The evaluation of paranasal sinuses and anatomical variations with dental volumetric tomography

Paranasal sinus region has a very complex and variable anatomy. There are many anatomical variations on sinonasal region and detection of these variations becomes important to avoid complications when endoscopic surgery was planned. Variations of paranasal sinuses includes concha bullosa, septum deviation, agger nasi cell, kuhn cells, haller cell, onodi cell, paradoxical middle concha, unsinate prosess variations and maxillary sinuse hypoplasia. Some of these variations can be detected with plain extraoral radiographs. However plain radiographies is not always sufficient to demonstrate complex anatomy of this area. CT is an excellent means of providing anatomical information of this region and routinely used for pre-operative planning prior to functional endoscopic sinus surgery. On the other hand cone- beam computed tomography (CBCT) has more advantages than CT with its compact design, short scanning times, low cost and low radiation dose.In this review, we aim to demonstrate the complex anatomy of paranasal sinus area. The wide spectrum of variations affecting paranasal region will be described and illustrated with useful CBCT imaging features.