Class ii malocclusion zz

Dr. ZIA UL ISLAMORTHODONTICS DEPARTMENT

ANGLE’S CLASS II The distobuccal cusp of the

upper 1st permanent molar occludes in the buccal

groove of the lower 1st permanent molar.

Angle has sub-classified class II malocclusions into two divisions:

Class II, division 1

Class II, division 2

Class II, division 1 malocclusion is characterized by proclined upper incisors with resultant increace in overjet.

Skeletal: Prognathic maxilla

Retrognathic mandible

Combination of both

Soft tissues:

Incompetent lips

Proclined upper incisor

Lower lip trap behind upper incisors

Proclination of upper incisors

Retroclination of lower incisors

Tongue thrust

Habits:

Digit sucking habit

Proclination of upper incisors

Retroclination of lower incisors

AOB or in less severe forms incomplete OB

Cross bite

Incresed LFH

Extra oral features

Class II divison 1

profile: convex

Shape of head : dolicocephalic

Mento labial sulcus : shallow/deep

Hyper active mentalis: present

Hypo active upper lip: present

o classII molar relation,

that may vary from end on molar to fully fledged class II

o proclined maxillary anteriors with resultant increased overjet

o Flaring and spaced dentition

V – shaped palatal arch

Excessive curve of spee

Deep palate

Increased over bite

o Patient may have a short hypotonic upperlip

o Lip trap may be present(placing lower lip against the palatal surface of upper incisor)

o Abnormal buccinator activity leading to a constricted , narrow upper arch. Which predispose to posterior cross bite

o Hyper active mentalis muscle (retrognathic mandible)

Growth modification: Head gear (High pull, low pull, medium pull)

Functional appliances

Fixed appliances

Removable appliances

Surgery

Class II div I malocclusion or often complicated by the prescence of underlying skeletal abnormalities .

For Maxillary prognathism:

Face bow with head gear

For Mandibular deficiency:

at mixed dentition period myofunctinal appliance like activator or functional regulator

At the end of growth period, fixed functional appliance like Herbest applinace or Jasper Jumper.

For growth modification in

a growing patients:

1- Mild to moderate Class

II div. 1

2- Proclined upper incisors

3- No lower and upper

arch crowding

4- Deep overbite

5- Average or reduced

LFH.

Used for most complicated tooth movements which involve bodily tooth movement, intrusion, extrusion.

Removable appliances

Robert retractors

-Proclined upper incisors

-Spaced upper incisor

-Normal or reduced overbite

Surgery

Based on underlying skeletal pattern a maxillary set back or mandibular advancement is undertaken after the completion of growth.

Correction of Cross bite

Removeable appliance

Fixed appliance

Cross bite elastics

Coffin spring

Quad helix

Correction of deep bite

Removeable anterior bite planes

Fixed appliances

Class II, division 2

The upper central incisors are retroclined ; the overjetis minimal but may be increased.

Type A:- the four maxillary permanent

incisors are tipped palatally, without the occurrence of crowding

Type B: the maxillary central incisors are tipped palatally and the maxillary laterals are tipped labially.

Type C: the four maxillary permanent incisors are tipped palatally with thecanine labial positioned.

Skeletal: Prognathic maxilla

Retrognathic mandible

Combination of both

Soft tissues:

The lips are almost always of adequate length to

meet without strain.

Frequently the lip line is high relative to the upper

incisor crown, and the higher the lip line the more

retroclined the upper incisors are liable to be.

There is often a well-developed labiomental fold.

Retroclined upper central incisors.

Upper lateral incisors are at an average angulations or are proclined.

Overbite.

Lingual crossbite of the 1st

and occasionally 2nd

premolar.

Class II molar, canine & incisor relationship.

The lower incisors may cause ulceration of the palatal tissues due to deep bite

retroclination of the upper incisors leads to stripping of the labial gingivae of the lower incisors.

lingual cross bite of 1st and 2nd premolars the owing to the relative positions and widths of the arches, and possibly to trapping of the lower labial segment within a retroclined upper labial segment

Relief of gingival trauma

Correction of incisors and molar relation

Relief of crowding and local irregularities

no treatment

extraction only

removable appliance

fixed appliance

functional appliance

orthognathic surgery

The deep anterior over bite can be reduced by use of anterior bite plane or fixed appliances incorporating anchor bends.

The incisors inclination often necessitates the use of torquing springs.