The effects of extractions in facial vertical changes

Ma, Joon; Yoon, Young Jooh; Kim, Kwang Won

Abstract

The purpose of this investigation were to evaluate facial vertical changes occurring in patients treated orthodontically with first premolar, second remolar and second molar extractions ; to comoare these changes with those occurring in patients treated orthodontically without extractions ; and finally, to evaluate the effects of extractions in facial vertical changes. Cephalometric records of 50 male & female nonextraction patients and 88 male & female extraction patients were obtained from the department of orthodontics at Chosun University, College of Dentistry. The second molar fully erupted patients to have little variation according to growth were chosen as the sample for this investigation. For comparisons, the samples of 88 male & female according to growth were subdivided into 42 first premolar extraction, 24 second poemolar extraction, and 22 second molar extraction patients. Fourteen cephalometric measurements were selected to examine whether orthodontic extraction treatment led to vertical changes or not. The pretreatment and posttreatment lateral cephalographs were taken on the same radiographic unit. SPSS/PC+ statistical program was used to compare and to analyze the changes between "before & after" orthodontic treatment. The results of this study were as follows : 1. There were no statistical significances in any cephalonemtric measurements between "befor & after" orthodontic treatment regardiess of orthodontic extractions for each group. 2. On average, the upper 6 to palatal plane and the lower 6 to mandibular plane after orthodontic treatment were increased in all group. This means most of orthodontic mechanics are extrusive in nature. Especially, in orthodontic extraction casds, it may caused by orthodontic mechanics for space closure and alignments. 3. On average, in the second molar extraction gruop, the facial vertical dimension was increased after orthodontic treatment. It may be induced as a result of moving the molars distally to gain enough space to correct the molar relationship and to simultaneously improve the deep bite. 4. There was no statistical significance between orthodontic extractions and facial vertical changes. This means that orthodontic extractions have no influence on facial vertical changes. 5. The cephalomentric measurements with statistical significance in ficial vertical changes for each group were PP-MP, Op-MP, 1 to PP and 1 to MP