Multiple talon cusps, dens in dente and concrescence in a child with hypomelanosis of Ito

Hypomelanosis of Ito (HI) is a rare neurocutaneous disorder most likely caused by chromosomal mosaicism. HI patients may suffer from numerous clinical manifestations, but the expression of the disease is highly variable. Ophthalmologic, musculoskeletal, neurologic, and dental anomalies may be associated with the syndrome. The dental abnormalities found in HI include talon cusps, a single maxillary central in-cisor, enamel defects, hypodontia, and irregularly spaced teeth. The aim of this case report is to present multiple talon cusps, dens in dente and concrescence of maxillary permanent incisors in an 8-year-old boy affected with hypomelanosis of Ito. This unusual dental anomaly has been described in two previous reports of this neurocutaneous syndrome. HI can be difficult to diagnose, these dental findings may help to identify the syndrome in cases where other findings are minimal or atypical.

舌系带过短儿童中舌系带长度与下颌切牙不齐／咬合类型的关系

目的：研究舌系带过短儿童中舌系带长度与下颌切牙不齐、咬合类型之间的关系。材料与方法：本研究包纳了80位舌系带过短的儿童．年龄7～12岁。按Kotlow’s分类法将患者进行分类．测量下颌切牙拥挤度．确定磨牙关系，最后采用Fisher精确概率检验和卡方检验来进行统计学分析．利用Pearson相关系数法进行相关性检验。结果：在80名患儿中．45名（56．3％）为轻度舌系带过短．23名（28.8％）为中度舌系带过短．12名（15％）为重度舌系带过短。其中，59名（73．8％）患儿为轻度牙列不齐．18名（22.5％）为中度牙列不齐．3名（38％）为重度牙列不齐：56名（70％）为安氏Ⅰ类咬合．17名（21.3%）为安氏Ⅱ类咬合，7名（8．8％）为安氏Ⅲ类咬合。因此．在伴下切牙不齐的舌系带过短患者中．不同舌系带长度和咬合类型之间无显著相关性．但舌系带的长度和下切牙不齐呈显著正相关。此外．舌系带长度／下切牙不齐与年龄之间均呈显著正相关。结论：轻度及中度舌系带过短与下切牙不齐、咬合类型之间无明显相关性。