Craniofacial asymmetry and temporomandibular joint internal derangement infemale adolescents: A posteroanterior cephalometric study

Unilateral or bilateral pathology of the osseous components of the temporom andibular joint (TMJ) can result in pronounced facial asymmetry because of dissimilar size and shape of the right and left sides of the mandible. To d ate, it is unknown whether abnormalities of the soft tissues of the TMJ are associated with greater than normal craniofacial asymmetry. In this study, we investigated the amount of craniofacial asymmetry in female orthodontic patients with unilateral or bilateral TMJ internal derangement (TMJ ID) re lative to the amount in female patients without TMJ LD. The total sample co nsisted of 80 female adolescents. Bilateral TMJ magnetic resonance images w ere used as a database for objectively scoring the severity of TMJ ID. Cran iofacial asymmetry was measured from posteroanterior cephalograms. Females with bilateral TMJ TD had significantly greater asymmetry in the vertical p osition of the ante-gonion. If the TMJ ID was more advanced on the right si de, the ipsilateral ramus was shorter, resulting in significant asymmetry i n this region. In all other craniofacial regions, the amount of asymmetry w as not significant between females with normal TMJs and those with TMJ LD. The results indicate that a female orthodontic patient with bilateral TMJ I D or unilateral right TMJ ID may present with or develop a vertical mandibu lar discrepancy.