MANAGEMENT OF CLASS I
MALOCCLUSION
PRESENTED BY: HAFSA SARA ZUBAIRBDS
OBJECTIVES:• OCCLUSION• CLASS I OCCLUSION• CLASS I MALOCCLUSION• LINE OF OCCLUSION• CAUSES OF CLASS I
MALOCCLUSION• BIMAXILLARY PROTRUSION• FEATURES OF BIMAXILLARY
PROTRUSION• FEATURES OF CLASS I
MALOCCLUSION• DIAGNOSIS• MANAGEMENT OF CLASS I
MALOCCLUSION
WHAT IS OCCLUSION ?
“ Occlusion is the relationship of the maxillary and mandibular teeth when the jaws are in fully closed position.”
CLASS I OCCLUSION
CLASS I MALOCCLUSION
• Normal relationship of the molars, but line of occlusion incorrect
o Malposed teetho Rotationso Others
LINE OF OCCLUSION FOR UPPER ARCH :
Smooth curve passing through the central fossa of each upper molar and across the cingulum of upper canine and incisor teeth.
oFOR LOWER ARCH:• The same line runs along the buccal cusp and incisal edges of lower teeth.
CAUSES OF CLASS I MALOCCLUSION
DEVELOPMENTAL GENETIC ENVIRONMENTA
L
DEVELOPMENTAL CAUSESINCLUDES: Congenitally missing teeth. Malformed teeth. Supernumerary teeth. Impacted teeth Ectopic eruption
GENETIC CAUSES:
Plays major role for malocclusion where there is discrepancy between the size of jaws and size of teeth.
ENVIRONMENTAL CAUSES
CAUSED BY: Injuries which has two types:
BIRTH INJURIES:
› Fetal moulding› Trauma during birth from usage of
forceps.
CONT…. INJURIES THROUGHOUT LIFE:
Trauma to teeth can lead to:
Damage to permanent tooth bud.
Premature loss of primary teeth leads to permanent tooth movement.
Direct injury to permanent teeth.
MOST COMMON FORM :
• BIMAXILLARY PROTRUSION
WHAT IS BIMAXILLARY PROTRUSION ??
The patient exhibits a normal class I molar relationship but the dentition of both the upper and lower arches are forwardly placed in relation to facial profile.
FEATURES
FEATURES OF BIMAXILLARY PROTRUSION
EXTRAORAL FEATURES
CEPHALOMETRIC FINDINGS
INTRAORAL FEATURES
EXTRAORAL FEATURES Decreased
nasolabial angle due to proclined maxillary anteriors.
oShallow mentolabial sulcus due to proclined mandibular anteriors.
oLips may be incompetent.
oConvex facial profile.
CONT…
INTRAORAL FREATUES
Maxillary and mandibular anterior proclination.
Class I molar relationship (2)
CONT…. Class I canine
relationship (may be)
CONT… Spacing
between teeth. (may be)
CEPHALOMATRIC FINDINGS Decreased
interincisal angle.
Increased incisor mandibular plane angle
CONT….. Increased SNA and SNB, if
there is prognathism of jaws.
FEATURES OF CLASS I MALOCCLUSION
INTRAORALEXTRAORAL
EXTRAORAL FEATURES: Straight profile.
Harmonious face
INTAORAL FEATURES: Class I molar
relationship (2)
Class I canine relationship (3)
CONT… Class I incisor
relationship
Spacing
CONT… Crowding
Bimaxillary protrusion
CONT… Cross bite
Open bite
CONT…. Deep bite
Rotations
DIAGNOSIS:• HISTORY• CLINICAL EXAMINATION• STUDY MODELSRADIOGRAPHS:• OPG• LATERAL CEPHALOGRAM
DIAGNOSIS:• HISTORY• CLINICAL EXAMINATION• STUDY MODELS
RADIOGRAPHS• OPG• LATERAL CEPHALOGRAM
MANAGEMENT OF CLASS I MALOCCLUSION
MANAGEMENT :AIMED AT CORRECTION OF DISTURBANCE IN LINE OF OCCLUSION LEADING TO
• CROWDING• SPACING• OPEN BITE• CROSS BITE• DEEP BITE• ROTATIONS• BIMAXILLARY PROCLINATION
‘’CROWDING’’
CROWDING:‘Is defined as malalignment of teeth caused by
inadequate space.’
• Occurs due to GENETIC or ENVIRONMENTAL factors.
• Classified as: Mild crowding --- less than 4mm per arch. Moderate crowding --- 5 to 9mm per arch. Severe crowding --- 10mm or more per
arch.
Before carrying out treatment, following aspects should be considered. Degree of crowding. Site and position of crowding. Patient’s age.
• MILD CROWDING• Resolves without extraction.• Proximal stripping• Alignment of teeth by labial bow or z-
spring.
MODERATE CROWDING
• Arch expansion (quad helix applaince)• Distalization of molars.
SEVERE CROWDING• Extraction of all 1st premolar• Retract canine by canine retractor• Align anteriors by labial bow.• Retention by hawley’s retainer.
SPACINGLOCALIZEDGENERALIZED
SPACING:‘Gaps between two teeth or many
teeth’
• Can be:• Localized (space present in
localized regions or areas)
• Generalized (space present in entire arch)
GENERALIZED SPACING• Results from hypodontia along with small
teeth (microdontia) in well developed arches.
• IN CASE OF MICRODONTIA:
• Eliminate spaces between anteriors, leaving a space between canine and 1st premolar.
• Give prosthesis or implant.
LOCALIZED SPACING• It results from loss of tooth due to trauma, or
hypodontia or due to presence of midline diastema.
Intervention is required in cases with:Diastema greater than 3mm, no space for perm. lateral incisors to erupt. Permanent canines have erupted, diastema still present. Labial frenum has not migrated to labial attached mucosa. Congenitally missing incisors. Presence of supernumerary teeth.
INTERVENTIONS INCLUDE: Eliminate cause: i.e. high labial frenum
attachment.
Removable appliance• Finger spring• Finger spring with labial bow• Split labial bow
Frenectomy
Implants
Fixed appliances: Pin and tube appliance
CROSS BITE
CROSS BITE:
‘Refer to a condition where one or more teeth may be abnormally bucally or lingually with reference to the opposed tooth or teeth.’ (GRABER)
TYPES OF CROSS BITE:ANTERIOR
CROSS BITE
SINGLE TOOTH
MULTIPLE TEETH
POSTERIOR
CROSS BITESINGLE TOOTH
UNILATERAL
BILATERAL
MANAGEMENT: ANTERIOR CROSS BITE:
SINGLE TOOTH:• Z- spring
MULTIPLE TEETH:• Expansion screw
POSTERIOR CROSS BITE:
SINGE TOOTH:• Cross-elastics
CROSS ELASTICS
UNILATERAL CROSS BITE: Functional appliance
Quad helix W arch Coffin spring
QUAD HELIX
W- ARCH
COFFIN SPRING
BILATERAL CROSS BITE::• Quad helix• W arch• RME by hyrax screw
Hyrex screw
OPEN BITE
OPEN BITE‘ Open bite is the failure of a tooth or
teeth to meet antagonists in the opposite arch.’
TYPES OF OPEN BITE
SIMPLE ANTERIOR OPEN
BITE SIMPLE
POSTERIOR OPEN BITE
COMPLEX OR SKELETAL OPEN
BITE
MANAGEMENT• SIMPLE ANTERIOR OPEN BITE:
o Due to digital sucking.
o MIXED DENTITION:o Habit breaking by tongue spikeso Arch expansion
o LATE MIXED DETITION AND EARLY PERMENANT DENTITION:
oHabit breaking.
• SIMPLE POSTERIOR OPEN BITE: (RARE)o CAUSES:
o Ankylosed primary molarso Lateral tongue thurst
oEARLY TREATMENT:o Removal of ankylosed primary tooth.
• COMPLEX OR SKELETAL OPEN BITE:
o EARLY MANAGEMENT:o Bionatoro Frankel appliance
o ADULT SKELETAL OPEN BITE:
o Orthognathic surgery
DEEP BITE
DEEP BITE:
‘condition of excessive overbite, where the vertical measurement b/w maxillary and
mandibular incisal margins is excessive when the mandible is brought into centric occlusion.’
(GRABER)
MANAGEMENT• GROWING AGE:
o Anterior bite planes • INTRUDE ANTERIORS BY:o Fixed applianceo J. hooks vertical pull headgear• Erupt posterior
• NON GROWING AGE:
o ORTHOGNATHIC SURGERYo Lefort 1
BIMAXILLARY PROTRUSION
BIMAXILLARY PROTRUSIONMANAGEMENT
• Extract all 1st premolars.
• TREATMENT DEPENDS UPON ANGULATION OF CANINE:
o DISTALLY INCLINED CANINE:o Retract canine and align incisors using
retainer.o MESIALLY INCLINED CANINE:
o Fixed appliance
ROTATIONS
ROTATIONS:• SINGLE TOOTH:
• REMOVABLE APPLIANCES:• Double cantilever spring • Labial bow
• MULTIPLE ROTATIONS:• FIXED APPLIANCE
• SEMI- FIXED APPLIANCE:• High labial bow with t- spring
Double cantilever spring
High labial bow
T spring
REFERENCES:• CONTEMPORARY ORTHODONTICS BY
WILLIAM R. PROFFIT
• HANDBOOK OF ORTHODONTICS BY ROBERT E. MOYERS
• ORTHODONTICS PRINCIPLE AND PRACTICE BY BASAVARAJ PHULARI
Top Related