A rare maxillary lesion: a case report of developing complex odontoma in the left maxilla of a 5-year-old child

Objective: This study aims to report the clinical diagnosis and management of a 5-year-old child with developing complex odontoma in the left maxilla, and to review the literature regarding its clinical features, imaging findings, and pathological characteristics, so as to provide clinical insights for early diagnosis and individualized treatment of pediatric maxillary developing complex odontoma. Materials and methods: A 5-year-old male presenting with a "left maxillary mass" was evaluated. Clinical examination assessed facial morphology and dental development. Panoramic radiography and cone-beam computed tomography (CBCT) were used to determine the lesion's location and imaging characteristics. The surgically resected specimen was sent to the Ningbo Clinical Pathological Diagnosis Center for gross and histopathological examination. Postoperative follow-up was conducted for 24 months to monitor wound healing, dental development, and potential recurrence. We implemented a proactive monitoring approach, which included regular follow-up visits every three months during the first year. During these visits, we assessed the growth and development of the surrounding teeth and evaluated the edentulous area for any signs of potential complications. Results: Clinical examination revealed a left maxillary mass without significant facial asymmetry, and the child was in the stage of dental development. Imaging confirmed an expansive lesion in the left maxilla. Pathological examination identified a 4.5 × 4 × 0.5 cm grayish-white to reddish, firm tissue, leading to a final diagnosis of developing complex odontoma. The lesion was completely removed via curettage. At the 24-month follow-up, no recurrence was observed, the surgical site had healed well, dental development was normal, and no complications such as secondary caries were noted. Conclusion: Pediatric maxillary developing complex odontoma often presents with subtle symptoms and atypical imaging features, leading to delayed diagnosis. Multimodal imaging combined with pathological examination enables accurate diagnosis. Complete excision via curettage, accompanied by long-term follow-up, effectively restores maxillary structure and function, supports normal dental development, and reduces recurrence risk, making it a viable treatment strategy for pediatric maxillary developing complex odontoma.