Association between use of asthma drugs and prevalence of demarcated opacities in permanent first molars in 6-to-8-year-old Danish children

Objectives: Demarcated opacities in permanent first molars are common developmental tooth defects, characterized by areas with insufficient mineralization of the enamel. The defects present clinically as a continuum from creamy-white demarcated opacities, yellowish-brown demarcated opacities to macroscopic loss of tooth substance. The etiology is sparsely elucidated, but asthma drugs have been suspected to increase the prevalence. The aim of this study was to examine the prevalence of demarcated opacities in permanent first molars among 6-to-8-year-old children with prescriptions and without prescriptions for asthma drugs. Methods: In a cross-sectional study in two Danish municipalities, all children aged 6-8 years (n = 891) were included. A total of 745 (83.6%) went through a dental examination during which demarcated opacities and tooth substance loss due to these were recorded. The analyses were restricted to 647 children in whom all four permanent first molars had erupted. Data on use of asthma drugs from birth until the time of the dental examination were obtained from a population-based pharmaco-epidemiological prescription database. Results: Among 47 children with prescriptions for both inhaled beta(2)-agonists and inhaled corticosteroids before the age of 3 years, 15 (31.9%) had demarcated opacities of any type, and six children (12.8%) had opacity-related loss of tooth substance. Among 264 children with no prescriptions for either inhaled or oral asthma drugs from birth until the date of the dental examination, 96 (36.4%) had demarcated opacities of any type, and 13 (4.9%) had opacity-related loss of tooth substance. The odds ratio (OR) of any demarcated opacity, and of opacity-related loss of tooth substance in children with prescriptions for both inhaled beta(2)-agonists and inhaled corticosteroids before the age of 3 years was 0.82 (95% CI: 0.39-1.65), and 2.42 (95% CI: 0.70-7.43). Conclusions: Children with prescriptions for inhaled asthma drugs before the age of 3 years did not have an overall increased risk of demarcated opacities in first permanent molar but they seemed to have an increased risk of the severe demarcated opacities, i.e. opacities resulting in macroscopic loss of tooth substance, and possibly a need for restorative care.