Differences in temporomandibular joint pain and age distribution between marrow edema and osteonecrosis in the mandibular condyle

This study investigated the differences of age distribution and temporomandibular joint (TMJ) pain between marrow edema and osteonecrosis in the mandibular condyle. Subjects consisted of 35 TMJs in 35 patients with abnormal bone marrow on MR images who were selected from a consecutive series of 527 patients with TMJ disorders. Proton density and T2-weighted MR images taken in the oblique sagittal and coronal planes were used to diagnose condylar marrow abnormalities and divide them into either edema or osteonecrosis. The differences in TMJ pain and age distribution for these two abnormalities were assessed with the one-sided Wilcoxon rank sum test with 0.05 alpha level. The degree of pain was higher in joints with marrow edema than in joints with osteonecrosis (p = 0.033). The mean age was higher in joints with osteonecrosis (p < 0.001). Our results suggest that there is more severe pain in TMJs with marrow edema of the mandibular condyle than in those with osteonecrosis. Since the patients with marrow edema have lower age, it also appears that marrow edema may be a precursor condition for osteonecrosis of the TMJ.     

The correlation of temporomandibular joint sounds with joint morphology in fifty-five autopsy specimens

Joint sounds from 55 fresh temporomandibular joint autopsy specimens were correlated with the macroscopic examination of joint morphology. Fifty-eight per cent of the joints were silent. Two thirds of these showed normal superior disc positions and remodeled articular surfaces, whereas one third exhibited anterior disc displacement. Twenty per cent of the joints elicited clicking and showed anterior disc displacement. Twenty-two per cent of the joints elicited crepitation and exhibited mostly arthrosis of the articular surfaces and perforation of the discs. Our results confirm previous statements that clicking and crepitation may be looked upon as signs of abnormal joint morphology, clicking indicating anterior disc displacement and crepitation usually indicating arthrosis. Absence of sound alone, however, should not be accepted as an indication of a normal joint.     

Osseous and muscular changes after vertical ramus osteotomy. A magnetic resonance imaging study

Magnetic resonance (MR) imaging was performed about 2 years after vertical ramus osteotomy of 10 patients to study changes in the mandibular condyle, cortical and cancellous bone of the proximal fragment, and muscles of mastication. MR imaging observations of the surgically treated patients were compared with findings in 10 asymptomatic untreated control subjects. The results showed that the MR appearance of bone marrow of the mandibular condyle was normal in all patients and in all control subjects. No MR evidence of avascular necrosis of the mandibular condyle was found. MR imaging artifacts from microscopic metallic particles were seen in all surgically treated regions. Thickening of the buccal and lingual cortical bone with narrowing of the bone marrow space was seen bilaterally in eight patients and unilaterally in two patients. Slight medial tipping of the mandibular condyle was seen unilaterally in two patients. Atrophic changes with decreased muscle volume and fatty replacement of muscle tissue was seen unilaterally in eight patients. None of these alterations were seen in the control subjects. MR imaging appears to be an excellent method to study morphologic changes of the muscles of mastication and osseous fragments after orthognathic surgery of the mandible. Thickening of the cortical bone and narrowing of the bone marrow space of the proximal fragment was frequently seen after vertical ramus osteotomy of the mandible and most likely represents remodeling associated with normal healing.     

Destructive lesions of the mandibular condyle following diskectomy with temporary silicone implant

Dacron-reinforced silicone is widely used as disk-replacement implant material in the temporomandibular joint. A retrospective radiographic analysis was undertaken in a series of thirty-two patients on whom diskectomy had been performed. Twenty patients had received temporary silicone implants, whereas twelve patients had surgery without disk-replacement implants. Six of the patients with implants had destructive lesions of the mandibular condyles at follow-up examinations, but no such lesions were seen in any of the patients who had surgery without implants. Histologic analysis of material removed from one patient who had a second operation showed multiple particles of foreign material surrounded by focally marked inflammatory reaction with foreign body granulomas. The underlying cartilage and bone showed focal resorption and bone destruction. Electron microscopy combined with energy-dispersive x-ray microanalysis showed that the foreign material contained silicone. It was concluded that the radiographically observed destructive lesions of the mandibular condyle may be a sign of a reactive synovitis induced by silicone particles abraded from the silicone implant.     

Horizontal condylar angle in relation to internal derangement of the temporomandibular joint

The angle between the horizontal condylar long axis and the frontal plane was measured and correlated with arthrographic diagnosis in 364 consecutive temporomandibular joint patients. There were no statistically significant associations between the horizontal condylar angle and the arthrographic diagnosis. The condylar angle of the contralateral joint however, was, found to be larger in patients with unilateral anterior disk displacement than in patients with normal temporomandibular joints. There is no immediate explanation of this finding, but it supports previous observations and may contribute to the understanding of the etiology and the pathogenesis of internal derangement of the temporomandibular joint.     

Long-term evaluation of meniscectomy of the temporomandibular joint

Meniscectomy for treatment of pain and dysfunction of the temporomandibular joint is a controversial operation because of the possible late complications of limitation of movement and pain. Therefore, the long-term results of this operation were clinically and radiologically investigated in a sample of 15 patients that had had meniscectomies performed during the period from 1947-1960 (mean follow up, 29 years). On clinical examination, all patients were free of pain, none had subjectively experienced dysfunction, and all but one could open their mouths more than 39 mm. Two thirds of the operated joints were crepitant. Radiologically all joints showed structural hard-tissue changes, mainly the presence of osteophytes and flattening of the condyle and tubercle. Absence of joint space was seen in half of the joints. The results indicate that meniscectomy relieves joint pain and eliminates subjectively perceived dysfunction in the long term despite the presence of clinical and radiologic signs of degenerative joint disease; however, as the condition of many patients who have temporomandibular joint disorders improves over time without surgery, there is a need for a controlled study on the value of meniscectomy.     

Narrowing of the dental pulp chamber in patients with renal diseases

Narrowing of the dental pulp chamber was studied radiologically in fifty one patients with renal diseases. Two thirds of the patients were suffering from terminal uremia and were treated either by renal transplantation or with hemodialysis. The remaining patients were nonuremic and were treated with immunosuppressants because of progressive renal disease. There were significantly more patients with narrowing of the dental pulp chamber among the transplant patients than among the other patients. The transplantations included the use of higher doses of corticosteroids than the other treatments. As the median dose of corticosteroids was higher and total plasma steroid clearance was lower in the patients with narrowing of the dental pulp chamber than in the other patients, the amount of this drug received and its pharmacokinetics seemed to be an essential factor in the initiation of narrowing of the dental pulp chamber.     

Temporomandibular joint sounds in patients with disc displacement

Temporomandibular joint sounds have been viewed as signs of different pathological changes. However, the correlation between joint sounds on the one hand and function and morphology of the joint on the other, are not well documented. We have therefore presurgically recorded sound from 35 operated joints with disc displacement and have studied arthrographically and during surgery the position, function and configuration of the disc as well as arthrotic changes. 12 joints were silent, 12 elicited reciprocal clicking, 3 single clicking, and 8 crepitation. Joints with reciprocal clicking consistently showed disc displacement with reduction and silent and crepitating joints showed disc displacement without reduction. All joints with reciprocal clicking as well as most silent joints demonstrated non-arthrotic articular surfaces, whereas crepitation was recorded in both arthrotic and non-arthrotic joints. Our results implied that crepitation is a rather unreliable sign of arthrosis. Reciprocal clicking can be considered as an accurate sign of reduction of anteriorly displaced discs. However, neither the degree of displacement nor the degree of deformation of the disc could be disclosed by analysis of the sound. This information can only be obtained by further examination, such as arthrotomography.     

Arthrographic and clinical characteristics patients with disk displacement who progressed to closed lock during a 6-month period

The course of 61 patients with a clinical and arthrographic diagnosis of disk displacement with reduction was followed for 6 months. Progression to closed lock (disk displacement without reduction) occurred in 12 patients (20%). A retrospective analysis of the findings from the clinical and arthrographic examination at the first consultation revealed that the intensity of temporomandibular joint pain during chewing and the degree of disturbed joint function were more pronounced and the frequency of temporary locking was higher in the patients who progressed to closed lock compared with those who did not progress to closed lock. A deep anterior recess of the lower joint compartment was found in ten (83%) of the twelve joints that progressed to closed lock. This type of a deep anterior recess was seen in only five (11%) of the forty-nine patients who did not progress to closed lock. Progression seems to be more likely in patients with pronounced joint pain and disturbed joint function, temporary locking, and a deep anterior recess of the lower joint compartment. These clinical and arthrographic features may be used during evaluation of patients with disk displacement with reduction.