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牙中牙是“牙内有牙”。1859年由 Tomes氏首先描述。这种异常是牙乳头在发育过程中发生的变异;套叠的结构可以是单个或多个突入,部止于冠部或牙根。牙中牙并不罕见,X 线检查其发病率由0.25%高达10%。这么大的差异,欲其说是人群间的不同,不如说是研究者诊断标准各异。这种病人大多数累及上颌侧切牙,据pindborg 报道其它可能罹及的牙齿,依其出现减少的次序为:中切牙、前磨牙、尖牙和磨牙。在下颌牙、乳牙或多生牙很少发生。套叠结构可能与口腔相通。因此,口腔龋齿细菌能够在其中生长繁殖,致使在牙底部或壁部发生龋病。由于壁相当薄,牙髓往往易被感染,这种异常所致根周、牙周脓肿
Dental teeth is “teeth in the teeth.” First described by Tomes in 1859. This anomaly is a variation in the papilla that occurs during development; the structure of the nest can be single or multiple inbursts, stopping at the crown or root. Tooth teeth are not uncommon, the incidence of X-ray examination from 0.25% up to 10%. Such a big difference, want to say is the difference between the crowd, it is better that researchers have different diagnostic criteria. Most of these patients involve the maxillary lateral incisors. According to pindborg, other possible teeth are reported, in decreasing order: central incisors, premolars, canines and molars. In mandibular teeth, deciduous teeth or multiple teeth rarely occur. The nested structure may communicate with the mouth. As a result, oral cariogenic bacteria can grow and multiply therein, causing dental caries in the floor or wall of the tooth. Due to the relatively thin wall, pulp is often easily infected, this anomaly caused by root circumference, periodontal abscess