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.

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.

Bacterial promotion of bisphosphonate-induced osteonecrosis in Wistar rats.

Clinically, bisphosphonate-related osteonecrosis (BRON) only occurs in the jaw (BRONJ). We aimed to determine differences between the jaw and other bones, as well as the relationship between periodontal pathogens and BRON. Twelve male Wistar rats were divided into two groups: group Z (n=6) were subcutaneously injected with zoledronic acid weekly for 4 weeks; group C (n=6) were injected with saline. One week after the final injection, rats in both groups were divided into three subgroups: Aa subgroup was injected with freeze-dried Aggregatibacter actinomycetemcomitans into bone marrow of the mandibles and femurs, while CFA and saline subgroups were injected with complete Freund's adjuvant (CFA) or saline using the same protocol. Four weeks after those injections, the rats were euthanized. Areas of osteonecrosis were measured histologically. Statistically, rats in group Z showed significantly wider osteonecrosis areas in both mandibles and femurs with each type of local injection than rats in group C. In group Z, mandibles and femurs stimulated with A. actinomycetemcomitans or CFA had significantly wider osteonecrosis areas than those stimulated with saline. We have developed a rat model with BRONJ-like lesions. Our results showed BRON to develop not only in the jaw but also in other types of bone following an inflammatory stimulus.

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.

Evaluation of interleukin 1 as a mucosal adjuvant in immunization with Streptococcus sobrinus cells by tonsillar application in rabbits.

To evaluate interleukin 1 (IL-1) as a mucosal adjuvant in the induction of salivary antibodies to Streptococcus sobrinus, S. sobrinus together with IL-1 was applied through the palatine tonsils of rabbits. IL-1 caused approximately 50 and 100% increases in the antibodies reacting against S. sobrinus fragments in the saliva and blood plasma, respectively, compared to the antibodies in those same fluids after tonsillar applications of S. sobrinus alone. In the case of the addition of IL-1, the antibodies reacting to the protein antigens of S. sobrinus increased in each fluid, without affecting the antibodies reacting to saccharide antigens. Delayed-type hypersensitivity to S. sobrinus, characterized by ear swelling and by an increase in IFN-gamma mRNA in RT-PCR analysis, was found to be induced only in rabbits immunized with IL-1. S. sobrinus protein antigens caused ear swelling as intense as that caused by S. sobrinus fragments. Thus, IL-1 induced an antibody response and cell-mediated immunity mainly reacting to protein antigens of S. sobrinus.