Malocclusion and quality of life in Tanzanian schoolchildren

Objective: The main objective of this study was to assess the prevalence of malocclusion, its associated factors, its impact on quality of life and estimate its socio-dental treatment need in children living in Kinondoni and Temeke Districts of Dar es Salaam, Tanzania. Methods: Cross sectional surveys of children aged 3-5 and 12-14 years, residing in two districts of Dar es Salaam region, was conducted from November 2005 to June 2006. A stratified proportionate two stage cluster sample design with primary schools as the primary sampling unit (N = 1601 Survey I) and a census (N = 253 Survey II) was utilized. In survey I, participants from the selected primary schools (12-14 year-olds) were clinically examined for decayed, missing and filled teeth due to caries, according to the criteria described by the World Health Organization (1997). Oral hygiene was assessed using simplified Oral Hygiene Index by Greene and Vermillion (1964). Interview schedules for 12-14 year-olds were conducted using structured questionnaires, which included socio-demographic details, perceived oral problems, satisfaction / dissatisfaction with mouth and teeth and Kiswahili version of the Child Oral Impacts on Daily Performances (Child-OIDP) and also questions regarding their perceived general and oral health conditions and oral health related behaviors. In Survey II (3-5-year-olds) parents were interviewed regarding their socio-demographic details and their children’s sucking habits and feeding methods. In both surveys (I and II) malocclusion was assessed according to the criteria by Björk et al. (1964) with some modifications by al-Emran et al. (1990). Data were analyzed using Statistical Package for Social Scientists, SPSS version 14.0. Cross tabulation and Chi-square statistics were used to assess bivariate relationships. Multivariate analyses were performed by multiple logistic regression, with 95% confidence interval (CI) given for the odds ratios indicating statistically significant relationship if both values were above or below 1. Results: The overall prevalence of malocclusion was 63.8% in 12-14 year-olds and 32.5% in 3-5 year-olds. For the 12-14-year-old children, residing in Temeke (a less socio-economically privileged district) was associated with higher odds (OR 1.8) of being diagnosed with an open bite, after controlling for socio-demographic factors. When subjects with and without caries experience (DMFT) were compared, those with DMFT > 0 were more likely to have any type of malocclusion (SMO>0), a midline shift, Angle Class II/III and an open bite. Oral hygiene varied in unexpected direction with malocclusion (a midline shift) in this study. For the 3-5- year-old children, malocclusion (an open bite) was associated with sucking habits. After controlling for socio-demographic variables, only current sucking habits and gender remained significant determinants for an open bite with the odds ratios of 13.5 and 2.2, respectively. The Kiswahili version of the Child-OIDP inventory preserved the overall concept of the original English version and was applicable to use among primary schoolchildren. A total of 28.6% of the participants had at least one oral impact. Problem with eating was the performance reported most frequently followed by cleaning teeth in both districts. The most frequently reported causes of impacts were toothache, ulcer in mouth and position of teeth. Furthermore, moderate proportions of primary schoolchildren reported problems related to teeth and mouth; ranging from 7.7% (space position) to 20.7% (pain). The odds ratios of having problems with teeth position, spaces, pain and swallowing if having any malocclusion were respectively, 6.7, 3.9, 1.4 and 6.8. A total of 23.3% primary schoolchildren were dissatisfied with dental appearance and function. Primary schoolchildren dissatisfied with their dental appearance were less likely to be Temeke residents and having parents of higher education. They were more likely to report problems with teeth position (OR= 4.3) and have oral impacts (OIDP>0) (OR=2.2). The socio-dental treatment need of 12% was five times lower than a normative estimate of 63.8% based on the overall prevalence of malocclusion (SMO>0). Conclusion: The study showed that, caries and social demographic status (in terms of district of residence) were associated with malocclusion in primary schoolchildren. Sucking habits and gender were associated with malocclusion in pre-school children. Kiswahili version of the Child-OIDP inventory was applicable for use among Tanzanian primary schoolchildren. Oral impacts and dissatisfaction with teeth appearance and function were not common among 12- 14-year-olds. The socio-dental treatment need of 12% was five times lower than a normative estimate of 63.8% based on the overall prevalence of malocclusion (SMO>0). Thus, prophylactic measures which may either totally prevent or at least lessen the development of many forms of malocclusion are recommended, with a particular emphasis to less affluent societies. Moreover, clinical measures of malocclusion together with reported functional- and psychosocial impact scores determined subjects’ evaluation of their teeth appearance and function and hence demand for orthodontic care, therefore these should be taken into account when estimating treatment needs