Expression of fibronectin-binding integrins in gingival epithelium in drug-induced gingival overgrowth

BACKGROUND AND OBJECTIVE

Gingival overgrowth is a side-effect of nifedipine and cyclosporin medications. Integrins are transmembrane glycoproteins that mediate cell adhesion, regulate cell proliferation and participate in the regulation of tissue fibrosis. The aim of this study was to investigate whether expression of epithelial cell integrins is linked to the development of drug-induced gingival overgrowth.

MATERIAL AND METHODS

Human gingival biopsies of patients taking nifedipine, cyclosporin, or a combination of both medications, were used. Expression of the alpha5beta1, alphavbeta1 and alphavbeta6 integrins, and of cellular extra domain A of fibronectin, was localized in frozen sections using immunohistochemistry.

RESULTS

The activated conformation of the beta1, alpha5beta1 and alphavbeta6 integrins were more frequently expressed in distinct locations in the oral epithelium in the combined drug group. Cellular extra domain A of fibronectin, a ligand for both alpha5beta1 and alphavbeta6 integrins, was expressed within the connective tissue of all groups. It was also expressed around the basal keratinocytes of the control, nifedipine and cyclosporin-induced gingival overgrowth groups, but not in the combined medication group. No relationship between the presence of inflammation and integrin expression was found.

CONCLUSION

The results indicate that expression of certain integrins is up-regulated in the epithelium of drug-induced gingival overgrowth where they could participate in controlling the formation of elongated rete ridges and tissue fibrosis.

MMP-3 and -8 expression is found in the condylar surface of temporomandibular joints with internal derangement

BACKGROUND

Internal derangement is one of the most common disorder of the temporomandibular joint (TMJ). The aim of this study was to investigate the associations of matrix metalloproteinase (MMP)-3 and -8 expression in articular condylar surface with different stages of TMJ internal derangement according to Wilkes (Minn Med, 1978; 61: 645-52) and osteoarthrosis (OA) according to Dijkgraaf et al. (J Oral Maxillofac Surg, 1995; 53: 1182-92).

METHODS

The study was based on 54 condylar specimens obtained during TMJ surgery. Immunohistochemistry using antibodies specific to MMP-3 and -8, represented in cartilage destruction, was carried out.

RESULTS

In all tissue specimens, MMP-3 expression was intense in the surface layer but showed less intensive staining in the deeper layers. Some MMP-8 expression was also seen. The severity of TMJ internal derangement, however, did not seem to have a statistically significant correlation (P<0.05) with the expression of these enzymes.

CONCLUSION

The study confirms that distinct expression of MMP-3 and -8 is found in the condylar surface of TMJs with internal derangement.

Matrix metalloproteinases in mild and severe temporomandibular joint internal derangement synovial fluid

OBJECTIVES

The first objective of this study was to verify the presence of and identify the molecular forms of matrix metalloproteinases (MMPs), including collagenases (MMP-1, MMP-8, and MMP-13) and gelatinases (MMP-2 and MMP-9), in the synovial fluid (SF) of mild and severe temporomandibular joint internal derangement (TMJ-ID). Another objective was to evaluate whether the SF MMPs are potential diagnostic markers that reflect the stage of intra-articular inflammation in the TMJ.

STUDY DESIGN

The subjects were 44 patients with mild (n = 16) or severe (n = 28) TMJ-ID; they were classified on the basis of subjective symptoms, clinical and radiographic findings, and surgical observations. The patients were surgically treated, and SF samples were collected immediately before the operation. The collagenase activity of SF samples was analyzed by means of a type I collagen degradation assay. The levels and molecular forms of the SF MMPs as well as the tissue inhibitors of MMPs (TIMP-1 and TIMP-2) were analyzed with Western immunoblotting and gelatin zymography.

RESULTS

The SF of both the mild and the severe TMJ-ID patients exhibited free collagenase activity and activity capable of further degrading the (3/4)(alphaA) fragments. Ninety-two-kilodalton proMMP-9 and its 121-kD complex form, as well as 72-kD proMMP-2 were significantly increased in the mild TMJ-ID group (P <.05 in all cases). Both 70- to 80-kD neutrophil type and 45- to 55-kD mesenchymal cell-type MMP-8 (corresponding to the latent and active forms) were observed in mild and severe TMJ-ID SF, but they predominated in mild TMJ-ID. Both MMP-1 and MMP-13 were observed in both groups, and in mild TMJ-ID SF the low-molecular weight forms of MMP-1 indicated activation of the enzyme.

CONCLUSIONS

The degradation of type I collagen in the TMJ is evidently due to the collective action of many collagenolytic MMPs present in the SF of patients with mild and severe TMJ-ID. The elevated levels of MMP-2, MMP-9, and MMP-8 in the SF of patients with mild TMJ-ID eventually reflect the active phase of TMJ destruction. These observations may have considerable diagnostic and therapeutic significance in the management of TMJ disorders.

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

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.

Biocompatibility of nickel-titanium shape memory metal and its corrosion behavior in human cell cultures

Nickel-titanium alloy (Nitinol) is a metallic biomaterial that has a unique thermal shape memory, superelasticity, and high damping properties. Nitinol is potentially very useful in orthopedic surgery, for example. At present, there are not enough confirmative biocompatibility data available on Nitinol. The aim of our study was to clarify the primary cytotoxicity and corrosion rate of Nitinol in human cell cultures. Comparisons were made with stainless steel (Stst), titanium (Ti), composite material (C), and control cultures with no test discs. Human osteoblasts (OB) and fibroblasts (FB) were incubated for 10 days with test discs of equal size, 6 x 7 mm. The cultures were photographed and the cells counted. Samples from culture media were collected on days 2, 4, 6, and 8, and the analysis of metals in the media was done using flameless atomic absorption spectrophotometry. The proliferation of FB was 108% (Nitinol), 134% (Ti) (p < 0.02), 107% (Stst), and 48% (C)(p < 0.0001) compared to the control cultures. The proliferation of OB was 101% (Nitinol), 100% (Ti), 105% (Stst), and 54% (C) (p < 0.025) compared to the controls. Initially, Nitinol released more nickel (129-87 micrograms/L) into the cell culture media than Stst (7 micrograms/L), but after 2 days the concentrations were about equal (23-5 micrograms/L versus 11-1 micrograms/L). The titanium concentrations from both Nitinol and Ti samples were all < 20 micrograms/L. We conclude that Nitinol has good in vitro biocompatibility with human osteoblasts and fibroblasts. Despite the higher initial nickel dissolution, Nitinol induced no toxic effects, decrease in cell proliferation, or inhibition on the growth of cells in contact with the metal surface.

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.

Clinical, magnetic-resonance imaging and surgical findings in patients with temporomandibular joint disorder--a survey of 47 patients

The purpose of this study was to evaluate and correlate the clinical, magnetic-resonance imaging (MRI), and surgical findings in 47 patients with temporo-mandibular joint (TMJ) disorders. 51 TMJs (24 right, 27 left) were operated on, because 4 patients underwent treatment of both TMJs. The best correlation between MRI and surgical findings was noted in connection with position of the disk. This was surgically confirmed altogether in 88% of cases (45/51). The clinical diagnosis was confirmed by surgical findings in 75% of cases of anterior dislocation of the disk with reduction and 89% of cases of anterior dislocation of the disk without reduction. Bone changes noted by MRI were confirmed by surgery in 71% of cases. MRI was excellent especially relating to disk position and changes in disk morphology. The results show also that there are findings using MRI, e.g. of joint effusion, which cannot be confirmed during surgery.

Development of the neurocranium after transsutural fixing by new, resorbable poly-L-lactide miniplates. A comparison to fixing with the common titanium miniplates

The right coronal sutures of twelve (12) newborn rabbits were fixed with commercially available, self-reinforced poly-L-lactide miniplates, with eight (8) rabbits sham treated with titanium miniplate fixation as reference experiments, in order to demonstrate the possible effects on skull growth. After six (6) months follow-up, both types of plate were detected to have caused a similar asymmetry in the neurocranium. Therefore, in our opinion, fixing across growing sutures, even with the new biodegradable devices, should be avoided.

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.

Cystatin A and B in the development of human squamous epithelia

The expression of cystatin A (Acid cysteine proteinase inhibitor) and B (Neutral cysteine proteinase inhibitor) during human embryogenesis was studied immunohistochemically by using the PAP-complex method. Both inhibitors were visible first in the developing mucosal tissue at the age of about 9 weeks. In the fetal epidermis (periderm), cystatin B was demonstrated at the age of 11 weeks and cystatin A at 12 weeks. In these young fetuses, the staining was visible in the basal cells, whereas in fetuses older than 17 weeks the staining of both inhibitors diminished in the basal cells. In the skin of 17 to 25 weeks old fetuses, the epidermal staining of cystatin B become weaker than that of cystatin A, and at the age of about 26 weeks, cystatin B disappeared totally. At this stage, cystatin A was localized in the cytoplasm of the middle to upper cell layers of the epidermis. In the squamous epithelia of the mucosal tissues, the staining of the both inhibitors reached their maximal intensity when the fetuses were about 16 weeks old. At the mature fetuses, infants as well as adults, both cystatin A and B seemed to be present in wet squamous epithelia while in the epidermis only cystatin A was expressed.

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.

Surgical and prosthetic treatment of the atrophic mandible

Two vestibuloplasty methods and a muscle-formed method for improving the retention and stability of complete mandibular dentures were compared in 19 edentulous patients with advanced mandibular bone resorption. The resorptive changes in the alveolar crest and any relapse in the extended vestibule after surgery were monitored for 2 yr. Simultaneous production of the first new complete dentures, to which the labial plate is added during the surgical procedure, and firm circummandibular fixation during primary healing will guarantee the best surgical and prosthetic results. This order of treatment also eliminates unnecessary surgical procedures. A muscle-formed method for extending the baseplate of a complete mandibular denture was found to be a useful alternative for patients with highly advanced mandibular bone resorption.

Weight changes after jaw fixation due to sagittal split ramus osteotomy for correction of prognathous

Body weight changes, energy intake and symptoms experienced were studied in 13 patients whose jaws were fixated due to osteotomy for protruding mandible. All except one patient lost weight and the mean weight loss was 7.5 +/- 5.3 kg. The weight reduction was higher in the obese patient (11 +/- 4.2 kg), but also patients of normal weight lost 4.7 +/- 4.6 kg. The reduction of daily energy intake from the preoperative state as 1.5 +/- 1.0 MJ and was in obese patients about twice as much as in the lean ones (2.1 +/- 0.8 MJ and 1.0 +/- 1.0 MJ, respectively). The reduction of energy intake per loss of body weight by 1 kg was in all patients 8.5 +/- 0.67 MJ, in obese 8.3 +/- 0.64 MJ and in lean patients 8.6 +/- 0.75 MJ. The loss of weight was temporary and the patients regained their weights largely or wholly after the fixation period. Ten patients of the 13 felt hunger during fixation period, two had abdominal pains, five constipation and two pollacisuria. Jaw fixation due to osteotomy for protruding mandible decreased the food intake of the patients much and deteriorated their nutritional status by considerable weight loss. Thus advice about fortifying the diet is indicated so that the patients could consume food of high energy content during intermaxillary fixation due to sagittal split ramus osteotomy for correction of prognathous.

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.