Soghra Yassaei - Associate professor, Department of Orthodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Farzaneh Eslami - Postgraduate student, Department of Orthodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
‪Roya Ghafouri fard - Postgraduate student, Department of Pediatrics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Aim: Considering the importance of stability on the orthodontic treatment outcomes, the instability may cause dentoskeletal and soft tissue changes in patients after the treatment. The aim of this study was to evaluate dentoskeletal and facial soft tissue relapse in class II patients whom have been treated with functional appliances. Materials and Methods: ۲۳ patients with Class II Division ۱ malocclusion who had received treatment with Farmand functional appliance and had at least two years of post treatment follow up, were evaluated using cephalometric analysis for dentoskeletal and soft tissue changes. The lateral cephalometric radiographs of the patients immediately after the treatment (T۱) and two years follow up (T۲) were traced and statistical analysis was performed to obtain the amount of occurred relapse between T۱ and T۲.Results: The mean decrease of ANB angle between T۱ and T۲ was ۰.۷۳ º, which was not statistically significant. Overall, the mean changes of skeletal and dental variables (FMA, GOGN-SN, U۱ to SN, U۱ to FH and IMPA) in T۱ and T۲ were not statistically significant. For the soft tissue variables, the mean increase of the nasolabial and mentolabial angle in T۱ and T۲ were not significant. The mean changes of Z and H angles in T۱ and T۲ were ۰.۵۳º and ۰.۶۳ º, which were not statistically significant. Conclusion: Dentoskeletal and soft tissue facial changes that occurred during treatment with Farmand functional appliance remained stable at least ۲ years after treatment. 

Functional appliance, class II divison ۱, Malocclusion, Relapse