Classification of Malocclusion

1. 1 Classification of malocclusion Classification of malocclusion Prepared by Prepared by Dr Dr: : Mohammed Alruby Mohammed Alruby ارذتعم كاتا نم عم ايساق نكت لا C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

2. 2 Normal in orthodontics: Normal means: healthy average, ideal, efficient occlusion There is a range of normality in human but no exact standard by which normal can be measured, to recognize abnormality, it is necessary to have knowledge of normal Normal occlusion: it is the usual or accepted relationship of species of teeth in the same jaw and those in the opposing jaw when the teeth are approximated in terminal occlusion and mandibular condyles are in centric position in glenoid fossa. Characteristic of normal occlusion: 1-Each arch is regular with the teeth at ideal mesiodistal and buccolingual inclination at the correct proximal contact relationship at each interdental contact area 2-All teeth must be angulated slightly mesialy 3-The buccal surfaces of incisors are labially inclined, but from the canines posteriorly the buccal surfaces are progressively more lingually inclined 4-The upper arch overlaps the lower one either from anterior or posterior segment 5-Absence of rotation and tight proximal contact relationship 6-falt occlusal plane 7-when the teeth are in maximum intercuspation, the mandible is in position of centric relation as both condyles are in symmetrical retruded unstrained position in the glenoid fossa 1-Anterior segment: a-Each lower tooth (except central incisors) contact with the corresponding upper tooth and tooth anterior to it b-The lower incisors edges occlude within the cingulum plateau of the upper incisors and their inclination are such that the over jet is 2-3mm and over bite is between 1/3 to ½ of the height of the lower incisors c-The midlines coincide and the occlusal plane is only slightly curved 2-Anterior posterior relationship: = the incisal edge of the incisors should follow a smooth curve ant.post, this is usually for the lower incisors because of their relatively equalize = the maxillary lateral incisors edges are slightly lingual to that of maxillary central because the difference in labiolingual thickness. = the canines serve as corner stone between anterior and posterior teeth, they are slightly more buccal or labial than lateral and bicuspid, this more pronounced in maxillary than mandibular one. 3-Buccal segment: The upper and lower teeth have correct inter-cuspal relationship, as the upper canine occludes in the embrasures between the lower canine and 1st premolar 4-Axial inclination: = the long axis of maxillary teeth tends to meet in the area of the Cresta Galli at cranial base, this means that the long axis of the teeth is convergent apically = the long axis of maxillary central and lateral incisors is more convergent than that of molars and bicuspid = the long axis of canine follows the lateral wall of the nose = the long axis of mandibular molars and bicuspid are divergent buccolingual 5-Crown angulation: = the long axis of posterior mandibular teeth tends to be parallel mesiodistally = the long axis of posterior maxillary teeth tends to inclined distally C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

3. 3 NB: canine and 1 NB: canine and 1st st molars are prominent outside the arch due to increase buccolingual dimension molars are prominent outside the arch due to increase buccolingual dimension Six keys to normal occlusion: Key 1: Molars relationship; a-the distal surface of distal marginal ridge of upper 6 contacts and occludes with the mesial surface of the mesial marginal ridge of lower 7 b-the mesio-buccal cusp of upper 6 falls within the groove between the mesial and middle cusp of lower 6 c-the mesio-palatal cusp of upper 6 seats in the central fossa of lower 6 key 2: crown angulation, mesio-distal tip; in normally occluded teeth, the gingival portion of the long axis of each crown is distal to the occlusal portion of that axis, the degree of that tip varies with each tooth type. Key 3: crown inclination, labiolingual or buccolingual torque: Crown inclination is the angle between a line 90 degree to the occlusal plane and a line tangent to the middle of the labial or buccal clinical crown a-Anterior crowns, central and lateral incisors: In upper incisors, occlusal portion of the crown’s labial surface is labial to the gingival portion In all other crowns, the occlusal portion of the labial surface is lingual to gingival portion. b-Upper posterior crown, cuspids through molars: The lingual crown inclination is slightly more pronounced in the molars than in cuspids and bicuspids c-Lower posterior crowns, cuspids through molars: The lingual inclination progressively increases. Key 4: rotation: Teeth must be free of undesirable rotation Key 5: tight contact: Contact point must be tight Key 6: curve of spee: It is imaginary curve, in the horizontal dimension passing through the condyle and buccal cusps of the teeth ending at the incisal edge of the mandibular central incisors. It is measured from the most prominent cusp of the lower 7 to the incisal edge of the most prominent lower 1 =A flat curve of spee is the most respective to normal occlusion and not deep than 1.5mm Principles of orthodontic classification: Classification in orthodontics is concerned chiefly with recognition of deviation from biologic norm. classification of malocclusion entails consideration of age, sex and general development and employs dental casts, cephalometric and other biometric aids. In clinical examination of mouth and dentition for purpose of establishing a classification, it is necessary to relate face, jaws and teeth to 3 dimensions of space and with maturative state of the patients according to the following: 1-Morphologic development of dental arches and their relationship to each other and to face and cranium 2-Relationship in the vertical and anteroposterior and transverse in the same arch and in the opposing arches 3-Displacement of individual teeth and groups of teeth 4-Crowding associated with excessive mesial or distal displacement of buccal and anterior tooth segments C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

4. 4 Purpose of classification: 1-For additional reasons and for ease of references 2-For purpose of comparison and for ease in self-communication. 3-It indicates the proper procedures in treatment 4-It facilitates, more accurate conclusion about the etiology, progresses, retention and presentation of malocclusion Deciduous normal occlusion: 1-Except the deciduous molars all other teeth are spaced, the spacing in deciduous teeth is a rule or at least not abnormal 2-Curve of spee is less marked than the permanent teeth because: short arch length anteroposterior, and the cusps of posterior is short and occlusal table is flat 3-The buccal cusps of maxillary deciduous molars and the incisal edge of maxillary deciduous incisors overlaps the mandibular one but the degree of overlap differ because of short cusps 4-The maxillary incisors and canine are larger than the mandibular one and the mandibular molars are larger than the maxillary one (mesiodistally) 5-All the maxillary teeth except the 2nd deciduous molars occlude with two opposing teeth, the upper E occlude only with lower E 6-Long axis of the teeth is nearly parallel to each other 7-Midline rule and symmetry similar to the permanent dentition 8-Terminal flash plane Mixed dentition occlusion: Early mixed: 1-The anteroposterior and transverse assessment of normal occlusion is made on the basis of deciduous teeth only 2-The vertical assessment at this phase is difficult to be estimated since the permanent incisors are still in the process of eruption and may be not in contact 3-The incisors may erupt with spacing between them but this is not abnormal up to the full eruption of permanent canine 4-After full eruption of 6 the arch continuity is established, and at this stage, the evaluation of occlusion is made on the basis of 6, deciduous canine and permanent incisors. 5-The distal contour of upper 6 and lower 6 are on straight vertical plane and there is no interdigitating and this is temporary and may adjusted after close lee way space by late mesial shift 6-From this stage till 12 years of age the dental arches discontinued again due to loss of deciduous canines and molars and their replacement by permanent one Late mixed: This stage starts from 9—12 years of age it is little value in evaluating the occlusion because all dentition is in state of constant fluctuation (1)- primary classification: a- cephalic anomalies: deformities of osseous component of the head in general, which affect the dental occlusion and dento-facial development. Treatment of malocclusion by orthodontic means alone in these cases is usually not effective cephalic anomalies include: 1-Microcephalus; usually accompanied by receding chin 2-Microcephalus: usually accompanied by spacing of teeth, mandibular prognathism or other form of malocclusion C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

5. 5 3-Osteogenic, neurogenic, and trophic disturbance of maxilla and mandible as hyperostosis of maxilla accompanied by overgrowth in width and depth of mandible and retardation of dentition and enlargement of the jaws b- dysgnathic anomalies: a term suggested by Lischer to denote growth developmental anomalies of teeth, dental arches, alveolar processes jaws and other oral structures, these include the following: 1-Macroglossia, abnormal labial Frenum and other muscular hypertrophy or atrophic disturbance 2-Facial clefts: cleft palate and lips 3-Total or partial a gnathia, total or partial absence of maxilla or mandible 4-Severe changes in form, structure, and relationship of jaws and teeth which may or may not associated with systemic disease as muscular dystrophy allergy, severe chronic childhood disease endocrine and nutritional disturbance mongolism c-Euognathic anomalies: a term suggested by Lischer used to denote anomalies of teeth alone which affect occlusion with malformation of alveolar process but without deformity of jaws and facial features Euognathic anomalies include the following: 1-Disturbance in degree of tooth development: impaction, retardation and incomplete eruption 2-Position of teeth or tooth in relation to line of occlusion or any 3 plane of space = Lischer suggested the suffix (version) to classify malposition of a tooth or teeth in relation to line of occlusion = teeth can assume one or some combination of the following position: 1-Linguoversion; toward the tongue 2-Labioversion: toward the lip or cheek 3-Mesioversion: mesial to normal position 4-Distoversion: distal to normal position 5-Inferaversion; higher in maxilla or lower in mandible than the line of occlusion 6-Supraversion: below (in maxilla) or above (in mandible) the line of occlusion 7-Torsiversion: rotated in its long axis 8-Axiversion; wrong axial inclination 9-Transversion: wrong order in the arch (transposition) ++ imberication: irregular arrangement of teeth due to lack of space (2)-Classification by body type: (Berger): Classification of dental arches according to body type is advocated by Berger who used Kretschmer’s somatic type as an adjunct in classifying arch forms According to Kretschmer, human body may be divided into the following somatic type: 1-Long and slender (leptosomatic or asthenic): a tall, thin person with narrow shoulder, slim arms and hands. Face is narrow and mandible is underdeveloped and bridge of the nose overdeveloped in length 2-Short and squat (Pyknic): a person who is comparatively short with short neck and compact trunk, the face is broad and less high than leptosomatic type C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

6. 6 3-Muscular type (athletic): a person with strongly developed muscles, broad shoulders and fully developed chest. The mandible is square and fully developed == these types do not always occur in their pure state and any one type may show features of any of others (3)- Classification according to etiology: a- Bennett classification: class I: abnormal position of one or more teeth due to local etiologic factors class II: abnormal development of upper and /or lower arch due to developmental defect of the bone class III: malrelatioship of the upper and lower arches to each other and between the upper and /or lower arch to the face due to developmental defect of the bone b- Moyers classification: classify cases according to their primarily tissue involved 1-Osseous: = Include problems in abnormal growth size, shape, or proportion of any bones of craniofacial complex. When any bone of the face develops in a disturbed manner, this may be reflected in an orthodontic problem, for example: Class III may be due to mandibular hypertrophy and Class II due to mandibular inadequacy = osseous dysplasia or skeletal disharmony is a component of many malocclusions seen most frequently, most Class III malocclusion are skeletal in origin and deep bite or cross bite may have skeletal basis 2-Muscular: This group includes all problems in malfunction of dento-facial musculature, any persistence alteration in the normal mandibular movement or muscle contractions may result in distorted growth of facial bones or abnormal positions of the teeth. = a simple lip sucking habit may give rise to class II dentition and profile = sometimes several habit patterns combine to make a complicated syndrome as thumb sucking, the sucking habit itself is a complicated neuromuscular reflex involving many muscles of the face, TMJ, tongue. Continued sucking may narrow the maxillary dental arch that result in tooth interferences and the mandible shifted posteriorly by muscles to a position of better occlusal function = this category includes: Functional slides into occlusion due to occlusal interference Abnormal pattern of mandibular closure Abnormal muscle contraction as tongue thrusting during swallowing, mouth breathing 3-Dental: Include problems affecting the teeth and their supporting structures, care must be taken to determine whether the dental abnormality is a primary or secondary problem and include: Malposition of teeth Abnormal number of teeth Abnormal size of teeth Abnormal texture of teeth (4)- Naming malposition of individual teeth and group of teeth; a- individual teeth: Lischer’s nomenclature used to describe malposition of individual teeth and it simply adding suffix- version to a ward to indicate the direction from the normal position as described C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

7. 7 b- vertical variation of group of teeth; deep bite: a term applied when there is excessive vertical overlap of incisors open bite: a term applied when there is a localized absence of occlusion while the remaining teeth are in occlusion and it may be anterior or posterior. c-Transverse variation of groups of teeth: cross bite: a term used for abnormal buccolingual relationship of the teeth it may be buccal or lingual, anterior or posterior, unilateral or bilateral buccal cross bite: buccal cusps of lower teeth occlude buccal to buccal cups of upper teeth lingual cross bite: buccal cusps of lower teeth occlude lingual to lingual cusps of upper teeth, this known as scissors bite (5)- Angle’s classification: 1899: based on the following criteria 1- the most indicative irregularity of the teeth is in anteroposterior direction 2-upper 6 is the key of occlusion, although this tooth may vary slightly in position, Angle thought that this variation is natural and associated with the variety of facial types. The relative fixity of this tooth permits it to be considered a reference point 3-the curvature and size of line of occlusion is unique for each individual 4-normal mesio-distal relation of canines and mesio-buccal cusps of upper 6 in relation to lower 6 Class I: The mandibular dental arch and the body of the mandible are in normal relation to the maxillary one with the mesio-buccal cusp of upper 6 occlude with buccal groove of lower 6 and mesio-lingual cusp of upper 6 occlude in central fossa of lower 6 when jaws are at rest and teeth are approximated in centric occlusion. Malocclusion in class I is localized anterior to 1st molars and may be in the following: = Local abnormalities: 1-Crowding in incisors teeth 2-Labial inclination of upper incisor teeth 3-Anterior cross bite 4-Posterior cross bite 5-Impaction of premolars and canines 6-Deep over bite 7-Open bite anterior or posterior 8-Local abnormalities due to premature loss of deciduous molars and forward drifting of permanent molars with loss of space in premolar region. = Disproportion in size between the teeth and basal bone resulting in crowding or spacing of the teeth Class II: = The mandibular dental arch and the body of the mandible are in distal relation to the maxillary one by half the width of 6 of width of premolar. = The mesio-buccal cusp of upper 6 occlude in the space between mesio-buccal cusp of lower 6 and distal aspect of buccal cusp of 2nd premolar = The mesio-lingual cusp of upper 6 occlude mesial to the mesio-lingual cusp of lower 6 = Class II divided into 1-Class II division 1: which: Maxillary incisors in labioversion Excessive over jet and deep bite V –shaped upper arch C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

8. 8 Short upper lip with failure in anterior lip seal Mandible may be deficient and chin under developed 2-Class II division 2: which: Maxillary lateral incisors may overlap the central which in linguo-version Deep over bite Normal upper lip and lip seal with deep mental groove Mandible in a good size Broad upper arch = When one side is class I and the other is class II is called subdivision (unilateral arrangement) Class III: The mandibular dental arch and the body of the mandible are in bilateral mesial relation to the maxillary dental arch as, the mesio-buccal cusp of upper 6 occlude in the interdental space between distal aspect of distal cusps of lower 6 and mesial aspect of mesial cusps of lower 7 The teeth are in centric occlusion and mandibular condyle is within glenoid fossa Class III subdivision; the molar relation is class III in one side and class I in other side NB: pseudo class III, postural pre-normal occlusion, bit of accommodation: = the lower dental arch is postured forward in relation to the upper dental arch while the condyle are outside their normal position within the glenoid fossa = it may be result of premature loss of both upper E as the child protrude the mandible to bring lower posterior part in contact with the upper to achieve bite of comfort = it can be differentiated from true Class III by the following: 1-The mandible can assume a normal mesio-distal relationship by manual retrusion of the mandible 2-The condyles are in forward position outside the glenoid fossa with the teeth in occlusion 3-Lower incisors may be inclined labially due to pulling action of muscles to retrude the mandible to its original position and also this may cause some lingual inclination of upper incisors Validity of Angle’s classification: 1-The 1st permanent molar is not a fixed point of the skull may be extracted or shifted after extraction of E or 5 2-It is possible to have class II dental arch on skeletal class I 3-In class II, the classification does not differentiate between true mandibular retrusion and maxillary protrusion, and also in class III either true maxillary retrusion or mandibular protrusion 4-It is show anomalies in anteroposterior direction only and neglect any anomalies in vertical and transverse directions ((modification of Angle’s classification)): (1)- Lischer modification: 1912 Lischer introduced the following to explain Angle’s classification: = Neutrocclusion or class I = Distocclusion or class II = Mesioclusion or class III = Lischer also designed the following tooth position and dental arch deviations: 1-Buccocclusion: when dental arch, quadrant or group of teeth is buccal to normal 2-Linguocclusion: when dental arch, quadrant or group of teeth is lingual to normal 3-Supraocclusion: abnormally deep bite of group of teeth or one dental arch occludes over the opposing arch so the teeth in the respective jaws overlap abnormally C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

9. 9 4-Infraocclusion: when dental arch, quadrant or group of teeth are in open bite relationship (2)- Dewey’s modification: 1915 Dewey divided Angle’s class I into the following types; Type 1: crowded maxillary anterior teeth, the canines may be in axioversion or infraversion Type 2: maxillary incisors in labioversion Type 3: one or more maxillary incisors are in linguoversion relative to the mandibular teeth (anterior cross bite) Type 4: the posterior teeth are in buccoversion or linguoversion relative to their opposing counterpart, while incisors and canines are in normal alignment and the dental arch and the body of the mandible are in normal Type 5: permanent molars have drifted mesialy usually as a result premature loss of 2nd deciduous molars and the remaining teeth are in normal relationship == This is an important observation because since it may lead to confusion of class I with class II or class III if the proper reconstruction of the original of the molar is not made == Dewey also added the following modification to Angle’s class III: Type 1: the maxillary and mandibular teeth are in normal alignment separately; the incisors are edge to edge bite when dental arches are approximated Type 2: the maxillary dental arch is in normal alignment, the mandibular incisors are lingual to maxillary one and crowded Type 3: the maxillary incisors are crowded, the mandibular arch is well developed and the maxillary arch is underdeveloped and the mandibular teeth are in normal alignment (6)- Simon’s classification: three plane of occlusion 1922 = Since the growth of the face jaws occur in the three planes of space, height, width, and depth, abnormalities also may occur in any one of the foregoing planes = it relates the denture to the face and cranium in the three planes of space: (1)Frankfort horizontal plane: or the eye ear plane 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 (notch above the tragus of the ear) this plane is used to determine deviations in the height of dental arches and teeth in relation to face and cranium (2)The orbital plane: is a perpendicular at 90 degrees to FH plane at the margin of the bony orbit directly under the pupil of the eye. This plane is used to determine sagittal deviations in anteroposterior relation of dental arches and the axial inclination of the face and the cranium (3)Median sagittal (raphe) plane: is determined by two points approximately 1.5cm apart on the median raphe of the palate = the raphe median plane passes through these two point at right angles to FH plane = used to determine deviations in the general form and width of the dental arches and axial inclination of teeth in relation to the midline of the palate and the head = in normal arch relationship according to Simon, the orbital plane pass through the distal axial aspect of the canine and this known as (the law of canine) === Simon’s classification is based on the following:==== 1-Deviation from the raphe or median sagittal plane: a-Contraction: a part or all of the dental arch is contracted toward the raphe median plane, the abnormality may be alveolar, dental, anterior, unilateral, or bilateral C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

10. 10 b-Distraction: a part or all of dental arch is wider than usual from the raphe median plane (cross bite) 2-Deviation from FH plane: The angle between FH and Oc plane, the form of occlusal curve and the inclination of the teeth axes are determined from this plane a-Attraction: the distance between occlusal plane and FH is shorter than normal, this distance is as a rule normally shorter in young than in older persons b-Abstraction: the distance between occlusal plane and FH is longer than normal 3-Deviation from orbital plane: Sagittal symmetry and inclination of axes of teeth are determined from this plane a-Protraction: teeth in one or both arches and or jaws are too far forward, normally the orbital plane passes through the distal incline of canine b-Retraction: the teeth, one or both dental arches and or jaws are too far retruded, the orbital plane passes too far anteriorly to the canine deviations of dental arches in relation to the orbital plane according to Simon may occur as follows; -Both jaws in normal relation to each other -Upper jaw normal, lower jaw mesial -Upper jaw normal, lower jaw distal -Lower jaw normal, upper jaw mesial -Lower jaw normal, upper jaw distal -Upper jaw mesial, lower jaw distal -Upper jaw distal, lower jaw mesial In addition, the relation of the palatal vault to the face and the cranium also may be determined by means of the three planes of spaces (7)- Skeletal relationships: skeletal pattern can be divided into: Class 1 skeletal: = normal anteroposterior relation of the mandibular basal arch to the maxillary basal arch = this condition is favorable for the development of normal dental occlusion = patient profile is orthognathic = classification of skeletal pattern also has the relationship of the teeth as follows: Division 1: local mal-relation of incisor, canine or premolar teeth Division 2: maxillary incisor protrusion Division 3: maxillary incisors in linguoversion Division 4: bi-maxillary protrusion Class 2 skeletal: = The mandibular basal arch is post-normal to the maxillary basal either due to maxillary protrusion, mandibular retrusion, or both. The profile of patient is retro-gnathic Division 1: maxillary dental arch is narrower than mandibular one and there is crowding in the canine region, cross bite reduced vertical height protrusion of the maxillary anterior teeth. Division 2: lingual inclination of maxillary incisors, lateral incisors may be normal or in labioversion Class 3 skeletal: C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

11. 11 = the mandibular basal arch is pre-normal to the maxillary basal arch either due to maxillary retrusion, mandibular protrusion or both = the profile of patient is pro-gnathic (8)- Ackerman-Proffit system:1969 = Ackerman and Proffit proposed a scheme which embodies the Angle’s classification and five major characteristics of malocclusion within a Venn diagram = to utilize this classification method, diagnostic information is required about the dentition itself, occlusal relationship and skeletal jaw relationships = this is derived from clinical, radiographic examination and photographic or cephalometric evaluation of dental and facial proportions = since the degree of alignment and symmetry of the teeth within the arches is common to all dentitions, It represented as the universe—group 1 Their profile is represented as major set ---group 2 within the universe Lateral, anteroposterior and vertical deviation from the normal with their interrelationship as inter-locking subsets expressed as group 3 through 9 within the profile set = when one classifying using this method, the alignment and symmetry of the teeth in the dental arches are analyzed the patient profile is viewed C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

12. 12 (9)- British standard institute classification: 1983 = this is based upon incisor relationship and was first described by Ballard and Wayman 1964 and the terms used are similar to those of Angle’s classification, which can be a little confusing as no regard is taken of molar relationship = patients are generally aware of incisor segment rather than buccal segment relationship thus its correction is of a central concern of much orthodontic treatments, the categories are as follows: Class I: lower incisors edge occludes with or lie immediately below cingula of upper incisors Class II: lower incisors edge lies posterior to cingula of upper incisors, and has two subdivisions a-Division 1: upper central incisors are proclined or with average inclination with large overjet b-Division 2: upper central incisors are retroclined, overjet is usually minimum or may be increased Class III: lower incisors edge lies anterior to the labial surface of upper incisors, overjet ir reduced or reversed (10)- Moyers analysis of Class II malocclusion: This method to describe the class II for the following purposes: 1-To localized and quantify any possible skeletal contributions to class II malocclusion 2-To identify dental displacements associated with class II malocclusion 3-To group cases with similar needs for ease in planning treatment 4-To determine the best treatment for special needs of particular case A-Horizontal types: Type A: = normal skeletal profile and normal anteroposterior position of jaws = mandibular dentition placed normally on its base but the maxillary dentition is protracted resulting in class II relationship and greater mesial overjet and overbite than normal = sometimes could a dental class II Type B: = midface prominence associated with a mandible of normal length = measures of maxillary prognathism is greater than normal but the mandible is in a normal relationship anteroposteriorly Type C: = class II profile, though the maxilla and mandible are further back beneath the anterior cranial base than normal = smaller facial dimension than other class II types on average = lower incisors are tipped labially while upper incisors are either upright or tipped off the base labially according to the vertical category = significantly more women than men are seen in type C Type D: = retro-gnathic skeletal profile because small mandible than normal = midface is normal or slightly diminished = lower incisors are upright or lingually inclined while upper incisors are labially inclined Type E: = class II profile with prominent midface and a normal or even prominent mandible = bi-maxillary protrusion class II malocclusion appear to be horizontal type E and the incisors are in strong labioversion = both dentition is bi-maxillary dento-alveolar protrusion C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

13. 13 Type F: = it is large heterogeneous group with mid skeletal class II features = it appears to be a milder form of type B, C, D, or E B-Vertical types: Type 1: = anterior face height is greater than posterior face height = mandibular and occlusal planes are steeper than normal = Palatal plane may be tipped = anterior cranial base tends to be upward = this type called steep mandibular plane case Type 2: = square face and occlusal, mandibular, and palatal planes more horizontal than normal, nearly parallel = gonial angle is smaller than normal = anterior cranial base appears horizontal = incisors more vertical position than normal, and skeletal deep bite results Type 3: C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby

14. 14 = palatal plane tipped upward anteriorly with decreased upper anterior facial height ---- open bite = mandibular plane is steeper than normal, a severe skeletal open bite results Type 4: = mandibular occlusal, palatal lines are tipped downward, although the mandibular line is neer normal leaving the lip line unusually high on maxillary alveolar process = gonial angle is relatively obtuse = this type is rare Type 5: = Mandibular and occlusal lines are placed normally = palatal plane is tipped downward, gonial angel is smaller than normal = the result is skeletal deep bite similar to but different than the vertical type 2 = lower incisors are found in extreme labioversion whereas the upper incisors are vertical. With my best wishes’’’’;……….. C Clla as ss siif fiic ca at tiio on n o of f M Ma allo oc cclusion clusion Dr. Mohammed Alruby Dr. Mohammed Alruby