Donald J. Macher

Use of protrusive splint therapy in anterior disk displacement of the temporomandibular joint: A 1- to 3-year follow-up

Sixty-eight patients, who were determined clinically (by the presence of audible and palpable-joint sounds) and arthrographically to have meniscus displacement with reduction, had protrusive splints constructed, and the results were evaluated for a minimum of 1 year to a maximum of 3 years. Eighteen additional patients, arthrographically determined to have meniscus displacement with reduction, served as a nontreatment group for comparison. Odds ratios were calculated to compare the proportions of subjects who experienced follow-up symptoms on the two regimens. Results indicated that with splint therapy there was a statistically significant reduction of the intensity of jaw joint pain, temporal headache, ear pain, and pain in front of the ear, and there was a decrease in the probability of a closed lock condition developing. Splint therapy is less likely to reduce frontal headache, neck pain, and clenching of teeth.

Effect of a surgically created disk displacement on mandibular symmetry in the growing rabbit

PURPOSE The purpose of this study was to evaluate the contribution of unilateral disk displacement to growth changes in the young New Zealand White rabbit. METHODS Ten female rabbits aged 10 weeks were included in this study. The five experimental rabbits had unilateral anterior disk displacement surgery. The five controls had no surgery. The rabbits were killed at 22 weeks of age, and the mandibles hemisected and radiographed. Cephalograms were digitized and analyzed by conventional methods. RESULTS The gross appearance showed shortening and flattening of the articulating surface in the experimental group (P < 0.05). No significant shortening and flattening was found in the control group. CONCLUSION These observations suggest that surgically created internal derangement can produce altered growth in the mandible.

Temporomandibular joint: Surgically created disk displacement causes arthrosis in the rabbit☆

To document a causal relationship between temporomandibular joint disk displacement and arthrosis, the disk was surgically displaced in one temporomandibular joint in each of three rabbits. The rabbits were sacrificed after 4 weeks and the mandibular condyles were studied radiographically and histologically. All three joints that underwent disk displacement had radiographic and histologic evidence of arthrosis, which included erosion of the bone, irregularity and fissure formation of the articular soft tissue cover, disruption of the subchondral layer of cartilage cells, and chondrocyte proliferation. No radiographic or histologic changes occurred in the joints that were untouched. The results suggest that surgically created disk displacement can cause arthrosis in the temporomandibular joint of the rabbit.

Creation of disc displacement in human temporomandibular joint autopsy specimens

The purpose of this study was to investigate the possibility of iatrogenically creating disc displacement in the human temporomandibular joint (TMJ). Fourteen fresh TMJ autopsy specimens with superior disc position were selected for the study. The upper and lower joint spaces were exposed via a preauricular incision and two to three superficial mediolateral incisions were made in the inferior surface of the posterior disc attachment (ie, retrodiscal tissue). After these incisions were made it was possible to manually displace the disc anteriorly. To maintain the disc in the anterior position the condyle was positioned against the posterior disc attachment in a manner corresponding to the closed mouth position. The joints were then fixed in this relationship and magnetic resonance imaging (MRI) was repeated using the same scanning plane and scanning parameters as before intervention. After imaging, the joints were cryosectioned to show the degree of disc displacement. Histologic analysis was made of the posterior disc attachment. Postoperative MR images and cryosections showed the disc to be displaced anteriorly in 12 of the 14 joints. Displacement of the disc was complete in eight joints (the entire mediolateral dimension of the joint) and partial (only in the lateral part of the joint) in four joints. The disc remained in a superior position in two joints. Cryosections and histologic analysis showed the incisions in the inferior aspect of the posterior disc attachment to be superficial. The results of this study suggest that the integrity of the inferior aspect of the posterior attachment of the disc to the condyle is essential for keeping the disc in its position superior to the condyle.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthrographically assisted splint therapy: A 6-month follow-up

After repositioning splint therapy, 51 patients were evaluated for a minimum of 6 months. Forty-five (88%) of the patients were considered to have been treated successfully, whereas six (12%) patients required surgery to correct meniscal displacement. A detailed analysis of signs and symptoms before and after splint treatment is in progress.