The evaluation of the effects of extraction and nonextraction fixed orthodontic treatment on soft tissue profile of adolescent boys and girls

Adolesan Dönemde Kız ve Erkek Bireylerde Çekimli ve Çekimsiz Sabit Ortodontik Tedavilerin Yumuşak Doku Profile Etkisinin İncelenmesiThe aim of this study was to evaluate the soft tissue profile changes of adolescent boys and girls who were treated with either extraction or nonextractions. The extraction and nonextraction treatment groups were included 15 girls and 15 boys and the control groups which were constructed to eliminate the effect of growth and development, included untreated 11 girls and 11 boys.The inclusion criteria were as follows: ANB angle between 0 - 4º, SN/GoGn values between 32 - 38º, no use of functional orthopedic treatment prior to the fixed orthodontic treatment and no use of extraoral appliances, no molar distalization or maxillary expansion appliances or any other intraoral appliances during the fixed orthodontic treatment, no missing teeth and no craniofacial anomalies. All subjects exhibited growth and development stages prior to Mp 3 union stage at the begining of treatment.Lateral cephalograms, hand-wrist radiographs which were taken before and after the study were evaluated. Statistical evaluation was made by using the parametric and nonparametric tests according to compatibility results.The results revealed that the extraction treatment had no different effect on soft tissue profile between boys and girls, but nonextraction treatment had different responses on lower lip position between girls and boys. When nonextraction groups were considered, lower lip protrusion according to the vertical reference line and lower lip thickness were higher in boys than in girls. Therefore statistically significant difference was found between this two grups.Key Words: Soft tissue profile; Extraction and nonextraction treatment; Growth and treatment changes; Gender difference