ARCH LEVELING,DEEP BITE CORRACTION

1. ARCH LEVELING & OVERBITE
CONTROL
PRESENTING BY:
DR.RAHUL TIWARI

2. Definition:
The tooth movements needed to achieve passive engagement of a steel
rectangular wire of 0.019 X 0.025 dimension of suitable archform, into
a correctly placed preadjusted 0.022 bracket system.

3. Development of deep overbite:
Lower anterior teeth normally
erupt until contact is made with
upper anterior teeth.
The tongue can restrict over-
eruption of lower incisors in
some class II cases.

4. If the molar relationship is
class II, the lower incisors can
erupt until they contact the
palate. This can cause a steep
anterior curve of Spee.
Unrestricted eruption of
lower 2nd molars in class II
case contributes to
development of posterior part
of curve of Spee.

7. Skeletal convexity
Vertical dimension & growth
Freeway space
Anterior esthetics

8. NON - EXTRACTION TREATMENT
Initial arch wire placement: When flat archwires are placed into
dental arches with curves of Spee, the archwires tend to return to their
original shape & this starts the bite opening process. Also, expression of
the tip in the brackets begins the bite opening process.
Bite plate effect: Introducing bite plate effect in deep bite
cases is helpful in following ways:
•It allows early placement of brackets on lower incisors.
•Anterior bite plates can produce an intrusive force on lower incisors.
•Anterior bite plates allow for the eruption, extrusion & or uprighting of
posterior teeth.

10. The importance of second molars:
In average to low angle deep bite cases, the earliest possible
banding or bonding of the second molars is most beneficial in
bite opening.
Inclusion of the second molars provides an excellent lever
arm for eruption & extrusion of premolars & first molars, and
assists in incisor intrusion.

11. Bite opening curves :
In the great majority of cases after rectangular SS wires have been in
place for 6 weeks, the arches are normally level & adequate bite
opening has been achieved. If this is not so, bite opening curves can be
placed into the rectangular steel wires.

12. Anteroposterior issues and elastics:
1.Intermaxillary elastics can contribute to bite opening effect by
assisting
in extrusion of molars as the A/P problem is corrected.
2.They are beneficial in treatment of most growing patients. If possible
they
should be avoided in most non growing patients and adult high angle
cases.

13. EXTRACTION TREATMENT
Most of the mechanical treatment procedures described for deep bite
non extraction cases, also apply to the deep bite extraction cases.
However, there are two other important factors in extraction deep bite
cases:
 With extraction cases lower incisors are normally maintained in their
position or brought to a more retroclined position. This makes the bite
opening more difficult.
 If space closure is attempted before proper arch leveling and
overbite control, it will lead to bite deepening.

14. Overbite control during leveling & aligning:
1.There is tendency for incisors and canines to tip mesially after placement
of the opening archwires. Canine lacebacks should be used to resist this
mesial tipping of the canines and to retract these teeth effectively without
distal tipping. Elastic forces should be avoided.
2.When canines are unfavourably angled, it may be beneficial to avoid
bracketing the incisors until the canine roots have been retracted
3.An alternative technique involves placing a bend in the archwire mesial
to the canine.
4.According to MBT, incisors that are in reasonably good alignment should be
bracketed & included in the initial archwires. This provides greater stability to
the archform & minimizes distal tipping of the canines.

15. Overbite control during space closure:
It is important to use light forces during space closure.
Heavy forces causes bite to deepen in two ways:
1.The canines can tip into the extraction sites causing archwire
deflection
and binding. The sliding mechanics then becomes ineffective, and the
overbite deepens.
2.Excessive forces overpowers the incisor torque control of the
rectangular
wire, causing distal tipping and bite deepening.

16. Early management of openbite:
•Finger and thumb sucking appliances.
•Palatal expansion in case with narrow maxilla.
•Palatal bars and lingual arches on the molars.
•Posterior bite plates on upper and lower posterior teeth.
•Removal of deciduous canines and sometimes premolars.
•High pull facebows and vertical chin cups.
•Myofunctional therapy.
•If adenoids and tonsils are responsible then their removal.

17. Management of openbite during full orthodontic treatment:
1. If upper and lower arches are crowded and/or show protrusion,
upper and lower bicuspid extractions can be considered.
2. If the lower arch does not require extraction of lower incisor
retroclination, and the molars are more than 3-4 mm class II,
extractions of upper bicuspids only can be considered.
3. Appropriate bracket placement.
4. Second molars should be banded in early and middle stages.
5. If class II or class III elastics are required, they should be attached
posteriorly to premolars rather than molars.