关键词: 融合牙, 乳牙额外牙, 恒牙先天缺失, 牙齿发育迟缓

Abstract: Objective: To investigate the incidence and clinical characteristics of maxillary deciduous fused incisors by panoramic radiographs. Methods: A total of 76288 panoramic radiographs of subjects aged 3 to 8 years old in the image database of our hospital were collected from January 2018 to December 2023, and the incidence of maxillary deciduous fused incisor was observed, as well as the abnormalities in inherited permanent teeth of fused teeth were also recorded. Results: The incidence of maxillary deciduous fused incisors was 0.21% (153/76288). There were more fused teeth in boys than girls (P＜0.05), and more fused teeth in unilateral than bilateral (P＜0.01), but the difference between left and right sides of fused teeth was not statistically significant (P>0.05). Of the 153 fused teeth, 138 subjects had normal number of maxillary deciduous incisors and 15 subjects had supernumerary deciduous teeth. In 138 subjects, 74.15% of them had congenital inherited permanent teeth absence. In the maxillary permanent incisors without missing, 42.11% had microdontia and 36.84% had delayed tooth development. In 15 subjects of maxillary supernumerary deciduous teeth, 20.00% had supernumerary teeth in permanent dentition. There were 2 subjects with triple teeth of maxillary deciduous incisors. Conclusion: Maxillary deciduous fused incisors are usually fused with 2 teeth, and triple teeth are rare. The fused teeth of maxillary deciduous incisor are more male than female, and unilateral than bilateral. Fused teeth affect the length of dental arch, teeth arrangement, and even appearance, and often are associated with abnormalities of permanent teeth and permanent dentition.

Key words: fused teeth, supernumerary deciduous tooth, congenital permanent teeth absence, delayed tooth development