Effects of orthognathic surgery on facial expression recognition

点击翻译按钮获取中文摘要

The purpose of the present study was to investigate the effects of orthognathic surgery on facial expressions by using a special computer system.A facial expression is defined as a movement of grid points in a generic three dimensional face model. A personal frontal face image was manually adjusted to a generic model. Facial expressions of a personal facial model could be produced according to Action Units on Facial Action Coding System. Six averaged facial images were made of three groups with consisted of facial photos of pre and post treatment. One group was treated for mandibular protrusion, the second for maxillary protrusion and the third for crowding. Each group was consisted of 5 female patients. Six expressions (Surprise, Fear, Disgust, Anger, Happiness and Sadness) were produced from the averaged facial image before and after orthodontic treatment. Ninety-nine Japanese subjects and forty Chinese subjects had their expressions estimated.Happy, surprise, fear, disgust and sad faces produced from the averaged face ori the post orthognathic surgery were expressed in the deeper way than ones produced from pre orthognathic surgery. Happy face produced from the post treatment of the maxillary protrusion was expressed in a deeper way than the other same one. Fear, disgust and sad faces produced from the averaged face on the post treatment of the crowding, were expressed in a deeper way than the other same one. Surprise produced from pretreatment of the maxillary protrusion was expressed in the deeper way than the other same one.The form of the lip changed by the orthognathic surgery, and the facial expression also changed. The present study was suggested that facial expression become rich after orthognathic surgery.