Objectives: This study aimed to investigate the clinical characteristics of congenital deciduous teeth absence and its permanent teeth performance type by using panoramic radiographs.
Methods: A total of 15 749 panora-mic radiographs of 3-6-year-old children with deciduous dentition were collected from January 2020 to December 2021. The incidence of congenital deciduous teeth absence was observed, and the abnormality of permanent teeth was recor-ded. SPSS 24.0 software was used for statistical analysis.
Results: The incidence of congenital deciduous teeth absence was 2.54% (400/15 749), which was found in 217 girls and 183 boys, and the difference between the genders was statistically significant (P=0.003). The absence of one and two deciduous teeth accounted for 99.75% (399/400) of the subjects. In addition, 92.63% (490/529) of mandibular deciduous lateral incisor was congenitally absent, 44.80% (237/529) of deciduous teeth was absent in the left jaw, and less than 55.20% (292/529) was absent in the right; the difference between them was statistically significant (P=0.017). The absence of 96.41% (510/529) deciduous teeth in the mandibular was significantly more than that of 3.59% (19/529) in the maxillary, and the difference between was statistically significant (P=0.000). Furthermore, 68.00% (272/400) and 32.00% (128/400) of deciduous teeth were absent in unilateral and bilateral, respectively, and the difference was statistically significant (P=0.000). Four types of congenital deciduous teeth absence with permanent teeth were observed as follows: 1) 73.91% (391/529) of permanent teeth was absent; 2) 20.60% (109/529) of permanent teeth was not absent; 3) the number of fused permanent teeth accounted for 4.91% (26/529); 4) the number of supernumerary teeth was 0.57% (3/529).
Conclusions: Although the absence of congenital deciduous teeth is less common than that of permanent teeth, it affects deciduous and permanent teeth to some extent. Dentists should pay attention to trace and observe whether abnormalities are present in the permanent teeth and take timely measures to maintain children's oral health.
目的: 应用曲面断层技术研究乳牙先天缺失的特点及其继承恒牙的表现类型。方法: 收集2020年1月—2021年12月就诊的3~6岁乳牙列期儿童的曲面体层片，共纳入15 749张，观察记录乳牙先天缺失的发生情况，同时记录其继承恒牙是否存在异常。应用SPSS 24.0统计软件分析所得的数据。结果: 乳牙先天缺失的发生率为2.54%（400/15 749），女性217例多于男性183例，性别间差异有统计学意义（P=0.003）；乳牙先天缺失1~2颗例数占99.75%（399/400）；下颌乳侧切牙先天缺失颗数占92.63%（490/529）；左侧乳牙先天缺失颗数占44.80%（237/529），右侧乳牙先天缺失颗数占55.20%（292/529），两者差异有统计学意义（P=0.017）。上颌乳牙先天缺失颗数占3.59%（19/529），下颌乳牙先天缺失颗数占96.41%（510/529），两者差异有统计学意义（P=0.000）；单侧乳牙缺失占68.00%（272/400），双侧乳牙缺失占32.00%（128/400），两者差异有统计学意义（P=0.000）。乳牙先天缺失其继承恒牙有4种表型：1）继承恒牙缺失颗数占73.91%（391/529）；2）继承恒牙不缺失颗数占20.60%（109/529）；3）继承恒牙融合牙颗数占4.91%（26/529）；4）继承恒牙多生牙颗数占0.57%（3/529）。结论: 虽然乳牙先天缺失较恒牙先天缺失少见，但是乳牙先天缺失在一定程度上影响到乳牙列和恒牙列，口腔医生应注意追踪观察恒牙列是否存在异常，及时采取措施，维护儿童口腔健康。.
Keywords: congenital deciduous teeth absence; congenital permanent teeth absence; fused tooth; panoramic radiograph; supernume-rary teeth.