Korean J Orthod.  1992 Sep;22(3):531-556.

A study of holographic interferometry on the initial reaction of maxillofacial complex to the maxillary protraction using the antenna type modified protraction head gear

• Lee KG
• Ryu YK

Abstract

The majority of the commonly used protraction headgears for the protraction of small and/or retropositioned maxilla not allow a change in the point of force application or direction of the force delivery to attain predictable results because of the position of the upper and lower lips to avoid discomfort to the patient. The purpose of this study was to investigate the initial reaction of maxillofacial complex according to the change of force variables such as direction and point of force application with designing an antenna type-modified protraction head gear. A macerated human skull with well aligned upper teeth was used to experimental model and the investigation was done by double exposure holographic interferometry. Fringe patterns of each protraction conditions were compared and analized. The results were as follows. (Frontal view) 1. The Counterclockwise rotation of the maxilla was showed by parallel protraction to occlusal plane and the fringe was decreased in number as higher point of force application. 2. Generally, the number of fringe was increased in 500gm of protraction force than in 300gm. 3. When apply the protraction force to the maxilla with rapid palatal expansion, the direction of fringe patterns was differed from the protraction without expansion. 4. In most of cases, the counterclockwise rotation was decreased in case of the direction of the force is 20degrees downward to occlusal plane compared to the paral1el direction. 5. At the point of force application is 15mm above and the direction of force is 20 downward to occlusal plane, the translation of the maxillary complex was showed.

MeSH Terms

Dental Occlusion
Head*
Humans
Interferometry*
Lip
Maxilla
Models, Theoretical
Skull
Tooth