Lateral incisor agenesis among 10-16-year-old pre-orthodontic patients

AIM: This study aims to evaluate the prevalence of congenitally missing lateral incisors among 10-16-year-old pre-orthodontic patients. METHODS AND MATERIALS: The study was conducted at the Department of Orthodontics at the Lithuanian University of Health Sciences (ethics approval: 2023-BEC2-295). A minimum sample size of 343 pre-orthodontic patients was required to detect differences with a 5% confi dence interval and 95% confi dence level (population, 3141). From September to December 2023, a total of 435 pre-orthodontic treatment orthopantomograms (OPGs) and medical records of patients aged 10 to 16 years were analyzed. Inclusion criteria: (1) no history of orthodontic treatment or craniofacial interventions; (2) no permanent tooth loss due to trauma, caries, or periodontal disease; (3) no congenital abnormalities or syndromes; (4) high-quality OPG. Jamovi (version 2.3) was used for statistical analysis. A value of p<0.05 was stated as signifi cant. RESULTS: Out of 435 pre-orthodontic patients (mean age: 13.1±1.76 years), 276 (60.9%) were female and 177 (39.1%) were male. 159 pre-orthodontic patients (35.1%) had congenitally missing teeth in their permanent dentition, whereas 294 (64.9%) showed no evidence of tooth agenesis. The prevalence of tooth agenesis was considerably higher in females than in males (p=0.014). Of the patients with tooth agenesis, 49 (30.8%) were missing lateral incisors. Lateral incisors were affected by tooth agenesis in the following order: #12 in 8.2%, #22 in 7.1%, #32 in 1.3%, and #42 in 0.9% of patients. Maxillary arch was signifi cantly more often affected by agenesis of the lateral incisors than the mandibular arch (p<0.001). Only three pre-orthodontic patients had bilateral agenesis of the lateral incisors; unilateral agenesis was observed signifi cantly more frequently (p<0.001). CONCLUSIONS: The study revealed that lateral incisor agenesis was present in 10.8% of preorthodontic patients aged 10 to 16 years, with a higher prevalence observed in females compared to males.