Aim: To assess the lower incisors proclination in class 2 malocclusion patients undergoing functional appliance therapy and it’s associative factors Background: Class II malocclusion occurs when the lower dental arch is more posterior than the upper dental arch. Currently there are many treatment approaches available in orthodontics for class II malocclusion which includes extraoral traction appliance, functional jaw orthopaedic appliance, arch expansion mechanism, extraction procedures and surgical procedures. The class II malocclusion includes altered molar relationship from class I normal molar relationship, proclination of anterior teeth of upper and lower arch either it involves only upper arch proclination or bimaxillary proclination, skeletal modifications like prognostic maxillary bone or retrognathic mandibular bone. The results of different treatment approaches are varying for different patients according to various factors but the ultimate aim of all treatment approaches is to bring confident smiles. Materials and Methods: The class 2 malocclusion patient undergoing functional appliance therapy in Saveetha dental hospital were included in the study and their pre operative and post operative cephalometric radiographs were collected for the assessment of lower incisors proclination which has to be correlated with various associative factors like age, sex, years of treatment undergone. Results: Mean age of the study sample was 11.12 ± 1.56 years. Mean reduction of lower incisors proclination with twin block appliance was statistically significant (p< 0.005). There was no statistically significant difference between males and females in lower incisors with twin block appliance Conclusions: The twin block appliance treatment are statistically significant reduction lower incisor proclination of class 2 malocclusion patients. There was no statistically significant difference between males and females in lower incisors with twin block appliance