This study compared the maxillary sinus volume, orbital volume, and frontal sinus volume of the healthy and affected sides in patients with hemifacial microsomia（HFM）, and examined the possibility that the disease had affected the inside skeletal structure of the face.
　　A survey was conducted among 12 patients with HFM（Pruzansky-Kaban classification：Type II）, excluding those with maxillary sinusitis or mucosal thickening, and 10 patients who visited to the hospital due to trauma were included as the control group. After constructing the 3DCT images of these patients, the maxillary, orbital, and frontal sinuses were extracted, and their volumes were measured using a 3D measurement software. Intragroup and intergroup comparisons of the HFM and control groups were performed statistically.
　　The maxillary sinus volume of patients with HFM（Type II）proved to be significantly smaller by 13.5% on the affected side than on the healthy side in the intragroup comparison, while in the intergroup comparison, it was significantly smaller by 18.8% than that in the control group. The orbital volume of HFM was found to be 4.1% significantly smaller on the affected side than on the healthy side in the intragroup comparison, but there was no significant difference in the intergroup comparison with the control group.
　　Our results suggest that the facial deformity in patients with HFM（Type II）was affected by asymmetry in the lower to the middle part of the face, while the upper part of the face was not affected.

　　Reconstruction of fractured orbital wall with unsintered hydroxyapatite and poly L-lactide composite（u-HA/PLLA）system has been gaining in popularity. However, few studies have reported the size of bone defect or inserted sheet. In this study, we examined the utility of u-HA/PLLA system retrospectively, evaluating both of them. This study included 10 patients（mean age, 43 years；8 men and 2 women；mean follow-up period, 15 months）who underwent surgical repair of orbital wall fractures with u-HA/PLLA system from 2014 to 2020. Clinical data were collected from the medical records, which included pre- and postoperative symptoms, the size of bone defect and inserted sheets, postoperative complications. 9 patients complained diplopia preoperatively, all of which experienced improvement after surgery. The mean area of bone defect was 3.6 cm² and the maximum was 6.6 cm². The average of the maximum side-to-side lengths of bone defects was 20.2 mm, and 23.4 mm was the average of those of inserted sheets. The average of the maximum front-to-back lengths of bone defects was 24.7 mm, and 25.4 mm similarly. No postoperative complications were found. In conclusion, u-HA/PLLA system seems to be useful in reconstruction of relatively large bone defect due to its structural stability, biocompatibility and low reactivity to tissue.

　　Pulmonary thromboembolism rarely occurs after surgery in children with no systemic underlying disease. There have been no reports of pulmonary thromboembolism after craniomaxillofacial surgery in Japan to date. However, we report a rare case of pulmonary thromboembolism after Le Fort III distraction osteogenesis that did not lead to sudden patient death.
　　The patient was a 10-year-old girl with Crouzon syndrome. Le Fort III distraction osteogenesis was performed for midface hypoplasia and obstructive sleep apnea syndrome. On the 6th postoperative day, the patient developed headaches and exhibited cyanosis while walking. Pulmonary thromboembolism was diagnosed using chest X-ray, echocardiography, and systemic enhanced computed tomography. As anticoagulant therapy, thrombolytics and cardiac catheterization were not effective in removing the thrombus；therefore, surgical thrombectomy was performed and it was removed. During this treatment for pulmonary thromboembolism, Le Fort III distraction was continued and the targeted amount of elongation was reached on the 23rd postoperative day.　　Pulmonary thromboembolism is a rare complication in the craniomaxillofacial region. However, if pediatric intensive care unit management or several days of bed rest is required for children, we should also include additional measures focused on the prevention of pulmonary thromboembolism.

　　Mixed implants comprising hydroxyapatite granules and tricalcium phosphate composite（HAP/TCP）are expected to be histotropic and result in a lower frequency of foreign body reaction. We report a case of postoperative aseptic cyst after reconstruction of the orbital medial wall and floor using two HAP/TCP plates. The patient visited our hospital 3 years after reconstruction because of diplopia. Magnetic resonance imaging revealed a cyst on the artificial bone implant compressing the eyeball. The cyst and HAP/TCP were removed under general anesthesia. Although histological examination demonstrated surface ossification around the HAP/TCP, no bone fusion with surrounding bone was noted. Bacterial examination revealed the cyst to be aseptic. This supports the theory that repeated irritation due to two HAP/TCP plates causes inflammatory responses involved in cyst formation. This case suggested that long-term follow-up is necessary after reconstruction using HAP/TCP.

　　Neurofibromatosis type 1（NF1）is rarely accompanied by sphenoid dysplasia and calvarial defects. Patients with orbital wall defects require surgical treatment when they have severe exophthalmos, which is a cause of corneal erosion and loss of vision. We report a 32-year-old woman with NF1 who presented with pulsatile exophthalmos and bulging of the temporal region due to large bone defects in the orbit and around the pterion. Orbital and calvarial reconstruction was performed together with iliac bone grafting and titanium plate insertion. The patient had no recurrence of the symptoms during 10 years of follow-up. In this case, the transcranial approach was helpful to expose the deep orbital lesion and fix the implants. Although bone resorption is problematic, iliac bone grafting is useful for the following reasons: it can be sufficiently harvested to cover both the orbital wall and the calvarial defects, and can be easily shaped to fit into the defects.