[Measurement of cortical bone thickness of zygomatic alveolar ridge in adolescents by Cone-beam CT and its correlation with cervical vertebral bone age].

PURPOSE: To measure the cortical bone thickness of zygomatic alveolar ridge in adolescents and explore the correlation between cortical bone thickness and cervical vertebral bone age.

METHODS: Cone-beam CT data of 80 adolescents were collected, including 20 adolescents with cervical vertebral bone ages of Cvs3, Cvs4, Cvs5 and Cvs6, respectively. CBCT images were reconstructed with the maxillary occlusal plane as the reference plane. Cortical bone thickness of different slices in the left maxillary zygomatic alveolar ridge area was measured in the direction parallel to and 60° from the reference plane, and the measured data were statistically analyzed by SPSS 21.0 software package.

RESULTS: When the measurement direction was parallel to the reference plane and at 60°, the cortical bone thickness in the zygomatic alveolar ridge area of Cvs3-Cvs6 adolescents was (0.90±0.09) -(1.72±0.21) mm and (1.35±0.44)-(3.98±1.48) mm, respectively. There was significant difference in cortical bone thickness between Cvs4 and Cvs5 group(P＜0.05). Spearman correlation analysis showed a strong positive correlation(P＜0.01) between cortical bone thickness of zygomatic alveolar ridge and cervical vertebral bone age in adolescents.

CONCLUSIONS: The cortical bone thickness of zygomatic alveolar ridge in adolescents increases with the increase of cervical vertebral bone age, and the cortical bone thickness may increase significantly during Cvs4-Cvs5. In terms of cortical bone thickness, all slices of zygomatic alveolar ridge of CVS3-CVS6 adolescents are suitable for implanting miniscrews, and the anterior slices should be selected for implantation as far as possible for Cvs3 and Cvs4 adolescents.