Incidence, Heritability of Maxillary Lateral Incisor Agenesis Familial Aggregation of Maxillary Lateral Incisor Agenesis

Background: A common problem that requires orthodontic intervention is maxillary lateral incisor agenesis. A common treatment for this problem is to open space for a maxillary lateral incisor implant. However, that treatment is expensive. Often, parents with this problem wonder if their children will also have this anomaly. Objective: To determine the relative risk of a parent with maxillary lateral incisor agenesis to have a child with the same problem. Design/Methods: This was a compilation of 4 research projects that had been performed in the past on large populations to determine the heritability and relative risk of maxillary lateral incisor agenesis. Previous studies had been performed in Portugal, Sweden, Utah, and Israel. Several hundred individuals with maxillary lateral incisor agenesis were identified, and the pedigrees of their families were explored. Results: The percentage of the population affected by maxillary lateral incisor agenesis was between 1% and 2%. The relative risk for maxillary lateral incisor agenesis in a child of a parent who had that anomaly was around 15 to 16 times greater. In addition, the authors determined that microdontia of the maxillary lateral incisor is a milder form of maxillary lateral incisor agenesis. Conclusions: There is a significant familial aggregation of maxillary lateral incisor agenesis, and microdontia of maxillary lateral incisors is part of the same phenotype. Reviewer's Comments: This study has good valuable information. I have treated many patients with maxillary lateral incisor agenesis. In looking back at these families that I have treated, I would agree that the risk certainly is higher in families where the problem has already occurred. I simply did not know what that increased relative risk was in the past. These authors have shown that the risk is relatively high at 15 times greater than in the general population. (Reviewer-Vincent G. Kokich, Sr, DDS, MSD).