Oral habits, prevalence and effects on occlusion of 4-15 year old school children in Lagos, Nigeria.

Aim: To determine the prevalence of oral habits and assess the effects of these habits on the occlusion in a group of Nigerian schoolchildren.
Method: A cross-sectional study of 928 children aged 4-15 years from Eti -Osa local government area in Lagos, Nigeria. The sample population was selected from 2 private and 3 public schools.
Results: Three hundred and sixteen children (34.1%) of total children examined, exhibited one form of oral habit or another. The most common habit observed was digit sucking which was observed in 17% of the children. Increased overjet was observed in 33% of the habit children. This was significantly higher than findings in children without the habit who recorded an increased overjet of 25.3%. Anterior open bite was observed in 12.5% of habit children and 3.1% of non-habit children. Statistically significant differences in the occurrence of upper incisor proclination, lower incisor retroclination and lip incompetence were also observed occurring more frequently in the oral habit group. Posterior crossbite was observed in 1.9% of the habit group and 1.5% of the non-habit group. This difference was not statistically significant.
Conclusion: This study shows an increased prevalence of oral habits when compared to previous studies in this region. Increased overjet and anterior open bite were the most commonly occurring occlusal anomalies associated with oral habits. There is a need to reduce the occurrence of permanent occlusal deformation due to the persistent form of these habits through dental health education among Nigerian children.