchorage required for a given anteroposterior correction is about the same for all appliances. Overcorrection of the Class II case is the greatest challenge in this area. If corrected only to the desired and position, many Class II cases will show a relapse of overjet and a deepening of the bite. These patients benefit from overcorrection to an edge to edge position and maintenance of that position with night time Class II elastics for six to eight weeks, followed by settling into an ideal Class I relationship. Other Class II cases have a Class III growth tendency in retention and clearly would not benefit from overcorrection in the finishing stage. However, growth prediction is difficult, regardless of the appliance system. Establishing correct tip of the upper and lower anterior teeth The tip built into the face of preadjusted bracket eliminates the need for 2nd order bends in the anterior segments, making treatment much more efficient. Wire bending will occur in only two situations. 1. When brackets are improperly placed relative to the vertical reference lines of the anterior teeth (although it is much easier to reposition the brackets than to place unnecessary bends in the anterior segments of both archwires). 2. When irregularly shaped anterior teeth, such as peg shape lateral incisors, are present.10

There is also a mechanical advantage to built in tip in cases of anterior spacing. Without anterior archwire bends, the wire slides through the bracket slots far more efficiently, allowing effective use of sliding mechanics for space closure. 3. establishing correct torque of the upper and lower anterior teeth If protruding incisors tipped while they were being retracted, lingual root torque as a finishing procedure may be required. The anterior torquing needs of patients vary so widely that no single set of bracket torque values can meet the needs of all the cases seen in an orthodontic practice. Therefore, it is often necessary to adjust the torque in the upper and lower anterior segments at various stages of treatment with a preadjusted appliance. The most common examples is during overjet correction of the moderate to severe Class II case, when torque is frequently lost in the upper anterior segment while the lower incisors are angulated forward. In this situation, it may be necessary to compensate by adding lingual root torque to the upper anterior teeth and labial root torque to the lower anteriors. Such compensatory bends should be placed early in the space closure and overjet correction phase, to avoid having to re establish lost torque during the finishing stage. One of the great virtues of pretorqued brackets is that, even in the .022 appliance, tipping of incisors can be largely prevented during retraction and space closure. For this reason, torquing auxillaries for the .022 edgewise appliance have almost disappeared from contemporary use. In addition, full dimension nickel titanium or bets titanium arch wires can be used to torque incisors with .022 brackets (provided the brackets have torque built in), further reducing any need for auxiliary arches). One torquing auxiliary deserves special mention: the burstone torquing arch. It can be particularly helpful in patients with Class II division 2 malocclusion whose maxillary central incisors are severely tipped lingually and require a long distance of torquing movement, while the lateral incisors need little if any torque. Because of the long lever arm, this is the most effective torquing auxiliary for use with the edgewise appliance. It is equally effective with the .018 or .022 appliance. Two factors determine the amount of torque that will be expressed by any rectangular archwire in a rectangular slot: the inclination of the bracket slot relative to the archwire, and the tightness of the fit between the archwire and the bracket. With the .018 appliance, it is assumed that the rectangular archwires used for finishing will fit tightly in the bracket slot, i.e., that the finishing archwire will have a minimum dimension of .017 or .018. With the .022 appliance, on the other hand, some brackets may have extra built in torque to compensate for rectangular finishing archwires that will have more clearance. Torque will not be expressed to the same extent with a .019 wire in a .022 bracket as with an .017 wire in an .018 bracket. The difference amounts to several degrees of torque. Obviously, it is important to know what finishing wires were intended in any given straight arch appliance. 11

For full expression of the torque built into brackets in the .022 edgewise appliance, it is better to use an .021 x 025 beta titanium arch wire for finishing, taking advantage of the greater resilience of this modern material. A less effective alternative is .021 x 0.25 braided rectangular steel wire. A solid .021 x .025 steel wire cannot be recommended because of its stiffness and the resulting extremely high forces and short range of action. Correction of vertical relationships If the first two stages of treatment have gone smoothly, no change in the vertical position of incisors will be needed during the finishing stage of treatment. At this stage, anterior open bite is more likely to be a problem than residual excessive overbite, but either situation may occur. Excessive overbite Before attempting to correct excess overbite at the finishing stage of treatment, it is important to carefully assess why the problem exists, and particularly to observe the vertical relationship between the maxillary lip and maxillary incisor. An excessive curve of Spee with relative elongation of the lower incisors may still be the cause of overbite, but by this stage of treatment, the problem is often slight elongation of the maxillary incisors. If so, an auxiliary intrusion arch is the preferred solution. If a rectangular finishing archwire is already in place, the simples approach may be cut this archwire distal to the lateral incisors and install an auxiliary intrusion arch. Alternatively, if the patient is still growing and relative rather than absolute intrusion would be satisfactory, a light round continuous archwire with an accentuated curve of Spee (.016 or .018) can be placed, and an auxiliary arch added to it. As a general rule, if an auxiliary depressing arch is added to a continuous base archwire, the base arch should be a relatively small round wire, while if the base arch is segmented, the segments should be rectangular wire. It is important to remember that when an auxiliary intrusion arch is used, a stabilizing transpalatal lingual arch may be needed to maintain control of transverse relationships and prevent excessive distal tipping of the maxillary molars. The greater the desired vertical change in incisor position, the more important it will be to have stabilizing lingual arch in place, and vice versa. Small corrections during finishing usually do not require placing a lingual arch.

Anterior open bite As with deep bite, it is important to analyze the source of the difficulty if an anterior open bite persists at the finishing stage of treatment. Only rarely is a persistent open bite caused by lack of eruption of the upper incisors, and elongating these teeth is usually undesirable. If the open bite results12 from

excessive eruption of posterior teeth, whether from a poor growth pattern or improper use of interarch elastics, correcting it at the finishing stage can be extremely difficult. High pull headgear to the upper molars is the best approach if excessive vertical development of the posterior maxilla is the basic problem, and this treatment will have to be continued until growth is nearly complete, usually well into the retention period. If no severe problems with the pattern of facial growth exist, however, a mild open bite at the finishing stage of treatment is usually caused by an excessively level lower arch. This condition is managed best by elongating the lower but not the upper incisors, creating aslight curve of spee. Because of the stiffness of the rectangular archwire futile to use vertical elastics without altering the form of the archwires to provide a curve of spee in the lower arch. Moreover, it is preferable to replace a heavy rectangular lower archwire with a lighter round wire before using anterior vertical elastics. Posterior marginal ridge discrepancies, which may also contribute to the open bite, should be eliminated with small vertical steps in the archwires. The preferred approach is to place a light round wire (.016 or .018) in the lower arch, with a slight curve of spee and any necessary vertical steps to correct marginal ridge discrepancies, while retaining a full dimension rectangular archwire in the upper. Light elastic force is then used to elongate the lower incisors and close the open bite. Elongating anterior teeth in this way, of course, is no substitute for controlling posterior vertical development. If carried to an extreme, this will reintroduce overjet and produce an esthetically uneacceptable relationship even if proper occlusion is achieved. Correction of midline discrepancies Most minor midline discrepancies of 3mm or less can be easily corrected with rectangular wires in the finishing stage (greater discrepancies require attention earlier in treatment). A relatively common problem at the finishing stage of treatment is a discrepancy in the midlines of the dental arches, this condition can result either from a preexisting midline discrepancy that was not completely resolved at an earlier stage of treatment, or an asymmetric. Closure of spaces within the arch. Minor midline discrepancies at the finishing stage are no great problem, but it is quite difficult to correct large discrepancies after extraction spaces have been closed and occlusal relationships have been nearly established. As with any discrepancy at the finishing stage, it is important to establish as clearly as possible exactly where the discrepancy arises. Although coincident dental midlines are an important component of midline discrepancy will be reflected in how the posterior teeth fit together it is undesirable esthetically to displace the maxillary midline, bringing it around to meet a displaced mandibular midline. A correct maxillary midline is important for good facial esthetics, while a small displacement of the mandibular midline creates no esthetic difficulty. If a midline discrepancy results from a skeletal asymmetry, it may be impossible to correct it orthodontically, and treatment decisions will have to be made in the light of camouflage versus surgical correction. Fortunately, midline 13

discrepancies in the finishing stage are not usually that severe and are caused only by lateral displacements of maxillary or mandibular teeth. Usually, the midline discrepancy is accompanied by a mild class II or III relationship on one side. In this circumstances, the midline can often be corrected by using asymmetric Class II (or Class III) elastic force. As a general rule, it is more effective to use Class II or III elastics bilaterally with heavier force on one side than to place a unilateral elastic. However, if one side is totally corrected while the other is not, a unilateral elastic is usually tolerated reasonably well by the patient. It is also possible to combine a Class II or Class III elastic on one side with a diagonal elastic anteriorly, to bring the midlines together. An important consideration in dealing with midline discrepancies is the possibility of a mandibular shift contributing to the discrepancy. This can arise easily if a slight discrepancy in the transverse position of posterior teeth is present. For instance, a slight narrow maxillary right posterior segment can lead to a shift of the mandible to the left on final closure, creating the midline discrepancy. The correction in this instance, obviously, must include some force system (usually careful coordination of the maxillary and mandibular archwires, perhaps reinforced by a posterior cross elastic) to alter the transverse arch relationships. Occasionally, the entire maxillary arch is slightly displaced transversely relative to the mandibular arch so that with the teeth in occlusion, relationships are excellent, but there is a lateral shift to reach that position. Correction again would involve posterior cross elastics, but in a parallel pattern. If a midline discrepancy is more from displacement of mandibular than maxillary teeth, or vice versa, the difference in stability with rectangular versus round wires can be used to help in correcting the situation. If the maxillary midline is correct while the mandibular midline deviates slightly toward one side, and a mild Class II relationship still exists on that side, replacing the rectangular mandibular finishing arch with an .016 or .018 round wire, while retaining a full dimension rectangular arch in the upper arch, can facilitate correction with a unilateral Class II elastic. This approach should be reserved for small discrepancies, and it is important to carefully observe and control any expansion of the lower molar while a Class II elastic is worn against a light archwire. Prolonged use of Class II or III elastics during the finishing stage of treatment should be avoided, but a brief period of interarch elastic force is often necessary to obtain final positioning of teeth. There are five methods of elastic wear for specific situations; 1. A single Class II elastic on one side and a double class II elastic on the other, for cases with a bilateral Class II component. 2. A single Class II elastic on one side only, when the overjet results in a slight Class II relationship on that side and the opposite side is in a Class I position. 3. Class III elastics on one side and Class II elastics on the other, for cases with the corresponding dental relationships.14

4. A single Class III elastic on one side only, when that side is in a class III position and the opposite side has a class I dental relationship. 5. An anterior cross elastic, when the discrepancy occurs primarily I the anteiror segments. Asymmetrical elastics should be used for a minimum period of time, and only with rectangular archwires, because of their tendency to cant the occlusal plane. The archwires should be tied back while these elastics are worn so that the wires do not slide around the arch, causing unwanted space opening and distortion of the archform. Co-ordinating arch wire widths and form Upper and lower arch wires should be co-ordinated from the early stages of treatment through to the rectangular wire stage. This will help eliminate unwanted and trouble some cross bite in the finishing stages. Most arch width discrepancies can be fully corrected by the time rectangular wire stage has been reached. This can be done by narrowing or widening the arch wire at the beginning of the treatment. With some asymmetry cases the patients arch form may show distortion in the anterior segment particularly in the canine area. This can be treated by using cross elastic in canine areas and by canting the arch wire in the opposite direction to the arch asymmetry. Archwire canting and elastic wire will often help correction of anterior asymmetries even before the finishing stages of treatment. Tooth size discrepancies Tooth size discrepancy problems must be taken into account when treatment is planned initially, but many of the steps to deal with these problems are taken in the finishing stage of treatment. Reduction of interproximal enamel (stripping) is the usual strategy to compensate for discrepancies caused by excess tooth size. When the problem is tooth size deficiency, it is necessary to leave space between some teeth, which may or may not ultimately be closed by restorations. One of the advantages of a bonded appliance is that interproximal enamel can be removed at any time. When stripping of enamel is part of the original treatment plan, most of the enamel reduction should be done initially, but final stripping can be deferred until the finishing stage. This procedure allows direct observation of the occlusal relationships before the final tooth size adjustments are made. Tooth size deficiency problems are often caused by small maxillary lateral incisors. Having a small space distal to the lateral incisor is usually esthetically and functionally acceptable. Addition of composite resins to small teeth is an excellent way to compensate for tooth size problems, and is often the best plan for small incisors. It is better to add small amounts of resin on both sides of a small15tooth

than a large amount on one side. During finishing, segments of coil spring are usually placed on the finishing archwire to precisely position the small tooth. The composite buildups should be done as soon as possible after the patient is in retention, but not until soft tissue inflammation has been resolved. More generalized small deficiencies can be masked by altering incisor position in any of several ways. To a limited extent, torque of the upper incisors can be used to compensate: leaving the incisors slightly more upright makes them take up less room relative to the lower arch and can be used to mask large upper incisors, while slightly excessive torque can partially compensate for small upper incisors. These adjustments require third order bends in the finishing archwires. It is also possible to compensate by slightly tipping teeth, or by finishing the orthodontic treatment with mildly excessive overbite or overjet, depending on the individual circumstances. Establishing correct posterior crown torque Correct posterior crown torque is essential in preventing posterior interferences and allowing for the seating of centric cusps. The torque built in to posterior or brackets eliminate the need for archwise bonds in most situations. Nevertheless there is often a tendency for upper palatal cusps to be situated below the occlusal plane, requiring posterior buccal root torque to be placed in rectangular finishing wires. In the lower arch first and second molars can show undesirable lingual tipping and it may be necessary to and bucccal crown torque to the rectangular arch wires in the lower molar regions. Establishing marginal ridge relationships and contact points Marginal ridge relationships are mainly determined by bracket heights during the finishing stages of treatment. The most common method of measuring bracket heights with the standard edgewise appliance involved measuring a specific distance from the incisor or occlusal surface of each tooth. For example upper central incisors bracket were frequently placed 5mm above the incisal edge at the tooth. When the patients teeth were large the bracket was placed more incisally when compared to a patient with small teeth the 1st 2nd 3rd order bonds placed in standard edge wise archwires could compensate for the variation in bracket position. However such wire bending would not be acceptable for a preadjusted appliance designed to accommodate the maximum percentage of patient. A more reliable guideline is the center of the clinical crown as described by Andrews which provides a consistent bracket position regardless of tooth size. Incorrect bracket height becomes apparent early in the leveling and aligning stages of treatment. McLaughl in and Bennett are found it effective to reposition brackets as early as possible, so that time is not wasted stepping archwires or repositioning brackets during the finishing stage. A .014 round wire can be used to step any improperly positioned brackets, and at the next appointment these brackets can be repositioned with a heavier archwire and virtually no loss of treatment time. 16

There are other times in treatment when brackets can be repositioned to save time during finishing and detailing. For example, when newly erupted teeth such as second molars are bracketed or banded, other brackets can repositioned as necessary at the same appointment, since it is usually necessary to return to a smaller archwire to pick up the previously unbracketed teeth. Another method has been introduced by L. Colin Ress, in which if a bracket placement error is detected early enough for instance, with an .016 x .016 x .022 archwire in an .018 slot the problem can be corrected fairly quickly without round tripping. Instead of removing the archwire, rebonding the bracket, and placing a new multistranded or nickel titanium wire, the following technique can be used. 1. Make a 2nd order bend in the existing archwire, and wait four to eight weeks. 2. Carefully monitor the amount of activation in the wire at the next appointment. 3. Once the tooth has the correct mesiodistal inclination, bond a new bracket in the ideal position, using an unbent archwire as a guide. The next large archwire can usually be used, since the bent archwire will have been in place for at least eight weeks. Checking cephalometric objectives Progress headfilms should be taken about halfway through treatment to allow time for reassessment of anchorage and possible changes in the division of treatment time. It is prefarable to take final cephalometric headfilms three or four months before debonding, rather than after completion of treatment. Taking a headfilm at the end of treatment may be important for the orthodontists education and for evaluating the success or failure of the treatment, but it provides no practical advantage to the patient. If the cephalogram is taken before debonding, minor tooth position correction can still be made. Important factors to evaluate with progress and final cephalometric x-rays include the antero posterior position of the incisors, the incisor angulations, changes in the occlusal plane, the extent to which vertical development has occurred or been restricted, and the success of the case. Superimposition of the progress and final x-rays on the pretreatment x-ray will help determine the orthodontic change that has occurred. Maintaining the closure of all spaces It is important that space closure be maintained particularly in extraction cases, by using passive tiebacks in the finishing stage. Otherwise, spaces frequently open during finishing and must be reclosed. It is also beneficial in extraction cases, when dropping to a smaller archwire for relevelling or picking up previously unerupted teeth, to use lacebacks from molars to cuspids until the rectangular wire is resumed.17

Evaluating facial and profile esthetics Esthetic evaluation is an ongoing process during all stages of orthodontic treatment. A projection of esthetic goals should be made as part of the treatment plan the facial and profile esthetics can then be monitored clinically, as well as with progress and final cephalometric x-rays. The orthodontic look: By Roth 1. Flattened profile 2. Straight upper lip 3. Obtuse nasolabial angle All three are attributable primarily to a lack of torque in the upper incisors. Roth brackets for upper centrals and laterals have 12 and 8 degrees respectively. If a wire that fills the slot (0.021 x 0.025 inch, for example) is used and sufficient time (usually 3 months) is allowed for the built-in torque to express itself, this dentofacial problem can be avoided. 4. No mesial tip in cuspids 5. No mesial tip in incisors Both of these esthetically and functionally undesirable axial inclinations are routinely avoided with the ample mesial tip in all straight wire appliance upper and lower anterior brackets. 6. 7. 8. 9. Central incisors longer than laterals. Occlusal plane across upper anterior curved downward at the midline. Premaxilla elongated downward from class II elastics. Lots of gum tissue a gummy smile

This group is attributable to the following: (a) faulty bracket placement that positions the upper centrals longer than the upper laterals, (b) thin or weak arch wires with no anterior reverse curve to assure even and equal intrusion of the upper incisors, and (c) prolonged use of Class II elastics. Checking for TMJ dysfunctions such as clicking and locking TMJ dysfunction is a broad subject whose full discussion would be beyond the scope of this seminar. However, we recommend that the clinician: 1. Document any evidence of TMJ dysfunction prior to treatment, and inform the patient that such symptoms exist. 2. Monitor the patient for symptoms of TMJ dysfunction during treatment. If problems are managed before the development of true internal derangement, then joint function can often be re-established without permanent damage. Such treatment often involves a short phase of splint therapy and physical therapy, concurrent with the orthodontic treatment, until the symptoms are eliminated. It is elastics while managing the TMJ problem. 18

3. Monitor the patient for symptoms of TMJ dysfunction during retention. Taking tomographic x-rays before treatment, as well as two to three months before debonding, is helpful in detecting irregularities within the joint and in evaluating the clinical position of the condyle. It is generally accepted that orthodontic patients benefit from the establishment of a sited and reasonably concentric condylar position. A forward or retruded condyle can be corrected during the finishing stages, in conjunction with minor changes in anteroposterior and vertical jaw position. For example, if a patient shows an anterior skid with a corresponding anterior condylar position, the headgear or class II elastics can be continued until the anterior skid is eliminated and the condyle seats in the fossa. Conversely, if a patient has a significantly posterior condyle with no evidence of an anterior skid (Fig. 35), a slight amount of anterior skid can be provided so that the condyle is more centered. This can be done by ceasing the use of Class II elastics and headgear or by using Class III elastics. It is especially important in cases that show a developing Class III tendency. Finally, if the condyle is in a reasonably concentric position with no clinical evidence of an anterior skid, the patient can be debonding and left in that position, which will allow for normal TMJ development and function after orthodontic treatment. While we cannot predict physical or emotional stress, we can provide the structural environment that will best withstand stressful forces.

Checking functional movements Before debonding, the patient should be checked for interferences during protrusive movements and lateral excursions. It is important that the lower eight most anterior teeth make contact with the upper six most anterior teeth during protrusive movements. This normally requires a slight widening of the archform in the bicuspid area so that the mesial of the lower bluspids contacts the distal of the upper cuspids. In lateral excursions, the patient should experience cuspid rise with slight anterior contact and disclusion of posterior teeth on both the working and balancing sides. Second molars should normally be banded to prevent interferences in this critical area during lateral excursions. Preadjusted appliances are helpful because they provide for anterior and posterio torque adjustment, which is critical in establishing an ideal functional occlusion. Determining if all habits have been corrected Habits such as tongue thrusting will usually have been corrected before the finishing stage is reached, because as the patient grows, airway size increases and 19

the tongue can assume a more posterior position. Also, as the dental environmental that supported the habit is improved orthodontically, the tongue and lip musculature adapt to the improved environment and normal function begins to occur. We have observed that about 80 percent of tongue thrust habits correct themselves before the finishing stage. Patients with severe habits should be referred for myofunctional therapy early in treatment or even before treatment. Correction of rotations and overcorrection where needed Most rotations will have been eliminated before the finishing stages, particularly if force levels are kept low. Any remaining rotations can be corrected during finishing by one of three methods. 1. Rubber rotation wedges under the rectangular archwire. 2. Steiner rotation wedges these are useful because they can be placed after the archwire is in position. 3. Lingual elastics we have found this the most effective method. It is helpful to have the study models near the treatment area so that pre existing rotations can be evaluated and slightly overcorrected during finishing. This overcorrection helps minimize relapse, particularly in extraction cases. A note should be made in the patients record of any severe rotations before treatment. Fiberotomics can then be scheduled either just before debonding or after the tissue has had time to heal once appliances have been removed.

Establishing a relatively flat plane of occlusion Reasons for completing cases to a relatively flat occlusal plane, according to Andrews, include the proper fit curve of Spee is left in the lower arch, for example, there is a tendency toward increased overjet, since the lower teeth occupy less room than the opposing upper teeth. Deep bite cases also benefit from overcorrection of the curve of Spee, because most deep bites tend to relapse. If the occlusal planes are not leveled before finishing and detailing, the archwires will not slide easily through the bracket slots during space closure with sliding mechanics. Final settling of teeth At the conclusion of Class II or III correction, particularly if interarch elastics have been used, the teeth tend to rebonded back toward their initial position despite the presence of rectangular archwires. In addition, it is not uncommon for a 20

full dimension rectangular archwire, no matter how carefully made, to hold some teeth slightly out of occlusion. Because of the rebound after Class II or III treatment, it is important to slightly overcorrect the occlusal relationships. In a typical class II, anterior deep bite patient, the teeth should be taken to an end to end incisor relationship, with both overjet and overbite totally eliminated, before the headgear or elastic forces are discontinued. Similar over correction is needed for other problem, providing some latitude for the teeth to rebound or settle into the proper relationship. These considerations lead to formulation of two rules in finishing treatment: 1. Interarch elastics and headgear should be discontinued, and the rebounded from use should be allowed to express itself, 4 to 8 weeks before the orthodontic appliances are removed. 2. As a final step in treatment, the teeth should brought into a solid occlusal relationship without heavy archwires present. The final step of finishing, therefore, appropriately called settling since its purpose is bring all teeth into a solid occlusal relationship before the patient is placed in retention. There are 3 ways to settle the occlusion; 1. By replacing the rectangular arch wires at the very end of treatment with light round arches 0.016 in 18 slot 0.016 or 0.018 in to a 22 slot to provide freedom for movement of the teeth to find their own occlusal level. 2. With laced posterior vertical elastics after removing the posterior segments of the arch wires. 3. After the bands and brackets have been removed with the use of tooth positioners. Replacing rectangular wires with light round arch wires at a very end of the treatment was the original method recommended by tweed in the year 1940. These light round arch wire must include any 1st or 2nd order bend in rectangular arch wire. It is unnecessary for patient to wear light posterior vertical elastic during this setting but they can be used if needed these light arches will quickly settle the teeth into final occlusal and should remain in place for only a few weeks at most the disadvantage of undersized round wires at the end of treatment is that some freedom of movement for settling of posterior teeth is desired but precise control of anterior teeth is lost as well. It was not until the 1980 that orthodontist realized the advantage of removing only the posterior part of the rectangular finishing wire leaving the anterior segment (typically canine to canine or 1st premolar to 1st premolar and sign the lace elastic to bring the posterior teeth in to tight occlusion. This method sacrifices a 21

large degree of control of the posterior cross bite for the majority of patients who had well aligned posterior teeth from the beginning however this is a remarkably simple and effective way to settle the teeth into their final occlusion. Michael Steffen (1987) has introduced a method for final settling of the occlusion by use of the five cent tooth positioner. His finishing procedure is a six week sequence of controlled settling that has been most gratifying to the authors, because of the degree of refinement it produce, and for the patients, because it signals the end of treatment. If you want to establish credibility with your patients, tell them the appliances come off in six weeks if they follow instructions then keep your word. At the beginning of the sequence, maxillary and mandibular arches carry ideal finishing wires. Both are removed and sectioned. The maxillary wire is cut 3mm distal to each lateral incisor bracket, the mandibular wire 3mm distal to each canine bracket. Both are bent lingually on the ends to avoid irritation. The posterior sections are discarded, and the anterior sections are replaced, 0 ties are placed on the upper and lower lateral and lower canines. K ties are placed distogingivally on the upper and lower centrals. If the maxillary buccal cusps are striking mandibular bracket at this time, the brackets should be ground down. This step is critical, because teeth will not settle against interferences. Elastics should be worn day night for three weeks. If teeth fit properly after three weeks, the patient then wears the elastic at night only for three more weeks. If all goes planned, the bands and brackets are removed at the end of six weeks. For a Class II pull, a , 202 elastic is started over the lower second and upper first molar. The upper second molar is not included. The elastic is twisted and engaged over the next two teeth, and the sequence is repeated to the maxillary central incisor on the opposite side of the midline. A elastic begun on the left side will end on the maxillary right central incisor and mandibular left central incisor, stretching across the midline. For a Class III pull, a , 2.2 elastic is strated over the upper and lower second molars. The elastic is twisted between each pair of teeth and ends on the central incisors on opposite sides of the midlines. McLaughlin and Bennett using a lower 0.014 round archwire and a upper 0.014 round sectional wire from lateral incisor to lateral incisor. This is accompanied by vertical triangular elastics. If the teeth have settled properly after two to four weeks, then the patient can be scheduled for debonding. If the teeth are into correctly positioned, the patient can return to heavier archwires for additional finishing. It may also be necessary to reposition brackets at this point, but normally any repositioning should have been done earlier in treatment.22

Another advantage to letting a case settle without rectangular archwires is that the patient can establish an individual archform, within certain limits. The archform used in treatment may be slightly wider or narrower than the patients archform, and the settling phase allows correction of minor variations. In addition, retainers will fit more properly after settling than if they immediately follow rectangular wires. Removal of bands and bonded attachments Removal of the bands is accomplished by simply breaking the cement attachment and then lifting the band off the tooth. For upper molars and premolars teeth a bond removing plier is first in lingual side then buccal surface is elevated by the plier. For the lower posterior teeth the band removing plier is applied first on buccal and then an lingual side. Maxillary anterior bands are removed from the labial surface with an anterior bands removing plier while tightly fitted mandibular anteriors band usually must be slit with an cutting plier to make it possible to take them off. Bonded brackets must be removed without damaging the enamel surface this is done by creating a fracture within bonding material or between brackets and the resin and then removing the residual resin from the enamel surface. With metal brackets applying cutting plier to the base of the brackets so that the bracket bends has disadvantage of destroying the bracket which otherwise could be reased but this is safest method enamel damage from debonding metal bracket as compare as ceramic bracket is rare. It also is easy to fracture a ceramic bracket while attempting to remove it. These will happen because the ceramic brackets have little or no ability to deform. They are either intact or broken. There are three approaches to these debonding problems; 1. Grind away the bracket rather than attempting to break them loose. 2. Modify the interface between the bracket and the bonding resin to increase the chance that when force is applied the failure will occurs between the brackets and bonding materials. 3. Use heat to soften the bonding, resin so that the bracket can be removed with lower force. Study has show that the risk of pulpal damage and patients discomfort is minimal when electrothermal instrument used for ceramic bracket cement left on the teeth after debonding can be removed easily by scaling but residual bonding resin is more difficult to remove. The best result is using a carbide but at moderate speeds in dental hand piece. The hand scaler can no longer be considered desirable for the removal of heavily filled resins as it produce deep gouges in the enamel.23

Positioners for finishing An alternative to segmental elastic or light round arch wires for final settling is a rubber or plastic tooth posterior. A positioner is most effective if it is placed immediately after removal of fixed appliance. Normally it is fabricated 4-6 week before removing appliance taking impression of the teeth and a registration of occlusal relationship and then resetting the teeth in the laboratory incorporating minor changes in position of each tooth to produce appropriate settling. All erupted teeth should be included in the positioner to prevent supraeruption. As part of laboratory procedures bonds and brackets are trimmed away any band space is closed. This indirect approach allows individual tooth positioner to be adjusted with considerable precision bringing each tooth to a desired final relationship. The positioner is fabricated by either a hard rubber or soft plastic material which their inherent elasticity to move the teeth slightly to their final position. Tooth positioner has two advantages a. It allows the fixed appliance to be removed somewhat more quickly (some finishing could have been done with the final arch wires can be left to the positioner). b. It not only position the teeth but also massage the gingiva. Which is almost always at least slightly inflamed and swollen after comprehensive treatment. This stimulation is an excellent way to promote a rapid return to normal gingival contour. Disadvantages of tooth positioner 1. Require a considerable amount of laboratory fabrication time and therefore they are expensive. 2. Settling with positioner tend to increase the overbite as compare to light elastics. This is a disadvantages for patients who originally had deep bite and advantages if the initial problem was an anterior open bite. 3. A positioner does not maintain the correction at rotracted teeth so minor rotation may recur. 4. Good patient cooperation is essential. Indications i. A gingival condition with more than the usual degree of inflammation and swelling at the end of active orthodontics. ii. An open bite tendency so that settling by mild depression rather than elongation of posterior teeth is needed.24

Contra indications i. ii. iii. iv. Severe malalignment Severe rotated teeth Deep bite tendency An uncooperative patient

Timing Patient should wear the positioners at least 4 hours during the day and during sleep. Since the amount of the tooth movement by positioner incline rapidly after a few days of use in excellent schedule is to remove the orthodontic appliance clean the teeth and apply a fluoride treatments and place the positioner immediately asking the patients to wear it as nearly full time as possible for the first two days after. That it can be worn on the usual night 4 hours daily schedule. As general rule a tooth positioner in a cooperative patient will produce any changes, which is capable within 3 weeks. Beyond that time if the positioner is continue it serving as a retainer rather than a finishing device and as general rule. Positioners are not good retainers as there is an old says. That positioners are working hopefully or playfully. Special finishing procedure to avoid relapses A. Control of unfavourable growth B. Control of soft tissue rebound i. ii. Over treatment Adjunctive periodontal surgery

Control of unfavourable growth Changes resulting from continued growth in a Class II, Class III, deep bite, or open bite pattern contribute to a return of the original problem, and so are relapse in that sense. These changes are not attributed to tooth movement alone, however, but to the pattern of skeletal growth. It is more accurate to say that their control requires a continuation of active treatment than to describe this treatment as specific procedures to prevent relapse. For patients with skeletal problem who have undergone orthodontic treatment, this active retention takes one of two forms. One possibility is to continue extraoral force in conjunction with orthodontic retainers (high-pull) headgear at night, for instance, in a patient with a class II open bite growth pattern). The rather appropriate option is to use a functional appliance rather than a conventional retainer after the completion of fixed appliance therapy. Control of soft tissue rebound25

A major reason for retention is to hold the teeth until soft tissue remodeling can take place. There are two ways to deal with rebounding; 1. Over treatment so that any rebound will only bring the teeth back to their proper position. 2. Adjunctive periodontal surgery. To reduce rebound from elastic fibres in the gingiva. In some cases permanent retention is required to maintain the desired relationship. Over treatment Since it can be anticipated that teeth will rebound slightly toward their previous position after orthodontic treatment. It is logical to position them overcorrected at the end of the treatment only a small degree of over treatment is compatible with precise finishing of orthodontic case. a. Correction of Class II or Class III malocclusion after discontinuation of elastic or headgear. It can be expected that the teeth will rebound 1-2mm. So this degree of over treatment is required the rebound from the forces used forces used for Class II or Class III correction occur within 3-4 week. Where as relapse due to unfavourable growth appear after several month. Cross bite correction Whatever the mechanism used to correct cross bite it should be over correct by 1-2mm. Before the force system is released. Irregular and rotated teeth The over correction of irregular and rotated tooth should be during 1 st and 2nd stages. But maintaining of those over correction during finishing stage by adjusting the wings of single brackets or by pinching shut one of a paire of twin bracket is necessary. Adjunctive periodontal surgery A major cause of rebound after orthodontic treatment is the network of elastic supra crestal gingival fibres. As a general rule as teeth are moved in to a new position these fibres tend to strech and they remodle very slowly. If the pull of this fibres could be eliminated a major cause of relapse of previously irregular and rotated tooth should be eliminated. In fact if supracrestal fibres are sectioned and allowed to seal while the teeth are held in proper position relapse caused by gingival elasticity is greatly reduced. Sectioning of supracrestal fibres can be carried out by two methods26

1. The first method originally developed by EDWARDs is called circumferential supracrestal fibrotomy (CSF). 2. Another method is to make an incision in the centre of each gingival papilla sparing the margin but separating the papillary from just below. The margin to 12mm below the height of bone buccally and lingually this method called as papilla dividing procedure. Neither the CSF nor the papilla dividing procedure should be done until malaligned teeth have been corrected and held in their new position for several month so this surgery is done toward the end of the finishing phase of treatment. It is important to hold the teeth in good alignment while gingival heating occurs. This means that surgery should be done either a few weeks before removal of orthodontic appliance or if it is performed at the same time the appliance is removed a retainer must be inserted almost immediately. Experience has demonstrated that sectioning the gingival fibres is an effective method to control rotational relapse but does not control. The tendency for crowded incisors to again become irregular. Conclusion The real value of the preadjusted appliance become apparent in finishing stage. The more accurate the appliance the less time and effort is required during finishing stage. The built in tip torque and in-out allowed the orthodontists to spend less time treating the appliance with 1st, 2nd and 3rd order bends. Never the less the misconception developed that no wire bending is required at all with the new preadjusted system. Although it is true that very little bending is needed during initial stages of treatment but bending the wire to produce the proper tooth position during finishing stage is part of the game. This is because the appliances prescriptions are based on averages, they cannot possibly account for all the variation of the tooth size and morphology, secondly an improper bracket placement and need for over correction make any one of the order bend compulsory. So if the tip torque and in-out compensation built in to the appliance is accurately suited to the patient dentition, as treatment proceeds toward completion there should be only minimal wire bending required to complete the treatment. Since clinically this cannot be the case and ultimately we have to think of tooth position rather than bracket position and it is the result that is important and not the processes. Therefore we should not really care what the position in term of axial inclination, torque height, in-out if they are not what we have to want, then we have to put a little bend in the arch wire, wherever we need it. As Andrews once said, if you go on a long journy, you dont walk all the way, you flay most of the way and then take taxi and walk the final hundred yards. In the same way preadjusted bracket will take you most of the way, but. The fine turning still relies on the ability of the orthodontic to bend wire. 27

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