Hannu Pernu

MR abnormalities of the lateral pterygoid muscle in patients with nonreducing disk displacement of the TMJ.

ABSTRACT The aim of this study was to investigate the pathological changes of the lateral pterygoid muscle (LPM) using magnetic resonance imaging (MRI) in patients with anterior disk displacement with nonreduction (ADDnr) of the temporomandibular joint (TMJ) and to compare the abnormal findings of the LPM with the clinical symptoms and other pathological MRI alterations of the TMJ. Bilateral or unilateral ADDnr was demonstrated in 142 patients by MRI (176 TMJs; 106 females; 36 males; range 19 to 72 years; mean 43.9 years). In 123 TMJs, the LPMs were clearly observed in MRIs and analyzed in this study. Pathological changes of the LPM were found in 92 TMJs (74.8%) in MRI. Hypertrophy, atrophy and/or contracture were detected in the superior belly of the LPM (SBLPM) (35.8%, 44/123) or in the inferior belly of the LPM (IBLPM) (9.8%, 12/123) or in both bellies (29.3%, 36/123). The pathological changes of the LPM in MRI presented a significant association with the main clinical symptoms of TMJs with ADDnr, i.e. pain on jaw movement (P<0.01), pain in the LPM (P<0.01), pain in TMJ (P<0.05) and restricted jaw opening (P<0.05). The proportion of the abnormalities in LPM was significantly lower in TMJs with condylar limitation (63.6%) than in TMJs with condylar hypermobility (83.3%) and normal motion (88.9%)(P=0.008). Osteoarthritis was found to be correlated with condylar limitation (P<0.01). The results of this study indicate that the pathological changes of the LPM in TMJs with ADDnr could be detected by MRI and have a significant association with the main clinical symptoms of the patients. When condylar limitation happened, on the contrary, the pathological changes of the LPM in MRI were reduced. The alteration of the clinical symptoms in the patients with ADDnr might be associated with the pathological situations and symptoms of the LPM.

Clinical and computed tomographic findings in costochondral grafts replacing the mandibular condyle

PURPOSE The aim of this study was to evaluate by computed tomography (CT) and clinically the structure and function of costochondral grafts (CCG) used to replace the mandibular condyles. MATERIAL AND METHODS CT and clinical examination were performed in 11 patients with CCGs (9 female, 2 male; mean age at surgery, 25 years; range, 9 to 44 years) approximately 4.5 years after surgery (range, 5 months to 10.5 years). One mandibular condyle was replaced in six patients and two in five patients. RESULTS Facial asymmetry was observed in two cases and palpation tenderness of the TMJs or clicking and crepitation were found in 10 of 16 operated TMJs. In three cases coronal CT scans showed the graft to be situated laterally in the mandibular fossa, and lateral overgrowth of the graft was seen in three cases. In two cases, coronal CT slices showed that a new fossa had developed. In most cases translatory movement of the graft was minimal. The graft was either partially or almost completely mineralized, especially in cases with longer follow-up. CONCLUSIONS Most of the patients in this study seemed to have benefitted from replacement of the deformed mandibular condyle with a CCG as estimated by improved range of mandibular movements and decreased symptoms. There were some problems related to unpredictable growth and location of the graft, as well as restricted movement of the replaced condyle. In the future, care should be taken to ensure proper postoperative functional therapy and to examine the role of cartilage thickness on future growth in young patients.

Surgical treatment of condylar process fractures using axial anchor screw fixation: A preliminary follow-up study

PURPOSE The aim of this study was to evaluate use of the axial anchor screw system in the treatment of condylar process fractures. PATIENTS AND METHODS Seven adult patients with displaced condylar process fractures were treated using axial anchor screw fixation. Indications for surgery were severe dislocation of the condyle and occlusal changes. Clinical and radiologic examinations were performed 6 weeks, 6 months, and approximately 2 years postoperatively (range, 18 to 30 months). Clinical factors recorded were occlusion, range of mandibular movement, and findings on palpation of the temporomandibular joints. Ramus height and angulation between the mandibular ramus and the dislocated condyle were measured and compared with the contralateral side preoperatively and at the last follow-up. RESULTS The postoperative course was uneventful in most patients. All were free of pain, and the occlusion and facial symmetry were normal. Radiographs generally showed excellent fracture reduction. Translation of the condyles on mouth opening was symmetrical. No signs of resorption or osteoarthrosis were evident in most cases. However, some patients had complications. These involved unsatisfactory reduction in one patient causing osteolysis at the fracture line. In another patient bone over the screw fractured and the condyle and the screw tilted in a medial direction. CONCLUSION Treatment of condylar process fractures using the axial anchor screw system is ideal in certain cases. The complications and difficulties seen may be avoidable by appropriate patient selection and techniques.

Localization of three inhibitors of cysteineproteinases in the human oral mucosa

3 known human cysteineproteinase inhibitors--neutral cysteineproteinase inhibitor (NCPI), acid cysteineproteinase inhibitor (ACPI) and serum alpha-cysteineproteinase inhibitor (alpha-CPI)--were localized immunohistochemically in the squamous epithelium of the mouth by using the peroxidase-antiperoxidase complex method and formaldehyde-fixed paraffin-embedded tissue sections. Neither ACPI nor NCPI was found in the 2 to 3 most basal cell layers of the epithelium, but a strong cytoplasmic reaction was seen in the upper cell layers by using either anti-ACPI or anti-NCPI serum. In some cells the most dense stain precipitate was seen around or in the nucleus, and in the highest cell layers the staining was sometimes associated with the cell membrane. alpha-CPI was localized mainly in the epithelial stroma and in the intercellular space of the epithelium.

MRI findings concerning the lateral pterygoid muscle in patients with symptomatic TMJ hypermobility.

ABSTRACT Clinical studies have shown a close association between temporomandibular joint hypermobility (TMJH) and temporomandibular disorders (TMD). While pathological change of the lateral pterygoid muscle (LPM) is one of the most emphasized in studies of TMD, there have been no detailed clinical reports of the LPM studies using magnetic resonance imaging (MRI) in TMJH. This study investigates structural and pathological alterations involving the LPM in patients with TMJH using MRI. A retrospective analysis was made of high-field MRI images from 98 patients with TMJH. LPMs of 143 joints were analyzed. In 110 joints (77%), hypertrophy, atrophy, and contracture were found in the superior belly and/or the inferior belly of the LPM. Pathological changes were more frequently found in the superior rather than the inferior belly of the LPM. In the cases with abnormalities in both bellies of the LPM, hypertrophy of the inferior belly was usually found combined with other changes of the SBLPM. The results of this study indicated that the pathological changes of the LPM or MRI are not in frequent in patients with symptomatic TMJH.

Internal derangement of the temporomandibular joint: A histochemical study

The purpose of this study was to correlate histologic findings in temporomandibular joint (TMJ) condyles and discs with their macroscopic appearance at surgery. The 24 patients with internal derangement of the joint included 20 women and 4 men (mean age, 37 years; range, 18 to 61 years). The tissue lesions varied in degree from mild soft-tissue fraying and bone remodeling to extensive resorption and new cartilage and bone formation with high phosphatase enzyme activities, and even to loss of articular soft tissue and breakdown of cortical bone. Reactions may arise in the hard tissues before they occur in the articular surface layers.

The effect of surgical treatment of the temporomandibular joint: a survey of 70 patients.

ABSTRACT Most patients with temporomandibular disorders (TMD) can be successfully treated by conservative methods, but approximately 10–20 percent have persistent symptoms. The aim of this study was to evaluate the signs and symptoms of TMD in patients treated with open surgery of the TMJ. Seventy-two patients (13 men, 59 women, mean age 37 years, range 14–68 years) were evaluated during an eight-year period. Altogether 45 right TMJs and 39 left TMJs were treated, including both TMJs during the same operation in eight of the cases. The patients were evaluated at follow-up in 1997. The degree of TMD at follow-up was assessed using the anamnestic and clinical dysfunction Helkimo indices. Most of the patients reported at the follow-up that they were subjectively satisfied with the surgical treatment. The main clinical findings in the post surgical patients at follow-up were TMJ sounds and deviation of the mandible during opening. The tenderness in the masticatory muscles and TMJs on palpation was reduced significantly and the ranges of mandibular movement were improved for all the patients. The mean anamnestic and clinical indices decreased with a statistical significance from the shortest follow-up group (Group I) to the longest on group (Group IV) (p = 0.000). The conclusion of this study was that after open surgical treatment of the TMJ, the patients have significantly better functioning of the masticatory system and reduced signs and symptoms of TMD in the long term.

Changes in electrical activity of masseter and temporal muscles after temporomandibular joint surgery: A one-year follow up

The functioning of the masseter and anterior temporal muscles was recorded by electromyography (EMG) in 15 patients with disc interference of the temporomandibular joints, before surgery and three months, six months and one year afterwards. EMG recordings were made during maximal bite in intercuspal position and while chewing. The mean electrical activity in the masseter and anterior temporal muscles, both on the operated and nonoperated sides, decreased markedly three months after surgery, especially during maximal bite in intercuspal position, but increased to above the preoperative values at the one-year recording in both functions. Statistically, significantly lower activities were seen on the operated side in patients with anterior dislocation of the disc without reduction, as compared to patients with reduction of the disc. The EMG activities of the masseter muscles on the nonoperated side were significantly lower in women and in older patients, as well as in patients with a longer duration of symptoms than in men and younger patients.

Analgesic efficacy and tolerability of diflunisal in oral surgery

A double-blind, completely randomized study was carried out on 169 patients to compare the analgesic efficacy and tolerability of diflunisal with that of Veralgin after surgical removal of impacted third molars. One group received 1000 mg diflunisal (Donobid, MSD) 2 h preoperatively and then 500 mg twice daily for 2.5 days, and the other group Veralgin (aminophenazon. 286 mg, barbital. 114 mg, aethylmorph. hydrochlorid. 20 mg, Orion), a fixed combination widely used in Finland, 1 tablet twice daily beginning 2 h prior to operation. Visual analogue scales were used to estimate pain. Diflunisal was found to be superior in relieving pain in the early postoperative period, the associated frequency of adverse clinical experiences was lower and the final evaluation of analgesic efficacy by both the patients and the investigators, was in its favour. The study confirms that postoperative pain after third molar surgery can be controlled well without the use of mainly centrally acting combination analgesics.

The comparison of outcomes of surgically treated bilateral temporomandibular joint disorder in different groups: A retrospective study

Objectives: The main purpose of this study was to determine the prognosis and outcomes of the patients with bilateral temporomandibular disorder which underwent bilateral temporomandibular joint surgery in a consecutive number of patients in a retrospective study. Study Design: Sixty five patients with 130 bilateral TMJ were included the study with the selection from consecutive 256 TMJ patients who were treated with open surgery who do not respond to conservative treatment. 65 patients were divided in to 3 main groups according to the clinical diagnosis of bilateral TMJ site. In the first group comprised 29 patients with 48 TMJ, the clinical diagnosis was bilaterally presence of anterior disc displacement with reduction (ADDR). In the second group comprised 19 patients with 26 TMJ, bilateral presence of TMD consisted of anterior disc displacement without reduction (ADDNR) on both site. In the third group comprised 27 patients with 46 TMJ, bilaterally presence of TMD consist of ADDR on one site and ADDNR on another site. The patients in three different groups were operated either high condylectomy alone or high condylectomy with additional surgical procedures. Results: In the evaluation of pain relief, clicking, crepitation, headache, marked improvement was determined in all groups, but it was statistically insignificant in the comparison of 3 groups. Slight increase in maximal mouth opening was determined in the mean values of the 3 groups and also in the comparison of 3 groups it was not statistically significant. Conclusions: These similar succesfull outcomes of bilateral TMD with the respect of TMJ surgical procedures were obtained in 3 main groups although different diagnosis on the patients’ groups waspresent. Key words:Temporomandibular joint, prognosis, retrospective studies.