Analysis Of Related Factors Of The Open Gingival Embrasure In The Lower Anterior Teeth After Fixed Orthodontic Treatment

Objective:The aims of the present study were to determine the relevant factors of open gingival embrasure after fixed orthodontic treatment.Examing the factors associated with open gingival embrasure may provide theoretical basis and reduce the incidence of the open gingival embrasure in the lower anterior teeth after fixed orthodontic treatment.Methods:According to the frontal intraoral slide before and after fixed orthodontic treatment in the lower anterior teeth,50 open gingival embrasure as case group,73 normal gingival embrasure as control group.Each patient have intact frontal intraoral slide before and after orthodontic treatment,cephalometrics and panoramic radiography before treatment,intact model and case report before treatment.Sagittal bone pattern?vertical bone pattern and labial inclination of the lower anterior teeth before treatment were measured by cephalometrics.The severity of crowding of the lower anterior teeth,gingival angle,the width of the crown and length of the crown were measured by the pretreatment model.To record the gender,age,lengths of active treatment and the orthodontic scheme of patients(extraction or not).Spss21.0 software was used for statistical analysis.Two sample t test were conducted for the data of the measurement data.The ranked data use Wilcoxon rank sum test.A chi-square test is carried out for the unordered categorical variable.The test standard is 0.05.In order to find out the relative factors,the factors of significance were then carries on the second classification Logistic regression analysis.Providing guidance to the clinic.Results:1?Single factor analysis results of measurement data The lengths of active treatment of the case group was 26.29 ± 10.301 month and the control group was 21.97 ± 7.354 month.The difference was statistically significant(P<0.05).Case group of MP-FH was 33.306±7.3972 angle,the control group of MP-FH was 30.368±6.547 angle.The difference was statistically significant(P<0.05).Relative factors of labial inclination of the lower anterior teeth of L1-MP angle?L1-NB angle?L1-NB length had no statistical significance(P>0.05).Crown width,crown length,crown width/crown length which represent crown form have no statistical significance between the two groups(P>0.05).There was no statistically significant difference in the gingival angle between the case group and the control group(P>0.05).2?Single factor analysis results of unordered categorical variable The data of unordered categorical variable were checked by chi-square.There was no statistically significant difference in gender distribution between case group and control group.There were 30 patients with extraction and 20 patients with non-extraction in case group,19 patients with extraction and 54 patients with non-extraction patient in control group.The difference was statistically significant(P<0.05).There were 28 patients with?class skeletal pattern and 22 patients with non-?class skeletal pattern in case group,26 patients with?class skeletal pattern and 47 patients with non-?class skeletal pattern in control group.The difference was statistically significant(P<0.05).3?Single factor analysis result of ranked data The ranked data was checked by Wilcoxon rank sum test.The age is divide d into younger than 16 years,16 to 25 years old and older than 25 years.The d ifference was statistically significant(P<0.05).The subjects were grouped according to the severity of crowding,? °(less than 4 mm)?? °(4~ 8 mm crowdin g)and ? °(more than 8 mm).The difference was statistically significant(P<0.05).4?The factor of significance were then carries on the second classification Logisti c regression analysis.The results showed that age and the severity of crowding w ere significantly correlated with the occurrence of open gingival embrasure.Conclusion:1? The severity of crowding of the lower anterior teeth was correlated with the occurrence of the open gingival embrasure.The greater the crowding of the lower anterior teeth,the greater the likelihood of an open gingival embrasure.2?The age of the initial consult was correlated with the occurrence of the open gingival embrasure in the lower anterior teeth after orthodontic treatment.The old er the age of the initial consult,the greater the likelihood of an open gingival e mbrasure after the orthodontic treatment.3?The lengths of treatment,extraction,vertical bone pattern and sagittal bone pat tern have statistical significance when conduct single factor analysis.There was n o statistical significance in regression analysis.It suggested that it may be related to the occurrence of open gingival embrasure after fixed orthodontic treatment,but the influence is relatively small.4?Labial inclination of the lower anterior teeth,gingival angle and crown form ha ve no effect on the open gingival embrasure after the fixed orthodontic treatment.