class ii malocclusion (2)

CLASS II MALOCCLUSION

Usman & Mehmood

DEFINITION:

The lower dental arch is posterior to the upper in one or both the lateral segments.1

The lower first molar is distal to the upper first molar.1

DIVISIONS:

Division 1

Division 2

DIVISIONS

Class II division 1:

Bilaterally distal with narrow maxillary arch with protruding upper incisors.1

DIVISIONS

Class II division 2

Bilaterally distal with normal or square shape maxillary arch, retruded maxillary central incisors, and an excessive overbite.1

TYPES OF CLASS II DIVISION 2

TYPE A: central incisors retroclined and laterals proclined

TYPE B: central and lateral incisors retroclined and canines buccally placed

TYPE C: all anterior teeth retroclined

ETIOLOGY OF MALOCCLUSION Heredity

Habits Thumb sucking Digit sucking Tongue thrust Lip thrust Lip trap Lip biting Nail biting

ETIOLOGY OF MALOCCLUSION

Speech defects Abnormal sucking habits Psychogenic problems

CHARACTERISTICS

DIV 1DIV 2

Convex Straight to mildly convex

Short

Everted

Incompetent

Normal

Normal

Competent

Deep Deep or normal

Hyperactive Normal

CHARACTERISTICS

PROFILE

LIPS

a. Upper

b. Lower

c. Competency

MENTOLABIAL SULCUS

MENTALIS MUSCLE

CHARACTERISTICS contd.

Malar processNot prominentProminent

Lower facial heightNormal or increased Decreased

Arch form V shapedSquare, U shaped

Palatal vaultDeep Normal

Incisors Proclined Central retroclined; laterals proclined

CHARACTERISTICS contd…

Overjet Increased Decreased

Crown root angulations

Normal angleAxis of crown and root bent; collum angle

Path of closureNormal Backward path of closure

Interocclusal clearance

Normal/ Increased/ Decreased

Increased

Class II division 1 malocclusion

Class II division 2 malocclusion

CEPHALOMETRIC ANALYSIS

Except for the maxillary incisor positions, no basic difference in dentoskeletal morphology exists between class II division 1 and class II division 2 malocclusions

CEPHALOMETRIC ANALYSIS Class II division 1 Upper incisor to SN

plane angle increased

Increased upper incisor-soft tissue linear measurements

CEPHALOMETRIC ANALYSIS Class II division 2: Upper incisor to SN

plane angle decreased

Decreased upper incisor-soft tissue linear measurements

MANAGEMENT

Class II Division 1

Class II Division 2

MANAGEMENT

PROBLEMS:

Skeletal Dental Combination

MANAGEMENT Class II Division 1

OBJECTIVES: Improvement of esthetics Correction of increased overjet Correction of deep bite Alignment of anterior teeth Correction of class II molar

relationship Correction of deep Curve of

Spee Correction of any individual

problems

MANAGEMENT Class II Division 1

IN DECIDUOUS DENTITION:

Habit control

Supportive aids

MANAGEMENT Class II Division 1 IN MIXED DENTITION: DENTAL DISCREPANCY: Removable appliances Molar distalization Space maintainers Space gainers Habit breaking appliances

Vestibular shields Tongue guards/cribs

Myofuntional therapy Tongue positioning excercises Lip excercises

MANAGEMENT Class II Division 1

SKELETAL DISCREPANCY:

FOR MANDIBULAR DEFICIENCY

Myofunctional appliances

FR 1

Activator

Bionator Fixed functional appliances

(late mixed dentition)

Herbst appliance

Jasper Jumper

MANAGEMENT Class II Division 1

FOR MAXILLARY PROGNATHISM

Face bow with head gear

FOR COMBINATION

Activator with head gear

MANAGEMENT Class II Division 1

IN PERMANENT DENTITION: DENTAL DISCREPANCY: EXTRACTIONa. more than 5mm discrepancy in both the

arches – extraction of all first premolars b. 5mm discrepancy in upper arch only –

extraction of upper first premolars onlyc. >5mm in upper arch, 2.5 – 5mm in lower arch

--- extraction of upper first premolars and lower second premolars

d. Extraction of first or second molars

MANAGEMENT Class II Division 1

MANAGEMENT Class II Division 1

CLASS II ELASTICS

MANAGEMENT Class II Division 1

NON EXTRACTION: Spacing ALD less than 5mm

MANAGEMENT Class II Division 1

SKELETAL DISCREPANCY: MAXILLARY PROGNATHISM:

Segmental osteotomy Lefort 1 Alveolar corticotomy

MANDIBULAR DEFICIENCY: BSSO

MANAGEMENT Class II Division 2

TREATMENT OBJECTIVES:

Improvement of esthetics

Correction of incisor relationship

Correction of closed bite realtionship

Correction of incisor inclination and gingival trauma

Correction of molar relationship

Correction of occlusal plane

Correction of any individual abnormality

MANAGEMENT Class II Division 2

IN DECIDUOUS DENTITION: Usually not diagnosed Orthodontic treatment not required

MANAGEMENT Class II Division 2

IN MIXED DENTITION: Correction of deep bite;

anterior bite plane therapy

MANAGEMENT Class II Division 2

With normal incisor pattern, aligning of anteriors followed by myofunctional appliances to correct Class II relationship

MANAGEMENT Class II Division 2

In case of mild discrepancy (2 – 3 mm) distalizing upper first permanent molars to gain space for anteriors

MANAGEMENT Class II Division 2

IN PERMANENT DENTITION: DENTAL DISCREPANCY: Extraction ---- usually not required;

managed by combination of palatal expansion and proximal stripping

Anteriors aligned by a combination of double cantilever spring and labial bow, with or without expansion screw

MANAGEMENT Class II Division 2

MANAGEMENT Class II Division 2

In case of severe crowding upper first premolars extracted

If crowding in both arches – extraction of first/second premolars in both the arches

MANAGEMENT Class II Division 2

SKELETAL DISCEPANCY: Usually not seen Mandibular segmental osteotomy

MANAGEMENT

POST TREATMENT RETENTION Temporary or permanent Removable or fixed

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