Radiological examination of the relationship between the pterygomaxillary junction and fracture pattern.

BACKGROUND: Le Fort 1 (LF1) osteotomies are widely used to correct midface deformities. To move the maxilla freely, the ptery-gomaxillary junction (PMJ) must be separated. When performing this osteotomy, the pterygoid plate must remain intact. The objective of this study was to evaluate relationship between the anatomical features of the PMJ and fracture patterns in LF1 osteotomy. METHODS: Pre-operative and post-operative cone-beam computed tomography images of 41 patients (82 samples) who have undergone LF1 osteotomy surgery were radiologically evaluated. Morphologic measurements of the pterygomaxillary fissure area and pterygoid plate were carried out. Moreover, pterygomaxillary separation was divided into the clean-cut, maxillary sinus, and pterygoid plate fracture types. RESULTS: Statistically significant difference was observed between clean-type fracture and pterygoid plate fracture groups' thickness of the pterygoid process and thickness of the pterygomaxillary region. CONCLUSION: Anatomical variations make it difficult to separate the PMJ properly. Low thickness of PMJ increases the risk of unwanted fractures; however, according to our experience, the use of an osteotome with an incorrect angle, excessive force, and inexperienced surgeons can also cause undesirable pterygoid plate fractures.

Evaluation of Radiolucent Lesions Associated with Impacted Teeth: A Retrospective Study.

BACKGROUND: Impacted teeth are commonly asymptomatic and not associated with any pathologic lesions for years. Any change in the size of the follicle associated with impacted teeth may result in odontogenic cysts or tumors. CBCT plays an important role in determining the radiographic features of a lesion and therefore, is very helpful for accurate diagnosis and treatment planning. OBJECTIVE: This study aims to evaluate radiolucent lesions associated with impacted teeth in terms of age and sex distribution, localization, and comparison with the pathological diagnosis. METHODS: In this retrospective study, out of 6758 CBCT images, 400 images revealing radiolucent lesions were detected. The study included only 190 cases (regarding 180 patients) which had a matching histopathological evaluation. Data related to the age and sex of the patients, localization of the lesions, and their comparison with the pathological diagnosis were recorded and analyzed. RESULTS: The most encountered lesions were dentigerous cysts (60%) and odontogenic keratocysts (26.3%). Males were the most affected (63.3%). Most of the lesions were found in the left and right posterior mandible and mostly (66.8 %) associated with third molars. Out of 123 radiological diagnoses of dentigerous cyst cases, histopathological diagnoses confirmed 108 cases. Regarding odontogenic keratocyst, histopathological diagnosis confirmed 40 cases out of 48. CONCLUSION: Radiological diagnoses of the lesions mostly match with their pathological diagnosis unless their characteristics are changed due to infection. CBCT, as a technique enabling detailed imaging of the involved dental structures, is a helpful instrument for differential diagnosis.