Comparison of therapeutic effects of cervical headgear-twin block and conventional twin block appliances

Aim: The aim of this study is to compare the effects of conventional twin block (TB) and cervical headgear-twin block appliances (SHG-TB) on the dentoalveolar, skeleton and soft tissues in individuals with class II malocclusion in growth and development period. Methods: The data of this retrospective study consists of radiograph and photographic records of the patients in Adıyaman University Faculty of Dentistry, Department of Orthodontics. Individuals were divided into two groups according to the treatment of patients with class II division I anomaly caused by mandibular retrognathia. First group consisted of 15 individuals (9 girls, 6 boys, mean age: 12.34±1.23) treated with TB appliance, while the second group consisted of 16 individuals (9 girls, 7 boys, mean age: 12.50±1.30) treated with SHG-TB appliances, which is a combination of cervical headgear and TB appliances. In order to distinguish treatment effects from growth, a control group of 15 untreated individuals (9 girls, 6 boys, mean age: 11.82±1.16) from the archive was included in the study. Results: There was a statistically significant (p<0.001) improvement in the interdental (overjet) and maxillo-mandibular (ANB, Witts) measurements in the treatment groups. While both treatment groups showed a significant (p<0.001) improvement in the vertical direction of the mandible compared to the control group, there was no significant difference between the three groups in the sagittal direction of the mandible (p>0.05). While lower incisors showed significant proclination (IMPA) (p<0.05) in the TB group compared to the control group, no significant change (p>0.05) was found in the SHG-TB group. The lower incisors and molars (L1-MandVR and L6-MandVR) showed a statistically significant (p<0.001) mesialization in both treatment groups. Statistically significant differences (p<0.05) in the skeletal (SNA, SN/PP), vertical (SN/GoGn) and interdental (U1/L1) measurements were found in SHG-TB group compared to TB and control groups (p <0.05). Conclusion: The SHG-TB appliance was found to be more effective in the controlling of the maxillary growth and preventing lower incisor proclination than the TB appliance, while the TB device was more effective in the anterior movement of the mandible. Keywords: Cephalometry, Cervical headgear, Class II malocclusion, Twin block