Osteoblastoma is a benign neoplasm which commonly occurs in the vertebral column and long bones. The tumour grows slowly and rarely recurs after surgery. This report presents the clinicopathological and radiological findings of a case of recurrent osteoblastoma in the maxilla. A 7-year-old male patient visited our department with chief complaints of left facial swelling and pain. A panoramic radiograph showed a homogeneous radio-opaque expansile lesion in the left maxilla. The lesion was thought to be fibrous dysplasia and the patient underwent a surgical excision using the Caldwell-Luc procedure. Histopathological examination of the lesion confirmed it as benign osteoblastoma. The lesion recurred 6 months after the initial surgery. CT images revealed a large mass with multiple internal calcifications. Subsequently, the patient underwent mass excision with subtotal left maxillectomy. Follow-up CT scans at 1 year intervals showed no recurrence for 5 years. Dentomaxillofacial Radiology ( Keywords: osteoblastoma; recurrence; X-ray computed tomography Case reportA 7-year-old male patient visited our department with the chief complaints of left facial swelling and pain. His medical history was unremarkable. Clinical and radiographic examinations were performed. Intraoral examination revealed a firm gingivobuccal swelling extending from the left maxillary deciduous lateral incisor to the left maxillary permanent first molar. Panoramic radiographs showed a homogeneous radio-opaque expansile lesion in the left maxilla and the lesion involved the whole maxilla. The adjacent tooth germs were displaced and the innominate line in the left maxillary sinus was not detected (Figure 1). The lesion was thought to be fibrous dysplasia from the initial clinical and panoramic radiographic findings; therefore, mass excision using the Caldwell-Luc operation was performed. The surgical specimen was 3.5 cm in diameter and it was spherical, encapsulated and firm tissue. On histopathological examination, bony trabeculae surrounded by a single layer of plump osteoblasts of high cellularity were observed in the stroma. There was no atypia or mitotic activity in the osteoblasts or in the mesenchymal cells of the stroma. Most of the calcifications consisted of woven bone without obvious lamellation. Multinuclear giant cells were often identified around the osteoid. As the trabeculation progressed, the stroma changed into loose fibrovascular tissue. The lesion was finally diagnosed as benign osteoblastoma (Figure 2).The patient revisited our department with an enlarged swelling in the same region 6 months after the operation. CT images revealed a large well-defined mass composed of two locules with multiple internal calcifications. Owing to the expansive nature of the lesion, the left orbital floor was elevated and the lateral wall of the left nasal cavity was pushed towards the medial side (Figure 3). The patient had undergone mass excision with subtotal left maxillectomy. The surgical specimens were composed of two, solid, firm soft-tissue ...

The relative horizontal location of the alveolar crest with respect to the mandibular canal affected the ABH measurement on panoramic radiographs. In particular, ABH is overestimated when there has been resorption of the buccal aspect of the ridge, moving the alveolar crest lingually.

A dentinogenic ghost cell tumour (DGCT) is an extremely rare odontogenic tumour which is considered as a solid, neoplastic variant of calcifying odontogenic cyst. Intraosseous DGCTs are more aggressive than extraosseous DGCTs and have a high propensity for local recurrence. This report describes a case of a diagnosis of recurrent DGCT at the primary site and a distant donor site. A 25-year-old female patient visited a dental hospital for a complaint of facial swelling for the previous month. Incisional biopsy was performed and the specimen was diagnosed as DGCT. Partial mandibulectomy for tumour resection and iliac bone graft was performed. 2 years later, the tumour recurred on the mandible and iliac bone. The recurrent lesion on the donor site was diagnosed as metastasized DGCT. This report highlights the possibility of distant metastasis occurring at a graft donor site.

Intraosseous vascular malformation (IVM) is a relatively rare pathological condition that may pose significant risks, such as excessive bleeding, during surgical procedures. We present a case of an 18-year-old female patient with firm swelling in the left maxilla. A bony expansion over the left half of the maxilla with preservation of the outer cortex and a ground glass appearance on CT images initially revealed a possibility of fibrous dysplasia. However, a tentative diagnosis of IVM was made based on the vascular nature of the lesion as well as the patient's surgical history and additional imaging findings. IVM should be included in the differential diagnosis of an expansile bony lesion with trabecular alteration. Through the literature review, it was found that imaging findings, such as a neurovascular canal widening on CT images and a hyperintense signal on T1 weighted MR images, might be helpful in differentiating IVM from other pathologies.