Nobumi Ogi

Natural Course of Untreated Symptomatic Temporomandibular Joint Disc Displacement without Reduction

In some patients with disc displacement without reduction, the symptoms of pain and decreased range of motion have been observed to resolve spontaneously over time without treatment. The natural history of this condition, however, is not well-understood. Thus, to study the natural course of disc displacement without reduction, we followed 40 patients without treatment for a period of 2.5 years. The diagnosis was established by history and physical examination and confirmed with magnetic resonance (MR) imaging. After 2.5 years, 43% of the patients were asymptomatic, 33% had decreased symptoms, and 25% of the patients showed no improvement or had required treatment. MR evidence of osteoarthritis and advanced stages of internal derangement at the initial evaluation was associated with a poor prognosis. The result of this prospective cohort study indicated that approximately 40% of patients with symptomatic disc displacement without reduction will be free of symptoms within 2.5 years, one-third will improve, whereas one-quarter will continue to be symptomatic. This knowledge should be valuable for the treatment planning and evaluation of prognosis of patients with non-reducing symptomatic disc displacement.

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.

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.

Correlation between preoperative mouth opening and surgical outcome after arthroscopic lysis and lavage in patients with disc displacement without reduction

PURPOSE This study was designed to evaluate the efficacy of arthroscopic lysis and lavage for patients with limited mouth opening. The relationship between preoperative mouth opening and the surgical outcome was determined. METHOD Fourteen patients with 16 internally deranged joints were treated by arthroscopic lysis and lavage. All had received 10.4 (7 to 19) months of nonsurgical treatment before arthroscopy. The preoperative magnetic resonance images showed anterior disc displacement without reduction in all treated joints. RESULTS Twelve of the 14 patients (86%) showed good reduction in pain and improved range of jaw movement on average follow-up of 28.5 (13 to 66) months. Two patients showed no improvement after arthroscopy and required open surgical procedures. The preoperative mouth opening of the successful group averaged 29.4 (22 to 35) mm, whereas the two failed cases had 10- and 19-mm openings, respectively (P < .05). CONCLUSION Persistent limitation of mouth opening of more than 22 mm after nonsurgical treatment has a good prognosis when treated by arthroscopic lysis and lavage. However, those with greater limitation should probably have earlier surgical intervention.

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 short-term effect of discectomy on the osteoarthrotic temporomandibular joint in sheep

The short-term effect of discectomy on osteoarthrotic joints was tested experimentally in sheep. Bilateral temporomandibular joint (TMJ) osteoarthrosis was induced, and at 3 months discectomy was performed on one joint, with the other being left as a control. Neither masticatory nor mouth-opening disturbances had been found after discectomy. The animals were killed at 6 months, and the TMJs were removed, fixed, and assessed radiologically, macroscopically, and histologically. The control joints showed ongoing degenerative changes consistent with previous reports. The discectomy joints showed marked fibrous repair with joint surface remodelling rather than ongoing degeneration. This result is consistent with the clinical findings after discectomy for osteoarthrotic joints.

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.

Diagnostic accuracy of the ultrathin arthroscope for temporomandibular joint osteoarthrosis: Comparison of arthroscopic and histologic findings in a sheep model

The diagnostic accuracy of the ultrathin arthroscope was evaluated by examination of the superior joint space of the left temporomandibular joint in 20 sheep. At the time of induction of osteoarthrosis all joints were found to be normal. Six months later the arthroscopic examination was repeated and the results compared with the histologic examination. Similar findings were seen in 11 joints (55%), with arthroscopic overdiagnosis in two (10%) and underdiagnosis in seven (35%). Eight of 16 (50%) disc perforations were found. It was concluded that underdiagnosis occurred because the whole joint space cannot be examined arthroscopically and fibrillated tissue masks bone exposure.

The short-term effect of autogenous auricular cartilage graft following discectomy on the osteoarthrotic temporomandibular joint in sheep

The aim of this experimental study was to determine the effect of auricular cartilage graft replacement on the progression of experimentally induced osteoarthrosis in sheep. Bilateral osteoarthrosis was induced in the sheep temporomandibular joint (TMJ). Three months later, discectomy and autogenous auricular cartilage grafting were performed unilaterally. At sacrifice, three months postrepair and six months postinduction of osteoarthrosis, it was found that the untreated side had extensive condylar osteoarthrosis and the grafted side showed evidence of fibrous repair. The graft prevented intra-articular adhesions and reduced degenerative changes, but there was a tendency towards graft perforation. Auricular cartilage grafting was effective in minimizing osteoarthrotic effects on the TMJ in the early stages after grafting.

Short-term effect of the use of a frozen-stored disc allograft for repair of the osteoarthritic sheep temporomandibular joint: A preliminary report

PURPOSE The purpose of this experimental study was to evaluate the initial effect of a frozen-stored disc allograft on the osteoarthritic sheep temporomandibular joint (TMJ). MATERIALS AND METHODS Bilateral osteoarthritis was induced in the TMJ of four sheep. Three months later, unilateral discectomy and frozen-stored disc allograft replacement were performed. The donor disc had been obtained from a healthy animal at killing. The disc was stored in a deep freezer at -70 degrees C for 1 month and thawed just before grafting. The contralateral joints were undisturbed and served as a control at 3 months. At 6 months after the initial procedure, 3 months after the repair, the four sheep were killed. RESULTS All four grafted discs were perforated and displaced. In the repaired joints, the condylar articular surface was partly denuded in some areas, and part of the surface showed fibrous repair. The control joints showed osteoarthritic changes. CONCLUSION Frozen-stored disc allograft is not a satisfactory interpositional material in the osteoarthritic sheep TMJ.