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Background: Cases of facial asymmetry with chin deviation and canted occlusal plane represent a challenge in orthodontic treatment. Case Report: We report successful surgical orthodontic treatment for skeletal Class I with severe facial asymmetry. Miniscrew anchorage was used to decompensate the canted occlusal plane in presurgical orthodontic treatment with a fixed appliance by the intrusion of the maxillary right molars and extrusion of the left molars. Then, orthognathic surgery consisting of bilateral sagittal split osteotomy for asymmetric mandibular setback was performed. Treatment resulted in marked improvement of facial asymmetry. Conclusion: The use of miniscrew implant anchorage may represent a superior presurgical orthodontic treatment and expand the possibility of treatment by one-jaw surgery.

Highlights • MMTAH is a new clinical entity, misdiagnosed as temporomandibular joint disorder. • MMTAH is diagnosed based on a square mandible, cord-like masseter muscle aponeurosis, and limited mouth-opening. • Aponeurectomy combined with coronoidectomy is the treatment of choice for a better prognosis. • It is important to evaluate the patient’s compliance with mouth-opening training before surgery., Introduction Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new clinical entity that presents mainly with trismus due to hyperplasia of the masseter aponeurosis and temporalis muscle tendon. However, the etiological factors of this disease are unknown; it is often mistreated as temporomandibular joint disorder (TMD). Presentation of case We report a 32-year-old female patient complaining of bilateral pain in her jaw and difficulty opening her mouth. She was first diagnosed as TMD and treated with a splint; however, her symptoms did not improve. Clinical examination revealed a square mandible, tenderness in the left and right temporalis muscles and masseter muscles, and tenderness along the anterior border of the masseter muscle. Her maximum mouth-opening was 30 mm. Short TI inversion recovery magnetic resonance imaging showed areas of low intensity at the anterior border of the masseter muscle and around the coronoid process where the temporalis muscle tendon attaches. Consequently, the diagnosis made based on the clinical and radiographic findings was MMTAH. Bilateral coronoidectomy was performed, followed by a rehabilitation program for six months. The maximum opening was maintained at 48 mm two years after the operation. Discussion MMTAH was treated as type 1 TMD until it was recognized as a new disease at the conference for the Japanese Society for Oral and Maxillofacial Surgeons. Since then, many clinicians have become aware of this particular condition, and different treatment modalities have been proposed. Conclusion Clinicians should consider MMTAH as a differential diagnosis when the patient’s chief complaint is gradually decreasing mouth-opening.

We reported an extremely rare case regarding intraosseous clear cell variant of mucoepidermoid carcinoma in maxilla.

Introduction Vertical maxillary excess, a common orthodontic problem that leads to long faces and open bites, can be repositioned with a Le Fort I osteotomy. However, the Le Fort I osteotomy poses the risk of a variety of complications including descending palatine artery (DPA) injury. Although several Le Fort I osteotomy modifications were reported to avoid complications associated with this osteotomy, only a few of such studies were conducted in Japan, and details remain scarce. Patients and methods We performed a literature review regarding modifications of Le Fort I osteotomies, including Le Fort I with a horseshoe osteotomy, modified horseshoe osteotomy, unilateral horseshoe osteotomy, pyramidal osteotomy, and U-shaped osteotomy. We identified eight relevant studies conducted in Japan; one study did not provide the number of patients examined. The 77 patients (seven studies) with vertical maxillary excess who underwent orthognathic surgery were ≥17 years old. Discussion There were no severe complications after the modified Le Fort I osteotomies. The postoperative maxillary changes obtained by the conventional horseshoe, modified horseshoe, unilateral type of horseshoe, pyramidal, and U-shaped osteotomies were nearly repositioned to the planned position and remained stable for ≥12 months post-surgery. Conclusion Our review indicates that preserving the DPA can lower the incidence of intra- and post-operative complications. Each modification of the Le Fort I osteotomy (i.e., conventional horseshoe, modified horseshoe, unilateral horseshoe, pyramidal, and U-shaped osteotomy) has its respective advantages and indications., Highlights • Vertical maxillary excess (excessive maxilla growth) impairs functions/aesthetics • Vertical maxillary excess is treated with a conventional Le Fort I osteotomy. • Extensive bone removal for the descending palatine artery with impaction is needed. • Various modifications of Le Fort I provide better maxilla repositioning. • Modifications can preserve the DP artery and minimize complications.

Introduction: In cases with gummy smile or asymmetry of the maxilla, superior repositioning of the maxilla is required. If superior repositioning by a Le Fort I osteotomy alone is difficult, a horseshoe Le Fort I osteotomy can be used. Presentation of cases: Case 1: A 24-year-old Japanese woman patient presented with a gummy smile and an open bite. After we performed a horseshoe Le Fort I osteotomy, the maxillary segment was repositioned superiorly 3.0 mm at upper tooth number 1 (U1) and 5.0 mm at upper tooth number 6 (U6). Case 2: A 21-year-old Japanese man presented with severe facial asymmetry. After we performed a unilateral modified horseshoe Le Fort I osteotomy, the maxillary segment was superiorly repositioned 6.0 mm at the right U6. Discussion: This procedure eliminated the risk of intraoperative bleeding because it was unnecessary to remove bones around the descending palatine artery, and it was possible to maintain the chamber size of the nasal cavities. Conclusion: The horseshoe Le Fort I osteotomy is a reliable technique for cases with severe gummy smile or asymmetry of the maxilla.

A total of 55 patients who underwent orthognathic surgery from July 2002 to June 2005, were observed clinicostatistically. The results may be summarized as follows: 1. There were 11 males and 44 females. 2. The average age was 27.7 years, with an average of 22.3 years for males and 28.8 years for females. 3. The diagnosis of mandibular prognathism was made for 50 of the patients (90.9%). Sagittal split ramus osteotomy (SSRO) was performed on 37 (67.3%) cases. 4. The mean time of operation for SSRO was 2hr. 22min±1hr, and 11min and 4hr. 26min±1hr. 29min for the SSRO+Le Fort I osteotomy. 5. The mean blood loss was 130.9±157.9ml for SSRO and was 220.6±143.7ml for SSRO+Le Fort I osteotomy.

北海道医療大学歯学部付属病院の外来は1978年12月に開始し,入院病棟は1980年6月に24床で開始した.これまでの25年間における病棟入院患者の臨床統計的観察を行ったので報告する.結果は以下に示す.1.総入院患者数は3055例で総歯科新患の10.8%を占めていた.2.口腔外科疾患別では,顎変形症が最も多く393例で入院患者の12.9%を占めていた.3.病床稼働率は17.7%で,平均在院日数は14.2日で経年的に減少傾向にあった.4.25年間の入院診療報酬額は9億5715万円で歯科診療報酬額の20.4%を占めていた., The outpatient division of the Dental School hospital of the Health Sciences University of Hokkaido started in December 1978, and a hospitalization ward started with 24 beds opened in June 1978, and closed in April, 2005. Clinico-statistical observations for 25 the years while the inpatient division, was opened were evaluated. 1. The total number of inpatients was 3055, and comprised 11.8% in all initial patients of the dental hospital for the 25 years. 2. Patients with jaw deformities were the most common, 393 and comprised 12.4% of all hospitalized patients with oral and maxillofacial surgical complaints. 3. The rate of occupiod beds the operating bed ratio was 17.7% and the average length of hospitalization was 14.2 days. This number showed a tendency to decrease over the years. 4. The income from hospitalized care was 957.15 million yen and it comprised 20.4% of the total income of the dental department.

We report on pycnodysostosis presenting as severe snoring caused by pharyngeal narrowing in two siblings. Cephalograms showed pharyngeal narrowing at the level of the soft palate and the base of the tongue caused by the long soft palate and mandibular hypoplasia. From the literature review and our results, we suggest that respiratory insufficiency such as snoring or obstructed sleep apnea are common and under-appreciated symptoms of pycnodysostosis.

The purpose of this study was to investigate the relationship between cranio-cervical inclination and pharyngeal airway space (PAS) by measuring these parameters at different head postures in the same subjects and to obtain a regression equation to correct the values measured. Fifty lateral cephalometric radiographs taken at five different head postures per individual were obtained from ten adults (seven males and three females) aged from 25 to 30 years with nose breathers and Class I occlusion. The changes in cranio-cervical inclination produced by head extension were correlated with changes in the variables describing the PAS. The OPT/NSL (cranio-cervical inclination in the second vertebrae) and C3-Me (distance between the third vertebrae and the Menton) correlated strongly with PAS-TP (the most proximal distance measured between the posterior pharyngeal wall and the tongue base) in the pharyngeal airway space (r = 0.807 and 0.854 respectively). The regression equations were Y = - 27.177+0.39X (Y = PAS-TP, X = OPT/NSL), and Y = -21.105+0.402X (Y = PAS-TP, X = C3-Me), respectively. From these equations we could conclude that an increase of 10 degrees in OPT/NSL or 10 mm in C3-Me increased the pharyngeal airway space (PAS-TP) by about 4 mm.

Purpose The aim of the present study was to evaluate the accuracy of a formula predicting the change of pharyngeal airway space (PAS) on the cephalogram after mandibular setback surgery. Patients and Methods Twenty-nine female adults with mandibular prognathism underwent surgery by bilateral sagittal split ramus osteotomy. The postoperative anteroposterior (A-P) PAS dimension was calculated from the change of C3-Me (distance between the anteroinferior point of the third cervical vertebra and menton) using 2 cephalograms taken before treatment and at 1 year after surgery. The regression equation used was y = −21.105 + 0.402x (y: PAS; x: C3-Me; r = 0.854). Results The predicted and measured values were nearly same on average, and the difference between both ranged within ±1.5 mm for each case individually. Conclusion This study suggested that the postoperative A-P PAS dimension can be predicted from the change in C3-Me, matching the amount of the mandibular setback.

To evaluate the effect of bilateral sagittal split ramus osteotomy setback on the morphology of the pharyngeal airway, especially the structures of the soft palate and pharyngeal airway space (PAS), lateral cephalograms obtained from 49 women before treatment and 1 year after surgery were traced and compared. All patients underwent this osteotomy to correct mandibular hyperplasia. The data were corrected with the use of regression equations for the PAS, taking into account head posture. On average, the SNB angle decreased by 3.9 degrees, resulting in an increase of 4.1 degrees in OPT/NSL (head posture, defined as the craniocervical angulation at the uppermost part of the cervical spine). The morphology of the PAS and soft palate changed significantly (p < 0.01). The mean reduction in the PAS was 2.6 mm retropalatinally and 4.0 mm retrolingually. On average, the soft-palate length increased by 3.2 mm and the soft-palate angle increased by 4 degrees. These results show that mandibular setback surgery markedly decreases the PAS and changes the morphology of the soft palate.

The antero-posterior diameter of the pharyngeal airway space (PAS) at the level of the soft palate and base of the tongue was assessed in age-matched females with a normal mandible (n=31), mandibular retrognathism (n=30) or mandibular prognathism (n=38). All subjects were examined by lateral cephalometry. Measured variables were corrected with the use of appropriate regression equations to eliminate the effects of head posture on the PAS. The corrected data showed more clear-cut differences in the PAS among the three groups than did the measured data. Pharyngeal airway diameter was largest in the group with mandibular prognathism, followed by the normal mandible and mandibular retrognathism groups. These results indicate that the antero-posterior dimension of the PAS is affected by different skeletal patterns of the mandible.

The aim of this study was to investigate the position and course of the mandibular canal through the mandibular ramus using computed tomographic (CT) imaging and to relate the findings to performing sagittal split ramus osteotomies. The mandibles of 35 patients with skeletal Class III prognathism with symmetry (12 males and 23 females) were observed on transaxial computed tomograms acquired with a slice thickness of 2 mm. The position and course of the mandibular canal from the mandibular foramen to the mandibular body at the level of the second molar were measured at four specific locations in the same plane. Among the 70 rami examined, lack of a bone marrow space on the buccal side, including a fusion type anatomy with no buccal side cortical bone of the mandibular canal, were observed at the CT location between the mandibular foramen and mandibular angle. Our results suggest that special care must be taken when sagittal splitting is performed, and the safest location for the buccal corticotomy is anterior to the mandibular angle.

This study assessed the relationship between craniofacial characteristics and the size of the pharyngeal airway space (PAS), taking into account head posture. Sixty dental students 25-30 years of age (30 men and 30 women) were examined by lateral cephalometry. The data were corrected with the use of appropriate regression equations for the PAS. The PAS significantly correlated with hyoid position, maxillary and mandibular size, maxillary and mandibular prognathism, and mandibular inclination. A large, anteriorly positioned mandible was associated with a large PAS-TP (the most proximal distance between the posterior pharyngeal wall and the tongue base). Uvula length and PNS-Ba (the distance between the most posterior point of the hard palate and the most inferior point of the anterior foramen magnum) correlated with PAS-UP (the most proximal distance between the posterior pharyngeal wall and uvula). Our results suggest that the anteroposterior dimension of the PAS is substantially affected by the size of the enclosure surrounding the PAS, including the maxilla, mandible and soft palate.

A 68-year-old woman received a formocresol pulpectomy of the right lower lateral incisor. The temporary restoration was lost within hours. The next day, the patient suffered continuous pain, the gingiva sloughed, and the alveolar bone was exposed. Four days after treatment, the patient complained of moderate pain. Six days after the pulpectomy, the tooth spontaneously exfoliated. At this time she was referred to our hospital. The clinical diagnosis was chronic alveolitis. Treatment consisted of irrigation of the area. Three weeks after the pulpectomy, the dull pain had subsided, but the alveolar bone of the area showed increased mobility. Five weeks after the pulpectomy, the mobility of the alveolar bone was more significant and a sequestrectomy was performed with the patient under local anesthesia. The sequestrum of necrotic bone was approximately 10 × 5 × 5 mm in size. The patient has been symptom-free for 2 years since the sequestrectomy. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;95:736-8)