RESUMO
Objective@# To investigate the etiology, diagnosis and treatment principles of inherited permanent tooth embryo necrosis caused by alveolar bone resorption due to severe periapical periodontitis of deciduous teeth, in order to provide a reference for clinical diagnosis and treatment@*Methods@#The clinical data and related literature of a rare case of permanent tooth embryo necrosis were analyzed retrospectively.@*Results @#This case was a 5-year-old girl. Physical examination and X-ray examination revealed chronic periapical inflammation in 75. X-ray showed that the periodontal bone of tooth 75 was extensively destroyed; additionally, the permanent tooth germ of tooth 35 was incomplete and the development was delayed compared to that of tooth 45 because of severe periapical periodontitis in the primary teeth. The initial diagnosis was that-- the embryo of tooth 35 stopped developing due to inflammation and was necrotic after tooth 75 was extracted. The postoperative pathological examination report showed that most bone around the embryos of tooth 35 was sequestrated. Through literature review and analysis, it was found that the degree of periapical lesions in the primary teeth and the developmental stage of the tooth embryo have a great impact on the formation of permanent tooth embryos. Conservative methods such as root canal therapy are usually adopted as treatment. Permanent tooth embryo necrosis caused by periapical periodontitis of deciduous teeth is rare in the clinic, so it is necessary to judge the degree of inflammatory infiltration and of tooth embryo damage as soon as possible according to the clinical symptoms and imaging manifestations; and to make a correct treatment plan.@*Conclusion@#There are no objective and clear diagnostic and treatment criteria for the clinical diagnosis of the pathological state of permanent tooth embryo, thus, methods such as etiology elimination and follow-up observation are usually adopted for abnormal permanent tooth embryo development. Future research should focus on prevention and finding addtional effective methods for diagnosis and treatment.