Erosion and heterotopic bone formation after alloplastic temporomandibular joint reconstruction

Twenty-three temporomandibular joint arthroplasties using metallic condylar prostheses were performed because of severe ankylosis (8 patients), segmental mandibular resections in tumor surgery (9 patients), and after extensive trauma (2 patients). A clinical and radiological follow-up study showed heterotopic bone formation in 52% of cases and glenoid fossa resorption in 43%. In one patient with rheumatoid arthritis the condyle eroded through the skull base 10 months after surgery. Seven prostheses (30%) were removed and/or exchanged during the average 27.6-month follow-up.

Tumour markers and radiological examinations in the follow-up of patients with oral cancer

In 1986, a new follow-up programme for patients with oral cancer was introduced in our department. The follow-up programme included liver function tests, tumour markers and radiological examination. 63 patients were monitored to the end of 1990. The results showed that serum Carcinoembryonic Antigen (CEA) assays were not sensitive enough to detect early cancer, recurrences or metastases. Neither was there any difference between the preoperative CEA levels of patients with and without recurrence during follow-up. The levels of salivary CEA, were similar to those of healthy individuals. Serum CA 19-9 values were consistently normal. In 1 patient, the first sign of liver metastases was a high 5-nucleotidase level. No recurrences were detected by radiological examination. In conclusion, the importance of frequent and careful clinical observation is emphasized; all 20 recurrences at the primary site and in local lymphnodes were detected by clinical examination. For detection of oral cancer recurrences, several laboratory and radiological examinations seem unnecessary. The cost-benefit of those examinations is significantly low.

Normal mouse serum-derived factor(s) which inhibits growth of the interleukin-2-dependent cell line CTLL

Evidence is presented for the existence of a serum factor(s) (SF), which inhibits the growth of both the interleukin-2 (IL-2)-dependent cell line CTLL and the 2-day generation of CTL cells. This activity is found in the serum of both nude and euthymic mice and its suppressive effect can be detected about 18 hours after addition to CTLL cultures. The inhibitory activity elutes from a Sepharose 6B gel after the gamma globulin fraction (100-150 kD), and is precipitated by ammonium sulfate at 60 w/v% saturation. IL-3-mediated bone marrow colony formation is not inhibited by SF. It also does not suppress the growth of a panel of different tumor cell lines. The spleen cell responsiveness to both Con A and LPS activation is greatly reduced in the presence of SF. However, binding of radiolabelled IL-2 to CTLL cells was not blocked by SF, although the activity was greatly reduced by absorption to these cells. Our data support the existence of factor(s) in sera that may have a regulatory role on IL-2-mediated functions.

Is nasotracheal intubation safe in surgery for mandibular cancer?

A retrospective study of problems of postoperative airway maintenance after surgery for mandibular cancers was conducted. Twenty-seven patients treated in an intensive care unit after mandibular resection and primary reconstruction were included. The mean duration of nasotracheal intubation in 22 patients was 33.7 hours. Reintubation because of breathing difficulties was required in four cases. In one of these cases, failed intubation led to an emergency cricothyroidostomy. Failure to perform reintubation resulted in the death of one patient. One patient was tracheostomized after 5 days of nasotracheal intubation. Prolonged nasotracheal intubation after major surgery for oral malignant neoplasms may be an alternative to tracheostomy, provided that adequate monitoring is available after extubation. The safe duration of endotracheal intubation is difficult to determine. Primary reconstruction does not eliminate the need for an artificial airway after tumor surgery.

Topical application of 5% eutectic mixture of lignocaine and prilocaine (EMLA) before removal of arch bars

The analgesic effect of topical application of a 5% eutectic mixture of lignocaine and prilocaine (EMLA) was studied in 45 patients undergoing removal of oral arch bars used for the treatment of mandibular fractures. Employing a double-blind technique, either 4 g of the eutectic mixture (EMLA group, n = 15) or 4 g of a similar emulsion containing no local anaesthetic (placebo group, n = 15) was applied to the gingivae using a toothbrush and a standardised technique. In the control group (n = 15), infiltration anaesthesia with lignocaine was used only if requested by the patient during the removal of the arch bars. The patients in the EMLA group had significantly better analgesia (P less than 0.005) of the gingivae just before removal of the arch bars than patients in the placebo group, but by the end of the procedure the difference in analgesia was not significant. The number of patients who found the procedure pain-free was significantly higher in the EMLA group (7/14) than in the placebo group (2/15) (P less than 0.005). The plasma concentrations of both lignocaine and prilocaine were well below the toxic levels. Topical application of EMLA can be recommended for short procedures as an alternative to infiltration.

Decreased interleukin-2 beta-chain receptor expression by interleukin-4 on LGL: influence on the IL-2 induced cytotoxicity and proliferation

Addition of increasing amounts of interleukin-4 (IL-4) to large granular lymphocytes (LGL) had a selective downregulative effect on the interleukin-2 beta-chain (p70) receptor expression. A 40% inhibition of the p70 expression compared to untreated cells was already observed after a 24-h incubation with IL-4. This decrease in p70 receptor expression had a marked suppressive effect on their proliferative response to IL-2. In addition, LGL cultured in the presence of both IL-2 and IL-4 substantially decreased the cytotoxic activity against the erythroleukemia cell line K562. Our data therefore indicate an important regulative role for IL-4 on the LAK-generation.

A Sensitive Model System for In Vivo Monitoring of Baculovirus Gene Expression in Single Infected Insect Cells

We have developed a fast and sensitive system for the in vivo analysis of gene expression in baculovirus infected lepidopteran insect cells. A recombinant baculovirus containing a luciferase gene from the click beetle, Pyrophorus plagiophthalamus, under transcriptional regulation of the polyhedrin gene promoter of Autographa californica nuclear polyhedrosis virus (AcNPV) was used to infect a Spodoptera frugiperda cell line. Recombinant luciferase could be monitored by luminometry in real-time without disruption of the infected cells, allowing detection of synthesis as early as one hour after infection. The range of luminescence measurements was normally over four orders of magnitude, and the kinetics of luciferase synthesis and the levels of light produced in vivo closely correlated with the expression of polyhedrin in AcNPV infected cells when analyzed by SDS-PAGE. Additionally, single infected cells could be identified by CCD image analysis and flow cytometry.

Rigid internal fixation of mandibular fractures. An analysis of 270 fractures treated using the AO/ASIF method

The results are reported on 214 patients treated for 270 mandibular fractures, using rigid internal fixation. Of these, 172 fractures (63.7%) in 131 patients had been re-evaluated at final follow-up in connection with plate and screw removal, on average 15.2 months, postoperatively. Although one-third of the patients had a history of alcohol abuse, and 86% were treated with a delay of more than 24 h (mean 3.2 days), good primary bone healing was observed in 93.9% of the patients. Infections, seen in 6.1% of the patients, were related exclusively to inadequate stability of the fracture. Malocclusion, observed in 18.2% of 159 dentate patients, was caused by incorrect plate bending and insufficient fracture reduction. Immediate postoperative dysfunction of the inferior alveolar nerve in 58.1% of the cases, and of the mandibular branch of the facial nerve in 12.7%, was followed by almost total recovery 1 year after operation. It is concluded that rigid internal fixation is a reliable method of treatment, especially indicated for patients with reduced healing capacity and poor co-operation.

Radiologic follow-up of bone transplants to bridge mandibular continuity defects

Special radiologic imaging techniques were used to evaluate the results of nonvascularized bone grafts combined with rigid mandibular reconstruction plates. The radiologic findings divided 21 cases into three clearly distinct groups on the basis of resorption: slight (less than 15%), moderate (15% to 30%), and massive (more than 30%) (mean follow-up, 26 months). This division predicted the clinical results well. In contrast to earlier reports, it was shown that rigid plate bridging did not adversely influence the prognosis of the graft. Nor was early plate removal necessary to reach good ossification. Narrow-beam radiography and spiral tomography proved to be excellent tools for adequate evaluation of bone resorption and bony healing of mandibular grafts.

The histologic pattern of bone invasion by squamous cell carcinoma of the mandibular region

Surgical specimens from 16 nonirradiated patients with carcinoma of the mandibular region who had undergone resection of the mandible were investigated histologically to evaluate the presence, pattern and extent of bone involvement. Thirteen of the 16 carcinomas had invaded the mandibular bone. Two main patterns of growth were identified: seven carcinomas had infiltrated nonuniformly into the bone and six tumours had advanced as a compact front. Direct invasion from the oral mucosal tumour could be verified in 12 cases. Extension of four of these 12 tumours in bone clearly exceeded their dimension in the overlying mucosa. Carcinoma tissue in the mandibular canal, at a distance from the major tumour extension, was seen in two cases, whereas the periodontal ligament spaces were invaded only when there was a direct contiguous invasion by the tumour. The grade of histologic differentiation of the carcinoma did not definitely correlate with the frequency, pattern or extension of bone involvement. The results indicate that large tumour size, location on the mandibular alveolar ridge and clinical fixation to the mandibular bone predispose to, but are not prerequisites for bone invasion. Taken together, this study has shown that prediction of the presence and extent of bone involvement of the carcinoma located in the mandibular region is difficult on clinical grounds.

Elevated Plasma Levels of Neuropeptide Y Upon Electrical Stimulation of the Sympathetic Chain in Humans

Neuropeptide Y (NPY) a potent vasoconstrictor peptide, is co-stored with the classic neurotransmitter noradrenaline (NA) in certain peripheral sympathetic neurons and has been suggested to be a co-transmitter in vascular control. Surgical interruption of the sympathetic nerve supply of the upper extremity was performed to treat palmar hyperhidrosis in five patients. Intraoperative electrical stimulation (10 Hz; 0.5 ms; 0.5-3.0 mA) of the right and left sympathetic chains for 1 min was employed to determine the correct level for surgical excision. Blood pressure and heart rate were recorded continuously. Blood was sampled from the antecubital vein on the side subjected to stimulation for the determination of NPY-like immunoreactivity (LI) and plasma catecholamines. Blood samples were collected before and during stimulation, as well as 30 s and 2, 5, and 10 min after stimulation. A maximal blood pressure response was observed during the stimulation, but the magnitude varied markedly and was independent of the side on which the sympathetic chain was stimulated. During 3 of the 10 stimulations, the mean arterial blood pressure (MABP) increased 5-10 mm Hg, while in the other 7 an increase of 30-75 mm Hg was seen. No significant changes in heart rate or plasma adrenaline were found. The peak increase in NPY-LI plasma levels was noted 2 or 5 min after stimulation, while the corresponding peak for NA occurred during or 30 s after the stimulation. The maximal changes in plasma NPY-LI and NA were significantly correlated with the changes in blood pressure (NPY-LI, r = 0.80, p <0.01; NA, r = 0.84, p <0.01) as well as with each other (r = 0.95; p <0.001). It is concluded that, after electrical stimulation of the sympathetic chain in humans, plasma levels of both NPY-LI and NA rise, indicating release of these substances from sympathetic neurons. It is therefore possible that the vasoconstrictor peptide NPY is involved, together with NA, in the blood pressure response elicited by the stimulation.

Sensory disturbances associated with rigid internal fixation of mandibular fractures

Sensory status of the inferior alveolar nerve was monitored in 133 patients with 150 fractures in the region of the mandibular canal treated with rigid internal fixation preoperatively and 6 weeks postoperatively. Eighty-five of the patients were reevaluated on final follow-up at an average of 15.9 months. Preoperative sensory disturbance (58.5%) correlated significantly only with the presence of fracture displacement. The occurrence of postoperative paresthesia (76.0% at 6.2 weeks, 46.6% at 15.9 months) correlated significantly with the degree of mandibular edentulousness. Patients with edentulous mandibles, especially when a compression plate was used, suffered significantly more often from nerve injury than fully dentate patients. The results indicated that the sensory disturbance was caused by the surgical procedure. In contrast to previous assumptions, displacement of the fracture and preoperative sensory status did not correlate with postoperative occurrence of paresthesia.

Bridging of mandibular defects with two different reconstruction systems: an experimental study

To compare two different mandibular reconstruction systems, a 5-cm angular resection was performed in nine adult sheep. The defect was reconstructed using either a classic AO plate or the AO-THORP reconstruction system. The animals were killed 5, 9, and 14 weeks after operation. Serial sections with the plates and screws in place were prepared and studied histologically and with microradiography and fluorescence microscopy. Twenty-six percent of the 2.7-mm AO cortical screws were adequately fixed. The corresponding percentage for AO-THORP hollow screws was 73%. The main advantage of the latter system is the screw-plate locking principle, which allows plate stability to be maintained even if bone is resorbed under the plate. Whether the existence of a screw lumen is an advantage has not yet been established.

Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar fractures. A clinical and radiologic study of thirteen patients

Thirteen cases of high condylar fracture treated by open reduction and fixation with miniplates were monitored for an average of 18 months postoperatively. Satisfactory functional results were achieved clinically in all but one patient. Radiologically, however, signs of condylar resorption and osteoarthrosis were diagnosed in all patients. In four patients with associated multiple fractures of the facial bones, rapid complete resorption of the condyle was observed. These changes were markedly more severe than those observed in our previous study, in which osteosynthesis was performed by transosseous wiring and subsequent intermaxillary fixation for 3 to 7 weeks. Indications for rigid and nonrigid fixation in the surgical treatment of condylar fractures are discussed.

Effect of antiseptic mouthwashes on some clinical and microbiological findings in the mouths of lymphoma patients receiving cytostatic drugs

51 patients suffering from Hodgkin's disease or non-Hodgkin's lymphoma participated in this double-blind, cross-over study in which 2 antiseptic mouthwashes were tested for their effects on various periodontal index scores and salivary microbial counts. All patients were receiving combination cytostatic treatment based on methotrexate and doxorubicin. The patients (49 +/- 14 years old, 28 men, 23 women) were allotted at random to 2 groups. One rinsed with a 0.12% chlorhexidine gluconate (CHX) solution, the other with a 0.025% amine-stannous fluoride (AmF + SnF) solution 2x daily for 2 weeks. Both groups then continued rinsing with a 0.05% sodium fluoride (F) solution for 2 weeks, before switching over to AmF + SnF or CHX, respectively. All solutions had been prepared in such a way that they had the same colour and taste. Visible plaque index and gingival bleeding index scores were significantly reduced after periods of rinsing with CHX solution (P less than 0.001) and AmF + SnF solution (P less than 0.05). Microbiological cultivations of saliva specimens revealed significant reductions in mutans streptococci immediately after commencing rinsing, while lactobacilli and yeast counts were not affected.

Evaluation of various treatments for carcinoma of the mandibular region

Cancers of the mandibular region show the lowest survival rates of all oral cancers. In order to compare the effect of five different modes of treatment (including surgery and/or radiotherapy), a series of 159 patients was analysed. When adjustments were made for age, sex and tumour stage in a log-linear multivariate analysis, no differences between treatments in the 5-year relative survival rates (RSR) could be demonstrated for stage I and II tumours. In stage III and IV tumours, radiation treatment alone resulted in poor survival. Between the other four treatments, all including surgery, no statistically significant differences in the 5-year relative survival rates were found. Radiation therapy as an element in combination therapy may have postponed a recurrence but did not affect the 5-year survival rate. For advanced tumours, mostly responsible for the low overall 5-year RSR, higher survival rates can possibly be achieved by improving surgical treatment of the primary lesion and the neck. At present, however, only earlier diagnosis might significantly increase the survival rates.

Interleukin-4 downregulates the p70 chain of the IL-2 receptor on peripheral blood mononuclear cells

Data that support a differential regulation of the interleukin-2 receptor (IL-2R) alpha-(p55 or Tac) and beta-chain (p70) expression by IL-4 are presented. Cytofluorometric analysis performed on peripheral blood mononuclear cells, some of which had been nylon wool passed (enriched for T-cells), in the presence or absence of phytohemagglutinin (PHA) or OKT3, demonstrated that IL-4 has a dose-dependent capacity to inhibit beta-chain IL-2R expression, whereas the alpha-chain is nearly unaffected. We could also, as a consequence of the decreased p70 expression, detect a slight increase in the amounts of IL-2 obtained from PHA-stimulated cultures, when IL-4 was present. Further, the proliferative response, especially to IL-2, but also to PHA alone, was depressed in the presence of IL-4. These data thus give further support to the idea that not only the IL-2R complex as such, but also the two individual IL-2R chains, can be independently regulated.

Inhibition of CD3-induced Ca2+ signals in Jurkat T-cells by myristic acid

Stimulation of T lymphocytes with antibodies against the T cell receptor/CD3 complex induces within seconds a rise in the concentration of intracellular free Ca2+. Here we show that treatment with 20 microM free myristic acid completely inhibits this Ca2+ signal and the cellular proliferation in Jurkat T cells. Also lauric acid inhibited cell growth while its blocking effect on the Ca2+ signal was weaker than that of myristic acid. Other saturated free fatty acids were inactive. The inhibitory effect of myristic acid could be reversed by the addition of fatty acid free albumin, which will bind the fatty acid. Myristic acid, but not its methyl ester, inhibited both the anti-CD3-induced Ca2+ influx across the cell membrane and Ca2+ release from intracellular stores, but not the formation of inositol phosphates. In contrast, thapsigargin-induced release of Ca2+ from the same intracellular stores was unaffected by myristic acid. Thus, myristic acid specifically blocks T cell antigen receptor-CD3 induced Ca2+ mobilization in T cells.

Infection after rigid internal fixation of mandibular fractures: a clinical and radiologic study

Of 214 patients with mandibular fractures treated following the AO/ASIF principle of rigid fixation, 13 patients (6.1%) developed postoperative infection. The yearly percentage decreased remarkably during the study period. When rigid fixation became a routine method, the infection rate was as low as the corresponding figure for cases treated with nonstable techniques and maxillomandibular fixation (MMF). All but one of the infected fractures were in the angular region of the mandible. Teeth had been extracted from the fracture line in 9 of the 10 dentulous patients. It was concluded that erroneous techniques had been used in almost all infected cases, because compression could not be achieved when there was an irregular fracture line, an atrophic edentulous mandible, or inadequate stability due to removal of a tooth in the line of fracture. In five patients, successful reoperation was performed using a reconstruction plate. Detailed radiologic examination was useful in assessment of infection and in follow-up.

Changes in C-reactive protein associated with surgical treatment of mandibular fractures

C-reactive protein (CRP) levels were determined in 80 patients (67 male, 13 female), each with a single mandibular fracture in either the symphysis, body, or angle region. All patients underwent osteosynthesis (63 with rigid plate fixation following the AO/ASIF principle, 17 with miniplates). C-reactive protein levels were measured on admission and daily during hospitalization. Preoperative CRP levels (mean, 28.5 mg/L) varied according to the time that had elapsed since injury. After surgery, there was always an increase in CRP level. The level reached its maximum (mean, 73.2 mg/L) on the second day after operation. Postoperative CRP levels were significantly influenced by the time between trauma and surgery. Significant differences were also observed with different types of fixation. Fixation with rigid plates was associated with smaller increases in CRP level than was fixation with miniplates. The location of the fracture, associated condylar fractures, the use of maxillomandibular fixation, the presence or absence of a tooth at the fracture site, and the surgical approach did not affect the CRP levels. The significance of CRP measurement for interpretation of postoperative situations is discussed and examples of cases in which there was infection are described.

Reconstruction of orbital floor with polydioxanone plate

The use of a polydioxanone (PDS) plate for orbital reconstruction was evaluated in 20 patients with various traumatic defects of the orbital floor. The follow-up time was 9 to 45 months (mean 20.4 months). A CT scan was obtained in 13 patients. Radiographic analysis showed that in 12 of the 13 patients there was new bone in the orbital floor. Clinically, most patients had transitory postoperative diplopia (lasting for a mean of 29 days) because of overcorrection. Only 2 patients, however, suffered from persistent diplopia. In one patient, abducens nerve paresis was the cause. It is concluded that PDS is suitable for orbital floor reconstruction, at least in cases in which defects do not exceed 1-2 cm in diameter. Overcorrection seems necessary. The material is well tolerated, is totally absorbed and appears to be replaced by bone in nearly all cases.

Phosphotyrosine phosphatases are involved in reversion of T lymphoblastic proliferation

Resting T lymphocytes can be activated by mitogens or antigens to become T blasts, which revert spontaneously both in vivo and in vitro in extended cultures to secondary, memory T lymphocytes. We have studied the role of phosphotyrosine phosphatases (PTPase) in the reversion of lymphoblasts in extended, phyto-hemagglutinin-stimulated cultures of human T lymphocytes. Membrane-associated PTPase activity is high in resting T cells, but decreased during mitogen-induced blast transformation. When the blasts were reverting to lymphocytes, the PTPase activity increased more than twofold concomitantly with an elevated surface expression of CD45. When T blasts from phytohemagglutinin-activated cultures were kept in the presence of sodium orthovanadate, an inhibitor of PTPase, they maintained their lymphoblastic proliferation and did not revert to resting lymphocytes. This was accompanied by retention of a 48-kDa phosphotyrosine-containing protein. Our data indicate an important role for PTPase in the transition of lymphocytes from an activated to a resting stage.

Benign osteoblastoma of the mandible

Benign osteoblastoma is a rare osteoblastic tumour with osteoid and bone deposition. A rapidly growing osteoblastoma involving the area of the mandibular first and second molar of a 20-year-old female is described. Investigation of the collagenous components of the tumour by immunofluorescence was suggestive of a normal collagen synthesis by the tumour osteoblasts. The lesion is discussed with particular emphasis on its differential diagnosis and matrix constituents.

Non-Hodgkin's lymphomas presenting through oral symptoms

Non-Hodgkin's lymphomas (NHL) presenting through oral symptoms are rare. Between 1976 and 1987, a total of 17 cases (7 male, 10 female) were diagnosed in our departments. The first symptom was an intraoral tumour mass in 9 cases, loosening of teeth in 2 cases and paraesthesia in another 2. Most tumours (13/17) were located in the lower jaw. In only 5 cases had the referring physician or dentist suspected malignancy. In 3 cases, the histological diagnosis was Burkitt's lymphoma. The grade of malignancy was classified as low in 4 cases, intermediate in 3 and high in 8. None of the patients was HIV-positive. Nine patients died of their disease within 1-132 months (mean 18.3 months).