Radiographic evaluation of the superior alveolar canal: measurements of its diameter and of its position in relation to the maxillary sinus floor: a cone beam computerized tomography study.

OBJECTIVES

The superior alveolar canal with its contents is frequently reported as an anatomical point of consideration during lateral sinus floor elevation due to the danger of bleeding and of the subsequent impairment of vision of the surgical field. Malnutrition of the graft may also ensue. This radiographical study uses cone beam computerized tomography to identify the superior alveolar canal, to measure its diameter and its distance from the sinus floor at precise tooth positions to provide the implant surgeon with information about the position and the diameter of the canal.

MATERIAL AND

METHODS

One hundred and fifty-six patients (156) scanned with a Newtom VG device were included in this study. A dental and maxillofacial radiologist using the multiplanar capabilities of the device's software identified the canal and assessed its diameter and topography.

RESULTS

The canal could be identified in 82% of the cases with a mean diameter of 1.1 mm and a range of diameters between 0.2 and 2.6 mm. The distance from the floor of the sinus at various tooth positions ranged between 0 and 28.5 mm.

CONCLUSIONS

In the majority of our cases, the canal could be identified in at least one position, between the most posterior and the most anterior borders of the maxillary sinus. The large variation on the distance of the canal from the sinus floor dictates an individual evaluation of its position and not the use of mean values. Great care must be exercised by the radiologist to reliably identify the canal.