Introduction: Child Oral Impact on Daily Performance Index (C-OIDP) assesses the impact of oral health problems on children's daily activities. Objective: The study examines the correlation between Oral Health-Related Quality of Life (OHRQoL) and dental status among schoolchildren in a non-urban region of south-western Tanzania. Material and Methods: The clinical trial was carried out among school children in Ilembula. A Kiswahili version of the C-OIDP inventory was completed. Further, an oral examination was carried out, in which a mirror, dental probe, and flashlight were used to determine the caries prevalence and the oral hygiene. Results: 162 schoolchildren participated in the study (70 female, 92 male, age 12.30 ± 0.57 years, range 12-14 years). 96.30% of the subjects had experienced one problem with their mouths or teeth within the last 3 months. In 23.08% physiological dentition was the most common problem. 11.04% of the children complained about toothaches during this period. 66.03% had had one daily performance affected by their oral condition. The generic OIDP index differentiated between the proportion of subjects with (DMF/T > 0) or without (DMF/T = 0) carious lesions and with (Simplified Oral Hygiene Index [OHI-S] > 0) or without periodontal problems (OHI-S ≤ 1). Conclusion: C-OIDP index indicates a correlation between clinical oral health and the subjectively perceived impairment of the quality of life. An OHRQoL trial applying C-OIDP is a useful and important tool giving a comprehensive picture of the oral health situation in Ilembula. Further studies should document the course over several years. Keywords: Child Oral Impact on Daily Performance Index, Oral Health Related Quality of Life caries incidence, Tanzania, epidemiology

Introduction: Dental care facilities are rarely located in rural Tanzanian areas and do not meet the standard of western industrial nations. Objective: The aim of the study is to record the oral health situation of the local population of a non-urban region of Tanzania. Material and Methods: Two cohorts were examined. The first cohort comprises 164 children and adolescents (age 12.34 ± 0.66 years, range 12 to 16 years; 71 female, 93 male). In the second cohort 109 study participants with a minimum age of 18 years were included (age 34.09 ± 12.49 years, 65 female, 44 male). Participants were examined in schools and at the dental clinic in Ilembula. Clinically, DMF/T index, edentulous arches, oral hygiene index (OHI-S), and Angle classification were recorded. General conditions, eating habits, socioeconomic factors, and oral hygiene habits were surveyed. Results: DMF/T index of the adults was 2.93 ± 4.23 (female 3.66 ± 3.98, male 1.93 ± 4.38) and for children and adolescents 0,22 ± 0.58 (female 0.31 ± 0.71, male 0.16 ± 0.44). In addition to neutral occlusion (66.67%), there was an increased incidence of Angle III (23.81%). The oral hygiene index was 1.18 ± 0.94. Discussion and Conclusion: Compared to western countries, the prevalence of caries in Ilembula is not increased. However, caries usually remains untreated, which is reflected in higher tooth loss rates. In both age cohorts, a significantly higher DMF/T was found in female subjects. Further studies should follow to document the course over several years. Keywords: caries incidence, Tanzania, general oral health, epidemiology