Segmental Odontomaxillary Dysplasia: Unusual Tumoral Lesion.

Introduction: Segmental Odontomaxillary Dysplasia (SOD) is a non-hereditary, unilateral developmental anomaly recently included in the WHO's classification of head and neck tumors.

Case presentation: Here, we report the case of an 8-year-old boy presenting with unilateral maxillary enlargement and pain without facial asymmetry. Computed tomography revealed a hypodense area in the maxillary bone with altered bone structure and osseous expansion. An incisional biopsy showed fibrous hyperplasia in the gingiva, dysplastic dentin, and reversal lines in the bone trabeculae. Following the diagnosis of SOD, the patient was referred for treatment.

Conclusion: To date, only 72 cases have been reported. SOD typically manifests in early childhood, with a male predominance. While the etiology remains unclear, mutations in the PIK3CA gene have been associated with its development. Further research is needed to better understand the disease and improve patient management.