Classification of malocclusion/ dental implant courses by Indian dental academy

CLASSIFICATION OF MALOCCLUSION

INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com

CONTENTS • • • •

DEFINITIONS PURPOSE OF CLASSIFYING SYSTEMS OF CLASSIFICATIONS LIMITATIONS OF CLASSIFICATION SYSTEMS

• ANGLE CLASSIFICATION REVISITED

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Definitions Occlusion: The changing interrelationship of the opposing surfaces of max & mand.teeth occuring during movements of mand & the terminal full contact of max. & mand arches.

Not a static condition Normal occlusion [angle]: evenly placed rows of teeth arranged in graceful curve with harmony between upper & lower arches www.indiandentalacademy.com

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ANGLES PROTOTYPE IDEAL OCCLUSION

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Definitions Occlusion: The changing interrelationship of the opposing surfaces of max & mand.teeth occuring during movements of mand & the terminal full contact of max. & mand arches.

Not a static condition Normal occlusion [angle]: evenly placed rows of teeth arranged in graceful curve with harmony between upper & lower arches www.indiandentalacademy.com

Three factors 1.Occlusal inclined planes of cusps 2.Support given by harmonious size of both arches 3. Influence of muscles Characteristics of normal occlusion 1. Correct axial position of teeth 2. Normal over jet overbite 3. Normal relationship of individual teeth 4. Normal relationship of dental arches to each other & to face & cranium

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Malocclusion: An arrangement of teeth in a dentition &/or relation in the jaws to each other which is not according to the accepted morphologic configuration of human maxillodentofacial complex.

Classification: it’s a grouping of clinical cases of similar appearance for ease in comparison , handling & discussion

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Purposes of classification • • • • •

Ease of reference Self communication For comparison For traditional reasons Imp tool in diagnosis –treatment planning

In our concept of diagnosis it can be viewed as orderly reduction of data base to a list of pt s problems

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QUESTIONNAIRE, INTERVIEW

CLINICAL EXAMINATION

DATA BASE

CLASSIFICATION

PROBLEM =DIAGNOSIS LIST

ANALYSIS OF DIAGNOSTIC RECORDS

ORDERLY REDUCTION OF DATABASE TO LIST OF PROBLEMS www.indiandentalacademy.com

WHEN TO CLASSIFY

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Malocclusions are morphologic abnormality morphology Malocclusions involve 4 tissue systems Dental dysplasias Skeletal Skeletodental

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Classification systems  Angle’s system Modifications Lischers modification Deways modification      

Simons classification Ackerman proffit classification Malpositions Bennet classification Skeletal classification Modified Angles classification www.indiandentalacademy.com

Angle’s system E.H Angle -1899 Most uni. Used.

BASIS: Relationship of 1st per.molar teeth & alignment of teeth to line of occlusion Key to occlusion _ max 1st molar Basically describes the AP relationship It has 4 groups Normal occlusion Class I malocclusion Class II malocclusion www.indiandentalacademy.com Class III malocclusion

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Normal occlusion: normal molar relationship , teeth in line of occlusion Class I normal molar relation but teeth not in line of occlusion Class II a full premolar width disto-occlusion line of occlusion not specified Class III a full premolar width mesio-occlusion (resulting in a Class I range of 14 mm)

Class II a full premolar width disto-occlusion and Class III a full premolar width mesio-occlusion (resulting in a Class I range of 14 mm) Class I from a full premolar width in either direction to one half of a cusp in either direction (reducing the range of Class I to 7 mm)

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Class I malocclusion • AP relationship of max & mand molars correct • Normal AP relationship between max & mand • Usually Normal muscle function • Bimax protrusion • Diff between normal occlusion & class I

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Class II malocclusion • Relative MD relations of dental arches abnormal with all lower teeth occluding distal to normal Molar relation Consists of 2 divisions Same molar relation

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Class II Div I Mand denture may r may not be normal with respect to individual teeh Protrusion of max incisors Over eruption of incisors Narrow max arch V shape Abnormal muscle function Lower lip cushions upper teeth Accentuation of max arch Depending on tongue lower ant may / may not over erupt Class II Div I sub division

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Typical max incisor inclination in class I , II div I & cl. III

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Typical lip postures in cl II div 1

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Class II Div 2 Mand molars & mand arch ---post. Position with respect to max I molars & max arch Mand arch may or may not show individual irregularities An exaggerated COS Supraversion of incisors Mand labial gingiva traumatized Max arch –sometimes wider than normal Lingual inclination of max centrals , labial inclination of laterals Variations www.indiandentalacademy.com

Characteristic milalignments of upper ant teeth in class II div2

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Perioral muscle function - normal Abnormal path of closure due to combination of lingually inclined max incisors & infraocclusion of post teeth Class II Div 2 sub div

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Class III malocclusion • All the lower teeth occlude mesial to normal the width of 1 bicuspid tooth or more • mand # large bodily or situated mesially to an abnormal degree • Mand incisors in total cross bite • Lower ant. # excessively inclined lingually# lip pressure • Individual tooth irregularities • Constricted max arch deficient arch length • Tongue # floor of the mouth • Max incisors # more lingually inclined • constricted max arch www.indiandentalacademy.com

Facial profile & molar relationship

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Pseudo class III

• Postural , habitual class III • Lingually inclined max incisors gliding down lingual surfaces of mand incisors on closure • Mand guided ant displacement • Causes: occlusal prematurities Premature loss of pri. Posteriors Enlarged adenoids www.indiandentalacademy.com

Limitations of angle classification • Discrepancies in vertical & transverse plane • Inconsistency or gray areas which are not fully class II or class III • Cant be applied if I molars are ext’d or missing • Max molar may vary in AP relationship • Individual tooth malpositions # overlooked • Mixed dentition ?

• Malfunctions of muscles & problems of growth of bones were overlooked • Etiology ? www.indiandentalacademy.com

Lischers modifications

• Neutrocclusion or class I • Distocclusion or class II • Mesiocclusion or class III Buccocclusion Linguocclusion Supraocclusion Infraocclusion www.indiandentalacademy.com

Some malpositions of individual teeth “Version� to classify malpositions of teeth in relation to line of occlusion Transversion Linguoversion Labioversion Mesioversion Distoversion Torsiversion Axiversion

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Deways modification • Martin Deway class I 5 types class III 3 types Type 1:crowding of max. ant canines #labio axio or infaversion Type 2 :max incisors labioversion Type 3 :max incisors in linguoversion to mand incisors Type 4 :molars +/-premolars in bucco/ linguoversion Type 5:molars in mesioversion due to shifting www.indiandentalacademy.com

Modifications angles class III Type 1: Individually arches are well formed Teeth in normal alignment Edge to edge bite in occlusion bodily movement of mand arch Type 2: mand incisors – crowded lingual relation to max incisors Type 3 :underdeveloped max arch crowded max incisors Cross bite Well developed mand arch , mand teeth normally aligned www.indiandentalacademy.com

Simons classification • Paul simon • A 3D classification • Related denture to face & cranium in 3 planes 1.FH plane vertical relationships deviations in ht of arch & teeth irt face cranium 2. orbital plane Sagittal deviations in AP relation of arch , axial inclination of teeth to face & cranium Law of canine 3. Median Sagittal plane or raphe for deviations in gen form & width of arches & axial inclination of teeth www.indiandentalacademy.com irt midline of palate & head

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Deviations • In Orbital plane Protractions Retractions In FH plane Attraction Abstraction In Mid Sagittal plane Contractions Distractions www.indiandentalacademy.com

Demerits • Cumbersome • Confusing at times eg .intrusion of max teeth extrusion of mand teeth • Little used

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attraction

Ackermann proffit system • 1960 s by informal additions to angles system by identifying 5 major characteristics • Overcomes the major weakness of angle system incorporated evaluation of crowding & asymmetry • Recognizes relationship between protrusion & crowding • Includes transverse AP vertical planes • Incorporates information about skeletal jaw proportions • Used venn symbolic diagram or set theory www.indiandentalacademy.com

Set is defined on the basis of morphologic deviations from ideal Degree of alignment & symmetry are common to all dentitions outer envelope /universe [group I] Profile affected by many malocclusions # major set in the universe [ group 2] Deviations in 3 planes of space # represented by 3 to 9 group, which also includes overlapping sub sets www.indiandentalacademy.com

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advantages • Differentiation is made betw. Ske. & dental problems • Teaches a perspective about complexities of malocclusions • Readily adaptable to compute processing • Demerits • etiology ?

• Analysis is static , a functional analysis must still be made www.indiandentalacademy.com

Bennet ‘s classification • Based on etiology • 3 classes • Class I abnormal position of 1 or more teeth due to local causes Class II

Class III

abnormal formation of part / whole arch due to developmental defects abnormal relationship of arches arch & facial contour abnormal formation of arch www.indiandentalacademy.com

Skeletal classification • Class I , class II , class III • takes relationship of teeth also into consideration

Sk. Class I • Bones of face & jaws , harmony , & with head • Profile orthognathic 4 divisions Div 1. local malrelations of incisors , canine premolars Div 2 : max incisor protrusion Div 3: retroclined max incisors Div 4: bimax protrusion www.indiandentalacademy.com

Skeletal class 2 : sub normal distal mand development in relation to maxilla Max. arch narrower than mand Div 1 Crowding in canine region Cross bite Vertical ht Protrusion of max ant teeth Retrognathic profile Div 2 : lingual inclined max incisors laterals normal / labioversion Sk. Class 3 Overgrowth of mand, obtuse mand plane ang Prognathic mand www.indiandentalacademy.com

Malpositions • • •

Individual teeth Groups of teeth sagittal # labioversion with spacing without spacing linguoversion # deep bite , class II div 2 mesioversion , distoversion

• Transverse # buccoversion , linguoversion crowding ,spacing •

vertical # supraversion infraversion www.indiandentalacademy.com

Transverse occlusal deviations of post. segments

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3 categories of crowding [ in mixed dentition ] I degree crowding II degree crowding III degree crowding On etiology Primary hereditary Secondary mesial drift of post teeth Tertiary assoc with 3 rd molar eruption By taking inclination of teeth coronal crowding www.indiandentalacademy.com apical crowding

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Apical base dental arch width Normal relationship

Coronal crowding

Apical crowding

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Canine relationships • Class I The distal surface of the mand canine is with in 1 premolar’s width of the mesial surface of max canine • Class II The distal surface of the mand canine is distal to the mesial surface of max canine by at least a width of 1 premolar • Class III The distal surface of the mand canine is mesial to the mesial surface of max canine by atleast a width of 1 premolar www.indiandentalacademy.com

Incisor relationship • Class I Incisor margins of mand incisors occlude directly below the middle of the lingual surfaces of the max incisors • Class II Incisor margins of mand incisors lie behind the middle part of lingual surfaces of max incisors • Class III Incisor margins of mand incisors lie in front of the middle part of lingual surfaces of max incisors www.indiandentalacademy.com

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