Extra oral appliances

Extra Oral Appliances

• Skeletal problems

• Mand. Excess, Mand. Deficiency
• Max. Excess and Max. Deficiency
• (sagittal, vertical & transverse)
The goal of growth modification is to alter the unacceptable skeletal relationship by modifying the pt. facial growth to favorable size or position of the jaws.

• Principle of Growth Modifications

• Accelerate G. Of deficient bone.
• Restrain G. Of excessively growing bone
• Redirect the G. Of some bone difficult to be restrained like excessively growing Mand.

3 types of orthod. app. Can be used for growth modif.

1. extra oral appliances (orthopedic appliances)
2. functional appliances
3. interarch elastic traction


Extra oral functional inter arch

Types of extra oral appliances

1. head gear and face bow or j-hook
2. Chin cup
3. reverse pull face mask
Headgear is defined as a Strap worn around the back of the head to provide extra oral anchorage which is used to help pull the teeth back or influence the jaw growth.
It is used either with
Face bow or J hook

Head gear and face bow

Face bow

It consist of 2 bows made from 0.040”-0.050” stainless steel wire
The 2 bows are connected at the midline as in fig. in the previous slide
The outer bow is attached to the elastic or spring which is attached to the anchor unit(head strap)
The inner bow is attached to the tube of molar band on upper first molar so that the inner bow will transfer the force to the dentofacial structures.


Indication
Treatment of horizontal and vertical maxillary excess

Aim of Treatment

To control the growth of the maxilla in forward and downward direction

Ideal patient for treatment with Headgear and facebow

• Skeletal cl.II with excessive horizontal or vertical maxillary growth
• Protrusion of the maxillary teeth
• Good mandibular dental and skeletal morphology
• Normal or slightly excessive anterior face height
• Potential for continued spontaneous mandibular growth

Magnitude and Duration of E.O.Ffor Treatment of Class II

400 -600 gm / side

12-16 hour / day ( Evening & Night )

Treatment During pubertal growth period
Patient instructions

Used for retraction of canines or incisors

( only with fixed appliance with continuous arch wire )
J-hook