Three-dimensional cone beam computed tomography analysis of maxillary sinus and alveolar bone anatomy in the restorative axis of dental implants using radiopaque drill guides.

The objectives were to assess the sinus anatomy and alveolar ridge dimensions and to identify clinical factors and morphological relationships that may predict the characteristics of the sinus anatomy. A total 336 edentulous molar and 168 edentulous premolar regions were analyzed. The mediolateral maxillary sinus (5mm and 10mm above alveolar bone), lateral maxillary sinus wall, ostium height, and alveolar ridges were measured. Measurement regions were defined by radiopaque simulation of the restoration goal. Mean molar mediolateral dimensions were >10mm: first molar, 11.8mm (range 3.8-21.1mm); second molar, 12.2mm (range 7.9-20.1mm). The extent of the sinus differed significantly between premolars and molars (P<0.001). The first molar region had the highest mean value for the lateral sinus wall (2.4mm, range 0.2-7.9mm) and the greatest distance between the alveolar crest and simulated restorative goal (8.1mm, range 1.1-16.3mm). Septum prevalence was 46% in the molar region and 27% in the premolar region. A lower alveolar ridge height was associated with a wider transverse extent of maxillary sinus and consequently longer distances between the crest and restorative goal. Systematic three-dimensional analysis of the maxillary sinus yields precise preoperative information about sinus configurations. There were significant variations and relationships among characteristics of the maxillary sinus, ridge, and the restorative goal.