Bioabsorbable osteosynthesis materials are useful for maxillofacial fracture and orthognathic surgery because no secondary operation is needed. However, some risks (e.g. failure of the fixation, wound infection and late-onset inflammatory reaction) in bioabsorbable osteosynthesis have been reported. This study was conducted to investigate the late-onset inflammatory reaction of bioabsorbable osteosynthesis materials for orthognathic surgery. In the Department of Oral and Maxillofacial Surgery, Showa University Dental Hospital from July 2006 to December 2016, 398 cases who underwent orthognathic surgery using bioabsorbable osteosynthesis materials were investigated retrospectively. The materials were used in 309 cases for sagittal split ramus osteotomy and 162 cases for Le Fort I osteotomy and anterior maxillary alveolar osteotomy, respectively. No late-onset inflammatory reaction was found in the mandible, but it was observed in the maxilla in 8 cases (5.0%). The average duration until observation of late-onset inflammatory reaction was 33.4 months after the surgery. Scanning electron microscope findings of the removed materials showed fragmented ones with a rough surface. Moreover, a large amount of lymphocyte-like cells were attached to the rough surface. These results suggested that bioabsorbable osteosynthesis materials in the maxilla might have a higher risk of late-onset inflammatory reaction. Thus, careful consideration and long-term follow-up are necessary when using bioabsorbable materials for the maxilla in orthognathic surgery.

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This study aimed to compare cephalometric changes in the upper airway morphology, including the hyoid bone position, after the conventional Le Fort I (LF) osteotomy, and an LF and horse-shoe osteotomies. Twenty-two patients diagnosed as having skeletal maxillary protrusion at the Department of Oral and Maxillofacial Surgery/Orthodontics, Yokohama City University Medical Center, were included. They were divided into two groups as follows: 13 patients underwent LF and sagittal split ramus osteotomies (LF group); and 9 patients underwent LF, horse-shoe and sagittal split ramus osteotomies (HS group). The following linear variables were measured on lateral cephalometric radiographs taken before (T₀), immediately after (T₁), and 1 year after (T₂) surgery: palatal pharyngeal space (PPS), the length from the posterior pharyngeal wall to the posterior nasal spine (PNS); superior posterior palatal space (SPPS), the length from the posterior pharyngeal wall to the middle point between the PNS and the lowest point of the soft palate; middle posterior palatal space (MPS), the length from the posterior pharyngeal wall to the lowest point of the soft palate; inferior posterior palatal space (IPS), the length from the posterior pharyngeal wall to the tongue passing the lowest point of the second cervical vertebra; epiglottic pharyngeal space (EPS), the length from the posterior pharyngeal wall to the tongue passing the front end of the epiglottis; S-H, the length from the lowest point of the hyoid bone to the Sella; and C3-H, the length from the lowest point of the hyoid bone to the lowest front point of the second cervical vertebra. Statistical analyses were performed using the Mann-Whitney U test. P values of <0.05 indicated statistical significance. SPPS and MPS decreased at T₂ in the HS group. IPS and EPS increased at T₁ in both groups but decreased at T₂ in the HS group. S-H decreased at T₁ in both groups and at T₂ in the LF group. C3-H increased at T₁ in both groups but decreased at T₂ in the HS group. The anteroposterior diameter of the oropharynx was unchanged in the LF group because the tongue moved upward after the palate moved upward but changed in the HS group because the tongue moved backward and the oral volume decreased due to the absence of palatal segment movement. In conclusion, the anteroposterior diameter of the oropharynx decreased after backward and upward movements of the maxilla by LF and HS in the patients with skeletal maxillary protrusions.

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Opitz syndrome is a congenital disorder characterized by facial anomaly (ocular hypertelorism, widow's peak, broad nasal bridge, and strabismus), laryngotracheal and esophageal defects, genitourinary abnormalities (hypospadias, cryptorchidism, and hypoplastic / bifid scrotum), cleft lip and palate and mental retardation. This paper reports a female patient with mandibular prognathism with Opitz syndrome treated by orthodontic treatment, orthognathic surgery and glossectomy. The case was referred to our hospital at the age of 8 years with mixed dentition for the correction of anterior crossbite. A lingual arch and a face mask were used to improve the crossbite in the right anterior teeth and mandibular prognathism. At the age of 14 years after observing growth, mandibular prognathism became prominent and surgical orthodontic treatment was commenced. Orthognathic surgery was performed at the age of 15 years using Le Fort I and sagittal split ramus osteotomies. After surgery, her occlusion was unstable due to a large tongue and a glossectomy was performed at the age of 16. After post-surgical orthodontic treatment, the occlusion was good and stable.

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