Promoting oral health of adolescents through health promoting schools has been prioritized by the World Health Organization (WHO) for the improvement of oral health globally [1
]. Adolescents are in particular need for oral health promoting programs [2
]. Poor oral hygiene in terms of increasing accumulation of plaque and calculus with increasing age have been reported among children and adolescents in both developed- and developing countries [2
]. This situation might lead to periodontal problems later in adult life. In Tanzania, the Ministry of Health Policy guidelines have outlined periodontal problems to account for 80% of all oral diseases in the population [4
]. Poor oral hygiene in the general Tanzanian population aged 15 years and above is very common (65-99%) with prevalence of gingivitis ranging from 80-90% [5
]. According to Kerosuo et al [7
], a substantial proportion of school students aged 12-18 years and, girls less seriously than boys, presents with sign of gingivitis. In contrast, Kikwilu [8
] found a low prevalence of gingivitis and good oral hygiene status among school children in Morogoro.
Appropriate use of inter-dental measures, fluorides, dental services and tooth brushing, restricted frequency sugar intake and avoidance of tobacco consumption contributes to the prevention and control of oral diseases [1
]. A recently published national report considering 13-15 years old Tanzanian adolescents showed that about 90% reported daily tooth brushing, whereas the prevalence of adolescents confirming daily intake of sugar products remained at a moderate level [9
]. Studies have yielded lifetime prevalence rates of tobacco use, ranging from 0.4% to 12% in female- and male adolescents, respectively [9
]. Other studies from East Africa focusing adolescents and young adults have reported similar results with respect to oral health enhancing- and oral health detrimental behaviours [11
Untreated oral diseases might lead to dental pain, dysfunction and problems with daily activities [11
]. To date, oral health related quality of life, OHRQoL, pertaining, to the child- and adolescent populations of Sub-Saharan Africa have been given little attention in the literature. Few studies have assessed the socio-behavioural distribution of OHRQoL and its relationship with clinical indicators of oral hygiene status has yet to be investigated in younger age groups. Instruments are now available for measuring OHRQoL in school-aged children. The Child-OIDP was developed and tested among Thai schoolchildren aged 11-12 yr [14
]. It has been found to be a reliable and valid instrument when applied for instance to children and adolescents in Tanzania, France and UK [11
Socio-economic status has a profound effect on health- and health behaviours [17
]. However, inequality in health and oral health has not been focused to the same extent in adolescents as in adults [18
]. Evidently, the lower the material standard of living as measured by income, social class and social network- and support, the worse the level of oral health, whatever the measures used, being they clinical or self-reported oral health indicators [17
]. The World Health Organization (WHO) International Collaborative studies (ICS-I or II), have demonstrated a social gradient in adolescents' caries experience and periodontal status across high-and low income countries and various oral health care service systems [20
]. Moreover, social disparities in adolescents' oral health behaviours have been demonstrated in developing countries and elsewhere, with oral health detrimental behaviours being most common in subjects of lower socio-economic status [20
]. In Tanzania, previous studies have not given any clear-cut conclusion regarding the relationship between social status and indicators for oral health among children and adolescents.
Owing to scarce resources within the Tanzanian health care sector, it is important to select preventive strategies requiring few resources. It is evident, that oral health interventions through school can improve oral health and oral health related behaviour among adolescents [21
]. Youth is believed to be an important period for learning and maintaining health related activities that may carry over into adulthood [22
]. Although the Tanzanian oral health policy gives priority to children and adolescents as target groups for health care services, the oral health status and associated life style patterns of this age group are not well documented.
This study uses baseline data from a cluster randomized trial, integrating oral health into a health promoting school programme (LASH), to describe patterns of oral health status and oral health behaviours among secondary school students in Arusha, northern Tanzania. The aims were; 1) to assess the frequency of poor oral hygiene status and oral impacts on daily performances, OIDP, by socio-demographic- and behavioural indicators, 2) to examine whether socio-economic and behavioural correlates of oral hygiene status and OIDP differed by gender and 3) to examine whether socio-demographic disparity in oral health outcomes was explained by oral health behaviours. It was hypothesized that, socio-demographic factors influence oral health outcomes directly or indirectly through oral health related behaviours.