Comparison of face mask treatment with or without expansion screw in dentoskeletal changes of Class III patients

Dr. Akhoundi MS., 1 Dr. Khorshidian A., 2 Dr. Kharrazi-Fard MJ. 3

1 Associate Professor, Department of Orthodontics, School of Dentistry, Tehran University / Medical Sciences. Tehran, Iran. 2 Dentist, Dental Research Center , Tehran University / Medical Sciences. Tehran, Iran. 3 Dentist, Member Dental Research Center, Tehran University / Medical Sciences. Tehran, Iran.

(Received 7 March, 2009 Accepted 22 Sep, 2009)

Abstract

Background and Aim: Among various treatments available for patients with Class III malocclusion, orthopedic protraction of maxilla during the mixed dentition period has been reported to be beneficial in cases with maxillary deficiency. In such patients, however, the maxillary expansion is not sometimes needed. The aim of the present study was to evaluate the therapeutic effects of face mask with and without maxillary expansion screw in Class III malocclusion patients who had maxillary deficiency.

Materials and Methods: Twenty children with class III malocclusion were selected and randomly divided into two equal groups (A & B). The children in group A were treated with a protraction face mask, and patients in group B were treated with a face mask and removable slow maxillary expansion device. The cephalometric changes in maxilla and mandible, and alterations in dental relations were compared within and between groups before and after treatment. Before-after comparisons in each group were performed with paired sample t-test. Covariance analysis served for between groups comparisons.

Results: In group A, the overjet was improved and molar relation was changed into normal occlusion (Class I). The cephalometric analysis in group B revealed that Class III malocclusion was modified through a forward movement of the maxilla and a backward rotation of the mandible.

Conclusions: Face mask is a favorable treatment in improving the antero-posterior position of maxilla and mandible in Class III patients even if they don’t need palatal expansion.

Key words: Malocclusion, Angle Class III - Extraoral Traction Appliances- Palatal Expansion Technique.

Corresponding Author: Dr. Khorshidian A., Dentist, Dental Research center, Tehran University / Medical Sciences. Tehran, Iran.

e.mail: khorshidian_a @yahoo.com