Comparison of skeletal and dental effects of salivary leptin in normal and overweight patients after twin block therapy

Class II malocclusions can be treated in different ways according to the skeletal problem originates. Mandibular retrognathia is the most common cause of Class II malocclusion, and the ideal treatment goal is to stimulate the growth and development of the mandible. The Twin Block appliance is one of the most preferred functional appliances due to its advantages such as providing ease of use to patients and the ability to expand at the same time in the upper jaw, as it consists of 2 parts. In the functional treatment performed with Twin Block application, the mandible is positioned downwards and anteriorly, thus endochondral ossification is stimulated by the tension of the fibers in the mandibular condyle. This situation causes an increase in mandible size. Various factors have been reported in the literature that can alter endochondral ossification and hence treatment efficacy. One of these factors, the leptin hormone, is secreted more than normal in overweight patients due to excess adipose tissue. Therefore, it can be thought that the amount of endochondral ossification in overweight patients will increase due to the increase in leptin level. In a study using the mandibular condyle in rats as an endochondral ossification model, it was observed that leptin had a direct effect on the chondrocyte population in the condyle. While there are studies in the literature about the effect of leptin level on osteoclastic activity and endocontral ossification, there is no study that evaluates the effect of leptin amount on functional treatment efficiency. Thirty-two patients who applied to Bezmialem Vakıf University, Faculty of Dentistry, Department of Orthodontics for treatment; divided into two groups as overweight and normal weight. In the table determined by the World Health Organization for children and adolescents, overweight patients were composed of 85 percentile and above patients, and normal weight patients were comprised of individuals between the 85th and 15th percentile. In addition to the Height Weight Index, since the leptin level was directly proportional to the amount of adipose tissue of the patients, the fat ratio of the patients was also examined at the beginning of the treatment and at the end of the treatment. The fat rate of the patients was measured with the DEXA device in the dietetics department of Bezmialem Vakif University. The Twin Block appliances are designed as Clark introduced in 2002. Bite registration record for sagittal activation was achieved by taking forward 70 percent of the most forward position of the mandible; vertical activation was done by exceeding the 2-4 mm freeway space. The treatment was terminated after normal and overcorrection was obtained. The increase in condyle length due to endochondral ossification was evaluated using the Pancherz cephalometric analysis method, which consists of linear measurements from lateral cephalometric films at the beginning and at the end of the treatment. xiii Unstimulated saliva was collected from all patients at 5 different times (beginning of treatment, 1st month, 3rd month, 6th month and end) by non-invasive passive pouring method. Saliva sample (5 ml) was taken between 9 and 12 hours at least 1 hour after the meal. The samples were placed in the corner of the tube mouth and saliva was poured into the tube, with the patients sitting upright, their heads should be bent forward. The collected saliva was centrifuged for 15 minutes at 4˚C in an empty dry tube at 15,000 x g. 1 ml of the supernatant was stored in cryotubes at -80 ˚C in a deep freezer until the leptin analysis was performed. Then, leptin levels were measured photometrically from saliva samples with ELISA kits. According to the findings of this study, the treatment of overweight and normal weight patients having Class II division 1 malocclusion with the Twin Block appliance was successfully achieved. At the end of the treatment, Class 1 molar and canine relationships were obtained in both groups, overjet and overbite significantly decreased, and convex profile disappeared. While no statistically significant difference was found in the maxilla in the overweight and normal weight patient groups, a statistically significant (0.01 Keyword: Dental aygıtlar = Dental instruments ; Dişler = Teeth ; Kemik ve kemikler = Bone and bones ; Leptin = Leptin ; Maloklüzyon = Malocclusion ; Maloklüzyon-angle sınıf III = Malocclusion-angle class III ; Obezite = Obesity ; Tükürük = Saliva ; Vücut kitle indeksi = Body mass index ; İskelet = Skeleton