Determination of Primate Space on 4 to 5 Years Old Children of Tehran's Kindergarten in 2000

Statement of Problem: Nowadays, evaluation of the development of occlusion in deciduous teeth for creating corrective occlusion in permanent teeth is one of the most important objectives of pediatric dentistry. In other countries, a vast number of researches have been accomplished on the details of occlusion in deciduous teeth. But, unfortunately, there is still no accurate information about this in IRAN. The aim of this study was to evaluate the occlusion and interdental spaces of kindergarten children of Tehran. On this basis, some information were gathered by means of a cross-sectional, descriptive, analytic study on 248 children during their 4-5 years of age. All kinds of deciduous molar and canine occlusion were studied and registered. Anterior and posterior interdental spaces by means of a gauge with an accuracy of 0.05 mm were also measured. Collected data was analyzed by t-student and variance analysis. In most children, the facial feature was mesoencephalic and the profile was convex. The incidence of occlusion was Fluch Terminal Plane (FTP), Distal Step (DS) and Mesial Step (MS), respectively. There was a statistical significant relationship between the FTP, DS and MS molar occlusion and the occlusion of Class I, II and III canine (P<0.05). The prevalence of maxillary and mandibular primate spaces were 95% and 90% respectively, without significant difference between the two sexes. The anterior and posterior interdental spaces in maxilla were more than in mandible without significant difference in two sexes. There wasn’t also a significant difference between the occlusion of deciduous molars and mandibular anterior dental spaces, maxillary and mandibular posterior dental spaces and the maxillary and mandibular primate spaces. Meanwhile, there was a significant difference between the occlusion of deciduous molars and the maxillary anterior dental spaces (P<0.05). The maxillary anterior interdental space was less the others in bilateral distal step occlusion.