class ii malocclusion zz
TRANSCRIPT
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.