Prevalence and determinants of non-nutritive sucking on anterior open bite in children attending primary school

Anterior open bite (AOB) is a malocclusion that is depicted by lack of contact between the anterior teeth when the jaw is in maximum closure. It is one of the most complex malocclusions to treat and manage and it has been proven to affect speech, mastication and aesthetic appearance of the face. Aetiological factors of anterior open bite include unfavourable growth capacity and heredity, enlarged anatomic structures such as the tongue, tonsils or adenoids and environmental factors involving non-nutritive sucking (thumb/pacifier). The reported prevalence suggests that there is inconsistency in the extent of occurrence frequency of this occlusion as well as aetiological factors associated. The aim of this current study was to investigate the prevalence of non-nutritive sucking habits and determinants of AOB in Australian children aged seven to 12 years. MethodsA cross-sectional study was carried out involving 208 primary school children in the regional town of Orange, New South Wales, Australia. A questionnaire addressing sociodemographic data, medical conditions known to be associated with malocclusion, data of nutritive and non-nutritive sucking habits, and illustrations of different malocclusions to be selected for the child was administered to parents/guardians of children enrolled in primary schools in Orange New South Wales. Data analysis involved descriptive statistics, inferential, multivariate and neural analysis. Chi square tests (p <0.05) and odds ratio calculations were used for inter-variable comparisons. The impact of non-nutritive sucking and duration of non-nutritive sucking on anterior open bite were analysed using neural analysis.VResultsAccording to the information provided by the parents, the prevalence of AOB was 24.1% and of those AOB cases, 76% reported to have carried out thumb-sucking habits. No statistical significance was noted between the type of malocclusion and child’s aged at presentation (P=0.1786), the child’s gender (P=0.918) or whether the child had orthodontic intervention (P=0.1217). Of the children who commenced thumb-sucking at age two to five years, 100% had developed an AOB. No child with a duration of six months or less of thumb-sucking had developed AOB. Children who were bottle-fed were 1.9 times more likely to develop AOB than breastfed children. Children whose parents had lower levels of education were three times more likely to develop an abnormal bite. Neural analysis confirmed that both thumb-sucking and duration of thumb-sucking presented the highest association with anterior open bite. ConclusionsSocioeconomic factors and sleeping issues were linked to malocclusions. A significant relationship between abnormal bite and the need for tonsillectomy and/or adenoidectomy surgery was identified. Thumb-sucking and duration of thumb-sucking represented the strongest predisposing factors for anterior open bite. Breastfeeding provided a protective effect against the development of an abnormal bite, and conversely, bottle-fed children were more likely to develop an abnormal bite. Longer duration of breastfeeding and cessation of non-nutritive sucking habits, particularly thumb-sucking needs to be encouraged.