Abstract

Introduction: The mandibular anterior repositioning appliance (MARATM) is a fixed appliance intended for the correction of class II malocclusion. Many advocate the use of the MARA appliance to minimize patient non-compliance with treatment; however, little information is known as to the skeletal changes in the temporomandibular complex. The purpose of this study is to investigate the changes in the temporomandibular complex using both cephalometric and cone beam computerized tomography.

Materials and Methods: The initial and final treatment cone beam computerized tomography (CBCT) scans of 5 patients treated with the MARA appliance were collected from the Loma Linda University Orthodontics Clinic. Lateral cephalograms were constructed from the CBCT scans and a cephalometric tracing was created for each patient prior to treatment (T1) and after treatment (T2) with the MARA appliance. The T2 cephalometric tracings were evaluated for linear changes in the temporomandibular complex when related to stable cephalometric structures. Cephalometric landmarks were quantified and variations were measured for the mean and standard deviation of each landmark. Three dimensional condylar changes in width, length, depth, height, and volume were evaluated using direct measurements from the initial and final CBCT scans. The cone beam computerized tomography of the same 5 patients was superimposed and color mapped to show changes in the morphology of the temporomandibular joint (TMJ) complex. Measurements were compared using paired t-tests, repeated measures analysis of variation (ANOVA) and pairwise comparison of paired T-test, and a 2-way ANOVA with interaction comparison.

Results: The T2 lateral cephalograms showed changes in the TMJ complex with both the glenoid fossa and mandibular condyle moving posterior in relationship to pterygoid vertical. The center of the condyle had a more inferior position in relation to the Frankfort horizontal in patients treated with the MARA appliance. Cephalometric study showed a pattern of changes that was consistent with normal growth and development of the TMJ complex. The CBCT images showed changes in the width and depth of the condyle that were not statistically significant for the changes seen in the age matched control. The CBCT evaluation of mandibular length showed an increase in mandibular length, but it was not different from the increase seen in the control. The volume of the mandibular condyle was statistically significantly larger than the volume of the controls both prior to and after treatment.

Conclusions: This study demonstrated that there are changes occurring in the TMJ complex during treatment with a MARA appliance. These changes were determined to be consistent to the changes expected in normal growth and development of the TMJ complex.

LLU Discipline

Orthodontics and Dentofacial Orthopedics

Department

Orthodontics and Dentofacial Orthopedics

School

School of Dentistry

First Advisor

Caruso, Joseph

Second Advisor

Rungcharassaeng, Kitichai

Third Advisor

Rynearson, R. David

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

2014

Date (Title Page)

9-2014

Language

English

Library of Congress/MESH Subject Headings

Temporomandibular Joint Dysfunction Syndrome; Mandible - Growth & Development; Orthodontic Appliances; Jaw Relation Record; Radiography - Dental - Digital; Cone-Beam Computed Tomography

Subject - Local

Mandibular Anterior Repositioning Appliance; MARA; Class II Malocclusion; Cone Beam Computerized Tomography; CBCT

Type

Thesis

Page Count

55

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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