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.

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.

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.

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.

Features in subjects with the frontal occlusal plane inclined toward the contralateral side of the mandibular deviation.

INTRODUCTION: The frontal occlusal plane of the maxilla generally inclines toward the ipsilateral side of the mandibular deviation in subjects with facial asymmetry; however, a few patients with facial asymmetry have their frontal occlusal planes inclined toward the contralateral side. We aimed to investigate the morphologic and functional features of such patients. METHODS: The subjects were 40 patients with facial asymmetry divided into 2 groups based on the inclination of the frontal occlusal plane toward the ipsilateral or the contralateral side. We analyzed lateral and posteroanterior cephalometric radiographs and occlusal variables and evaluated temporomandibular joint symptoms. Statistical comparisons were performed between the 2 groups (P <0.05). RESULTS: The posteroanterior cephalometry significantly differed between the ipsilateral and contralateral groups. Occlusal force and occlusal contact area were significantly larger, and temporomandibular joint symptoms were more frequently found on the side of the upward-inclined frontal occlusal plane than on the opposite side in both groups. CONCLUSIONS: The features in the contralateral group in terms of occlusal force and temporomandibular disorders were clinically significant. Clinicians should note that the conditions associated with the contralateral group require less presurgical decompensation.

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.

Vital staining of palatal soft tissue in horseshoe Le Fort I osteotomy for superior repositioning of the maxilla.

In maxillary orthognathic surgery, superior repositioning of the maxilla is sometimes difficult, and removal of the bony interference, especially around the descending palatine artery, is very time-consuming in cases of severe maxillary impaction. A useful method introduced for superior repositioning of the maxilla is horseshoe-shaped osteotomy combined with Le Fort I osteotomy (horseshoe Le Fort I osteotomy). However, injury to the palatal soft tissue during horseshoe-shaped osteotomy may cause aseptic complications of the maxilla. Therefore, a safe method is required to prevent such injury to reduce the risk for aseptic necrosis. We describe here vital staining of palatal soft tissue in horseshoe Le Fort I osteotomy for safer superior repositioning of the maxilla.

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.

Endoscopic hemostasis with an ultrasonically activated device for hemorrhage from a branch of the maxillary artery during endoscopically assisted reduction of condylar neck fracture.

We describe here a case in which sudden hemorrhage from a branch of the maxillary artery during endoscopically assisted transoral reduction of condylar neck fracture was successfully controlled by endoscopic hemostasis with an ultrasonically activated device.

Use of a simple handmade retractor to protect the descending palatine artery during removal of posterior osseous interferences for maxillary impaction in Le Fort I osteotomy.

For accurate superior or posterior repositioning of the maxilla in Le Fort I osteotomy, bone removal around the descending palatine artery (DPA) and maxillary tuberosity is required. Because the most common site of hemorrhage in the Le Fort I osteotomy is the posterior maxilla, this bone removal provides surgeons to surgical frustration of DPA injury. When the DPA is injured during the bone removal and the ligation is performed, aseptic necrosis of the maxilla may occur. Therefore, we report the use of a simple handmade retractor to protect the DPA in Le Fort I osteotomy.

Le Fort I osteotomy under navigational guidance for posterior repositioning of the maxilla.

Because navigational guidance can localize the operative site 3-dimensionally during maxillofacial surgery and provide precision, reliability, and safety for surgeons, we report Le Fort I osteotomy under navigational guidance for posterior repositioning of the maxilla.

18F-fluorodeoxyglucose-positive Warthin tumor in a contralateral cervical lymph node mimicking metastasis in tongue cancer staging with PET/CT.

We report 18F-fluorodeoxyglucose-positive Warthin tumor in a contralateral cervical lymph node mimicking metastasis in tongue cancer staging with positron emission tomography/computed tomography.

Maxillary movement in distraction osteogenesis using internal devices in cleft palate patients.

OBJECTIVE: The purpose of this cephalometric study was to compare the actual movement with the planned movement of the maxilla by using internal maxillary distraction in cleft lip and palate patients. PATIENTS: Twelve patients, including eight with unilateral and four with bilateral cleft lip and palate, underwent maxillary advancement with internal maxillary distractors. MAIN OUTCOME MEASURES: Lateral cephalometric radiographs obtained preoperatively, predistraction, and postdistraction were used for analysis. The movement of the maxilla, angular change of the internal devices and rotation of the mandible were measured at each stage, and the planned vector of advancement predicted from the placement vector of the distractors was compared with the actual vector. RESULTS: Internal maxillary distractors were rotated in a clockwise direction during the distraction period. The angular change of the distractors was 7.7°. The amount of actual advancement at anterior nasal spine with distraction was 6.3 mm, which represented about 70% of the distance of activation of distraction. The actual advanced vector at anterior nasal spine was 9.7° smaller than the planned vector. The mandible underwent a clockwise rotation of 3.5°. CONCLUSION: In the internal distraction technique, the maxilla was advanced inferiorly to the planned vector and with a slight clockwise rotation. These results are useful for surgical planning when using internal distractors.

Effectiveness of subspinal Le Fort I osteotomy in preventing postoperative nasal deformation.

PURPOSE: This study sought to determine the effectiveness of subspinal Le Fort I osteotomy (SLFIO) in preventing nasal deformation, by analyzing changes in the nasal profile on three-dimensional computed tomography (3D-CT) images. PATIENTS AND METHODS: The participants were 39 Japanese patients with mandibular prognathism (6 men and 33 women) who underwent bilateral sagittal split ramus osteotomy and Le Fort I osteotomy with maxillary advancement: SLFIO was performed in 20 patients and conventional Le Fort I osteotomy (CLFIO) in 19 patients. All patients underwent modified alar base cinch suture, V-Y closure, and reduction of the piriform aperture. CT data acquired before and 1 year after the surgery were evaluated three-dimensionally with software to determine changes in the nasal profile. RESULTS: Changes in alar width, alar base width, nasal length, and nasofrontal angle were significantly smaller following SLFIO than following CLFIO, although there were no significant differences in nasal projection, nasal tip angle, or nasolabial angle between two procedures. CONCLUSION: SLFIO for anterior repositioning of the maxilla can prevent undesirable transverse soft tissue changes of the nose.

Human salivary gland stem/progenitor cells remain dormant even after irradiation.

Progressive loss of salivary gland function occurs in most patients undergoing head and neck radiotherapy. It is unclear whether adult salivary gland tissue contains stem/progenitor cells. In this study, we used a colony assay to clarify the presence of stem/progenitor cells in adult submandibular glands after irradiation. We developed a novel culture system that promotes single-cell colony formation with low density culture of irradiated and non-irradiated adult human submandibular gland cells using serum-free medium following serum-supplemented medium. The cells from all samples, except those obtained from the oldest patient who received the highest radiation dose, expressed acinar, ductal, and myoepithelial cell-lineage markers with reverse transcription-polymerase chain reaction (RT-PCR) and immunostaining. A sub-culture of these colonies with serum-free medium showed high multipotency. These results are the first description of presence of salivary gland stem/progenitor cells with self-renewal, high proliferation and multipotent differentiation activity in salivary glands, even after irradiation. The survival of the cells depends on radiation dose and cell aging.

Long-term stability after multidisciplinary treatment involving maxillary distraction osteogenesis, and sagittal split ramus osteotomy for unilateral cleft lip and palate with severe occlusal collapse and gingival recession: A case report.

In this report, we describe a case involving a 34-year-old woman who showed good treatment outcomes with long-term stability after multidisciplinary treatment for unilateral cleft lip and palate (CLP), maxillary hypoplasia, severe maxillary arch constriction, severe occlusal collapse, and gingival recession. A comprehensive treatment approach was developed with maximum consideration of strong scar constriction and gingival recession; it included minimum maxillary arch expansion, maxillary advancement by distraction osteogenesis using an internal distraction device, and mandibular setback using sagittal split ramus osteotomy. Her post-treatment records demonstrated a balanced facial profile and occlusion with improved facial symmetry. The patient's profile was dramatically improved, with reduced upper lip retrusion and lower lip protrusion as a result of the maxillary advancement and mandibular setback, respectively. Although gingival recession showed a slight increase, tooth mobility was within the normal physiological range. No tooth hyperesthesia was observed after treatment. There was negligible osseous relapse, and the occlusion remained stable after 5 years of post-treatment retention. Our findings suggest that such multidisciplinary approaches for the treatment of CLP with gingival recession and occlusal collapse help in improving occlusion and facial esthetics without the need for prostheses such as dental implants or bridges; in addition, the results show long-term post-treatment stability.

Removal of migrated dental implants from maxillary sinus 4 years 10 months after implant placement.

INTRODUCTION: Dental implant treatment has been applied widely in recent years. However, several complications sometimes have been reported. Although displacement of dental implants into the maxillary sinus commonly occurs during surgery, the migration of dental implants after a period of function, especially several years after dental implant placement, is very rare. CASE REPORT: We report here removal of migrated dental implants from the maxillary sinus 4 years and 10 months after dental implant placement.

Severe unilateral scissor bite and bimaxillary protrusion treated by horseshoe Le Fort I osteotomy combined with mid-alveolar osteotomy.

This report describes an orthognathic surgical case employing horseshoe Le Fort I osteotomy (HLFO) combined with mid-alveolar osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) for a patient with severe unilateral scissor bite and bimaxillary protrusion. A female patient (aged 26 years, 2 months) presented with a chief complaint of dysmasesis caused by scissor bite on the right side. The clinical examination revealed difficulty in lip closure and a convex profile. Overerupted right maxillary premolars and molars and lingual tipping of the right mandibular premolars and molars were indicated before treatment. After 3 months of presurgical orthodontic treatment, two-jaw surgery involving a combination of HLFO with mid-alveolar osteotomy and BSSRO was performed. A good interdigitation in the right side was established by superior-posterior-medial movement of the dento-alveolar segment of the maxilla. Next, both the maxilla and mandible were moved superiorly and posteriorly to correct the improper lip protrusion, thereby improving the patient's profile. Our results suggest that this new orthognathic surgery technique-achieved by combining HLFO with mid-alveolar osteotomy and BSSRO-is effective for adult patients exhibiting severe unilateral scissor bite and bimaxillary protrusion.