Malocclusion and tooth/arch dimensions in the deciduous dentition of pre-school children In Nairobi
Normal alignment of teeth not only contributes to oral health but also goes a long way in the overall well-being and personality of an individual. One of the values of monitoring children during the deciduous dentition is to prevent and intercept malocclusion. Objective: To determine the prevalence of malocclusion, dental anomalies and measure tooth/arch dimensions in the deciduous dentition of 3-5 year old school-going children. Setting: Public schools in Nairobi. Kenya. Study design and methodology: This was a to-part cross-sectional study. A total of 402 were examined and their occlusal status recorded. Of these, those with normal occlusion had alginate impressions taken and poured in dental stone to determine the mesio-distal tooth widths and arch dimensions. Measurements were done using an electronic digital calliper to the accuracy of 0.05mm. Data analysis was coded and analysed using SPSS 11.0. Student's T-test, Chi-square, Mann Whitney· and Krsukall Wallis tests were used for statistical analysis. Results: Bilateral mesial step was found in 70.1 % of the children, 27.1% had flush terminal, none had a distal step and 2.7% had asymmetric molar relationships. Class I canine was found in 78.9%, 7.2% with Class II, 5.5% with Class III and 8.5% were asymmetric. Seventy percent of the children had a class I incisor, 14.7% a class II, 13.2% a class III and 1.2% were asymmetric. Fifty percent of the children had an ideal xi overbite, 15.7% had an increased overbite, 19.4% a reduced overbite, 5% had an open bite and 4.2% had an edge-edge bite. Of the children examined, 4.7% had an anterior crossbite, 1.5% had a unilateral posterior crossbite and 0.2% a bilateral posterior crossbite. Generalized spacing was seen in 74.9% and 60% in the upper and lower respectively. Dental anomalies were found in 2.7% of the children and infraocclusion in 0.5%. Mesiodistal widths of all teeth and arch dimensions of males surpassed those of females. The upper first right molar(54), upper second right molar(55), upper right central incisor(51), lower left second molar(75), lower right second molar(85) and lower left first molar(74) were significantly larger in males than females. Upper and lower intercanine widths, upper intermolar, upper .and lower arch perimeter were all significantly larger in males than females. Conclusion: The mesial step was the most prevalent molar relationship and spacing was common for this population. Males generally had larger teeth and wider arch dimensions compared to females.