Prevalence of peg-shaped maxillary permanent lateral incisors: A meta-analysis

The aim of this meta-analysis was to gain more insight into the prevalence of peg-shaped maxillary permanent lateral incisors and their associations with race, population type, sex, and sidedness.

Electronic searches and supplementary hand searches initially yielded 3337 records. After applying inclusion and exclusion criteria, 30 articles about 36 studies were included. The overall pooled prevalence estimate was calculated with a random-effects model. An estimated risk ratio was used for sex comparison.

The overall prevalence of peg-shaped maxillary permanent lateral incisors was 1.8%. No publication bias was found. The occurrence rates were higher in Mongoloid (3.1%) than in black (1.5%) and white (1.3%) patients, and in orthodontic patients (2.7%) than in the general population (1.6%) and dental patients (1.9%). Women were 1.35 times more likely than men to have peg-shaped maxillary permanent lateral incisors. The prevalence rates of unilateral (0.8%) and bilateral peg-shaped maxillary permanent lateral incisors were approximately the same. However, among the unilateral lateral incisors, the left side (0.4%) was twice as common as the right side (0.2%). In addition, contralateral lateral incisor hypodontia was seen in 55.5% of the subjects with unilateral lateral incisors.

The prevalence of peg-shaped maxillary permanent lateral incisors varies by race, population type, and sex. The prevalence rates were higher among Mongoloid people, orthodontic patients, and women. Although the prevalence of unilateral and bilateral lateral incisors was the same, the left side was twice as common as the right side. Subjects with unilateral peg-shaped maxillary permanent lateral incisors might have a 55% chance of having lateral incisor hypodontia on the contralateral side.