Childhood risk factors for late eruption of permanent teeth

Abstract

BACKGROUND: Adequate knowledge of tooth emergence assists in diagnosis and treatment planning in pediatric dentistry and orthodontics; however, reports of perinatal influences on eruption of permanent teeth were limited in the literature. AIM: The study aimed to associate potential factors in early life with eruption status of permanent teeth of 12 years old children. DESIGN: Clinical examination of tooth emergence was conducted on a birth cohort of Hong Kong children from local secondary schools. Subjects’ background information including birth characteristics, prenatal and early childhood exposures, family socioeconomic status and medical records were prospectively collected. Children were divided into complete emergence (of 28 permanent teeth) and partial emergence groups based on clinical examinations. Bivariate analyses were used to assess the association of tooth emergence status with each potential factor. RESULTS: Complete background information and clinical data were available from 514 children. Maxillary central incisors were found to have emerged in all subjects, followed by first molars (99.9%), maxillary lateral incisors (99.6%) and mandibular canines (98.8%). Except for the maxillary (61.8%) and mandibular second molars (81.8%), over 90% of all other teeth had emerged. Bivariate analyses showed that the average birth weight in the partial emergence group was significantly lower compared to the complete emergence group (mean difference 0.2 kg, P = 0.006). Mode of birth delivery was significantly associated with tooth emergence status (P = 0.037). CONCLUSIONS: Birth weight and mode of delivery were associated with emergence of permanent teeth in a group of 12 years old children in Hong Kong.