00000ctm a22000003a 4500 UP-1685523046126317989 Buklod 20170306130533.0 m |o d | cr ||||||||||| 170306s xx d r |||| u| (iLib)UPMNL-00015382935 UPDent eng LG 993.5 2013 D4 L44 Lee, Rachelle Marie G. Effect of extraction of premolars in lip thickness, nasolabial angle and height of the lower anterior thirds of the face of UP College of Dentistry orthodontic patients treated with a fixed edgewise appliance Rachelle Marie G. Lee, Janine T. Sotomil; Lotus D. Llavore, Faculty Co-author. 85 leaves. Seminar Paper--Doctor of Dental Medicine--University of the Philippines Manila Introduction: In orthodontic treatment, premolar extraction becomes part of the pre-treatment if necessary. This type of extraction results in an unaesthetic profile if the diagnosis and treatment plan were not identified and executed appropriately. The authors reviewed records of orthodontic patients to determine the effect of premolar extraction after treatment. Methods: Review of records of 46 patients with lateral cephalograms and profile pictures in frontal view of pre-treatment and post-treatment records were compared. For lip thickness, it was measured from three mm below point A to the drape of the upper lip. The nasolabial angle was between the upper lip and columella tangents. Profile pictures were meausured into thirds and the ration of the height of lower anterior thirds to the height of the face was computed. Results: For the non-extraction group, the lip thickness of female subjects increased by .6944 mm and .8750 mm for the male subjects. The nasolabial angle of female subjects decreased by 1.2500mm and -.5625 mm for the male subjects. the lower anterior thirds of the face of female samples decreased by 1.1667 mm and .6875mm for the male subjects. For the not sex specific non-extraction group, the lip thickness decreased by .75mm. The nasolabial angle decreased by 1.0385mm and a decrease of 0.5962mm for the lower anterior thirds. For the extraction group, the lip thickness of female subjects increased by 2.0667 mm and 0.1667 mm for the male subjects. The nasolabial angle of the female subjects increased by 1.3667 and 7.3333 mm for the male subjects. The lower anterior thirds of the female subjects decreased by 0.4667 while an increase of 2.1667mm for the male subjects was observed. For the not sex specific extraction group, the lip thickness of the total population increased by 1.6250 mm. An increase of 2.8750 mm in the nasolabial angle was seen and a positive value of 0.1500mm for all subjects for the lower anterior thirds was computed. Conclusion: The values foe the mean lip thickness of extraction cases and the amount of changes in the mean height of the lower anterior thirds between males and females are the only ones which have significance. There is no sufficient evidence to say that there is a significant effect of premolar extraction in terms of the said parameters. Orthodontics. Lip thickness. Lower anterior. Nasolabial angle. Premolar extraction. Sotomil, Janine T. Llavore, Lotus D. UPMNL DENT LG 993.5 2013 D4 L44 Thesis