ASSESSMENT OF PRETREATMENT AND POST TREATMENT ARCH-WIDTH CHANGES IN EXTRACTION AND NON EXTRACTION CASES IN A CHINESE PATIENT POPULATION

The debate and controversy of extraction and nonextraction has nearly been 100 years old. Some researchers claim extraction to
constrict arch and subsequently create unaesthetic black triangles at the corner of the mouth, however recent studies show that instead
extraction treatment causes increase of archwidth in canine reason due to distal movement of canine in extraction space.
The aim of the study is to assess the archwidth change in extraction and non extraction treatments separately, with the objective to
compare thus obtained change of pre-treatment and post-treatment archwidth between extraction and nonextraction treatment.
The study consisted of two groups; the extraction group with sample size of 24 patients, patients whose first premolar were extracted
as treatment plan, male-14, female-10, other group was nonextraction group in which teeth was not extracted with sample size 14
patients, male-6, female-8. The archwidth measured at canine, second premolar and first molar. Pretreatment and post treatment values
for each group compared using paired t-test, and difference between pre and post treatment values for each group compared using
independent t-test. The SPSS 18.0 software used for the statistical purpose and 0.05 significance level for all calculations.
Statistically significant increase in archwidth in lower canine region, and decrease in archwidth in upper as well as lower second
premolar and molar region was noted in extraction cases (?<0.05). Whereas increase in archwidth in upper canine region of extraction
cases and all variables of nonextraction cases were noted though not significant