Martinelli-Kläy Carla Patrícia, Martinelli Celso Ricardo, Martinelli Celso, Macedo Henrique Roberto, Lombardi Tommaso
Laboratory of Oral & Maxillofacial Pathology, Oral Medicine and Oral and Maxillofacial Pathology Unit, Division of Oral Maxillofacial Surgery, Department of Surgery, Geneva University Hospitals, University of Geneva, 1211 Geneva, Switzerland.
Centre for Diagnosis and Treatment of Oral Diseases, Ribeirão Preto 14025-250, Brazil.
Dent J (Basel). 2019 Aug 1;7(3):76. doi: 10.3390/dj7030076.
Dentigerous cysts (DC) are cystic lesions radiographically represented by a well-defined unilocular radiolucent area involving an impacted tooth crown. We present an unusual radiographic feature of dentigerous cyst related to the impacted mandibular right second molar, in a 16-year-old patient, which suggested an ameloblastoma or odontogenic keratocyst (OKC) because of its multilocular appearance seen on the panoramic radiography. A multi-slice computed tomography (MSCT), however, revealed a unilocular lesion without septations, with an attenuation coefficient from 3.9 to 22.9 HU suggesting a cystic lesion. Due to its extension, a marsupialization was performed together with the histopathological analysis of the fragment removed which suggested a dentigerous cyst. Nine months later, the lesion was reduced in size and then totally excised. The impacted mandibular right second molar was also extracted. Histopathological examination confirmed the diagnosis of a dentigerous cyst. One year later, the panoramic radiography showed a complete mandible bone healing. Large dentigerous cysts can sometimes suggest other more aggressive pathologies. Precise diagnosis is important to avoid mistakes since DC, OKC and ameloblastoma require different treatments. Histological examination is, therefore, essential to establish a definitive diagnosis. In our case, MSCT and the tissue attenuation coefficient analysis contributed to guide the diagnosis and management of the dentigerous cyst.
含牙囊肿（DC）是一种囊性病变，在影像学上表现为一个边界清晰的单房透射区，累及一颗阻生牙的牙冠。我们报告了一名16岁患者中与右下颌第二磨牙阻生相关的含牙囊肿的一种不寻常影像学特征，由于在全景X线片上呈现多房表现，提示为成釉细胞瘤或牙源性角化囊肿（OKC）。然而，多层螺旋计算机断层扫描（MSCT）显示为一个无分隔的单房病变，衰减系数为3.9至22.9 HU，提示为囊性病变。由于其范围较大，进行了袋形缝合术，并对切除的组织进行了组织病理学分析，结果提示为含牙囊肿。9个月后，病变体积缩小，随后进行了完整切除。右下颌阻生第二磨牙也被拔除。组织病理学检查证实为含牙囊肿。1年后，全景X线片显示下颌骨完全愈合。大型含牙囊肿有时可能提示其他更具侵袭性的病变。准确诊断很重要，可避免误诊，因为含牙囊肿、牙源性角化囊肿和成釉细胞瘤需要不同的治疗方法。因此，组织学检查对于明确诊断至关重要。在我们的病例中，MSCT和组织衰减系数分析有助于指导含牙囊肿的诊断和治疗。
