TMJ internal derangement and adolescent craniofacial morphology: a pilot study.

Intrinsic and extrinsic factors influence the growth of mandibular condylar cartilage. Local environmental factors, such as temporomandibular disc displacement, may alter condylar cartilage growth resulting in facial changes. The aim of this study was to determine if there was an association between identifiable altered craniofacial morphology and disc displacement. Magnetic resonance imaging (MRI) was employed to determine disc position in 25 preorthodontic adolescent patients (mean age 12.8 years, range 10 to 17 years). Magnetic resonance imaging and lateral cephalometric radiography were performed with the teeth held in centric occlusion by means of a polyvinylsiloxane bite registration. Radiographs were traced and variability between tracings within patients was insignificant for all variables (p > 0.04) except Co-Go, S-Go, and SN/Go-Me (p < 0.01). For each patient, 10 linear, 4 angular, and 3 ratio measurements were compared with an age- and sex-matched population in the Craniofacial Growth Series. Multiple regression analysis showed positive and negative associations between disc displacement and cephalometric variables. R-square value was .91 for the left TMJ and .82 for the right. Disc displacement in an adolescent population may be associated with altered craniofacial morphology.