Permanent tooth agenesis in individuals with non-syndromic Robin sequence: a systematic review and meta-analysis

Objectives: To evaluate prevalence rates and patterns of permanent tooth agenesis in individuals with non-syndromic Robin sequence (ns-RS).

Material and methods: Two investigators independently carried out a literature search, using PubMed, Web of Science, Ovid, EMBASE and the Cochrane Library, identifying articles relating to permanent tooth agenesis, diagnosed using panoramic radiographs, in individuals with ns-RS. The outcomes desired were prevalence rates and patterns of permanent tooth agenesis. The final search was carried out in January 2017.

Results: Six articles were selected for inclusion, with a total of 448 individuals with ns-RS. Data available in each study varied which allowed conducting further specific meta-analyses only on sample sizes of 339 or 378 individuals from three or four of the six included articles. The overall estimated prevalence rate of permanent tooth agenesis was 42% (95% CI: 35%-48%), excluding third molars, with no sex predilection. In individuals with tooth agenesis, approximately 30% had one missing tooth while 40% had two missing teeth. Tooth agenesis was more commonly bilateral (Relative Risk 2) and found in the mandible (Relative Risk 1.6). The highest prevalence of permanent tooth agenesis was found for mandibular second premolars (26%) followed by maxillary second premolars (14%). The most common tooth agenesis patterns were the agenesis of both mandibular second premolars, followed by the agenesis of all second premolars.

Conclusion: Individuals with ns-RS have high prevalence rates of permanent tooth agenesis. The most prevalent tooth agenesis patterns are bilateral symmetric tooth agenesis, most commonly agenesis of both mandibular second premolars.