[Clinical natural course of temporomandibular joint intermittent closed lock].

OBJECTIVE: To investigate the clinical natural course of temporomandibular joint (TMJ) intermittent closed lock (ICL) through 24 months follow-up. METHODS: Sixty-eight patients with ICL were included, and 54 patients finished 24 months follow-up. The disease duration, frequency of joint lock and joint pain were recorded at the patient's first visit. Telephone interviews were taken for every month, and the frequency of joint lock and joint pain were recorded. According to the development of ICL, the patients were divided into 3 groups: symptom-worsened group, symptom-disappeared group, symptom-persisted group. RESULTS: There were 16 patients (30%) whose symptoms worsened into closed lock (disk displacement without reduction), 32 patients (59%) whose symptoms persisted during the 24 months follow-up, and 6 patients' (11%) symptoms disappeared. In symptom-persisted group, the frequency of joint lock decreased in 11/32 (34%), increased in 4/32 (13%), did not change in 17/32 (53%). There was no significant difference in gender, age, frequency of joint lock and joint pain recorded at the first visit among these 3 groups (P > 0.05). The disease duration in the symptom-disappeared group was much shorter than the other 2 groups (P < 0.05). CONCLUSIONS: ICL of TMJ was more likely to get worse into closed lock. There seemed no significant relation between the sequelaes of ICL and patients' gender, age, disease duration, frequency of joint lock and joint pain, and larger sample studies were necessary.

[Strengthen research on the relationship between oral diseases and systemic diseases].

Literatures have demonstrated the association between oral diseases and systemic diseases. For example, periodontitis is associated with coronary heart disease, diabetes, preterm low birth weight, and gastritis. Therefore, more relevant research on the relationship between oral diseases and systemic diseases should be carried out.

Long-term efficacy of botulinum toxin type A for the treatment of habitual dislocation of the temporomandibular joint.

Injection of botulinum toxin type A (BTX-A) into the lateral pterygoid muscles is a recently reported treatment for habitual dislocation of the temporomandibular joint (TMJ). We report five cases of dislocation in elderly patients with neurological or other severe systemic disease, and their successful treatment with one injection of BTX-A into the lateral pterygoid muscles. This is a relatively conservative option. Injection into the muscle is straightforward and can be done in outpatients with few complications. We recommend it as the first choice for patients with habitual dislocation and systemic or neurological diseases, particularly in the elderly.

[Positional changes of temporomandibular joint disk and condyle with insertion of anterior repositioning splint].

OBJECTIVE: To measure the positional changes of temporomandibular joint (TMJ) disk and condyle with insertion of anterior repositioning splint (ARS) using magnetic resonance imaging (MRI) for further understanding of the splint therapy mechanisms. METHODS: Twenty-two patients with temporomandibular joint clicks were included. 31 TMJs were diagnosed as anterior disk displacement with reduction (disk-displaced group), and the other 13 TMJs were normal (normal group). All joints were scanned oblique-sagittally by MRI before splint treatment in three positions including closed-mouth position of centric occlusion (the position before insertion of ARS), incisors' edge to edge position, and mandibular least forward protrusion position (the position after insertion of ARS). RESULTS: 1) Disk-condyle angle: In closed-mouth position, the average angle was 54.23 degrees in the disk-displaced group, while it was 9.80 degrees in the normal group; in incisors' edge to edge position and mandibular least forward protrusion position, the angle was reduced to normal in most of the disk-displaced cases. 2) Disk position: From closed-mouth position to incisors' edge to edge position or mandibular least forward protrusion position, the forward displaced disk moved backward significantly, while the disk with normal position did not change significantly in the three positions. 3) Condyle position: From closed-mouth position to incisors' edge to edge position or mandibular least forward protrusion position, the condyle moved forward and downward significantly both in the disk-displaced group and in the normal group. CONCLUSION: With insertion of the splint, the condyle moved anteriorly and inferiorly and the disk moved posteriorly, most of the anterior displaced disks could be reduced to normal positions in the joint fossa. The result indicated that the splint protruded condyle forward and prevented the backward reduced disk from displacing forward again during mouth closing.

Osteonecrosis of the mandibular condyle as a precursor to osteoarthrosis: a case report.

Osteonecrosis of the mandibular condyle is a rare condition characterized by a primary subchondral osseous breakdown of the condyle with secondary articular surface collapse. Despite these characteristics, it has proved to be difficult to diagnose. The present case of osteonecrosis of the mandibular condyle was initially diagnosed more than 2 years before. The diagnosis at that time was based on physical examination, plain film radiography, cone-beam computerized tomography, magnetic resonance imaging, and total body scintigraphy. The disease had progressed into severe osteoarthrosis at a 2-year follow-up using cone-beam computerized tomography. This report suggests that osteonecrosis may be a precursor of osteoarthrosis, and cone-beam computerized tomography may provide a sensitive radiographic technique for the diagnosis of osteonecrosis of mandibular condyle.

Dissociation of spinal microglia morphological activation and peripheral inflammation in inflammatory pain models.

We compared the effects of peripheral Freund's Complete Adjuvant (CFA) and formalin injection on spinal microglia activation. Both qualitative and quantitative analyses showed signs of microglia activation on the ipsilateral side of the lumbar dorsal horn on day 3, day 7 and day 14 after formalin injection. However, significant microglia morphological alteration was not found in the CFA model. At the injection site in the paw, CFA injection induced considerably more inflammation than formalin injection. Although spinal microglia might be activated in inflammatory pain models, morphologically, spinal microglia activation was not closely correlated with peripheral inflammation.

[The relationship between symptoms and signs of temporomandibular disorders and the patients' quality of life].

OBJECTIVE: To analyze the relationship between symptoms and signs of temporomandibular disorders (TMD) and the patients' quality of life (QOL). METHODS: A total of 492 TMD patients were included in this study. The clinical examination results were recorded using Fricton index of temporomandibular joint function. "Visual analog scale (VAS) evaluation of QOL disturbance" was designed to quantitate patients' QOL, to evaluate the degree that the patients QOL was affected. RESULTS: Chewing, daily life and emotion among all 8 items of QOL were frequently affected by TMD, and joint clicking had the least influence on QOL. Intermittent closed lock had more severe interference with QOL than joint clicking only. Severe and moderate pain or limited mouth opening affected the QOL more severely than mild pain or mild limited mouth opening. The simple linear relationship between Fricton index and patients' QOL was poor (r < 0.4). CONCLUSIONS: Pain is the most frequently seen symptom in TMD. TMD could affect patients' QOL, including both physical and social-psychological functions. The results suggest that the patients' QOL as well as TMD symptoms and signs should be considered in the management of TMD.

Cerebral cortical dysfunction in patients with temporomandibular disorders in association with jaw movement observation.

Temporomandibular disorders (TMD) represent a group of chronic painful conditions in the masticatory musculature and temporomandibular joint. To examine possible changes in cortical machinery in TMD patients, we compared neuromagnetic signals evoked by cortical neurons between healthy subjects and TMD patients while they were carefully observing the video frames of jaw-opening movements performed by another person. During the movement observation task in the healthy subjects, we found cortical activation in the following sequence with left hemisphere dominance: (1) the occipitotemporal region near the inferior temporal sulcus (human homologue of MT/V5 in monkeys), (2) the inferior parietal cortex (IPC), and (3) the anterior part of the inferior-lateral precentral gyrus (PrCG). In the TMD patients, however, we found deficit or marked attenuation of the neuromagnetic responses in the PrCG and IPC, while the activity of the MT/V5 showed no differences from that in the healthy subjects. In addition, we could not find any differences in cortical magnetic responses between healthy subjects and TMD patients when they were observing palm-opening movements, indicating that cortical dysfunction associated with jaw-movement observation is specific phenomena in the patients of TMD. Thus the present study provides new neuropathological evidence that TMD patients exhibit dysfunction of recognition mechanisms in cerebral cortex during motor observation, and suggests that disturbance of cortical functions regulating visuomotor integration would play a crucial role in development as well as aggravation of TMD.

Peripheral formalin injection induces long-lasting increases in cyclooxygenase 1 expression by microglia in the spinal cord.

UNLABELLED: Activated glia are a source of substances known to enhance pain, including centrally synthesized prostaglandins. We have previously shown that microglia are activated in the spinal cord following peripheral formalin injection. In the present study, we investigated cyclooxygenase (COX-1 and COX-2) expression in the spinal cord using immunohistochemistry and Western blots in the formalin pain model, to further understand how spinal glia modulate pain processing. We show that both COX-1 and COX-2 are constitutively expressed in the spinal cord. Hind paw formalin injection increased COX-1 expression, beginning at 1 day after injection and lasting at least 2 weeks, the duration of experiments. The COX-2 expression changed considerably less, with a significant increase of COX-2 protein level only observed at 2 h after injection. Double labeling studies showed that COX-1 was expressed in microglia and COX-2 was expressed in neurons. These data indicate that both COX-1 and COX-2 are increased in the spinal cord following formalin injection, but the time course and cellular sources are different, suggesting that both COX-1 (longer time points) and COX-2 (very short time points) may be involved in spinal modulation in the formalin pain model. Our study also suggests that spinal microglial activation may play a role in long-term hyperalgesia through the increased expression of COX-1. PERSPECTIVE: This article reports that COX-1 expression by microglia is increased in the spinal cord after peripheral formalin injection into the rat hind paw. This result could potentially help clinicians understand how COX-1 may be involved in pain processing and the role microglial activation plays in pain mechanisms.

[Diagnosis and management of 49 cases of hemangiomas in infants and children].

OBJECTIVE: To observe the management results of hemangioma in infants and children. METHODS: Forty-nine cases of hemangioma in infants and children managed from 1986 to 2004 were reviewed. During the management period, the incidence and first visit age and sex were recorded. The location and volume of the lesions were photographed and followed up at an interval of 3 to 12 months until the complete involution of the tumor. The treatment modalities used included local injection of prednisone in 16 cases, surgery in 6 cases, and the remaining 33 cases were observed without treatment. RESULTS: Thirty-three cases receiving no treatment involuted naturally. The complete involution age was found from 9 months to 10 years with average age of 5.4 years. The cosmetic results after involution were good. CONCLUSIONS: Most hemangiomas do not need treatment and can involute naturally. However, in cases with severe complications such as expansion, destruction and obstructive or congestive heart failure, treatment is indicated.