Evaluation of cortical bone density at the infrazygomatic crest area in adolescents via CBCT and its correlation with cervical vertebral maturation

Background In orthodontic treatment, microimplants provide critical anchorage, with cortical bone density being vital for implant stability. The infrazygomatic crest is a common implantation site, but adolescents exhibit significant variability in bone density due to individual growth differences. Cervical vertebral maturation (CVM) is a reliable indicator of skeletal growth, yet its correlation with infrazygomatic crest cortical bone density remains underexplored. This study aimed to evaluate cortical bone density at the infrazygomatic crest area in adolescents and assess its correlation with CVM to guide clinical microimplants placement. Methods Cone beam computed tomography data from 80 adolescents (20 per CVM stage Cvs3 to Cvs6) were analyzed. Images were reconstructed to establish the maxillary occlusal plane as horizontal and the mesiobuccal root apex of the left maxillary first molar as baseline. Cortical bone density was measured on the buccal cortex at heights of 13 mm, 15 mm, and 17 mm above baseline, across six mesiodistal layers from the second premolar to second molar region. Results Cortical bone density ranged from 656 ± 136 Hounsfield Units (HU) to 1244 ± 134 HU. Significant increases in cortical bone density occurred between Cvs4 and Cvs5 stages (from 656–1000 HU to 796–1172 HU; p < 0.01). Cortical bone density generally decreased distally and increased apically across most sites and stages. Spearman's rank correlation analysis revealed strong positive correlations between cortical bone density at all 18 measurement sites and CVM (correlation coefficients r = 0.555–0.731; p < 0.001). Conclusions Cortical bone density at the adolescent infrazygomatic crest significantly increases with advancing CVM, with a pronounced rise between Cvs4 and Cvs5 stages. Regarding cortical bone density, all layers of the infrazygomatic crest area in adolescents at the Cvs3 to Cvs6 stages are suitable for microimplants insertion. For adolescents at Cvs3 and Cvs4 stages, selecting anterior layers is recommended to access higher cortical bone density values.