CASE REPORTS ON MODES OF INTRUSION

Orthodontic intrusion

Definition

Intrusion refers to the apical movement of the geometric center of the root (centroid) in respect to the occlusal plane or plane based on the long axis of the tooth.

Classification

True intrusion is achieved by moving the root apices of the anteriors closer to the bony base.

Relative intrusion is achieved by keeping them where they are, while the mandible grows and the posterior teeth erupt.

Apparent intrusion is achieved by extrusion of the posterior teeth

Force value

According to Proffit the optimum force for intrusion is 15-25 gm.

INDICATIONS FORORTHODONTIC INTRUSION

Intrusion of anterior teeth in gummy smile Deep bite and reduced lower facial heightIntrusion of periodontally compromised teeth

Intrusion may be divided into 2 on the basis of the group of teeth on which it is applied.

a) incisor intrusionb) intrusion of posterior teeth 

Techniques

1.Anchor bendsAnchor bend is placed 3 mm mesial to the

molar tube, in such a way that there is gingival displacement of the anterior part of the arch wire therefore when the arch wire is placed in the bracket, there is a intrusive force acting on the anterior segment.

2.Gable bendThis is a modified bite opening bend given in

the arch wire distal to the canine. This tends to cause extrusion of the canines and the intrusion of the central and laterals

3.Intrusion Utility Arch

This was devised by RICKETTS with the help of basic biomechanical principles developed by BURSTONE.

4.Three piece intrusion arch

This appliance was introduced by BURSTONE, modified by SHROFF, LINDHAUER

5.Bite Planes

It is a modified hawley’s appliance with a ledge of acrylic behind the upper incisors. The presence of acrylic will result in disoccluding the posterior teeth and thereby free to erupt.

6.Molar Intrusion with Miniscrew Anchorage

Elastic traction applied to molars from implants for intrusion

Case reports-Intrusion utility arch

Venkat 12 /M

Begg’s anchor bend

Sweta 18 / F

Three piece intrusion arch

Ayesha begum 20/F

Bite plane

Yashvi chand 16 /M

Implant intrusion

Sharda 21/f

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