Anatomical analysis of periapical bone of maxillary posterior teeth: a cone beam computed tomography study

Objectives To investigate the periapical bone thicknesses of maxillary posterior teeth at the preferred level for root resection (3 mm apical to the root end) and to determine vertical distances from apex to maxillary sinus floor (MSF) using cone beam computed tomography (CBCT) scans. Methods CBCT scans were collected from 341 subjects (2389 teeth). Associations of bone thicknesses and vertical distances with age and sex were determined by one-way analysis of variance. Results At the level of root-end resection, buccal bone was the thickest over the mesiobuccal roots of second molars (mean, 2.99 mm) and thinnest over the double-root first premolars (mean, 0.29 mm). In maxillary posterior teeth, thicker buccal bone was found in men than in women. The mesiobuccal roots of second molars were nearest to the MSF (mean, 1.33 mm), and were also most frequently extended into the sinus cavity (15.81%). Subjects more than 40 years of age had larger vertical distances from root apices to MSF in the molar region, compared with younger subjects. Conclusions Generally, periapical bone was thicker in men, and root apices were located nearer to the MSF in younger subjects. Age and sex should be considered before endodontic microsurgery.