Measurement Report Of Primary Molars’ Occlusal Gingival Distance Reference Of 6-9 Years’ Old Children In Dalian

Purpose: To collect and analyze the clinical crown date of some children’s molars in Dalian by digital scanning model,oral health status information by checking and basic information of social factors by questionnaire,so as to provide clinical data for metal preformed crown of primary teeth and provide the reference for prevention of oral health care for children in Dalian.Method: A total of 83 children from 6 to 9 years old in Dalian were selected to collect basic information.Parents of children were investigated with questionnaires to understand their eating habits,brush habits and parental intervention measures.Then we examined the oral health of children and made a model for primary teeth.Using SHINING 3D scanner to make digital scanning for the models and using 3D Builder software to measure the clinical crown date of primary molars,including buccolingual diameter,mesiodistal diameter and the reference value of occlusal gingival distance.The SPSS 20 software was used to carry out statistical analysis of the measured data.Result:1、The buccolingual diameter of maxillary first primary molars is 5.30±0.58 mm,maxillary second primary molars is 6.37±0.80 mm,mandibular first primary molars is 3.99±0.52 mm,mandibular second primary molars is 5.81±0.57 mm.2、The mesiodistal diameter of maxillary first primary molars is 6.47±0.58 mm,maxillary second primary molars is 8.39±0.66 mm,mandibular first primary molars is 7.12±0.58 mm,mandibular second primary molars is 9.07±0.61 mm.3、The buccal side of occlusal gingival distance of maxillary first primary molars is 4.05±0.55 mm,maxillary second primary molars is 3.94±0.68 mm,mandibular first primary molars is4.63±0.54 mm,mandibular second primary molars is 4.24±0.51 mm.The lingual side of occlusal gingival distance of maxillary first primary molars is 3.33±0.46 mm,maxillary second primary molars is 3.88±0.55 mm,mandibular first primary molars is 3.18±0.44 mm,mandibular second primary molars is 3.28±0.47 mm.4、The occlusal gingival distance reference value range appears normal distribution,the reference values of homonymous primary molars have small difference,the difference is not statistically significant.5、The occlusal gingival distance reference values of primary molars have a difference between the boys and girls in the buccal side of the upper left second primary molars and buccal and lingual side of mandibular first primary molars,girls more than boys,the difference is statistically significant.There has difference between the boys and girls in the buccal and lingual side of maxillary first primary molars,the buccal and lingual side of the upper right second primary molars,the lingual side of the upper left second primary molars,the buccal and lingual side of mandibular second primary molars,the difference has no statistical significance.6、The occlusal gingival distance reference values have no significant linear relationship with the height and weight of children.7、The incidence of adjacent caries in primary molars is higher than that of simple occlusal caries.Conclusion: It is provided relevant information for the study of the anatomy and shape of the molars through the statistical analysis of the clinical crown data.At the same time,it enriches the clinical crown database in Dalian and provides a reference for the clinical application of metal preformed crown.The prevalence of caries in primary molars is different than that of primary teeth.The incidence of adjacent caries in primary molars is more common.It is important for school age children to develop oral health concept and behavior.Therefore,children’s oral health care measures need more diversified and systematic guidance.