A 6-year Longitudinal Study Of The Dental Arch And Palatal Arch Development Of The Children In Zhenghe, Fujian

Objective:The growth and development of the children's dental arch and jaw directly influence the establishment of occlusion and coordination of craniofacial morphology. From the primary dentition, mixed dentition to permanent dentition period, arch length, arch width and height of the palate has different characteristics at different stages. In the six-year longitudinal study, 64 children in the northern of Fujian Province have been observed. Gao Sheng hui, Sun Jia yi and other people have completed the first, second and third phase of the study In this study, the data of 2009 , 2003, 2005, and 2007 is comparatively analyzed. The report about the growth of same arch and palate dome among six-year longitudinal study has not been seen. In this study, the new 3DSS-STD-â…¡(color type) scanner is used to measure the dental cast and save the related data,To provide a basis for clinical and research pediatric dentistry.Materials and Methods:In this study, we choosed 64 children in Zhenghe County. Among these children, there were 31 boys and 33 girls. And the average age was 5 years old. Our research group had collected the arch dental cast at intervals 1 year since 2003. So we had the dental cast in 2003, 2005, 2007, and 2009. Firstly, we used 3DSS-STD-â…¡(color type) scanner to obtain the required three-dimensional surface point cloud image. Secondly, we used geomagic software to operate entity of the image, so we could obtain three-dimensional solid model. Thirdly, we used MSC MARC software in the model unit to obtain three-dimensional finite element model. Finally, the arch width, arch length, and palatal dome height had been measured and recorded.Results:1. The 3DSS-STD-â…¡(color type) scanner accuracy of the analysis has resulted results indicate that the disadvantages of the vernier as a measurement dental model. The 3DSS-STD-â…¡(color type) scanner not only had advantages of a non-contact and precision up to 0.01mm, but also had convenience to store and operate. But after the statistical analysis of the two measurements, the results have showed that there are no significant difference.2. The arch width analysis has indicated that dental arch development of girls was earlier than male children in about 5 to 9 old. In this stage, maxillary and mandibular arch width of girls was larger than boys. But in the stage of 9 to 11 old, development of dental arch was faster and width was larger in boys.3. The arch perimeter analysis has indicated that maxillary and mandibular arch perimeter had similar changes. The age of 5 to 7 and 9 to 11 stage, maxillary arch perimeter had relatively fast growth rate. But in the 7 to 9 old, development of the dental arch slowed relatively and its growth slowed down. In this stage, he changed of mandibular arch perimeter was not very clear and six-year growth of arch perimeter was relatively stable.4. The arch length analysis has resulted several conclusions: (1) The anterior dental arch length growth is with age. In 5 to 8 age, maxillary anterior arch length of girl was longer than boys,. But after 8 years old, boy's dental arch anterior length began to increase faster than girl's. In the stage of 6 years, mandibular anterior arch length of girl,s has always been longer. (2) The maxillary middle dental arch length began to decline in about 9 old. To 11 old, the middle arch length was similar with the length of 5 years. Since the 7 years, the mandibular middle dental arch length of began to decrease. To 11 old, the middle arch length is less than 5 old. (3) There had been a downward trend in the posterior dental arch posterior length during the stage 9 to 11. 5. The results of arched palate height have showed that the degree of palatal dome growth is grow with age in girls and boys during the 6 years. There was no significant difference between male and female children. In the stage 9 to 11 years, the growth rate of palatal dome was significantly higher than the growth rate of the previous four years. Conclusion :The research was a six-year longitudinal follow-up study which was about children's dome height and dental arch in the northern of Fujian Province. And had discussed the variation of dental arch and palatal dome height with the growth and development during the ages of 5 to 11. It will be an important significance in clinical practice, experimental design and teaching. The study will further expand and improve the research data in this field.