A Study Of The Measurements On The Tooth, Dental Arch And Palatal Arch Of The Children In ZhengHe, FuJian

Objective The Objective of the study is to obtain the data of the tooth, dental arch and palatal arch of the children in ZhengHe, FuJian, to know the development regularity and characteristic of the growth of the tooth, dental arch and palatal arch of the children, to accumulate data for the study of the growth of the tooth, dental arch and palatal arch of the children in FuJian.Methods The target of the study is 321 children who are between 3 and 9 years old in ZhengHe, jianou, FuJian. We measured dental model using calipers with digital and compasses. We measured the mesiodistal crown diameters, arch perimeters, arch width, arch length and palatal height. We analyzed the data using SPSS 11.5.Results1.The mesiodistal crown diameters1.1 About the bilateral asymmetry of the mesiodistal crown diametersBilateral asymmetry of some of the mesiodistal crown diameters of the deciduous tooth and permanent tooth was significant. Bilateral asymmetry of the deciduous tooth of boys was larger than that of girls. Mandibular deciduous lateral incisor was the most asymmetric in the deciduous tooth of boys. Mandibular deciduous canine was the most asymmetric in the deciduous tooth of girls.1.2 About the sexual dimorphism of the mesiodistal crown diametersSignificant sexual differences were found in more than half of the mesiodistal crown diameters of deciduous tooth, which are separated by left and right or no. The sexual dimorphism of the mesiodistal crown diameters of the maxillary deciduous central incisor was largest in all deciduous tooth. The sexual dimorphism of the mesiodistal crown diameters of the right mandibular permanent central incisor was significant. No significant sexual dimorphism was noted in other permanent tooth. The largest sexual dimorphism of the permanent tooth measured by us was mandibular permanent central incisor.1.3 About the variance of the mesiodistal crown diametersThe variance of the mesiodistal crown diameters of the most of tooth of boys was larger than that of girls, either in the deciduous tooth or in the permanent tooth2 . Dental arch2.1About the sexual dimorphism of dental arch2.1.1 Arch perimeterThe sexual dimorphism of the arch perimeter between the mandibular deciduous second molar and the arch perimeter between the maxillary deciduous second molar was significant. Both of the arch perimeter of boys were larger than that of girls.2.1.2 Arch widthThe sexual dimorphism of the arch width in most of groups divided by age and position is significant. The arch width of boys in these groups is larger than that of girls.2.1.3 Arch lengthThe sexual dimorphism of the arch lengthes in most of groups divided by age and position is not significant.2.2 About the comparison of arch among the groups divided by ageThe arch perimeter(except the arch perimeter between mandibular permanent first molars), the arch width(except the arch width between mandibular permanent first molars) and the arch length(except the arch length between maxillary incisors and permanent first molars , the arch length between mandibular incisors and permanent first molars) had some common regularity. It was that the data of the groups of 7-9 years old was larger than that of the groups of 5-7 years old. Every positions of the arch perimeter, the arch width and the arch length had no significant differences between the groups of 5-7 years old and the groups of 3-5 years old, except that the arch width between maxillary deciduous canines in the groups of 5-7 years old is larger than that of 3-5 years old.In a word, significant changes of the size of dental arch was noted in the period of 7-9 years old in the study. The possible reason is the eruption of the permanent incisors.3. Palatal heightNo significant sexual differences of the palatal height in every groups divided by age and position were observed.The significant changes of palatal height related to age was only noted in the palatal height between deciduous second molars. The significant differences of the palatal height between deciduous second molars in every groups divided by age were observed .ConclusionThese results indicated there are some regularity and characteristic in the growth and development of the dentition and occlusion of Fujian children. It is important to obtain the data of children and to study the regularity and characteristic of the growth of the tooth and dental arch of the local children. The study would be beneficial to the clinical treatment.