Teeth Width, Tooth Size Ratio, Arch Perimeters For A Referred Chinese Sample

Introduction: Correct diagnosis and treatment planning initially results in successfulorthodontic treatment. Identifying the abnormalities in tooth size and shape, archdimensions. Tooth size ratios lead to the correct treatment planning. Tooth size ratio isethnic; sex specific. Genetic and environmental factors play a role in that.Materials and methods: Mesiodistal tooth width and arch perimeters of108Tongjihospital orthodontic clinic patients (13-15) years old resembled angles malocclusiongroups.Results: Teeth showed significant tooth size differences among both gender and amongthe same individuals. Neither anterior nor overall tooth size ratio significant differencespresent among both genders. The present study mean anterior tooth size ratio is(78.57±3.2), higher than Bolton standard (77.2±0.22), whereas the mean overall toothsize ratio is (91.3±2.6) close to Bolton standard (91.3±0.26). The statistical analysis ofthe present research data confirms that tooth size ratio is population but not sex specific.This medical sample showed tooth size ratios significant differences with other southernChinese and other ethnic Chinese groups, also the anterior ratio in the three malocclusiongroups showed significant differences to Bolton standards.(30.5)%and (15.7)%ofpatients have an anterior and overall tooth size ratios greater than2SD from Bolton’smean, respectively. Some inter arch dimensions showed significant differences betweenboth genders.Conclusion: Anterior Bolton ratio can not be applied on Chinese population, and newstandards should be found for Chinese population, Hubei province population tooth sizeratios significantly differ from other Chinese ethnic groups, which prove the influence ofother than genetic factors in such differences; like environmental factors.