Association between 3-dimensional mandibular morphology and condylar movement in subjects with mandibular asymmetry.
BACKGROUND
The purpose of this study was to evaluate the hypothesis that 3-dimensional mandibular morphology is correlated with condylar movement in patients with mandibular asymmetry.


METHODS
Subjects were classified into 2 groups (n = 25 each): mandibular asymmetry with a menton deviation greater than 4 mm and no mandibular asymmetry with a menton deviation less than 4 mm. Linear and volumetric measurements of 3-dimensional mandibular morphology were recorded using computed tomography. Mandibular functional movement was recorded by computerized axiography (CADIAX; Gamma Dental, Klosterneuburg, Austria), and condylar path length, sagittal condylar inclination, and transverse condylar inclination on protrusion were measured. We calculated side-to-side asymmetry (shifted side vs nonshifted side) in mandibular morphology and assessed condylar movement by using an asymmetry ratio (nonshifted side/shifted side).


RESULTS
Significant differences in mandibular morphology and condylar movement were found between the 2 groups. In the group with menton deviation greater than 4 mm, significant correlations were found between the asymmetry ratio of mandibular morphology and condylar movement: ie, condylar path length and transverse condylar inclination. No significant correlations were found between any of these measurements in the group with menton deviation less than 4 mm.


CONCLUSIONS
In support of our hypothesis, the results suggested that 3-dimensional mandibular morphologic asymmetry is associated with condylar movement in subjects with mandibular asymmetry.
Division of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Michiyo
M
Ikeda
Division of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. Electronic address: mjmort@tmd.ac.jp.
Jun J
JJ
Miyamoto
Division of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Jun-Ichi
JI
Takada
Division of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Keiji
K
Moriyama
D000328:Adult; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007569:Jaw Abnormalities / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D008334:Mandible / Q000002:abnormalities; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009068:Movement; D014057:Tomography, X-Ray Computed; D055815:Young Adult