Co-occurrence of agenesis of the maxillary lateral incisors with other dental anomalies – a systematic review of the literature

Introduction
Hypodontia of the maxillary lateral incisors is a developmental disorder whose genetic basis has been documented scientifically. Coexistence of hypodontia and other dental anomalies may indicate the occur¬rence of mutations within a given gene, the expression of which may be manifested in various phenotypic combinations.

Objectives
The aim of the study was to determine the frequency of co-occurrence of agenesis of the maxillary lateral incisors with other dental anomalies and skeletal disorders, based on a systematic review of the literature.

Material and methods
An online database was searched using PubMed and Science Direct by entering the following keywords: maxillary lateral incisor agenesis and dental anomalies.

Results
A total of 1168 results were obtained. Eighteen articles from 1971-2016 that met the inclusion criteria were qualified for the analysis. Hypodontia of the maxillary lateral incisors is very often accompanied by other dental or skeletal disorders. These are most often: agenesis of another permanent tooth, ectopic maxillary canine eruption, distoangulation of mandibular second premolars, reduction of the overall size of the teeth, the occurrence of a peg-shaped or microdontic maxillary lateral incisor, the rectangular shape of crowns of the maxillary central incisors, taurodontism. Skeletal class III is much more common than in the general population and the vertical relationship is also reduced. The most frequent was distal relation on the molars and canines.

Conclusions
Based on information obtained from medical databases and library resources, it can be concluded that hypodontia of the maxillary lateral incisors is a condition predisposing to the co-occurrence of other disorders: size, structure, position and quantity of remaining permanent teeth. When planning orthodontic treatment, attention should also be paid to the frequent prevalence of skeletal III in these patients and to the reduced vertical relationship.