CLASSIFICATION OF MALOCCLUSION : CLASSIFICATION OF MALOCCLUSION BY:
DEPT OF ORTHODONTICS
JAIPUR DENTAL COLLEGE INTRODUCTION : INTRODUCTION OCCLUSION: The static relationship between occlusal surface of max and mand teeth or tooth analogues
MALOCCLUSION:. Any deviation from a physiologically acceptable contact of opposing dentitions.
CLASSIFICATION: the description of dentofacial deviations according to a common characteristic or norm. NEED OF CLASSIFICATION : NEED OF CLASSIFICATION ADAVNTAGES OF CLASSIFICATION : ADAVNTAGES OF CLASSIFICATION DIAGNOSIS AND TREATMENT PLANNING
UNDERSTANDING ASSOCIATED PROBLEM
COMPARISONS CAN BE MADE EASILY TYPES OF MALOCCLUSION : TYPES OF MALOCCLUSION INTRA ARCH INTER ARCH SKELETAL INTRA ARCH MALOCCLUSION : INTRA ARCH MALOCCLUSION Includes variation in individual tooth position or those affecting group of teeth within the same arch
Abnormal inclination( TIPPING)
Spacing and crowding ‘WITHIN SAME
ARCH’ Types : Types TYPES : TYPES DISTAL INCLINATION LINGUAL INCLINATION BUCCAL INCLINATION MESIAL INCLINATION Slide 9: Distal displacemment Mesial displacemment Lingual displacemment Buccal displacemment Slide 10: TRANSPOSITION INFRAVERSION SUPRAVERSION ROTATION Slide 11: DISTOLINGUAL OR MESIOBUCCAL ROTATION MESIOLINGUAL OR DISTOBUCCAL ROTATION Orientation Planes : Orientation Planes First we need to establish planes of reference in order to communicate which dimension our Problem lies. Transverse Vertical Sagittal INTER ARCH RELATIONSHIP : INTER ARCH RELATIONSHIP Malrelation of dental arches to one another upon skeletal bony basis that may themselves be normally related. TYPES: Sagittal plane malocclusions
Vertical plane malocclusions
Transverse plane malocclusions Sagittal plane : Sagittal plane Pre-normal occlusionMandibular arch anteriorly placed in centric occlusion.
Post-normal occlusionMandibular arch posteriorly placed in centric occlusion. Vertical plane : Vertical plane Deep bite
Excessive vertical overlap between maxillary and mandibular anteriors.
Open biteNo vertical overlap.- Anterior region- Posterior region Transverse plane : Transverse plane Includes various types of cross bites. Posterior crossbite Anterior crossbite Slide 17: SKELETAL MALOCCLUSION Due to abnormalities in maxilla or mandible in size, position or relationship between jaws.
Narrowing and widening of jaws causes crossbites
Variation affects lower facial height. Sagittal plane : Sagittal plane Transverse plane : Transverse plane Systems of Classification of Malocclusion : Systems of Classification of Malocclusion Angle’s classification
Dewey’s modification of Angle’s classification
Lischer’s modification of Angle’s classification
Incisor classification Slide 21: Angle’s classification It was introduced by Edward Angle in 1899.
Based on mesiodistal relationship of teeth, dental arches and jaws.
Maxillary 1st molar is taken as key to occlusion.
Three classes :
Class II division I
Class II division II
Class II subdivision
Class II division I subdivision
Class II division II subdivision
True Class III
Pseudo Class III
Class III subdivision Slide 22: Class 1 relation Class 2 malocclusion Class 1 malocclusion Class 3 malocclusion Class I : Class I A normal molar relationship exists but there is crowding,
misalignment of the teeth, cross bites, etc Class II : Class II Class II division I Anterior proclination
Deep incisor overbite
Abnormal muscle activity
Tongue occupies lower posture – narrowing of arch Slide 25: Class II division II Class II subdivision Class 2 molar relation
Lingually tipped upper central incisor
Labially tipped U lateral incisor
Ant. Deep overbite
Normal muscle activity Class 2 on one side only
Class 2,division 1,subdivison
Class 2,divison 2,subdivison Class III : Class III True Class III Pseudo Class III (postural/Habitual) Class III subdivision Genetic in origin
Lower incisor-lingually inclined
Enough space for tongue-lower position-arch narrowing Advantages of Angle’s Classification : Advantages of Angle’s Classification First comprehensive classification – most widely accepted.
Easy to use
Conveys precisely what was conceived for ie, relationship of mandibular teeth with respect to maxillary 1st permanent molar
Provided simple definition of normal occlusion Slide 28: Drawbacks of Angle’s Classification Considers malocclusion only in the anteroposterior plane and not in transverse/ vertical planes.
Considered 1st permanent molar as fixed points in the skull, not found to be so.
Deciduous dentition - can’t be applied
1st molar extracted - can’t be applied
Doesn’t distinguish between skeletal/dental malocclusion.
Doesn’t highlight etiology.
Individual tooth positions aren’t considered. DEWEY’S MODIFICATION OF ANGLE’S CLASSIFICATION : DEWEY’S MODIFICATION OF ANGLE’S CLASSIFICATION Angle’s Class I
Type I – Class I with crowded anteriors.
Type II – Class I with protrusive maxillary incisors.
. Slide 30: Type III – Class I with anterior cross bite.
Type IV – Class I with posterior cross bite.
Type V – Mesially drifted permanent molars due to early extraction of deciduous predecessors Slide 31: Angle’s Class III
Type I – upper and lower arches are normally aligned separately but show edge-to-edge bite/ incisor arrangement on occlusion.
Type II – mandibular incisors crowded and in lingual relation to maxillary incisors. Slide 32: Type III – maxillary incisors are crowded and in cross bite with
mandibular anteriors. Lischer’s modification of Angle’s classification : Lischer’s modification of Angle’s classification Neutro-occlusion – Angle’s Class I
Disto-occlusion – Angle’s Class II
Mesio-occlusion – Angle’s Class III
Mesioversion – mesial to normal position
Distoversion – distal to normal position
Linguoversion – lingual to normal position
Labioversion – labial to normal position
Infraversion – inferior or away from the line of occlusion
Supraversion – superior or extended past the line of occlusion
Axiversion – axial inclination is wrong, tipped
Torsiversion – rotated on its long axis
Transversion – transposed or changes in the sequence of position Slide 35: Bennet’s classification Class I – abnormal position of one or more teeth due to local causes.
Class II – abnormal formation of a part/ whole of either arch due to developmental defect of bone.
Class III – abnormal relation between upper and lower arches and between either arch and facial contour and co-related abnormal formation of either arch. Simon’s classification : Simon’s classification It is a craniometric classification relating dental arches in three planes i.e.,
FH plane [Frankforts Horizontal plane]
Mid-sagittal plane Slide 37: FH plane
Attraction –closer than normal to FH plane.
Abstraction –away from FH plane than
Normal Orbital plane
Protraction – Farther from orbital plane
Retraction – Closer/more posterior to orbital plane.
Distraction – away from mid sagittal plane
Contraction – closer to mid sagittal plane Ackermann-Profitt classification : Ackermann-Profitt classification Based on five characteristics
Overbite 1 2 3 4 5 Slide 40: Alignment
Interarch alignment and symmetry assessed when seen in occlusal view.
Dental arch is classified as ideal/crowded/spaced
can be convex/straight/concave
Includes assessment of facial divergence ie. Anterior or posterior divergence.
Include transverse skeletal and dental relationships.
Buccal and palatal cross bites are noted.
Further classified as unilateral or bilateral.
Distinction made between skeletal and dental cross bites. Slide 41: Class
Sagittal relationship of teeth is assessed using Angle’s classification as Class I / II / III.
Distinction made between skeletal and dental malocclusions.
Assessed in the vertical plane
Described as anterior open bite / posterior open bite / anterior deep bite / posterior collapsed bite.
Distinction made between skeletal and dental malocclusions. Slide 42: THANK YOU