Permanent tooth agenesis in non-syndromic Robin sequence and cleft palate: prevalence and patterns

Anneline De Smalen,Gem J C Kramer,Daan P F Van Nunen,Edwin M Ongkosuwito,Corstiaan C Breugem,Ruurd R Hermus,J Peter W Don Griot,Arjen J Van Wijk

doi:10.1007/s00784-016-2020-z

Abstract

ObjectivesPartial tooth agenesis is frequently observed in Robin sequence. Tooth anomalies are increasingly considered as an extended phenotype of the cleft palate population. The study objective was to compare the prevalence and patterns of tooth agenesis in a group of patients with non-syndromic Robin sequence (ns-RS) and a group with non-syndromic cleft palate (ns-CP).Materials and methodsThe panoramic radiographs of 115 ns-RS and 191 ns-CP patients were assessed for agenesis of the permanent dentition (excluding third molars) and the patterns recorded using the Tooth Agenesis Code.ResultsPartial tooth agenesis was observed in 47.8% of ns-RS and 29.8% of ns-CP patients with a greater prevalence in the mandibula than in the maxilla, particularly in ns-RS. The teeth most frequently absent in both groups were the mandibular second premolars and maxillary lateral incisors. Tooth agenesis was bilateral in two-thirds of affected ns-RS patients and one-half of ns-CP patients. In ns-RS, bilateral agenesis of the mandibular second premolars was more frequently observed in female than that in male patients. Completely symmetrical patterns of hypodontia were found in around 45% of ns-RS patients with tooth agenesis compared to 35% in ns-CP. No association was found between the extent of the palatal cleft and the severity of hypodontia.ConclusionTooth agenesis is more prevalent in ns-RS than that in ns-CP, demonstrates a much greater predilection for the mandible in ns-RS, and bears no relation to the extent of the palatal cleft.Clinical relevanceWhen compared to ns-CP, additional developmental disturbances are likely involved in the etiology of tooth agenesis in ns-RS. Future research could help identify the underlying genetic traits and aid in classifying patients in those with and without expected tooth agenesis in order to facilitate orthodontic management strategies.

Highlights

Tooth agenesis is the most common developmental anomaly of the human permanent dentition, its etiology still remains poorly understood
Partial tooth agenesis was observed in 47.8% of nsRS and 29.8% of Non-syndromic cleft palate (ns-CP) patients with a greater prevalence in the mandibula than in the maxilla, in Non-syndromic Robin sequence (ns-Robin sequence (RS))
This study examined the relation between tooth agenesis and the extent of the palatal cleft in both groups of patients

Summary

Introduction

Tooth agenesis is the most common developmental anomaly of the human permanent dentition, its etiology still remains poorly understood. Dental agenesis may occur either as an isolated trait or as part of a recognized congenital syndrome. Partial tooth agenesis or hypodontia is frequently observed in Robin sequence (RS). This congenital disorder bears the name of the French stomatologist Pierre Robin and consists of the triad of micro- or retrognathia, glossoptosis, and obstructive respiratory distress [1, 2]. The large majority of patients with RS are affected by a palatal cleft, though this is not universally perceived as an obligatory feature [3]. RS has been associated with a range of syndromes and chromosomal anomalies [4], yet is encountered in isolation

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