Evaluation of velopharyngeal function using high-speed cine-magnetic resonance imaging based on T2-weighted sequences: a preliminary study.

The objective was to introduce a new technique for visualizing the three-dimensional (3D) movements of velopharyngeal-related muscles using high-speed cine-magnetic resonance imaging (MRI) based on T2-weighted sequences. The evaluation of phonation- and water swallowing-related events was performed in 11 healthy subjects. Specifically, whether cine-MRI could precisely visualize normal velopharyngeal function during these two events was examined. The 3D movements of the soft palate, superior pharyngeal constrictor muscles, and levator veli palatini muscles were visualized in all 11 subjects. A noteworthy finding was that the magnetic resonance signals of the superior constrictor pharyngeal muscles and the levator veli palatini muscles were significantly higher during phonation and during water swallowing than at rest. This initial study suggests that the 3D movements of velopharyngeal-related muscles can be successfully and precisely visualized without side effects. The magnetic resonance signal changes seen in the superior pharyngeal constrictor and levator veli palatini muscles using the technique described here should be useful to develop better methods of evaluation of velopharyngeal function.

Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers.

BACKGROUND: 18F-fluoro-2-deoxy-D-glucose (18F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18F-FDG accumulation in neck-related muscles of patients after ND for oral cancer. MATERIAL AND METHODS: 18F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers. RESULTS: According to the extent of ND of cervical lymph nodes, the rate of patients with 18F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical sides. In addition, SUVmax of 18F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were increased according to the extent of the ND. CONCLUSIONS: In evaluating 18F-FDG accumulations after ND for oral cancers, we should pay attention to the 18F-FDG distributions in neck-related muscles including the non-surgical side as false-positive findings.

Maxillary single-jaw surgery combining Le Fort I and modified horseshoe osteotomies for the correction of maxillary excess.

A modified technique of horseshoe osteotomy combined with Le Fort I osteotomy for superior and posterior repositioning of the maxilla is presented. Eight patients with maxillary excess associated with retrogenia or microgenia were treated with this technique in combination with genioplasty. The maxillary segment was repositioned a maximum of 5.0mm posteriorly and 7.0mm superiorly at point A. The mandible autorotated anterosuperiorly to achieve sound occlusion. Point B moved 2.0-10.0mm anteriorly and 5.0-10.0mm superiorly. The pogonion moved 7.0-17.0mm anteriorly in combination with genioplasty. All patients obtained sound occlusion and a good profile after the operation. Almost no skeletal relapse was observed during 1 year of postoperative follow-up. Patients with long faces with maxillary excess and retrogenia often have small, unstable condyles. In these cases, because surgical intervention to the ramus can result in postoperative progressive condylar resorption, maxillary single-jaw surgery with a horseshoe osteotomy, thereby avoiding ramus intervention, is a less invasive option.

An osteonecrosis model induced by oral bisphosphonate in ovariectomised rats.

OBJECTIVE: To develop a model of osteonecrosis using oral bisphosphonate in ovariectomy-induced osteoporotic rats. MATERIALS AND METHODS: Thirty-six rats were subjected to ovariectomy or sham surgery. After 8 weeks, rats received oral alendronate (1.0 mg kg(-1) ) or saline once weekly for 4 weeks; then, serum C-telopeptide cross-linked collagen type I levels were measured to evaluate bone metabolism. Twelve rats from each group were injected with either lipopolysaccharide or saline into the bone marrow of the mandibles and femurs, and the areas of osteonecrosis were evaluated by histomorphometry. RESULTS: Serum C-telopeptide cross-linked collagen type I levels were significantly increased in the ovariectomy group (105.1 ± 2.1 ng ml(-1) ) compared with the sham group (78.9 ± 12.5 ng ml(-1) ); they were significantly reduced following oral alendronate administration in the ovariectomy group (91.0 ± 4.4 ng ml(-1) ). Following alendronate and lipopolysaccharide administration, extensive osteonecrosis was observed in the mandibles and femurs of ovariectomy (0.45 ± 0.08 mm(2) , 1.69 ± 0.72 mm(2) , respectively) and sham (1.12 ± 0.45 mm(2) , 1.84 ± 0.66 mm(2) , respectively) groups. Significantly wider osteonecrosis occurred in the mandibles of sham-operated rats than ovariectomy rats following alendronate or lipopolysaccharide treatment. CONCLUSIONS: We successfully developed a model of osteonecrosis in ovariectomised rats following oral bisphosphonate administration.

Intraoperative detection of viable bone with fluorescence imaging using Visually Enhanced Lesion Scope in patients with bisphosphonate-related osteonecrosis of the jaw: clinical and pathological evaluation.

UNLABELLED: There is no standard surgical protocol of bisphosphonate-related osteonecrosis of the jaws (BRONJ), because of the impossibility to visualize this feature intraoperatively. The aim of this study was to introduce how to provide preoperative labeling of the viable bone with minocycline bone fluorescence technique (MBFT) by using VELscope® and investigate histopathologically. INTRODUCTION: The American Association of Oral and Maxillofacial Surgeons (AAOMS) and the Japanese Society of Oral and Maxillofacial Surgeons (JSOMS) now recommend a more conservative treatment strategy. There is no standard surgical protocol of bisphosphonate-related osteonecrosis of the jaws (BRONJ) because of the impossibility to visualize this feature intraoperatively. The aim of this study was to introduce a mechanism providing preoperative labeling of a viable bone using minocycline bone fluorescence technique (MBFT) with VELscope® and to histopathologically investigate. METHODS: This report describes a surgical technique used in six patients with BRONJ who underwent jawbone resection under minocycline bone fluorescence imaging using VELscope®. Subsequently, we investigated and compared the clinical findings using VELscope® and histopathological findings. RESULTS: Histopathological examinations showed that the non-fluorescent moiety was consistent with the BRONJ lesions. CONCLUSIONS: The surgical treatments that were exactly performed using MBFT with VELscope® offered successful management of BRONJ. This bone fluorescence helped to define the margins of resection, thus improving surgical therapy for extended osteonecrosis.

Lipopolysaccharide aggravates bisphosphonate-induced osteonecrosis in rats.

The pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is highly controversial. We have previously reported the development of osteonecrosis by periodontal pathogenic stimulation in the jaw and femur of rats treated with bisphosphonate. Since the major toxicity factor of Gram-negative bacteria is lipopolysaccharide (LPS), the present study aimed to evaluate the relationship between osteonecrosis and LPS in a rat model of BRON-like lesions. Seventeen male rats were injected subcutaneously with zoledronic acid weekly for 4 weeks and divided into three groups: LPS (LPS administered into the bone marrow of the mandible and femur) and LPS plus polymyxin B (PMB) and saline groups (given neutralized LPS with PMB or saline, respectively, using the same protocol). At 4 weeks after the procedure, harvested specimens were analyzed using histomorphology (n=5 from each group) and histochemistry (n=1 each from LPS and LPS plus PMB groups). There was a significantly wider area of osteonecrosis in the LPS group as compared to the saline and LPS plus PMB groups in both the mandible (P=0.030 and P=0.009, respectively) and femur (P=0.002 and P=0.020, respectively). Our results indicate that LPS stimulation is deeply involved in the development and promotion of BRON.

Variety and complexity of fluorine-18-labelled fluoro-2-deoxy-D-glucose accumulations in the oral cavity of patients with oral cancers.

OBJECTIVES: To elucidate the points that require attention when interpreting fluorine-18-labelled fluoro-2-deoxy-d-glucose ((18)F-FDG)/positron emission tomography (PET) images by demonstration of (18)F-FDG accumulation in various areas of the oral cavity other than primary lesions in patients with oral cancers. METHODS: (18)F-FDG accumulations with a maximal standardized uptake value of over 2.5 in various areas of the oral cavity other than primary lesions were identified in 82 patients with oral cancers. RESULTS: (18)F-FDG/PET-positive areas, excluding primary tumours, included the front intrinsic muscles of the tongue (89.0%), upper and lower marginal parts of the orbicularis oris muscle (64.6%), sublingual glands, palatine tonsil, pharyngeal tonsil, and lingual tonsil. In addition, some areas in the jaws also showed accumulation. CONCLUSIONS: In patients with oral cancers, areas of (18)F-FDG accumulation in the oral cavity should be precisely identified and appropriately diagnosed, because accumulations can be seen in areas other than the primary tumour.

A novel modification of a bone repositioning device and a new technique for reestablishing facial contours after mandibular resection surgery.

A novel modification of a bone repositioning device previously published by the same authors is introduced. A flexible tube to define the intersegmental bony relationship is filled with light-cured resin. It solidifies following exposure to strong visible light for about 1 min. This technique can be used for bone positioning after mandibular resection surgery and during positioning of the proximal segment after sagittal split ramus osteotomy. The authors also propose a simple method for determining the contour of the reconstructed mandible to regain the original shape and form. The advantage of this technique is its simplicity and flexibility compared with other methods of bone positioning during mandibular segmental surgery.

The BMP signaling and its Smads in mandibular distraction osteogenesis.

AIM: The aim of the present study was to clarify the mechanism of signal transduction of bone morphogenetic proteins (BMPs) through their specific down signaling molecules Smads inducing bone formation in response to mechanical stimulus during distraction osteogenesis (DO) in the rat mandible. MATERIALS AND METHODS: Osteotomy of the left mandible was performed in 45 rats. Thirty rats underwent mandibular distraction (protocol; 5 days latency, 8 days distraction, and 2 weeks consolidation) while 15 rats served as non-distracted (fracture healing) group. The expression of BMPs-2,-4 and Smads 1, 5, and 8 were evaluated in the new regenerate area using immunohistochemistry. RESULTS: Expressions of BMPs-2,-4 and Smads 1, 5, and 8 were moderate during latency, significantly increased during distraction and decreased towards consolidation period. CONCLUSIONS: The enhanced expression of BMPs and its Smads during distraction compared to the non-distracted group suggests the possible role of BMP signaling pathway in translation of mechanical forces into biological results during DO.

Changes in temporomandibular disc position during growth in young Japanese.

PURPOSE: To detect the initial changes in temporomandibular disc position during growth with MRI examination in a prospective longitudinal study of a young Japanese population. METHODS: Forty-four temporomandibular joints in 22 healthy asymptomatic volunteers, mean age 11.8 years, age range 9-16 years, were examined by MRI. They were re-examined 2-3 years later. The mean age and age range at the second examination were 14.5 years and 12-19 years, respectively. The discs were assessed at three different locations by oblique sagittal planes at the lateral, central and medial parts, and the displacement was evaluated as a partial anterior or total anterior position. RESULTS: Six joints already had a partial anterior position of the disc at the initial examination and no developmental change in disc position was observed during the examination period. Nine joints developed partial disc displacement during the examination period. Every partial displacement was observed at the lateral part of the disc. One joint developed a total anterior position from the lateral to the medial images. CONCLUSIONS: Initial changes in the disc position are likely to start from the lateral part of the joint in the early teenage years and are often asymptomatic.

Functional evaluations of the parotid and submandibular glands using dynamic magnetic resonance sialography.

PURPOSE: To evaluate the functional differences between the parotid and submandibular glands using dynamic MR sialography. METHODS: In 30 volunteers, the time-dependent changes (dynamic changes) in the maximum area of the detectable parotid and submandibular gland ducts on dynamic MR sialographic images were analysed. RESULTS: Dynamic changes in the parotid gland ducts were detectable on MR sialographic images in all volunteers, but images of the submandibular gland ducts were detectable in only 23 volunteers. In addition, the dynamic changes in the submandibular gland ducts in these 23 subjects were less than those seen in the parotid gland ducts. A relationship was found between the changing ratio of parotid (Pearson r=0.448, P=0.013) or submandibular gland ducts (Pearson r=0.418, P=0.047) and the salivary flow rate during the stimulation period. CONCLUSIONS: Dynamic MR sialography allows evaluation of rest and stimulated functioning and morphological evaluation of the parotid and submandibular glands. This technique appears to have many possible applications in the dental, medical and biological fields.

Local delivery system of cytotoxic agents to tumors by focused sonoporation.

Recently, ultrasound-targeting microbubble destruction has been employed in molecular gene therapy, and a new potent nonviral gene transfer method known as 'sonoporation' has been developed. We investigated the efficiency of sonoporation toward growth inhibition of human gingival squamous carcinoma cell line, Ca9-22, in vitro and in vivo. The cytotoxicity of bleomycin (BLM) was investigated using flow-cytometric analysis and Hoechst's staining in vitro assay systems. We found that the delivery of BLM by sonoporation induced cytotoxic effect toward Ca9-22 cells in vitro. Our in vivo results showed that tumors nearly disappeared in Ca9-22 cell-implanted nude KSN/slc mice treated with a low dose of BLM followed by sonoporation during the 4-week experimental period. Histological analysis revealed that the cytotoxic effect was mainly apoptosis. We previously reported that the cytolethal distending toxin B (cdtB) from Actinobacillus actinomycetemcomitans, a periodontopathic bacterium, is responsible for cell cycle arrest and apoptosis in vitro. Thus, we used sonoporation to transfect a cdtB-expressing plasmid into Ca9-22 cells and examined cell viability in vitro and in vivo. We found that an administration of cdtB-expressing plasmid followed by sonoporation-induced marked growth inhibition of Ca9-22 cells and apoptotic cells were also observed in vitro and in vivo. These findings suggest that local administration of cytotoxic agents with sonoporation is a useful method for molecular cancer therapy.

Dynamic magnetic resonance sialography as a new diagnostic technique for patients with Sjögren's syndrome.

OBJECTIVE: To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome. METHODS: The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome. RESULTS: On the MR sialographs of all five patients with Sjögren's syndrome, the so-called 'apple-tree appearance' was seen. The difference in two functional parameters using the dynamic MR sialographic data was elucidated between the two groups. The maximum area of the detectable ducts in the group of patients was significantly smaller (P < 0.001) than that in the group of volunteers. The ratio of change in the detectable ducts in the group of patients was significantly lower (P = 0.011) than that in the group of volunteers. CONCLUSIONS: Our study suggests that dynamic MR sialographic data in addition to MR sialographic images might be useful for the diagnosis of Sjögren's syndrome.

A simple method for bone positioning of mandibular segments.

A simple bone-positioning technique is reported, using a combination of bone plates and a flexible tube filled with acrylic polymer. The flexible tube is solidified by injection of acrylic monomer. This technique is applicable for bone positioning after mandibular resection as well as positioning of the proximal segment after sagittal split ramus osteotomy. This technique has the advantages of greater simplicity and flexibility compared to previously reported methods of bone positioning.

Immunoadsorption plasmapheresis in acute ataxic neuropathy.

Acute ataxic neuropathy is characterized by sensory ataxia and areflexia. There is no established treatment. We tried immunoadsorption plasmapheresis 15 days after the onset for a 46-year-old woman suffering from this neuropathy. She could not walk even with assistance because of sensory ataxia. A sural nerve biopsy revealed active axonal degeneration and loss of myelinated fibers. We tried 5 sessions of plasmapheresis during 2 weeks. She could walk with assistance 12 days after the beginning of the plasmapheresis treatment. It took 3 months for her to be able to walk over 5 m without assistance, and she had severe sensory ataxia over a 17 month follow-up period. Immunoadsorption plasmapheresis started within 2 weeks after the onset of acute ataxic neuropathy may have beneficial effects if the axonal degeneration is mild. The plasmapheresis, however, should be continued for a longer period. A double blind study is necessary to clarify the effectiveness of this treatment on acute ataxic neuropathy.