B YN A N C Y K A D H I W A L A

CLASSIFICATION OF MALOCCLUSION

WHAT IS MALOCCLUSION?

• A malocclusion is a misalignment of teeth and/or incorrect relation between the teeth of the two dental arches. The term was coined by Edward Angle, the "father of modern orthodontics,"as a derivative of occlusion, which refers to the manner in which opposing teeth meet.

TYPES OF MALOCCLUSION

Intra-arch malocclusion:It includes variations in individual tooth

position and malocclusions affecting a group of teeth within an arch.Inter-arch malocclusion:

It comprises of malrelation of dental archs to one another upon skeletal bony bases.Skeletal malocclusion:

It involves the underlying bony bases.

CLASSIFICATION OF MALOCCLUSION& ITS ADVANTAGES

Angle’s system of classificationSimon’s classificationBennet’s classificationAckreman-profitt system of classification

ADVANTAGES OF CLASSIFICATIONI. It helps in diagnosis and treatment planning of the patient.II. It also helps in visualizing and understanding the problem

associated with malocclusion.

ANGLE’S SYSTEM OF CLASSIFICATION

• Edward angle introduced a system of classifying malocclusion in year 1899.

• It is based on mesio-distal relation of the teeth, dental arches and the jaws.

• According to Angle,maxillary first permenant molar is the key to occlusion.

• Based on the relation of the lower first permanent molar to the upper first permanent molar.

• He classified it into 3 types:• Class 1• Class 2• Class 3

ANGLES CLASS I

• Angle’s class 1 malocclusion is characterized by presence of normal inter-arche molar relation.

• The mesio-bucal cusp of the maxillary first permanent molar occludes in the bucal groove of mandibular first permanent molar.

• The patient may exhibit dental irregularities such as crowding,spacing,rotation missing tooth etc. these patients exhibit normal skeletal relation and normal muscle function

ANGLE CLASS II

• It characterized by class II molar relation where the disto-bucal cusp of upper first permanent molar occludes in the bucal groove of the mower 1st permenant molar. They are divided in 3 divisions:1. Division 12. Division 23. Subdivision

cont...

• Class II ,division 1:• It is characterized bey proclined upper incisors, with a resultant

increase in overjet.• Characterstic feature: the presence abnormal muscle activity

• the upper lip is usually hyptonic short and fails to lip seal. The lower lip cushions the palatal aspect of upper teeth. This feature is reffered as “zip trap”.

• Class II,division 2:• Characteristic feature is presence of retroclined upper central

incisors and proclined upper lateral incisors over lapping the central incisors.

• Patient exhibits a deeper anterior over bite.• Squarish apperance of arche seen.

• Class II,subdivision:• When class II molar realtion exists on one side and class I molar

relation on the other side, it is referred to as class II,subdivision

ANGLE CLASS III

• It is characterized by class III molar relation with mesio-buccal cusp of maxillary 1st permenant molar accluding in tnterdental space between the mandibular 1st and 2nd molars• Classified into 3 types as under:

1. True class III2. Pseudo class III3. Class III subdivision

cont…

• True class III:• This is skeletal class III malocclusion of genetic origin• Causes:

• Exclusively large mandible• Forwardly placed mandible• Smaller than normal manilla• Retropositioned manilla

• Lower incisors tend to be lingually inclined.

• Pseudo classIII:• This type of malocclusion is produced by forward movement of

mandible during jaw closure.thus it is also called as postural or habitual class III.

• Causes:• In case of premature loss of decidous posterious,the child tends to move the

mandible forward.• A child with enlarged adenoids,tends to move the mandible forward

• Class III subdivision:• It is a condition charaterized by class III molar relation on one side and

class I relation on other side

DEWEY’SMODIFICATION OF ANGLE’S CLASSIFICATION OFMALOCCLUSION

• Class I modification of dewey:• Type I: • class I malocclusion with crowded anterior teeth.

• Type 2:• Class I with protnesiue maxillary incisors.

• Type 3:• Class I malocclusion with anterior crossbite

• Type 4:• Class I molar relation with posterior crossbite.

• Type 5:• The permanent molar has drifted mesially due to early

extraction of second decidous molar or second premolar.

• Class III modification of dewey:• Type 1:• The upper & lower dental arches when viewed seperately are

in normal alignment. But when the arches are made to occlude the patient shows on edge to edge incisors alignment, suggestive of forward moved mandibular dental arche.

• Type 2:• The mandibular incisors are crowded and are in lingual

relation to the maxillary incisors.

• Type 3:• The maxillary incisors are crowded and are in crossbite in

relation to the mandibular anteriors.

LISCHER’S MODIFICATION OF ANGLE’S CLASSIFICATION

• Neutrocclusion: • Synonyms with angle’s class I malocclusion.

• Distoocclusion:• Synonym with angle class II malocclusion

• Mesioocclusion:• Synonym with angle’s class III malocclusion

• Buccocclusion:• Buccal placement of tooth or group of teeth.

• Linguocclusion:• Lingual placement of tooth or group of teeth.

• Supraocclusion:• When tooth or a group of teeth have erupted beyond normal level.

• Infraocclusion:• When tooth or a group of teeth have erupted to normal level.

• Mesioversion:• Mesial to normal position.

• Distoversion:• Distal to normal postion.

• Transversion:• Transposition of two teeth.

• Axiversion:• Abnormal axial inclination of tooth.

• Torsiversion:• Rotation of tooth around its long axis.

SIMON’S CLASSIFICATION

• This system of classification uses three anthropometric planes i.e • Frankfort horizontal plane• The orbital plane• Mid sagittal plane

contd..

• the Frankfort horizontal plane or the eye-ear plane:• It is determined by drawing a straight line through the margin of the bony orbit

directly under the pupil of the eye, to the upper margin of the auditory meatus (the notch above the tragus of the ear). This plane is used to determine deviations in the height of the dental arches and teeth in relation to the face and cranium.

• the orbital plane :• It is a perpendicular at right angles to the frankfort plane at the margin of the bony

orbit directly under the pupil of the eye. This plane is used to determine sagital deviations of the dental arches and the axial inclination of the teeth to the face and the cranium.

• Mid sagittal plane :• it is used to describe malocclusion in the transverse direction.• When a part or a whole arche is away from mid sagittal plane it is called’distraction’.• When a part or a whole arche is closer from mid sagittal plane it is

called’contraction’.

BENNET’S CLASSIFICATION

• Sir Normal Bennett introduced a classification of abnormalities of occlusion which was based on their etiology. Briefly the classification is as follows:

• Class I: • Abnormal position of one or more teeth due to local causes.

• Class II:• Abnormal formation of a part or whole of either arch due to

developmental defects of bone.

• Class III: • Abnormal relationship between upper and lower arches, and

between either arch and facial contour and correlated abnormal formation of either arch.

ACKERMAN-PROFITT SYSTEM OF CLASSIFICATION

• Ackreman&profitt in 1960 proposed a diagramatic classification of malocculation as below:

• Step 1(alignment):• It involves assesment of alignment & symmetric of the dental

arch.it is classified as ideal/crowded/spaced.

• Step 2(profile):• It involves the consideration of the profile. The profile is described

as conves/straight/concave.

• Step 3(type):• The transverse skelatal and dental relationship is evaluated. Bucal

and palatal crossbites if any are voted.

• Step 4(class):• This involves the assesment of the sagittal realtionship. It is

classified as angle’s I/II/III malocclusion.

• Step 5(bite depth):• Malocclusion in vertical plane are noted.

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