Abstract: Objective: To measure the bone width, the cortical bone thickness, and the height of maxillary sinus floor of infrazygomatic crest in adults and adolescents, and to compare the specific differences between two groups by cone beam computed tomography (CBCT). Methods: CBCT scans were taken in 30 individual normal occlusion adult volunteers and 30 adolescent Class Ⅰ patients. Multiple measurements were performed at infrazygomatic crest. The data were analyzed statistically. Results: The maximum width of infrazygomatic crest in adults and adolescents all located at the interradicular space of the maxillary second premolar and first molar. Thereafter, the values decreased gradually from root tips to basis cranii in every slice. The height of the maxillary sinus floor and infrazygomatic crest width in every slice showed a positive correlation. Conclusion: The bone width and cortical bone thickness of infrazygomatic crest in adults are thicker than those in adolescents. The infrazygomatic crest width becomes thicker as the height of maxillary sinus floor increases. Individual differences exist in the height of maxillary sinus floor. CBCT is needed in this region before inserting micro-implant anchorage.

Key words: Infrazygomatic crest, Bone width , Cortical bone thickness, Cone beam computed tomography , Micro-implant anchorage