Three-Dimensional Assessment of Temporomandibular Joint Morphology and Facial Asymmetry in Individuals with Different Vertical Skeletal Growth Patterns

The aim of the current study was to investigate, by means of Cone-Beam Computed Tomography (CBCT), condyle-fossa relationship, temporomandibular joint (TMJ) morphology and facial asymmetry in subjects with different vertical skeletal growth patterns. CBCT of 56 patients (112 TMJs) were categorized into three groups according to the mandibular plane angle (MP): Hypodivergent (MP <= 23 degrees), Normodivergent (23 degrees < MP < 30 degrees), and Hyperdivergent (MP >= 30 degrees). TMJ spaces, width and depth of the condyle and thickness of the fossa were measured. Horizontal and vertical measurements were used to assess facial asymmetry. One-way Analysis of Variance (ANOVA) and post-hoc Turkey tests were computed for the between-groups comparison. Statistical significance was set at p < 0.05. Larger anterior joint space and smaller condylar dimensions (medio-lateral diameter and medio-lateral thickness) were observed in the hyperdivergent group compared to the normodivergent and hypodivergent groups. Right condylar distances to midsagittal plane were significantly larger than left distances in all the three groups. A vertical pattern of growth in healthy individuals seems to be associated with condylar position and dimension, while facial asymmetry values do not differ among different vertical groups.

Automated summary

The aim of this study was to use CBCT to investigate the condyle-fossa relationship, TMJ morphology, and facial asymmetry in subjects with different vertical skeletal growth patterns. Results showed that the hyperdivergent group had larger anterior joint space and smaller condylar dimensions compared to the normodivergent and hypodivergent groups. Additionally, the right condylar distances to the midsagittal plane were significantly larger than the left distances in all three groups. Facial asymmetry values did not differ among the different vertical groups.