2. Introduction
A Class II Div.2 relationship is defined by the
British Standards classification when the lower
incisor edges occlude posterior to the cingulum
plateau of the upper incisors with retroclination
of the upper central incisors The overjet is
usually minimal, but may be increased .The
prevalence of this malocclusion in a Caucasian
population 10%.
3. Cont.
According to Angle's classification, in a Class II
Division 2 malocclusion where the mesiobuccal cusp of
the upper 1st permenent molar should be
at least half cusp anterior to the mesio buccal
developmental groove on lower 1st permenent molar,
and the upper central incisors should be retroclined
,The upper lateral incisors may be similarly retroclined
although in other cases, Particularly
in the presence of crowding, they may be proclined.
5. Types of cl ii div 2
Three types of cl ii div 2 can be distinguished based on
diffrences in the spatial conditions in the maxillary arch: Type A:- the four maxillary permanent
incisors are tipped palatally, without the occurrence of
crowding.
6. Cont.
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 the
canine labial positioned.
7. Main features of class ii div 2
1-retroclination of the upper incisors.
2-excessive incisal overbite (deep bite).
3-a low gonial angle.
4-square facial profile.
5-the lips have sufficient vertical dimension to
be able to meet in the rest position.
6-lips meet in front of the upper central
incisors.
7-There is commonly a pronounced labiomental groove beneath the lower lip.
9. Skeletal pattern
Class II division 2 malocclusion is commonly
associated with a mild Class ll skeletal pattern,
but may also occur in association with a Class 1
dental base relationship.
11. Soft tissue
The influence of the soft tissues mediated by the skeletal
pattern…
lower facial height is reduced
the lower lip line will effectively be higher
incisors relative to the crown of the upper
(more than 1/3 of crown
A high lower lip line will tend to retrocline the
upper incisors
Class II division 2 incisor relationships may also result
from bimaxillary retroclination caused by active
muscular
14. Soft tissue
in some cases the upper lateral incisors, which have
a shorter crown length, will escape the action of the
lower lip and therefore lie at an average inclination,
whereas the central incisors are retroclined
15. Dental factor
As with other malocclusions, crowding is commonly
seen in conjunction with a Class II division 2 incisor
relationship In the upper labial segment this usually
manifests in a lack of space for the upper lateral
incisors which are crowded and are typically rotated
mesiolabially out of the arch
In the same manner lower arch crowding is often
exacerbated by retroclination of the lower labial
segment. This can occur because the lower labial
segment becomes 'trapped' lingually to the upper labial
segment by an increased overbite
16. Cont.
the upper central incisors exhibit a more acute crown -
root angulation. this crown-root angulation could itself
be due to the action of a high lower lip line causing
deflection of the crown of the tooth relative to the root
after eruption.
reduced or absent palatal cingulum on the upper
incisors. This can be another factor contributing to the
excessive overbite.
17.
18. Traumatic deep bite
The lower incisors may cause ulceration of the palatal
tissues due to deep bite
19. Traumatic deep bite
retroclination of the upper incisors leads to stripping of
the labial gingivae of the lower incisors.
20. lingual cross bite
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
21. Differences between cl ii div 1 and cl ii div 2
feature
Div 1
Div 2
profile
convex
Convexity/ straight
lips
incompetent
competent
Lower facial height
Increase/normal
decrease
Arch form
V-shape
Square/ U-shape
incisors
proclined
CI
LI
Overjet
overbite
Increase
deep
Decrease
deep
Path of closure
normal
backward
retroclined
proclined
22. Treatment aims
1-To improve the aesthetics of the teeth
and the function of the teeth and jaws.
2-To relieve crowding and produce
alignment of the teeth within the arches
3-Where the overbite is excessive, to
reduce it.
4-If the overjet is increased, reduce it
23.
24. Treatment options
1-no treatment
2-extraction only
3-removable appliance
4-single fixed arch appliance
5-full upper and lower fixed
appliance
6-functional appliance
7-orthognathic surgery
25. Treatment options
No treatment:-In milder Class II Division 2
malocclusions in which the typical facial
appearance is acceptable, as is the overbite, and
the incisors are neither too retroclined nor too
crowded, advising no active treatment can be a
very reasonable approach to management
Extractions only:-This is rarely an acceptable
treatment approach in this type of malocclusion
.However , where buccal crowding is severe
with a tendency for the premolars to be
excluded from the arch this may be an option to
consider.
26. Treatment options
Removable appliances:-
1-In these types of malocclusion an upper
removable appliance is most frequently used to
assist in the reduction of the deep overbite
during the early stages of a fixed appliance
treatment (adjunctive support).
27. Treatment options
2-In a very limited number of cases a definitive simple
removable treatment alone may be appropriate. An
example might be where a labial spring is used to bring
back a single proclined lateral incisor into the arch
This movement would be performed after an 'en masse'
appliance had been used to move the teeth of the buccal
segments distally.
3-The use of an isolated removable appliance, particularly
in combination with a premolar extraction pattern, is
rarely prescribed in Class II Division 2 malocclusion.
28. Treatment options
Single fixed arch appliance:- overbite and upper
central incisor inclination is largely acceptable.
Extra-oral traction might then be applied to the
upper first molars. When sufficient space has been
achieved by this means or by a second premolar
extraction, an upper appliance may be fixed to the
teeth to align and derotate the upper lateral incisors.
Some limited torquing of incisor apices palatally may
be possible.
29. Treatment options
Upper and lower fixed appliance:-The most common
way to treat class ii div.2 .
Extraction pattern:-The first option, which should
always be considered, is whether this malocclusion
may be corrected on the basis of 'no extractions' or
Extraction of permanent second molars.
30. Treatment options
1- no extraction:-where the incisors
are retroclined,
torquing the root apices palatally will increase the arch
length and gain sufficient space to both align the dental
arches and reduce the overbite. In such a situation a
high level of patient compliance is essential since the
end result depends on the extra oral traction
(headgear) being worn by the patient for long periods
to supplement the anchorage.
31. Treatment options
2-with extraction:- we need extraction to gain space
In the following situations:*the incisors require more torque to achieve an acceptable
inter incisal angle.
*there is a deeper initial overbite.
*The crowding is more severe.
so premolar extractions might be considered (usually
four second premolars).
32. Treatment options
Overbite:-One of the chief reasons for employing a twin
arch fixed appliance is to correct the overbite to a stable
result. This is achieved by active intrusion of the lower
incisors to flatten the curve of Spee.
Interincisal angle:-the interincisal angle is obtuse at
the start of treatment. Obtaining a stable overbite
correction is dependent on torquing the incisor root
apices palatally to achieve a more acute (reduced)
interincisal angle.
33.
34. Treatment options
Functional appliances:- some functional appliances
are most effective in cases where the lower facial height is
reduced. The upper incisors are firstly proclined to create
a Class II Division 1 malocclusion then treat it with
functional appliance.
Types of functional appliances used in Cl ii div.2 :-Andresen appliance.
-The Harvold appliance.
-The Frankel appliance.
-Clark's Twin-Block appliance.
35. Treatment options
Clark's Twin-Block appliance
The Frankel appliance
These appliances are
designed to move the
mandible in a
forward position
Andresen appliance.
36. Treatment options
Orthognathic surgery:- In the more severe forms of
this malocclusion, where the facial profile is poor and the
overbite is very deep (and traumatic), a combination of
orthodontics and jaw surgery is the best approach.
initial pre surgical phase of fixed appliance orthodontics,
the upper incisors are proclined to create an overjet The
mandible is then advanced by surgery to reduce this
overjet and correct the facial profile.
37. Post-treatment stability
Lateral incisor alignment:- There is a very strong
tendency for the lateral incisors to return towards their original
position. This is particularly true if they were rotated. Where
possible the position of these teeth should be overcorrected
during treatment. Or prolonged retention but it is not yet
clear whether retention beyond six months does improve
stability or it merely postpones the relapse.
Overbites:- relapse of overbite reduction will occur unless
palatal movement of the incisor apices has reduced the
interincisor angle.
