In dentistry, tissue expanders have been used to obtain sufficient soft tissue for alveolar bone augmentation in the severely atrophic ridge. Herein, we review two cases of soft tissue augmentation using a self-inflating tissue expander in patients in the Department of Oral and Maxillofacial Surgery at Ewha Womans University Mokdong Hospital for bone graft and implant operations. The results of each patient were presented using pre-operative and post-operative radiographs and clinical exams. The results of our study indicate successful bone graft and implant surgery using a self-inflating tissue expander.

Purpose:Although there have been several studies of reduced airway space after mandibular setback surgery using the sagittal split ramus osteotomy technique, research on the risk factors for changes of the airway space is lacking. Therefore, this study was performed to examine airway changes and the position of the hyoid bone after orthognathic surgery, and to assess possible risk factors.Methods:In this retrospective study, 50 patients who underwent posterior displacement of the mandible by the bilateral sagittal split ramus osteotomy technique were included. Changes of the position of the hyoid bone and the airway space were analyzed over various follow-up periods, using cephalometric radiography taken preoperatively, immediately after surgery, eight weeks after surgery, six months after surgery, and one year after surgery. To identify risk factors, multiple regression analysis of age, gender, body mass index (BMI), posterior mandibular movement, and the presence of genioplasty was performed.Results:Inferor and posterior movement of the hyoid bone was observed postoperatively, but subsequent observations showed regression towards the anterosuperior aspect. The airway space also significantly decreased after surgery (P <0.05), and increased slightly up until six months after surgery. The airway space significantly decreased (β=0.47, P <0.01) as the amount of mandibular setback increased. However, age, sex, BMI, and presence of genioplasty were not associated with airway reduction.Conclusion:The amount of mandibular set back was significantly associated with postoperative reduction of airway space. It is necessary to establish a treatment plan considering this factor.