MAnagement OF class ||| malocclusion

1. MANAGEMENT OF
CLASS |||
MALOCCLUSION
Presented by :
TABINDA KHAN
(INTERN)

2.  CONTENTS Introduction
Features of class ||| malocclusion
Skeletal features of class ||| malocclusion
Etiology
Diagnosis
Treatment
*Interception during growth
*Treatment using fixed appliance
*Treatment of posterior & anterior crossbite
*Role of extraction
*Treatment of severe class ||| after growth
*Pseudo class|||

3. According to Angle's classification
* Highest incidence in Japan & Korea.
# Class ||| molar relation with the mesio-buccal cusp of the
maxillary 1st permanent molar occluding in the interdental space
between the mandibular 1st and 2nd molars.
• classified into:
- True class ||| malocclusion : skeletal class ||| malocclusion of
genetic origin
- Pseudo class ||| malocclusion : produced by a forward movement
of the mandible during jaw closure ( 'Postural' or 'Habitual' class |||
)

4. Features of class ||| malocclusion
A. Class ||| molar relationship
B. Incisors may be in an edge - to - edge or an anterior crossbite
° Not uncommon to find a normal Incisal relationship
C. Upper arch : narrow and short
Lower arch : broad
Posterior crossbite : common feature
D. Upper teeth : crowded
Lower teeth : often spaced
E. Concave profile due to the presence of a prominent chin
F. In Vertical growers : increased intermaxillary height may have an anterior openbite.
In some pt's a deep overbite may occur
G. Pseudo class ||| malocclusion is characterized by the presence of occlusal
prematurities resulting in a habitual forward positioning of the mandible ( forward
path of closure )

5. Features of class||| malocclusion
Skeletal features

6. Skeletal features of class ||| malocclusion
Class ||| malocclusion may manifest with various components of skeletal and
dentoalveolar components. Most class ||| are associated with underlying skeletal
malrelationships.
Some of the commonly seen skeletal features:
A) A short or retrognathic maxilla.
B) A long or prognathic mandible.
C) A combination of the above.
* Genetic
* Environmental factors such as postural habits and mouth breathing are also
believed to be contributory fctors.
* Other causes of prenormalcy include habitual forward positioning of the mandible
due to occlusal prematurities or enlared adenoids.
Etiology

7. Diagnosis
Diagnosis helps in determining the type of class ||| malocc. i.e. dental or skeletal,
pseudo or true .
Clinical examination - include observation of path of closure.
Study models and radiograps should also be taken.
A lateral cephalogram offers valuable information on the skeletal nature of the
malocc. These pt's often have a family history of other people having an anterior
crossbite or class ||| malocc .
* Now believed that severe class ||| malocclusion are caused by genetic
factors that have been made worse by the environmental factors

8. Dental class ||| malocc.- characterized by lack of sagittal skeletal discrepancy.
ANB angle is normal
Dental problem caused by labial tipping of the mandibular incisor and a lingual
tipping of the maxillary incisors.

9. Treatment
* Interception during growth :
Class ||| malocc. with an underlying skeletal malrelationship require early
interception to prevent skeletal malocc.
Aim : To improve the skeletal discrepancy thereby providing a more favourable
environment for future growth.
Class ||| malocc. should be recognised & treated early due to the following
reasons :
* Early interception reduces the severity of the developing malocc.
* Class ||| malocc. characterized by anterior crossbite often result in retarded
maxillary growth due to locking of maxilla within the mandible.
* The occlusal forces on the mandibular incisors exerted by the maxillary incisors in
crossbite encourage the continued forward growth of mandible further worsening
the pre-normalcy.

10. It also helps to
eliminate or reduce the
chances of orthognathic
surgeries in future.
Interception during
growth can be done by
using one of the
following technique :
°Myofunctional
Appliance
°Chin cup
°Face mask therapy

11. Myofunctional Appliances
Frankel ||| appliance : canbe used to intercept a class ||| malocc. due to
maxillary skeletal retrusion.
Treatment using the Frankel ||| appliance is more successful in pt's with a
functional shift of the mandible during closure of the jaw.
It can corporate vestibular shields in upper & lower sulcus.
The maxillary shields are placed away from the periosteum & allowing the
forward growth of maxilla.
Mandibular shields can be placed touching the alveolar process therefore they
help in restricting the mandibular growth.
The Frankel ||| appliance also produces a dentoalveolar effect by proclination
of upper anteriors and retroclination of lower anteriors.
It can also be used as retainer after facemask therapy for maxilla protraction

12. FR ||| appliance
to intercept class
||| due to
maxillary skeletal
retrusion

13. Chin cup therapy: used in the treatment of class ||| malocc. with protrusive
mandible & normal maxilla.
Two types : occipital pull chin cup
Vertical pull chin cup : used in pt's who exhibit a steep
mandibular plane angle & excessive anterior facial height.
Effects of chin cup include :
° Backward repositioningof the mandible.
° Redirection of the mandibular growth
° remodeling of the mandible with closure of the gonial angle
Chin cup with headgears are indicated in primary & mixed dentition periods
Force levels : 300-500 gms per side for 12-14 hrs of wear everyday

15. Face mask therapy : also known as Reversepull headgears.
Used in the treatment of mild to moderate skeletal class ||| malocclusion due to
retrognathic maxilla & a hypodivergent mandible
It consists of two pads that take anchorage from the forehead & the chin.
They are connected together by a midline wire frame that also has hooks that help
in anchoring elastics that strech from an intraoral splint which helps in the
protraction of maxilla.
The intraoral splint can includean expansion screw if expansion of maxillary arch is
required.
Protraction facemask is used for primary & mixed dentition periods.
Force level -300 - 500 GM's per side indicated for 12 - 14 hrs of wear everyday.
Commonly used types : delaire type, Tubinger type & Petit type facemask.

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Delaire type Tubinger type Petite type

17. * Treatment using fixed appliances
Best done in mixed dentition beore the eruption of permanent canines.
In pt's with mild to moderate class ||| skeletal pattern, a combination of
retroclination of lower incisors & proclination of upper incisors may be required.
Class ||| Intermaxillary elastic traction from the lower labial segment to the
upper molars can also be used to move the upper arch forwards & lower arch
backwards. However, care is required to avoid extrusion of molars which will
reduce overbite.
* Treatment of anterior crossbite
Mild anterior crossbite can be treated using lower anterior inclined planes or
removable appliances incorporating screws designed for anterior expansion.

18. * Role of extractions
Class ||| malocclusion characterized by mild mandibular prognathism & lower
arch crowding can be treated by extracting the lower 1st premolars followed by
fixed mechanotherapy.
This is an orthodontic camouflage of the underlying skeletal malocc.
* Treatment of posterior crossbite
Class ||| malocclusion are often accompanied by posterior crossbite.
It can be treated by rapid maxillary expansion.
* Tretment of severe class ||| malocclusion
Ater growth completion, it is treated by surgical & corrective procedures.
Class ||| due to maxillary deficiency is treated by maxillary advancement
procedures such as lefort| osteotomy.
Class ||| malocc. that are a result of mandibular set back procedures.

19. *Treatment of
pseudo class
||| malocc.
Pseudo class |||
malocc that
occurs as a result
of occlusal
prematurities
improves on the
removal of cause.

20. THANK YOU