Use of sonographic elastography of the masseter muscles for optimizing massage pressure: a preliminary study.

To examine the stiffness of the masseter muscle using sonographic elastography and to investigate its relationship with the most comfortable massage pressure in the healthy volunteers. In 16 healthy volunteers (10 men and 6 women), the Masseter Stiffness Index (MSI) was measured using EUB-7000 real-time tissue elastography. They underwent massages at three kinds of pressures using the Oral Rehabilitation Robot (WAO-1). A subjective evaluation regarding the comfort of each massage was recorded on the visual analogue scale. Elastography was also performed in two patients with temporomandibular joint dysfunction with the myofascial pain. The mean MSI of the right and left muscles in the healthy volunteers were 0.85 +/- 0.44 and 0.74 +/- 0.35 respectively. There was no significant difference between the right and left MSI in the healthy volunteers. The MSI was related to massage pressure at which the healthy men felt most comfortable. The two temporomandibular disorder patients had a large laterality in the MSI. The MSI was related to the most comfortable massage pressure in the healthy men. The MSI can be one index for determining the massage pressure.

Effects of a single arthrocentesis and a COX-2 inhibitor on disorders of temporomandibular joints. A preliminary clinical study.

Our aim was to examine the short-term effect of combined treatment with single arthrocentesis and a COX-2 inhibitor on 26 patients with severe symptoms of temporomandibular joint (TMJ) disorders. The severity of the disorders was graded according to the degree of restriction of mouth opening and pain score on a visual analogue scale. Synovial fluid was collected from the superior joint space of the affected TMJ, and arthrocentesis was done with isotonic saline, 200ml. Subsequently, etodolac, 400mg/day, was given for 2 weeks. At 14 days, patients were re-examined and further specimens of synovial fluid were collected. Patients generally lost their symptoms and the severity of the disorders improved significantly (P<0.01). The concentrations of total protein and albumin in synovial fluid decreased with no statistical significance. However, the concentration of matrix metalloproteinase-3 and its ratios to total protein and albumin did decrease significantly (P<0.05). Our results suggest that a larger controlled study is necessary to clarify the contributory effect of arthrocentesis and etodolac for patients with severe symptoms of TMJ disorders.

Ankylosis of the temporomandibular joint developing shortly after multiple facial fractures.

A 41-year-old male patient was referred for treatment of extensive facial fractures and lateral condylar dislocations. The patient underwent open reduction and fixation under general anaesthesia. Intermaxillary fixation was released in 2 weeks and mouth opening was 21 mm. Despite postoperative physical exercises, the range of motion decreased to 10 mm at 5 weeks after the surgery. MR arthrography revealed a fibrous ankylosis in the bilateral TMJs. Coronal CT scans depicted a bony outgrowth of the left TMJ tuber. The patient underwent surgery for the ankylosis including discectomy and coronoidectomy, and removal of the bony outgrowth. An interincisal distance of 30 mm on maximal mouth opening has been maintained for 14 postoperative months. The importance of imaging assessment was emphasized for diagnosing the precise pathologic state of the ankylosis and selecting an appropriate surgical treatment of choice.

Chronic dental infections mimicking temporomandibular disorders.

BACKGROUND: Trismus and jaw pain are not only caused by temporomandibular disorders (TMD), but also by various pathologies, namely infection, trauma, or neoplasms. TMD-like symptoms, as a result of the pathologies, may be confusing to a clinician. This paper reports two cases of chronic dental infection mimicking TMD. METHODS: Two patients were initially diagnosed with, and treated for, TMD. However the patients did not respond to the treatment. Limited range of motion and jaw pain were then clinically evaluated for differential diagnoses. Laboratory examinations and computerized tomography (CT) scans were carried out to disclose any underlying lesion. RESULTS: Laboratory examination, such as, C-reactive protein helped to detect latent infection. CT scans revealed insidious chronic dental infection imitating TMD. Surgical drainage and chemotherapy resolved the symptoms. CONCLUSION: The importance of a rational diagnostic process, including clinical and laboratory examinations and radiologic imaging, cannot be over-emphasized in elucidating true cause of the symptoms.

The effect of gap arthroplasty on temporomandibular joint ankylosis: an experimental study.

The aim of this study was to demonstrate the functional and anatomical changes after gap arthroplasty release of unilateral temporomandibular joint (TMJ) ankylosis. Five adult sheep weighing an average of 57 kg were used. All right joints were operated. Ankylosis was induced in the right TMJ by articular damage, disk removal and placement of a bone graft plus immobilization wire. At 3 months the gap arthroplasty were performed. All TMJs were examined functionally, radiologically, macroscopically and histologically. Functionally, the range of jaw movements decreased following induction of ankylosis (P<0.0001), increased immediately on release but was reduced again at 3 months after release (the vertical movement, no statistically significant difference; the right movement, P<0.001; the left movement, P<0.0001). Histologically, all operated joints showed fibrous adhesions across the gap, and further, the articular surface was irregular with osteophytes and with bony islands in the gap. This appearance is more consistent with a fibrous reankylosis than a functioning pseudo joint. This study shows that the gap arthroplasty for TMJ ankylosis did not restore the TMJ functionally and histologically to the preexisting state.

Quantitation of chondroitin-sulfates, disaccharides and hyaluronan in normal, early and advanced osteoarthritic sheep temporomandibular joints.

OBJECTIVE: To determine the relationship between synovial fluid, chondroitin sulfate disaccharide and hyaluronic acid to differing degrees of experimental temporomandibular joint (TMJ) osteoarthritis (OA). DESIGN: Twenty-four merino sheep were divided into three groups and had different TMJ surgical procedures to produce OA. Group I; control (six sheep), Group II; disc perforation (nine sheep) and Group III; disc perforation and articular damage (nine sheep). Synovial fluid was collected initially and at sacrifice at 3 months. Chondroitin 4-sulfate, chondroitin 6-sulfate and hyaluronic acid were measured and correlated to the OA histologic score. RESULTS: The chondroitin-sulfate levels were significantly increased (Group I to Group II P< 0.001; Group I to Group III P< 0.001), the hyaluronic acid levels decreased (Group I to Group II P< 0.01; Group I to Group III P< 0.01) with the increasing OA score. CONCLUSION: Chondroitin-sulfate and hyaluronic acid show a correlation with surgically created TMJ osteoarthritis in sheep model.

Survey of congenital anomalies associated with cleft lip and/or palate in 701,181 Japanese people.

There have been many reports on congenital anomalies associated with cleft lip and/or palate (CL/CLP) in Japan. However, these reports included data only on patients who came to hospitals; thus the real situation regarding these anomalies remains unclear. Therefore, we surveyed newborns at all delivery facilities in the central area of Japan for the presence of these anomalies, following their progress for 12 consecutive years; at the end of that time, questionnaires were collected and analyzed. In this article, we describe our results.

The effect of an intra-articular bone fragment in the genesis of temporomandibular joint ankylosis.

The aim of this study was to examine the effect of an intra-articular bone fragment on the genesis of temporomandibular joint (TMJ) ankylosis. Twenty-two adult sheep had a unilateral operation of removal of the temporal and condylar articular surfaces, plus discectomy with or without insertion of an intra-articular bone fragment. Functionally, radiologically, macroscopically and histologically, in the group with the intra-articular bone fragment, the joints showed more advanced ankylosis both at one and three months after the operation, as compared to the group with no intra-articular bone. This study shows that the bone fragment increases the extent of ankylosis in the sheep model. The clinical significance of the various experimental findings of this study and others in the same series is presented.

Further characterization of a CNS adenosine A2a receptor ligand [11C]KF18446 with in vitro autoradiography and in vivo tissue uptake.

PET assessment of the adenosine A2a receptors localized in the striatum offers us a potential new diagnostic tool for neurological disorders. In the present study, we carried out in vitro receptor autoradiography of a newly developed PET ligand [11C]KF18446 ([7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthin e) with rat brain sections. [11C]KF18446 showed a high striatum/cortex binding ratio (5.0) and low nonspecific binding (<10%), suggesting that [11C]KF18446 has characteristics comparable or slightly superior to [3H]CGS 21680 or [3H]SCH 58261, which are currently available representative A2a receptor ligands. Scatchard analysis indicated a Kd of 9.8 nM and a Bmax of 170 fmol/mm3 tissue in the striatum and a Kd of 16.4 nM and a Bmax of 33 fmol/mm3 tissue in the cortex. Seven xanthine-type and four nonxanthine-type adenosine receptor ligands with an affinity for the adenosine A2a receptors significantly reduced the in vitro binding of [11C]KF18446 to the brain section. The blocking effects were much stronger in the striatum than in the cortex, but did not necessarily parallel their affinity. On the other hand, four xanthine-type ligands and one nonxanthine-type ligand (SCH 58261) of the 11 ligands studied reduced the in vivo uptake of [11C]KF18446 in mice, but other ligands, including A1-selective and nonselective ligands and three nonxanthine-type A2a-selective antagonists did not. We conclude that [11C]KF18446 is a promising adenosine A2a receptor ligand for PET study.

Effect of limited jaw motion on ankylosis of the temporomandibular joint in sheep.

The purpose of this study was to investigate the effect of limited movement of the jaw on ankylosis of the temporomandibular joint (TMJ). Eighteen adult sheep were divided into two groups. In Group 1, the temporal and condylar articular surfaces were removed together with the disc on the right. In Group 2, we did the same procedures but in addition the jaw movements were limited by a wire. One sheep was killed just after the operation, four at one month, and four at three months, in each group. The range of jaw movements preoperatively and at the time of death were recorded. The joints were examined radiologically, macroscopically, and histologically. We used a scoring system to assess the radiological changes and histological extent of ankylosis. At one month, the joint spaces were filled with fibrous tissue, but a small joint space existed in all four joints in Group 1. In Group 2, there was full ankylosis in two joints and partial ankylosis in two joints. At three months, similar ankylotic changes were seen in both groups. The histological score for ankylosis at one month showed that those in Group 2 were significantly more ankylosed than in Group 1 (P<0.01). The range of jaw movements was more limited at one month in Group 2, both vertically and to the left, and was significantly decreased in both groups (P<0.01) at three months. Limitation of jaw motion hastens the progress of TMJ ankylosis.

Maternal risk factors in cleft lip and palate: case control study.

Three hundred and six mothers who gave birth to babies with cleft lip, or palate, or both, were matched with 306 who gave birth to healthy babies in the same area during the same time period. Significantly more babies in the cleft group had a family history of clefts (48/306 compared with 7/306, P<0.0001). In the cases studied, combined cleft lip and palate was significantly more common among boys (82/157 compared with 57/149, P=0.02) and cleft palate alone among girls (48/149 compared with 22/157, P=0.0002). Significantly more mothers reported some sort of illness during early pregnancy (101/306 compared with 74/306, P=0.02). There were no differences between the groups as far as dietary preferences were concerned but during early pregnancy the mothers who gave birth to babies with defects tended to drink less alcohol (<1 unit/week) (236 compared with 199, P=0.001) and less coffee (<1 cup/week) (159/306 compared with 131, P=0.03). However, in each case similar proportions gave up once the pregnancy was confirmed. Large multicentre studies are required to confirm or refute these findings.

11C-labeled KF18446: a potential central nervous system adenosine A2a receptor ligand.

UNLABELLED: To develop PET ligands for mapping central nervous system (CNS) adenosine A2a receptors that are localized in the striatum and are coupled with dopamine receptors, 3 11C-labeled xanthine-type adenosine A2a antagonists, [11C]KF18446 ([7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)-1,3,7-trimethylxanthin e), [11C]KF19631 ([7-methyl-11C]-(E)-1,3-diallyl-7-methyl-8-(3,4,5-trimethoxystyryl)xanth ine), and [11C]CSC ([7-methyl-11C]-8-chlorostyrylcaffeine), were compared with [11C]KF17837 ([7-methyl-11C]-(E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylx anthine). METHODS: The regional brain uptake of the tracers, the effect of the coinjected adenosine antagonists on the uptake, and the metabolism were studied in mice. In rats, the regional brain uptake of the tracers was visualized by ex vivo autoradiography (ARG). The A2a receptor binding of antagonist 1 was also measured by in vitro ARG. Imaging of the monkey brain was performed with PET with antagonist 1. RESULTS: In mice, the highest striatal uptake was found for antagonist 1 followed by antagonists 2 and 4. The uptake was inhibited by each of 3 KF compounds and by CSC, but not by an A1 antagonist KF15372. Another selective nonxanthine-type A2a antagonist SCH 58261 significantly decreased the striatal uptake of only antagonist 1, the labeled metabolites of which were less than 20% in the plasma 30 min postinjection, but were negligible in the brain tissue. In ex vivo ARG, antagonist 1 showed the highest striatal uptake and the highest uptake ratio of the striatum to the other brain regions. A high and selective binding of antagonist 1 to the striatum was also confirmed by in vitro ARG. PET with antagonist 1 visualized adenosine A2a receptors in the monkey striatum. CONCLUSION: These results indicate that antagonist 1 ([11C]KF18446) is the most suitable PET ligand for mapping adenosine A2a receptors in the CNS.

Search for PET probes for imaging the globus pallidus studied with rat brain ex vivo autoradiography.

We have evaluated the feasibility of using four positron emission tomography (PET) tracers for imaging the globus pallidus by ex vivo autoradiography in rats. The tracers investigated were [11C]KF18446, [11C]SCH 23390 and [11C]raclopride for mapping adenosine A2A, dopamine D1 and dopamine D2 receptors, respectively, and [18F]FDG. The highest uptake by the globus pallidus was found for [11C]SCH 23390, followed by [18F]FDG, [11C]KF18446 and [11C]raclopride. The receptor-specific uptake by the globus pallidus was observed in [11C]KF18446 and [11C]SCH 23390, but not in [11C]raclopride. Uptake ratios of globus pallidus to the striatum for [18F]FDG and [11C]KF18446 were approximately 0.6, which was twice as large as that for [11C]SCH 23390. In a rat model of degeneration of striatopallidal gamma-aminobutyric acid-ergic-enkephalin neurons induced by intrastriatal injection of quinolinic acid, the uptake of [11C]KF18446 by the striatum and globus pallidus was remarkably reduced. To prove the visualization of the globus pallidus by PET with [18F]FDG and [11C]KF18446, PET-MRI registration technique and advances in PET technologies providing high-resolution PET scanner will be required. The metabolic activity of the globus pallidus could then be measured by PET with [18F]FDG, and [11C]KF18446 may be a candidate tracer for imaging the pallidal terminals projecting from the striatum.

Effect of unilateral condylectomy on the sheep temporomandibular joint.

Unilateral condylectomy was performed on five young adult sheep. The animals were killed at three months and both joints and the excised condyles were examined macroscopically and histologically. All five showed pronounced regeneration of the condylar head on the operated side. The articular surface was fibrous and fused to the disc. Four of the five opposite joints showed medial remodelling. Young sheep have a higher regenerative capability than human adults of equivalent age, and similar reactions to those of children.

Short-term effect of deep-frozen stored auricular cartilage allograft repair on the osteoarthritic sheep temporomandibular joint.

The initial effect of deep-frozen stored auricular cartilage replacement was tested on the progression of experimentally induced osteoarthritis in sheep. Bilateral osteoarthritis was induced in the sheep temporomandibular joint. Three months later, discectomy and deep-frozen auricular cartilage allograft repair were performed unilaterally, with the other side being left as a control. Six months post induction of osteoarthritis, 3 months post repair, the sheep were killed. The stored auricular cartilage allografts were not firmly attached to the surrounding tissue and tended to be markedly thinned and perforated. The effect of storage detrimentally affected the properties of the graft.

Osteochondroma of the mandibular condyle. A case report.

A 52-year-old woman presented with pain on the right temporal region, restricted mandibular movement and a gradually developing malocclusion. Osteochondroma of the mandibular condyle was suspected based on diagnostic imaging. Local resection with preservation of the condylar head resulted in complete resolution of symptoms.

The role of the disk in sheep temporomandibular joint ankylosis.

OBJECTIVE: The purpose of this study was to determine the role of the disk in intraarticular ankylosis of the temporomandibular joint. STUDY DESIGN: Twelve adult sheep were divided into 2 groups. In group 1, removal of the temporal and condylar articular surfaces was performed on the right temporomandibular joint and the disk was maintained; in group 2, removal of the articular surfaces and diskectomy were performed on the right temporomandibular joint. One sheep from each group was killed just after surgery and 5 sheep from each group were killed at 3 months. The joints were examined radiologically, macroscopically, and histologically. The range of jaw movements was recorded preoperatively and at sacrifice. RESULTS: Each of 2 sheep in group 2 had lost 4% of their body weight by 3 months; all of the other sheep maintained or increased their weight. The range of jaw motion to the right was significantly lower in group 2 than in group 1 (P<.01). In group 1, fibrous repair of the articular surface and regeneration of the condylar head was seen. In group 2, each of the joints showed a total fibrous ankylosis with some calcification. There was a statistically significant difference in radiologic score between the groups (P<.0001). Histologic scores for group 1 demonstrated significantly lower scores on the degree of ankylosis scale and degree of calcification scale (P<.0001). CONCLUSIONS: This study showed that the presence of the disk prevented the development of fibrous intraarticular ankylosis of the temporomandibular joint.

Comparison of three PET dopamine D2-like receptor ligands, [11C]raclopride, [11C]nemonapride and [11C]N-methylspiperone, in rats.

We studied the tracer kinetics of three dopamine D2-like receptor ligands, [11C]raclopride ([11C]RAC), [11C]nemonapride ([11C]NEM) and [11C]N-methylspiperone ([11C]MSP), in anesthetized rats by tissue dissection, ex vivo ARG and PET in order to clarify their characteristics for PET imaging. The in vivo affinity of the three ligands for the striatum ([11C]MSP > [11C]NEM > [11C]RAC) obeyed the in vitro affinity for dopamine D2 receptors. The affinity of [11C]RAC and [11C]MSP for the cerebellum was very low, but the affinity of [11C]NEM for the cerebellum was compatible to that for the cortex and was not to be ignored. Also the affinity of [11C]MSP for the cortex was relatively high. [11C]RAC showed the highest selectivity. The striatal PET image with [11C]RAC was clearer than that with [11C]NEM or [11C]MSP, but the activity decreased much faster than that measured by tissue dissection because of the partial volume effect. The striatal activity with [11C]NEM remained high and that with [11C]MSP gradually increased. [11C]RAC and [11C]MSP, but not [11C]NEM, showed a high accumulation in the periorbital region.