Evaluation of orthodontic treatment outcome in patients undergoing extraction of mandibular first molar with PAR index and cephalometrics
WANG Qing-lin
HE Yong-jian
ZHOU Shao-yun
MA Ming-yu
LI Rong-xia
Abstract：Objective To access the clinical effect of orthodontic treatment for patients undergoing extraction of mandibular first molar.Methods Nineteen patients (three male and sixteen female)undergoing extraction of mandibular first molar because of caries or periapical disease were collected,who were treated in the Second Hospital Affiliated to Guangzhou Medical University from 2007 to 2016.All the patients were treated with orthodontic space closure using MBT preadjusted appliance and sliding mechanics and class Ⅱ or class Ⅲ elastics.Cephalometric films and casts that were taken before and after orthodontic treatment were measured and analysed.Results The average treatment time was (33.47 ±7.93) months.Thirteen cases (68.42％) were evaluated as greatly improved,six cases (31.58％) as improved,and no cases were evaluated as worse or no difference after treatment;the difference in weighted PAR score and each of the PAR score were statistically significant (P ＜ 0.05).There were significant changes in U 1-NA,U 1-NA and U 1-SN (P ＜ 0.05),but not in the rest of the values (P ＞ 0.05).Extraction spaces of mandibular first molars were closed.Good occlusal relationships and soft tissue profiles were achieved in all cases.Conclusion The first molar extraction could achieve satisfactory results under strict planning,appropriate control and careful clinical operation.
Keywords：PAR indexcephalometricsmandibular first molar extractioneffect evaluation
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 674-678 )