Size, shape and age-related changes of the mandibular condyle during childhood

Abstract

OBJECTIVE: To determine age-related differences in the size and shape of the mandibular condyle in children to establish anatomical reference values. METHODS: A total of 420 mandibular condyles in 210 children (mean age, 7 years) were retrospectively analysed by using computed tomography (CT) imaging. The greatest left-right (LRD) and anterior-posterior (APD) diameters and the anteversion angles (AA) were measured by two readers. An APD/LRD ratio was calculated. The shape of the condyles was graded into three types on sagittal images. Correlations of parameters with the children's age were assessed by using Pearson's correlation analyses. RESULTS: The LRD (mean, 14.1 +/- 2.4 mm), APD (mean, 7.3 +/- 1.0 mm) and LRD/APD ratio (mean, 1.9 +/- 0.3) increased (r (LRD) = 0.70, p < 0.01; r (APD) = 0.56, p < 0.01; r (rat) = 0.28, p < 0.01) while the AA (mean, 27 +/- 7 degrees ) decreased significantly (r (antang) = -0.26, p < 0.001) with age. The condylar shape as determined on sagittal images correlated significantly with age (r = 0.69, p < 0.05). Boys had significantly higher anteversion angles (p < 0.01), greater LRDs (p < 0.05) and greater mean ratios (p < 0.05). CONCLUSION: The mandibular condyle is subject to significant age-related changes in size and shape during childhood. As the size of the condyles increases with age, the anteversion angles decrease and the shape of the condyle turns from round to oval.