Presurgical CBCT assessment of maxillary neurovascularization in relation to maxillary sinus augmentation procedures and posterior implant placement.

PURPOSE: To provide more information to clinicians planning sinus grafting and maxillofacial surgical interventions, the present study evaluated the prevalence, diameter and location of the superior alveolar canals (SAC) using CBCT images.

METHODS

The maxillary sinus CBCT scans (i-CAT Classic(®), ISI, USA) of 100 adult patients (67 women and 33 men) aged 20-79 years [mean (SD) 40 (15)] were examined. A dentomaxillofacial radiologist observed the SAC based on CBCT image data and more specifically the parasagittal views to assess SAC's diameter and location.

RESULTS

The anterior and posterior SAC, double ASAC, intraosseous anastomoses and the extension of the anterior SAC to the piriform aperture were observed in 100, 73, 24.5, 38.5 and 84 % of the cases, respectively. The anastomosis was located between canine and first premolar in 43 % of the cases. The SAC diameters were in 80 % of the cases ≤1 mm, remaining canals had a diameter between 1 and 2 mm. The distance of the SAC to the alveolar crest ranged between 2.42 and 44.6 mm. The anterior SAC was more prevalent in the upper (53 %) and middle (44 %) thirds of the maxillary sinus, while the posterior SAC was more prevalent in the middle (36 %) and lower thirds (64 %). The distance was significantly bigger in men in some tooth positions.

CONCLUSIONS

Based on the present findings, one-fifth of the patients may have a diameter of the SAC >1 mm, large enough to cause bleeding and/or paraesthesia. CBCT imaging may assist surgeons to plan grafting and osteotomy procedures, while avoiding these neurovascular structures.