Evaluation of mandibular odontogenic keratocyst and ameloblastoma by panoramic radiograph and computed tomography.

OBJECTIVES: The purpose of this study was to describe and compare the main imagenological features of mandibular ameloblastomas and odontogenic keratocyst (OKC) using panoramic radiograph (PR) and CT. METHODS: The sample consisted of nine cases of ameloblastomas and nine cases of OKC. PR and CT images were analyzed according to shape, internal structure, borders, associated unerupted tooth, root resorption, expansion and perforation of cortical bones. RESULTS: PR evaluation allowed the identification of the lesion's location, presence of sclerosis in the periphery, presence of associated non-erupted tooth and expansion of the mandible's lower border cortical bone. CT was more accurate than PR in the assessment of the lesion shape, presence of inner bone septa, root resorption, buccolingual expansion and rupture of cortical bone. Most cases of ameloblastoma and OKC presented buccolingual expansion and erosion of cortical bone. Only ameloblastomas showed tooth root resorption. CONCLUSIONS: Although PR is very helpful and widely used, CT provides more precise information on buccolingual expansion, calcification, bone septa, perforation of cortical bones and tooth resorption, features that are frequently underdescribed in the literature, particularly in OKC.