关键词: 繁茂型牙骨质-骨结构不良, 锥形束CT, 鉴别诊断, 下颌磨牙

Abstract:

Cemento-osseous dysplasia (COD) is an uncommon, non-neoplastic benign fibro-osseous lesion of the jaws, characterized by cementum-like tissue deposition. It primarily affects middle-aged women of African and East Asian descent. Generally asymptomatic, this condition is frequently identified incidentally through radiographs showing radiopacities with radiolucent rims. This report presented a case of florid cemento-osseous dysplasia (FLCOD) in a 45-year-old Asian female. The patient exhibited secondary caries extending to the pulp chamber on the left mandibular first molar, showed no signs of pulpitis or periapical pathosis. Adjacent tooth (the left mandibular third molar) and contralateral molars (the right mandibular molars) responded normally to pulp vitality testing, with no swelling, sinus tracts, or mobility observed. Cone beam computed tomography (CBCT) revealed multifocal lesions with amorphous radiopacities and thin radiolucent rims without root resorption or cortical perforation in the periapical regions of bilateral mandibular molars. These findings reflected characteristic radiographic features of FLCOD, aligning with the World Health Organization (WHO) 2022 classification criteria. Significantly, three radiographic stages of COD were concurrently demonstrated through multifocal lesions involving six mandibular molars, providing a representative model of its natural progression. The initial osteolytic stage in teeth 38, 46, and 48 manifested as well-defined periapical radiolucencies with sclerotic borders; the intermediate stage in 36 and 37 featured punctate or nodular radiopacities within periapical radiolucency; while the mature terminal stage in 47 presented a homogeneous radiopaque mass bordered by a thin radiolucent rim. The diagnostic process prioritized exclusion of chronic apical periodontitis through confirmed pulp vitality and absence of infection. Cemento-ossifying fibroma (COsF) was dismissed based on solitary presentation and cortical expansion. Familial gigantiform cementoma (FGC) was differentiated by early diffuse jaw expansion and extensive involvement beyond COD. Cementoblastoma exclusion relied on pathognomonic features, specifically root resorption or compromised pulp vitality. Given the asymptomatic, non-progressive behavior of the FLCOD lesions, annual surveillance was implemented, with intervention limited to the restorative failure in tooth 36. At 12-month follow-up, the FLCOD lesions showed clinical-radiographic stability without secondary infection or progression. This case reflected the classic presentation of FLCOD as incidental, multifocal mandibular posterior radiopacities bordered by radiolucent rims. CBCT proved instrumental in delineating the lesions, providing diagnostic evidence. Long-term surveillance remains the cornerstone of management for COD. Invasive procedures are not recommended in cases with asymptomatic non-progressive behavior to prevent surgical complications.

Key words: Florid cemento-osseous dysplasia, Cone-beam computed tomography, Differential diagnosis, Mandibular molars