A Case of Synovial Chondromatosis of Temporomandibular Joint with Numerous Loose Bodies.

Here, we report a case of synovial chondromatosis of the temporomandibular joint (TMJ) with numerous loose bodies. A 56-year-old woman was examined in the oral surgery department for trismus and pain in the left TMJ when opening the mouth. Imaging indicated TMJ synovial chondromatosis, and the patient was referred to our department for further examination. Her facial features were symmetrical, and no occlusal abnormalities were found. The maximum mouth opening was 30 mm, and movement of the left mandibular condyle was restricted and accompanied by pain and joint sounds. Panoramic radiography showed deformation of the left mandibular condyle and radiopaque lesions surrounding it. Computed tomography showed numerous small granules around the left mandibular condyle, some of which were calcified. Magnetic resonance imaging showed anterior disc displacement without reduction in the left TMJ and hypointense lesions on T2-weighted images. Bone scintigraphy showed an accumulation in the area of the left TMJ. Based on the diagnosis of the left TMJ synovial chondromatosis, the lesions were removed, and plastic surgery on the mandibular condyle was performed under general anesthesia. We removed 386 white loose bodies. Histopathologically, the loose bodies were consistent with synovial chondromatosis lesions. The postoperative course was uneventful, with no recurrence or TMJ dysfunction approximately 5 years after the surgery, indicating that open surgery is the best course of intervention in such cases.

Clinical guidelines for total temporomandibular joint replacement.

Total joint replacement (TJR) of the temporomandibular joint (TMJ) is a promising surgical procedure and device for treating end-stage diseases of the TMJ. For the functional and aesthetic reconstruction of the oral and maxillofacial head and neck region, TMJ TJR significantly helps maintain the patient's quality of life in terms of a better diet, mastication, speech and social interaction. TMJ TJR was approved by regulatory authorities in 2019 in Japan, thus enabling the clinical application of the TJR system. However, the surgery demands particularly difficult and high-risk procedures, necessitating the prudent selection of indicated patients. The joint committee of the Japanese Society of Oral and Maxillofacial Surgeons and Japanese Society for Temporomandibular Joint is working together to develop an appropriate clinical guideline for TMJ TJR.

Difference in Response to a Motor Imagery Task: A Comparison between Individuals with and without Painful Temporomandibular Disorders.

The aim of the study was to investigate the difference in response to a motor imagery task between individuals with and without painful temporomandibular disorders (TMDs). The participants were 24 adults with and without TMD (TMD and control group, resp.). A set of photographic images of the profile view of a person's head and neck and a hand and a foot were presented in a random order. The set consisted of six different orientations with rotations of each image at 0, 60, 120, 180, 240, and 300 degrees and included left and right representations. The participants were required to view the image and make a decision as to whether it was a left or a right side presented, that is, mental rotation (MR) task. Data were collected on 48 tasks (including left and right) at each orientation for each body part. Reaction times (RTs) for correct answers and accuracy in making the left or right judgements were recorded. The RT was slower in the TMD group than in the control group. The RT for the profile image was slower than those for the hand and foot images. For images that were 180 degrees, the RT was slower and the accuracy was lower than those for five of the other image orientations. The judgements made about the 180-degree rotated image were more inaccurate compared to images of all other orientations among all types of stimuli.

Risk of osteoporosis in elderly individuals attending a dental clinic.

OBJECTIVE: Osteoporosis has become a critical public health problem with the rapidly aging population in Japan. It is necessary for dentists to know their patients' status because it influences dental treatment. The purpose of this study was to predict the risk of osteoporosis in elderly patients visiting a dental clinic by assessing mandibular cortical morphology on panoramic radiographs. METHOD: Three-hundred and thirty patients were divided into three classes based on the morphology of their mandibular cortex on panoramic radiographs. Mandibular cortical bone width at the mental foramen was also measured. Bone mineral density (BMD) was determined at the calcaneus using a quantitative ultrasound device. RESULTS: The mandibular cortical width decreased significantly from Class 1 (normal cortex), to Class 2 (moderately eroded cortex) and to Class 3 (severely eroded cortex). BMD was negatively correlated with age in both female and male patients. Most (108/186) female patients had a class 3 cortex with a low BMD. Among women, mandibular cortical width was significantly correlated with BMD. Thirty-three percent of the female had received a previous diagnosis of osteoporosis. In contrast, only 13.9% (20/144) of the male had a Class 3 cortex. In men, mandibular cortical width did not significantly correlate with BMD. Only a few of the men had received a previous diagnosis of osteoporosis. The number of remaining teeth did not correlate with low BMD in either sex. CONCLUSION: Our findings reveal that most elderly female patients visiting the dental clinic had a high risk of osteoporosis and a low BMD.

Characteristics of upper quadrant posture of young women with temporomandibular disorders.

[Purpose] This study aimed to investigate the characteristics of upper quadrant posture of young women with temporomandibular disorders. [Subjects] The participants were 19 female patients with temporomandibular disorders (patient group: mean age, 30.1 years) and 14 controls (control group: mean age, 24.6 years). [Methods] Outcome measures were the neck inclination angle (formed by a line connecting C7 and the ear tragus with a horizontal line), the angle of the shoulder (formed by a line connecting C7 and the acromial angle with a horizontal line), the cranial rotation angle (formed by a line connecting the ear tragus and the corner of the eye with a horizontal line), and the neck-length/shoulder-width ratio [the ratio of the neck length (from C7 to the tragus) to the width of the shoulder between the acromial angle]. The maximum range of mouth opening was measured using a scale. [Results] The neck inclination angle and maximum range of mouth opening were significantly smaller in the patient group than in the control group. No significant differences were observed in the other outcome measures between the two groups. [Conclusion] Temporomandibular disorders with limited mouth opening in young females are associated with the head position relative to the trunk.

15-Deoxy-Δ12,14-prostaglandin J2 induces PPARγ- and p53-independent apoptosis in rabbit synovial cells.

A ligand of peroxisome proliferator-activated receptor γ (PPARγ), 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2) induces apoptosis in various cells. However, the mechanism appears to be complex and cell-type specific. We investigated the mechanism of 15d-PGJ2-induced apoptosis of rabbit synovial cells. Exposure to 15d-PGJ2 resulted in DNA fragmentation accompanied by caspase-3 and -9 activations in the cells, suggesting occurrence of mitochondria-mediated apoptosis. Although the exposure also induced remarkable increase in p53 protein, its transcriptional activity was rather reduced, suggesting non-necessity of p53 in 15d-PGJ2-induced apoptosis. Covalent binding of 15d-PGJ2 to cellular proteins including p53 resulted in their insolubilization. N-acetylcysteine inhibited not only the 15d-PGJ2-induced apoptotic events but also the protein insolubilizations via its interaction with 15d-PGJ2. The studies using a PPARγ-agonist and -antagonist showed noninvolvement of PPARγ in 15d-PGJ2-induced apoptosis. The pre-exposure to pro-inflammatory cytokines did not affect the cytotoxicity of 15d-PGJ2 in synovial cells. Taken together, these results show that 15d-PGJ2 induces a mitochondria-mediated apoptotic pathway in p53- and PPARγ-independent manners.

Anesthetic considerations for masticatory muscle tendon-aponeurosis hyperplasia: a report of 24 cases.

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease entity characterized by limited mouth opening due to contracture of the masticatory muscles, resulting from hyperplasia of tendons and aponeuroses. In this case series, we report what methods of airway establishment were conclusively chosen after rapid induction of anesthesia. We had 24 consecutive patients with MMTAH who underwent surgical release of its contracture under general anesthesia. Rapid induction of anesthesia with propofol and rocuronium was chosen for all the cases. In 7 cases, intubation using the Macintosh laryngoscopy was attempted; however, 2 of those cases failed to be intubated on the first attempt. Finally, intubation using the McCoy laryngoscopy or fiber-optic intubation was alternatively used in these 2 cases. In 7 cases, the Trachlight was used. In the remaining 10 cases, fiber-optic intubation was used. Limited mouth opening in patients with MMTAH did not improve with muscular relaxation. "Square mandible" has been reported to be one of the clinical features in this disease; however, half of these 24 patients lacked this characteristic, which might affect a definitive diagnosis of this disease for anesthesiologists. An airway problem in patients with MMTAH should not be underestimated, which means that other intubation methods rather than direct laryngoscopy had better be considered.

Identification of a novel Staphylococcus pseudintermedius exfoliative toxin gene and its prevalence in isolates from canines with pyoderma and healthy dogs.

Staphylococcal exfoliative toxins are involved in some cutaneous infections in mammals by targeting desmoglein 1 (Dsg1), a desmosomal cell-cell adhesion molecule. Recently, an exfoliative toxin gene (exi) was identified in Staphylococcus pseudintermedius isolated from canine pyoderma. The aim of this study was to identify novel exfoliative toxin genes in S. pseudintermedius. Here, we describe a novel orf in the genome of S. pseudintermedius isolated from canine impetigo, whose deduced amino acid sequence was homologous to that of the SHETB exfoliative toxin from Staphylococcus hyicus (70.4%). The ORF recombinant protein caused skin exfoliation and abolished cell surface staining of Dsg1 in canine skin. Moreover, the ORF protein degraded the recombinant extracellular domains of canine Dsg1, but not Dsg3, in vitro. PCR analysis revealed that the orf was present in 23.2% (23/99) of S. pseudintermedius isolates from dogs with superficial pyoderma exhibiting various clinical phenotypes, while the occurrence in S. pseudintermedius isolates from healthy dogs was 6.1% (3/49). In summary, this newly found orf in S. pseudintermedius encodes a novel exfoliative toxin, which targets a cell-cell adhesion molecule in canine epidermis and might be involved in a broad spectrum of canine pyoderma.

Antimicrobial susceptibility and methicillin resistance in Staphylococcus pseudintermedius and Staphylococcus schleiferi subsp. coagulans isolated from dogs with pyoderma in Japan.

To understand species distribution, trends of antimicrobial susceptibility and prevalence of methicillin resistance in canine staphylococci in Japan, 190 coagulase-positive staphylococci (CoPS) were isolated from dogs with pyoderma in 2 Japanese veterinary referral hospitals. Using a multiplex polymerase chain reaction (M-PCR) method, two CoPS species were identified: 170 Staphylococcus pseudintermedius (89.5%) and 20 S. schleiferi subsp. coagulans isolates (10.5%). In these isolates, susceptibility to 7 antimicrobial agents was determined. Overall, the levels of susceptibility to cefalexin (CEX), amoxicillin/clavulanic acid (CVA/AMPC), minocycline (MINO), ofloxacin (OFLX), norfloxacin (NFLX), lincomycin (LCM) and clindamycin (CLDM) in S. pseudintermedius isolates were 38.2, 52.4, 34.7, 31.2, 34.1, 1.2 and 11.2%, respectively. In S. schleiferi subsp. coagulans isolates, 55% demonstrated susceptibility to CEX, 80% to CVA/AMPC, 70% to MINO, 45% to OFLX or NFLX and 30% to CLDM. None of S. schleiferi subsp. coagulans isolates was susceptible to LCM. To determine the prevalence of methicillin-resistant strains, we used a PCR method, which enabled detection of the fragment of mecA gene in 66.5% (113 of 170) in S. pseudintermedius and 30.0% (6 of 20) in S. schleiferi subsp. coagulans isolates. The frequencies of susceptibility to CEX, CVA/AMPC, OFLX, NFLX and CLDM were significantly lower in methicillin-resistant CoPS than in methicillin-susceptible CoPS isolates. These data suggest a high level of methicillin resistance in staphylococci isolated from dogs with pyoderma in Japan.

Possible difficult laryngoscopy caused by masticatory muscle tendon-aponeurosis hyperplasia: we anesthesiologists should be aware of this disease.

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease entity characterized by limited mouth opening due to contracture of the masticatory muscles resulting from hyperplasia of tendons and aponeuroses. The other clinical feature is that the face of the patient with this disease displays a square mandible configuration. Muscle relaxants provide no relief for the limited mouth-opening ability. Anesthesiologists need to suspect difficult airway when patients have limited mouth opening with square mandible configuration. MMTAH can therefore be a possible cause of difficult intubation.

Mechanical stretch enhances NF-kappaB-dependent gene expression and poly(ADP-ribose) synthesis in synovial cells.

Temporomandibular joint disorders (TMD) show complex symptoms associated with inflammation, pain and degeneration of the peripheral tissues including synovium. Although it is believed that excessive mechanical stress on synovium causes development of TMD, the molecular mechanism by which mechanical stress triggers TMD has still remained unclear. In order to examine the effect of mechanical stress on synoviocytes, rabbit synovial cells were cyclically stretched in vitro. The stretch efficiently increased the gene expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and NF-kappaB responsive reporter gene constructs. The interruption of NF-kappaB activating pathway by inhibitors resulted in the abrogation of those expressions, indicating the pivotal role of NF-kappaB in the mechanical stretch-mediated COX-2 and iNOS expressions. In parallel, the stretch remarkably increased NO production and poly(ADP-ribose) (PAR) synthesis, suggesting that excessive amounts of NO causes DNA injury and in turn activates PAR synthesis by poly(ADP-ribose) polymerase (PARP). The inhibition of PAR synthesis by a PARP inhibitor or a radical scavenger enhanced the mechanical stretch-induced gene expressions in a NF-kappaB-independent manner, implying an involvement of PARP in the gene expression. Taken together, these results demonstrate that mechanical stress on synovial cells not only induces gene expressions of COX-2 and iNOS but also affects PAR synthesis.

Multiplex-PCR method for species identification of coagulase-positive staphylococci.

In veterinary medicine, coagulase-positive staphylococci (CoPS) other than Staphylococcus aureus have frequently been misidentified as being S. aureus strains, as they have several phenotypic traits in common. There has been no reliable method to distinguish among CoPS species in veterinary clinical laboratories. In the present study, we sequenced the thermonuclease (nuc) genes of staphylococcal species and devised a multiplex-PCR (M-PCR) method for species identification of CoPS by targeting the nuc gene locus. To evaluate sensitivity and specificity, we used this M-PCR method on 374 staphylococcal strains that had been previously identified to the species level by an hsp60 sequencing approach. We could successfully distinguish between S. aureus, S. hyicus, S. schleiferi, S. intermedius, S. pseudintermedius, and S. delphini groups A and B. The present method was both sensitive (99.8%) and specific (100%). Our M-PCR assay will allow the routine species identification of CoPS isolates from various animal species for clinical veterinary diagnosis.

15-Deoxy-Delta(12,14)-prostaglandin J(2) impairs the functions of histone acetyltransferases through their insolubilization in cells.

The cyclopentenonic prostaglandin 15-deoxy-Delta(12,14)-PG J(2) (15d-PGJ(2)) is a metabolite derived from PGD(2). Although 15d-PGJ(2) has been demonstrated to be a potent ligand for peroxisome proliferator activated receptor gamma (PPARgamma), the functions are not fully understood. In order to examine the effect of 15d-PGJ(2) on histone acetyltransferases (HATs), several lines of cell including mouse embryonic fibroblast (MEF) cells were exposed to 15d-PGJ(2). Three types of HAT, p300, CREB-binding protein (CBP), and p300/CBP-associated factor (PCAF), selectively disappeared from the soluble fraction in time- and dose-dependent manners. Inversely, HATs in the insoluble fraction increased, suggesting their conformational changes. The decrease in the soluble form of HATs resulted in the attenuation of NF-kappaB-, p53-, and heat shock factor-dependent reporter gene expressions, implying that the insoluble HATs are inactive. The resultant insoluble PCAF and p300 seemed to be digested by proteasome, because proteasome inhibitors caused the accumulation of insoluble HATs. Taken together, these results indicate that 15d-PGJ(2) attenuates some gene expressions that require HATs. This inhibitory action of 15d-PGJ(2) on the function of HATs was independent of PPARgamma, because PPARgamma agonists could not mimick 15d-PGJ(2) and PPARgamma antagonists did not inhibit 15d-PGJ(2).

Expression analysis of CCL27 and CCL28 mRNA in lesional and non-lesional skin of dogs with atopic dermatitis.

Chemokines are important regulators of the selective recruitment of inflammatory cells into sites of allergic inflammation. Since canine atopic dermatitis (AD) shares many clinical features of human AD, patterns of chemokine production in dogs may also be similar with those in humans. The aim of this study was to examine mRNA expression of CCL27 and CCL28 in lesional skin of dogs with AD to demonstrate similarity of chemokine production with human counterparts. RNA was extracted from skin biopsy specimens of 12 dogs with AD. The mRNA expression of CC chemokines (CCL4, CCL19, CCL20, CCL21, CCL24, CCL27 and CCL28) was analyzed by quantitative real-time PCR and was compared between lesional and non-lesional skin. Seven types of chemokines examined were constitutively expressed in both lesional and non-lesional skin. It was found that mRNA expression levels of CCL27 and CCL28 among the chemokines were significantly different between lesional and non-lesional skin (P<0.05). Expression level of CCL27 mRNA in lesional skin was significantly lower than that in non-lesional skin. On the other hand, CCL28 mRNA expression in lesional skin was found to be higher than that in non-lesional skin. These results suggest that CCL28 but not CCL27 may play important roles in immunopathogenesis of canine AD, indicating that experimental canine study may provide additional information that can be extrapolated to human AD.