Multiple Schwannomas Arising in the Midline Space Between the Bilateral Genioglossus Muscles and Left Submandibular Space.

Schwannomas mostly occur as solitary tumors, and multiple schwannomas are very rare. Schwannomas in the submandibular space are extremely rare. Furthermore, schwannomas in the midline space between the bilateral genioglossus muscles are even rarer. We report multiple schwannomas arising in the midline space between the bilateral genioglossus muscles and left submandibular space. Because the common differential diagnosis of the midline deep sublingual lesions does not include schwannoma for the rarity, surgeons should consider schwannoma in the differential diagnosis.

A Novel Orthognathic Surgery With a Half-Millimeter Accuracy for the Maxillary Positioning Using Prebent Plates and Computer-Aided Design and Manufacturing Osteotomy Guide.

This retrospective study aimed to assess the accuracy of prebent plates and computer-aided design and manufacturing osteotomy guide for orthognathic surgery. The prebent plates correspondent to the planning model were scanned with a 3-dimensional printed model for guide design and used for fixation. Forty-two patients who underwent bimaxillary orthognathic surgery using computer-aided design and manufacturing intermediate splint with the guide (guided group: 20 patients) or with conventional fixation under straight locking miniplates (SLMs) technique (SLM group: 20 patients) were analyzed. A deviation of the maxilla between the planned and postoperative positions was evaluated using computed tomography, which was taken 2 weeks before and 4 days after the surgery. The surgery time and the infraorbital nerve paranesthesia were also evaluated. The mean deviations in the mediolateral ( x ), anteroposterior ( y ), and vertical directions ( z ) were 0.25, 0.50, and 0.37 mm, respectively, in the guided group, while that in the SLM group were 0.57, 0.52, and 0.82 mm, respectively. There were significant differences in x and z coordinates ( P <0.001). No significant difference in the surgery duration and paranesthesia was seen, suggesting the present method offers a half-millimeter accuracy for the maxillary repositioning without increasing the risk of extending surgery duration and nerve complication.

Synergistic Enhancement of Protein Recruitment and Retention via Implant Surface Microtopography and Superhydrophilicity in a Computational Fluid Dynamics Model.

The exact mechanisms by which implant surface properties govern osseointegration are incompletely understood. To gain insights into this process, we examined alterations in protein and blood recruitment around screw implants with different surface topographies and wettability using a computational fluid dynamics (CFD) model. Compared with a smooth surface, a microrough implant surface reduced protein infiltration from the outer zone to the implant thread and interface zones by over two-fold. However, the microrough implant surface slowed blood flow in the interface zone by four-fold. As a result, compared with the smooth surface, the microrough surface doubled the protein recruitment/retention index, defined as the mass of proteins present in the area per unit time. Converting implant surfaces from hydrophobic to superhydrophilic increased the mass of protein infiltration 2-3 times and slowed down blood flow by up to two-fold in the implant vicinity for both smooth and microrough surfaces. The protein recruitment/retention index was highest at the implant interface when the implant surface was superhydrophilic and microrough. Thus, this study demonstrates distinct control of the mass and speed of protein and blood flow through implant surface topography, wettability, and their combination, significantly altering the efficiency of protein recruitment. Although microrough surfaces showed both positive and negative impacts on protein recruitment over smooth surfaces, superhydrophilicity was consistently positive regardless of surface topography.

Anatomical Relationship Between the Lingual Nerve and Submandibular Duct.

ABSTRACT: The purpose of this study was to investigate the anatomical relationship between the lingual nerve and submandibular duct. This study included 1403 patients with submandibular or sublingual gland diseases who underwent intraoral removal of submandibular gland sialoliths, submandibular glands, or sublingual glands. Of all patients, 33 patients underwent bilateral surgeries. All surgeries were performed a single surgeon, and the anatomical relationship between the lingual nerve and submandibular duct was always identified intraoperatively and recorded in the operation recorded. The anatomical relationship was investigated based on the intraoperative findings. The lingual nerve which crosses above the submandibular duct was detected in 8 of 1436 sides (0.6%). There were 4 in the right sides and 4 in the left sides. The lingual nerve below the submandibular gland was seen in 99.4%. Although the lingual nerve crosses above the submandibular duct with a rarer incidence, surgeons should beware of injuring the lingual nerve during intraoral salivary gland surgery.

Intraoral Styloidectomy Using an Endoscope With Tissue Retractor.

ABSTRACT: The extraoral approach with the risk of facial nerve injury and the visible scar is commonly performed for an elongated styloid process, because intraoral styloidectomy is challenging for the deep and limited surgical field. The authors report minimally invasive intraoral styloidectomy using an endoscope with tissue retractor. A 57-year-old female was referred to our department with a left pharyngeal foreign body sensation and pharyngeal pain after head turning and neck compression. Clinical and radiological diagnosis was an elongated styloid process (Eagle syndrome). Because the styloid process could be palpated intraorally, the patient underwent endoscopically-assisted intraoral styloidectomy without tonsillectomy under general anesthesia as minimally invasive surgery. The styloid process was resected safely with a piezoelectric surgical device under endoscopic guidance. The postoperative course was uneventful without complications.

Huge Submandibular Gland Mucocele With Diagnostic Difficulties.

ABSTRACT: Submandibular gland mucoceles, which are very rare cystic lesions, make differentiation from other cystic neck masses such as plunging ranula and cystic lymphatic malformation difficult. The authors report a rare huge submandibular gland mucocele with diagnostic difficulties. A 39-year-old woman with painless swelling in the left submandibular region underwent OK-432 injection therapy with a diagnosis of plunging ranula at another hospital. However, she was referred to our department for recurrent swelling. Computed tomography showed a well-circumscribed, multilocular, low-density lesion in the left submandibular region. Fine needle aspiration was performed, and the content of the cystic lesion was yellowish-brown serous fluid. After the fine needle aspiration, computed tomography was performed. The cystic lesion was radiologically diagnosed as submandibular gland mucocele. Therefore, the patient underwent endoscopically-assisted intraoral removal of the sublingual and submandibular glands under general anesthesia. The pathological diagnosis was submandibular gland mucocele.

Clinical Anatomy of Feeding Artery of the Submandibular Gland.

ABSTRACT: The purpose of this study was to investigate the clinical anatomy of the feeding artery of the submandibular gland (SMG). A total of 199 SMG removals were performed in extraoral or intraoral approach with/without endoscopic assistance by a single surgeon. The feeding artery of the SMG was always identified intraoperatively and recorded in the operation record. The clinical anatomy of the feeding artery of the SMG was investigated based on the intraoperative findings. The facial artery was ligated and transected for the involvement of tumor or severe inflammation in 16 (8.0%) procedures. The feeding artery was investigated in the remaining 183 procedures. The mean number of the glandular branch was 1.5. There were 1 branch in 98 procedures (53.6%), 2 branches in 80 procedures (43.7%), and 3 branches in 5 procedures (2.7%). Detailed anatomical knowledge of the feeding artery of the SMG is useful for proper dissection of the SMG and preservation of the facial artery.

A 3-Dimensional Finite Element Analysis of Resected Mandibular Bone to Determine the Most Stable Implant Positions for a Fixed Prosthesis.

This study was conducted to determine the most secure implant positioning on the marginally resected mandible to support a fixed complete denture through finite element analysis. Three or 4 implants were placed at near, middle, or far positions from the resected margin in a simulation model with a symmetrical marginal defect in the mandibular symphysis. The height of the residual bone was 5, 10, or 15 mm. The 4 possible implant patterns for 3 or 4 implants were defined as (1) asymmetrically isolated position 1 to position 2, (2) asymmetrically isolated position 1 to position 3, (3) asymmetrically isolated with greater-length position 1 to position 2, and (4) 2 implants symmetrically positioned on each side of the defect. The von Mises stress in the resected and peri-implant bone with respect to the occlusal force was calculated. Initially, because the peri-implant bone stress around the isolated implant at the near position was greater than at the middle and far positions regardless of the residual bone height, the near position was excluded. Second, the von Mises stress in the resected bone region was >10 MPa when the isolated implant was at the far position, and it increased inversely depending on the bone height. However, the stress was <10 MPa when the isolated implant was placed at the middle position regardless of the bone height, and it was significantly lower compared with the far position and equivalent to the symmetrically positioned implants. Furthermore, the use of a greater-length implant reduced peri-implant bone stress, which was even lower than that of the symmetrically positioned implants. These results suggest that the asymmetrically positioned 3-implant-supported fixed denture, using a greater-length isolated implant, placed neither too close to nor too far from the resected margin, can be an effective alternative to the symmetrically positioned 4-implant-supported fixed denture.

Straight Locking Miniplate Technique Achieves Submillimeter Accuracy of Condylar Positional Change During Bimaxillary Orthognathic Surgery for Patients With Skeletal Class III Malocclusion.

PURPOSE: The straight locking miniplate (SLM) technique is a straightforward method to accurately reposition the maxilla during bimaxillary orthognathic surgery. The present study evaluated the accuracy of the SLM technique in maintaining the condylar position during surgery without the use of a cutting guide. PATIENTS AND METHODS: The present prospective, single-center study was conducted at Yokohama City University between 2016 and 2017 and included patients with skeletal Class III malocclusion. The patients were divided into 2 groups according to the fixation method used for the mandibular segments. The mandibular segments were fixed with miniplates either manually (manual group) or using the SLM technique (SLM group). Computed tomography was performed before and 3 days after surgery to compare the condylar position. The bodily and rotational movements of the condyle were analyzed. RESULTS: The subjects were 18 Japanese patients (36 condyles) who had undergone bilateral set back surgery with Le Fort I osteotomy. The amount of bodily movements in the manual and SLM groups were 1.44 and 0.62 mm, respectively. The degree of rotational movement in the sagittal plane in the manual and SLM groups was 3.33° and 0.23°, respectively. The bodily and rotational movements in the SLM group were significantly smaller than those in the manual group (P < .05 and P < .01, respectively). CONCLUSIONS: These results suggest that use of the SLM technique reduces the risk of condylar positional changes to less than 1 mm during orthognathic surgery without the use of any complex devices or a cutting guide.

Computational Fluid Simulation of Fibrinogen around Dental Implant Surfaces.

Ultraviolet treatment of titanium implants makes their surfaces hydrophilic and enhances osseointegration. However, the mechanism is not fully understood. This study hypothesizes that the recruitment of fibrinogen, a critical molecule for blood clot formation and wound healing, is influenced by the degrees of hydrophilicity/hydrophobicity of the implant surfaces. Computational fluid dynamics (CFD) implant models were created for fluid flow simulation. The hydrophilicity level was expressed by the contact angle between the implant surface and blood plasma, ranging from 5° (superhydrophilic), 30° (hydrophilic) to 50° and 70° (hydrophobic), and 100° (hydrorepellent). The mass of fibrinogen flowing into the implant interfacial zone (fibrinogen infiltration) increased in a time dependent manner, with a steeper slope for surfaces with greater hydrophilicity. The mass of blood plasma absorbed into the interfacial zone (blood plasma infiltration) was also promoted by the hydrophilic surfaces but it was rapid and non-time-dependent. There was no linear correlation between the fibrinogen infiltration rate and the blood plasma infiltration rate. These results suggest that hydrophilic implant surfaces promote both fibrinogen and blood plasma infiltration to their interface. However, the infiltration of the two components were not proportional, implying a selectively enhanced recruitment of fibrinogen by hydrophilic implant surfaces.

Orthognathic Surgery and Implant-Supported Bridge in a Class III Patient Injured in a Motor Vehicle Accident.

Occlusal and esthetic rehabilitation of jaw deformities in patients with partially edentulous maxilla are challenging procedures. This article describes a patient involving a skeletal Class III, 36-year-old male patient with a single bilateral anterior partially edentulous maxilla resulting from injuries sustained in a motor vehicle accident; his anterior teeth had been lost for more than 10 years. His lip protruded from the lateral view due to the proclined upper incisors and mandibular protrusion.Because of the facial deformity and inadequate prosthesis of the maxilla, the prosthesis had dropped out repeatedly. Bone deficiency was prominent in the area of the anterior maxillary region and required augmentation for implant restoration.Consultation among the prosthodontist, orthodontist, and patient led to a decision to perform an orthognathic surgery and bone graft before implant treatment. After orthodontic treatment combined with orthognathic surgery, 3 dental implants were placed with simultaneous iliac bone graft for prosthetic rehabilitation. The treatment restored the maxillary dental arch, which supported the upper lip with appropriate occlusion, both esthetically and functionally. After a 2-year clinical follow-up, the orthoprosthesis of the maxilla remained stable, and the patient was satisfied with the outcome of treatment. The combination of orthodontic, surgical, and dental implant treatment could be an option for skeletal Class III patients with bone-deficient, edentulous jaws.

Daily Cisplatin and Weekly Docetaxel versus Weekly Cisplatin Intra-Arterial Chemoradiotherapy for Late T2-3 Tongue Cancer: A Pilot and Feasibility Trial.

Background and objectives: The aim of present study was to compare the treatment results of daily cisplatin (CDDP), weekly docetaxel (DOC) intra-arterial infusion chemotherapy combined with radiotherapy (DIACRT) regimen and weekly CDDP intra-arterial infusion chemotherapy combined with radiotherapy (WIACRT) for patients with tongue cancer. Materials and Methods: Between January 2007 and December 2016, a total of 11 patients treated with WIACRT and 45 patients treated with DIACRT were enrolled in the present study. In the DIACRT group, 25 patients had late T2, and 20 patients had T3. A total of nine patients had late T2 and two had T3 in WIACRT (p = NS). In DIACRT, the treatment schedule consisted of intra-arterial chemotherapy (DOC, total 60 mg/m²; CDDP, total 150 mg/m²) and daily concurrent radiotherapy (RT) (total, 60 Gy). In WIACRT, the treatment schedule consisted of intra-arterial chemotherapy (CDDP, total 360 mg/m²) and daily concurrent RT (total, 60 Gy). Results: The median follow-up periods for DIACRT and WIACRT were 61 and 66 months, respectively. The five-year local control (LC) and overall survival (OS) rate were 94.5% and 89.6% for the DIACRT group, and 60.6% and 63.6% for the WIACRT group, respectively. The LC rate and OS of the DIACRT group were significantly higher than those of the WIACRT group. As regards toxicities, no treatment-related deaths were observed during the follow-up periods in both groups. Conclusions: DIACRT was found to be feasible and effective for patients with tongue cancer and could become a new treatment modality.

Computational fluid dynamics study of intra-arterial chemotherapy for oral cancer.

BACKGROUND: Intra-arterial chemotherapy (IAC) for oral cancer can deliver a higher concentration of anticancer agent into a tumor-feeding artery than intravenous systemic chemotherapy. However, distribution of anticancer agent into several branches of the external carotid artery (ECA) in IAC has not demonstrated sufficient treatment efficacy. To improve the effectiveness of IAC, the flow distribution of anticancer agent into the branches of the ECA in several IAC methods was investigated using computational fluid dynamics (CFD). METHODS: Patient-specific three-dimensional vessel models were created from CT images of 2 patients with tongue cancer. Catheter models were combined with the vessel models. Thirty-two models were generated with varying vertical and horizontal positions of the catheter tip. With the use of a zero-dimensional resistance model of the peripheral vessel network, conventional IAC and superselective IAC were simulated in 30 and 2 models, respectively. The flow distribution of anticancer agent into the branches of the ECA was investigated in 32 models. Additionally, the blood streamline was traced from the inlet of the common carotid artery toward each outlet to examine the flow of anticancer agent in all models, and the wall shear stress of the vessel was calculated for some models. RESULTS: The CFD simulations could be conducted within a reasonable computational time. In several models, the anticancer agent flowed into the target artery only when the catheter tip was located below the bifurcation of the ECA and each target artery. Furthermore, the anticancer agent tended to flow into the target artery when the catheter tip was shifted toward the target artery. In all ECA branches that had flow of anticancer agent, the blood streamlines to the target arteries contacted the catheter tip. Anticancer agent flowed into only the target artery in patients' models for superselective IAC. However, high wall shear stress was observed at the target artery in one patient's model. CONCLUSIONS: This CFD study showed that location of the catheter tip was important in controlling the anticancer agent in conventional IAC. The distribution rate of anticancer agent into the tumor-feeding artery tended to increase when the catheter tip was placed below and toward the target artery. Although superselective IAC can reliably supply anticancer agent to the target artery, high wall shear stress at the target artery can occur, depending on vessel geometry of the patient, which may cause serious complications during the treatment.

Significance of the Lateral Thoracic Artery in Pectoralis Major Musculocutaneous Flap Reconstruction: Quantitative Assessment of Blood Circulation Using Indocyanine Green Angiography.

Free tissue transfer is the preferred reconstruction option in most major head and neck reconstructions. The pectoralis major muscle musculocutaneous (PMMC) flap is commonly used in salvage of necrotic free flaps and is the first choice for patients who are not candidates for free flaps. The lateral thoracic artery (LTA), which is thought to contribute to blood perfusion of the inferior and lateral mammary area, is not preserved in a conventionally harvested PMMC flap. With regard to blood supply, it has been suggested that the LTA should be preserved, in addition to the pectoral branch of the thoracoacromial artery, when a skin island is designed in the lower chest to attain a pedicle length sufficient for head and neck reconstruction. However, an effect on hemodynamic improvement using the LTA has not been shown quantitatively. In this study, we examined 8 patients with oral cancer who underwent reconstruction procedures with a bipedicle PMMC flap that included the LTA, in addition to the thoracoacromial artery. Intraoperative indocyanine green angiography was performed to examine circulation to the PMMC flap with or without LTA clamping after harvesting. After image processing, data were analyzed using a new quantitative perfusion assessment system with parameters that we recently established for assessment of peripheral arterial disease of the lower limbs. All patients had good clinical courses with whole-flap survival, no vascular insufficiency of the skin island, and no fistula formation. Intraoperative indocyanine green angiography showed an increased inflow rate into the skin island in an LTA-declamped condition in all cases, implying that the preserved LTA increased the blood supply to skin islands in the pectoralis major muscle. We conclude that preserving the LTA in a PMMC flap can increase blood perfusion and stabilize the vascularity of the flap, making the reconstruction more effective and reliable than with use of a conventionally harvested flap. Therefore, it is worthwhile to preserve the LTA as a major contributor to a lateral and distal PMMC flap.

Deltopectoral flap revisited for reconstruction surgery in patients with advanced thyroid cancer: a case report.

BACKGROUND: We present the cases of 2 patients with invasive thyroid cancer, who underwent reconstructive surgery using a deltopectoral flap. Although the overall rate of extrathyroidal extension in patients with thyroid cancer is quite low, skin invasion is the most common pattern observed. Reconstructive surgery, involving local skin flaps, is required in these patients. The deltopectoral flap relies on the blood supply from intercostal perforators of the internal thoracic artery and usually requires skin grafting to the donor site. The internal thoracic artery is rarely sacrificed in these cases, even in an advanced surgery such as in patients with invasive thyroid cancer. CASE PRESENTATION: A 55-year-old man with a distended thyroid gland presented to our hospital. He underwent advanced surgery, including skin excision, because we suspected that his tumor was thyroid cancer. The defect was covered with an ipsilateral deltopectoral flap via transposition of the flap, without skin grafting. In the second case, a 67-year-old woman with thyroid cancer that metastasized to her neck lymph nodes presented to our institution. Although the ipsilateral internal thoracic artery was sacrificed near its origin during tumor resection, the deltopectoral flap was raised in the usual manner without any complications. The skin defect caused by the tumor resection was covered with the flap. The patient had an uneventful clinical course for more than 2 years of follow-up. These 2 cases show the effectiveness of using the deltopectoral flap as a reconstructive option for patients with thyroid cancer who underwent radical surgery, resulting in a skin defect. The first case shows that this flap does not always require skin grafting to the donor site. To our knowledge, the second case may be the first report of a deltopectoral flap that was safely raised and applied with resection of the bifurcation of the ipsilateral internal thoracic artery. CONCLUSIONS: Although thyroid cancer surgery with surrounding skin excision is a rare procedure, we found that the deltopectoral flap was useful and should be the first choice for patients undergoing reconstructive surgery, whether the bifurcation of the ipsilateral internal thoracic artery is sacrificed.

An accurate bimaxillary repositioning technique using straight locking miniplates for the mandible-first approach in bimaxillary orthognathic surgery.

Bimaxillary orthognathic surgery has been widely performed to achieve optimal functional and esthetic outcomes in patients with dentofacial deformity. Although Le Fort I osteotomy is generally performed before bilateral sagittal split osteotomy (BSSO) in the surgery, in several situations BSSO should be performed first. However, it is very difficult during bimaxillary orthognathic surgery to maintain an accurate centric relation of the condyle and decide the ideal vertical dimension from the skull base to the mandible. We have previously applied a straight locking miniplate (SLM) technique that permits accurate superior maxillary repositioning without the need for intraoperative measurements in bimaxillary orthognathic surgery. Here we describe the application of this technique for accurate bimaxillary repositioning in a mandible-first approach where the SLMs also serve as a condylar positioning device in bimaxillary orthognathic surgery.

Investigation of blood flow in the external carotid artery and its branches with a new 0D peripheral model.

BACKGROUND: Patient-specific modelling in clinical studies requires a realistic simulation to be performed within a reasonable computational time. The aim of this study was to develop simple but realistic outflow boundary conditions for patient-specific blood flow simulation which can be used to clarify the distribution of the anticancer agent in intra-arterial chemotherapy for oral cancer. METHODS: In this study, the boundary conditions are expressed as a zero dimension (0D) resistance model of the peripheral vessel network based on the fractal characteristics of branching arteries combined with knowledge of the circulatory system and the energy minimization principle. This resistance model was applied to four patient-specific blood flow simulations at the region where the common carotid artery bifurcates into the internal and external carotid arteries. RESULTS: Results of these simulations with the proposed boundary conditions were compared with the results of ultrasound measurements for the same patients. The pressure was found to be within the physiological range. The difference in velocity in the superficial temporal artery results in an error of 5.21 ± 0.78 % between the numerical results and the measurement data. CONCLUSIONS: The proposed outflow boundary conditions, therefore, constitute a simple resistance-based model and can be used for performing accurate simulations with commercial fluid dynamics software.

Computational Fluid Dynamic Study of Nasal Respiratory Function Before and After Bimaxillary Orthognathic Surgery With Bone Trimming at the Inferior Edge of the Pyriform Aperture.

PURPOSE: This study aimed to evaluate the influence of maxillary impaction orthognathic surgery on nasal respiratory function and the efficacy of bone trimming at the inferior edge of the pyriform aperture. MATERIALS AND METHODS: The participants were 10 patients (3 male and 7 female patients) with mandibular prognathism who underwent bimaxillary orthognathic surgery with maxillary impaction. The surgical procedures performed were Le Fort I osteotomy with bone trimming at the inferior edge of the pyriform aperture and bilateral sagittal split osteotomy. Three-dimensional models of the nasal cavity were reconstructed from preoperative and postoperative computed tomography images. Furthermore, we remodeled the nasal valve region based on the postoperative models by adding a 1-mm and 2-mm stenosis to investigate the effects of bone trimming at the inferior edge of the pyriform aperture on the pressure effort. The 3-dimensional models were simulated with computational fluid dynamics, and the results of the pressure effort and the cross-sectional area (CSA) were compared for the anterior, middle, and posterior parts of the nasal cavity. The Wilcoxon signed rank test and Spearman rank correlation coefficients were used for statistical comparisons (P < .05). RESULTS: In the preoperative and postoperative models, there were considerable correlations between the CSA and the pressure effort in each part of the nasal cavity. The postoperative pressure effort showed a tendency to decrease and the CSA showed a tendency to increase in each part of the nasal cavity. In four 2-mm stenosis models, the pressure effort in the anterior nasal cavity was larger than the preoperative pressure effort and the CSA of the anterior nasal cavity was smaller than the preoperative CSA. CONCLUSIONS: Bone trimming at the inferior edge of the pyriform aperture appears to be useful for avoiding nasal respiratory complications with maxillary impaction.

Use of self-tapping metal screws for temporary fixation of a resorbable plate system in maxillofacial surgery.

Resorbable plate systems have been used in maxillofacial surgery to obviate the need for plate removal. However, resorbable plates and screws are very costly, and refixation with additional screws may be necessary when reduction or repositioning of the bone segment is inaccurate. Here we report the use of self-tapping metal screws for temporary fixation of a resorbable plating system in maxillofacial surgery to avoid the use of additional screws following inaccurate fixation or the reuse of resorbable screws, which may result in loosening.

U-shaped Osteotomy Around the Descending Palatine Artery to Prevent Posterior Osseous Interference for Superior/Posterior Repositioning of the Maxilla in Le Fort I Osteotomy.

In maxillary orthognathic surgery, superior repositioning of the maxilla is sometimes difficult, and removal of bony interference, especially around the descending palatine artery (DPA), is very time-consuming in cases of severe maxillary impaction. Posterior repositioning of the maxilla for removal of bony interference between the posterior maxilla and the pterygoid process is also technically difficult. Because the most common site of hemorrhage in Le Fort I osteotomy is the posterior maxilla, this bone removal is a source of frustration for surgeons in DPA injury. When the DPA is injured during bone removal and ligation is performed, aseptic necrosis of the maxilla may occur. Therefore, a simple and safe method for maxillary superior/posterior repositioning is required to remove osseous interference around the DPA. The authors describe here U-shaped osteotomy around the DPA to prevent posterior osseous interference for superior/posterior repositioning of the maxilla in Le Fort I osteotomy.