Is the panoramic radiography sufficient for detecting the relationship of the posterior maxillary teeth with maxillary sinus floor? A retrospective study comparative with cone-beam computed tomography

BACKGROUND: The topographical description of the relationship between the upper posterior roots and the maxillary sinus is essential for decreasing the risk of complications during surgical or nonsurgical procedures and to detect possible sinus pathologies. For the evaluation, the most commonly used imaging method is panoramic radiography. This study aims to investigate the reliability of panoramic radiography according to cone-beam computed tomography (CBCT), which is extremely successful in the three-dimensional evaluation, by examining the relationship between the maxillary teeth and the sinus floor.MATERIALS AND METHODS: A total of 350 teeth were analyzed according to their topographic relationship to the maxillary sinus using panoramic and CBCT images. Two parameters were used to evaluate the safety of the panoramic radiograph on the posterior maxillary region. First, the topographic relationship was classified according to the criteria organized by Shahbazian et al. and compared both the imaging methods by the McNemar–Bowker test. Then, the diagnostic reliability test was performed for panoramic radiography according to the topographic classification. Second, 248 linear vertical measurements were made between the apexes of the roots and the sinus floor in the maxillary posterior region and then compared between the panoramic and the CBCT images.RESULTS: The McNemar–Bowker test showed that there was a significant relationship between the two imaging methods in both the dental groups (premolar teeth P = 0.030 and molar teeth P = 0.014). Furthermore, a total of 124 measurements were analyzed using the Mann–Whitney U-test and no statistically significant difference was found between the two imaging methods (P = 0.576).CONCLUSION: Although reliable results were obtained in panoramic radiographs when compared to CBCT images, panoramic radiography may not be sufficient before the surgical procedure. Nevertheless, when the posterior maxillary teeth are not too close to the sinus floor, panoramic radiographs can be used safely for the initial diagnostic evaluation.