Temporomandibular Joint Osseous Morphology of Class I and Class II Malocclusions in the Normal Skeletal Pattern: A Cone-Beam Computed Tomography Study.

Xiao-Chuan Fan,Lin-Sha Ma,Diwakar Singh,Xiao-Feng Huang,Xiaohui Rausch-Fan,Li Chen

doi:10.3390/diagnostics11030541

Abstract

(1) Background—The aim of the present study was to evaluate the correlation between the temporomandibular joint (TMJ) osseous morphology of normal skeletal pattern individuals with different dental malocclusions by using cone-beam computed tomography (CBCT). (2) Methods—The CBCT images of bilateral TMJs in 67 subjects with skeletal class I and average mandibular angle (26 males and 41 females, age range 20–49 years) were evaluated in this study. The subjects were divided into class I, class II division 1, and class II division 2 according to the molar relationship and retroclination of the maxillary incisors. Angular and linear measurements of TMJ were evaluated and the differences between the groups were statistically analyzed. (3) Results—Intragroup comparisons showed statistical differences for articular eminence inclination, the width of the glenoid fossa, the ratio of the width of the glenoid fossa to the depth of the glenoid fossa, the condylar angle, and the intercondylar angle between the malocclusion groups. The measurements of the glenoid fossa shape showed no significant difference between the left and right sides. Females showed more differences in the morphological parameters of TMJ between the three malocclusion groups than the males. (4) Conclusion—The present study revealed differences in the TMJ osseous morphology between dental class I and class II malocclusions in the normal skeletal pattern.

Highlights

The temporomandibular joint (TMJ) is one of the most complex joints in the human body
The participants included were limited to skeletal class I with an average mandibular angle, which was defined as 0.7◦ ≤ ANB ≤ 4.7◦, 21.2◦ ≤ Frankfort horizontal (FH)–MP ≤ 33.4◦, 27.3◦ ≤ SN–GnGo ≤ 37.7◦ [22]
The height of the articular fossa might not be a specific index to distinguish between different malocclusions according to samples of the study

Summary

Introduction

The temporomandibular joint (TMJ) is one of the most complex joints in the human body. The unique anatomy of the TMJ allows for the hinging movement of the mandible and is considered a ginglymoid joint. The condyle-disk complex process slides over the posterior slope of the articular eminence. For patients with a steeper articular eminence, the condyle is forced to move more inferior and the disk rotates more prominent when protruding or opening. This may lead the mandible to move more vertically during the functional movement [6]. It is reported that a patient with steeper articular eminence is more likely to develop internal dysfunctions, such as anterior disk displacements, than a patient with a flatter articular eminence [7,8]

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Discussion

Conclusion