ABSTRACT
OBJECTIVE: To determine spacing and crowding according to ethnic group, gender and dental emergence stage among Tanzanian African and Caucasian children. DESIGN: Cross-sectional epidemiological clinical study. SETTING: A total of 869 African (428 boys, 441 girls) and 706 Caucasian (319 boys, 387 girls) school children, aged 3(1/2)-16 years. MAIN OUTCOME MEASURES: Comparison of spacing and crowding between African and Caucasian children according to gender and dental emergence stage. RESULTS: Spacing was more often found in the maxilla, while crowding was more common in the mandible. Only during the transition of the maxillary permanent front teeth was there significantly more spacing in Caucasians. No gender differences were found. In both samples spacing decreased during later emergence stages. Crowding was more often found in Caucasian children than in African children. In Caucasian children the frequency of crowding increased with advanced emergence stages, while for Africans the trend was not consistent. CONCLUSION: When planning resources for orthodontic treatment for different populations as well as planning treatment for individuals, ethnic background and emergence stage of the dentition need to be considered.
Subject(s)
Black People , Diastema , Malocclusion/ethnology , White People , Adolescent , Black People/ethnology , Black People/statistics & numerical data , Child , Child, Preschool , Cross-Sectional Studies , Cuspid/pathology , Dentition, Mixed , Epidemiologic Studies , Ethnicity/statistics & numerical data , Female , Finland/epidemiology , Humans , Incisor/pathology , Male , Malocclusion/epidemiology , Mandible/pathology , Maxilla/pathology , Sex Factors , Tanzania/epidemiology , Tooth Eruption/physiology , Tooth, Deciduous/pathology , White People/statistics & numerical dataABSTRACT
Two groups of Finnish children, 1008 from the eastern part of the country and 569 from the western part, aged 5 to 16 years, were examined to determine the timing of permanent tooth emergence and any regional variation therein. The probit analysis was used to calculate the median ages of eruption. Permanent teeth in the first phase of the mixed dentition erupted earlier and premolars erupted later than previously reported for Scandinavian populations. The former finding could reflect the secular trend; the latter is probably related to the dramatically improved dental health in Finnish children. No regional variation in eruption was found. The median ages of eruption of permanent teeth determined in the present study are suggested for use as national standards for permanent tooth emergence in Finland, separately for girls and boys.
