Biomedical subjects

R Gassner

Publications and source records attributed to R Gassner.

At least 19 recordsLinked to original sources

PubMed2001

Cyclic tensile strain suppresses catabolic effects of interleukin-1beta in fibrochondrocytes from the temporomandibular joint.

OBJECTIVE: To discern the effects of continuous passive motion on inflamed temporomandibular joints (TMJ). METHODS: The effects of continuous passive motion on TMJ were simulated by exposing primary cultures of rabbit TMJ fibrochondrocyte monolayers to cyclic tensile strain (CTS) in the presence of recombinant human interleukin-1beta (rHuIL-1beta) in vitro. The messenger RNA (mRNA) induction of rHuIL-1beta response elements was examined by semiquantitative reverse transcriptase-polymerase chain reaction. The synthesis of nitric oxide was examined by Griess reaction, and the synthesis of prostaglandin E2 (PGE2) was examined by radioimmunoassay. The synthesis of proteins was examined by Western blot analysis of the cell extracts, and synthesis of proteoglycans via incorporation of 35S-sodium sulfate in the culture medium. RESULTS: Exposure of TMJ fibrochondrocytes to rHuIL-1beta resulted in the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), which were paralleled by NO and PGE2 production. Additionally, IL-1beta induced significant levels of collagenase (matrix metalloproteinase 1 [MMP-1]) within 4 hours, and this was sustained over a period of 48 hours. Concomitant application of CTS abrogated the catabolic effects of IL-1beta on TMJ chondrocytes by inhibiting iNOS, COX-2, and MMP-1 mRNA production and NO, PGE2, and MMP-1 synthesis. CTS also counteracted cartilage degradation by augmenting expression of mRNA for tissue inhibitor of metalloproteinases 2 that is inhibited by rHuIL-1beta. In parallel, CTS also counteracted rHuIL-1beta-induced suppression of proteoglycan synthesis. Nevertheless, the presence of an inflammatory signal was a prerequisite for the observed CTS actions, because fibrochondrocytes, when exposed to CTS alone, did not exhibit any of the effects described above. CONCLUSION: CTS acts as an effective antagonist of rHuIL-1beta by potentially diminishing its catabolic actions on TMJ fibrochondrocytes. Furthermore, CTS actions appear to involve disruption/regulation of signal transduction cascade of rHuIL-1beta upstream of mRNA transcription.

Animals↗

PubMed2001

Tumor necrosis factor alpha-dependent proinflammatory gene induction is inhibited by cyclic tensile strain in articular chondrocytes in vitro.

OBJECTIVE: To understand the intracellular mechanisms of the action of mechanical strain on articular chondrocytes during inflammation. METHODS: One of the major mediators responsible for cartilage destruction in inflamed articular joints is tumor necrosis factor alpha (TNFalpha). Therefore, in this study we examined the intracellular mechanisms of actions of cyclic tensile strain (CTS) on the recombinant human TNFalpha (rHuTNFalpha)-induced proinflammatory pathways in primary cultures of chondrocytes. The expression of messenger RNA (mRNA) for TNFalpha-dependent proinflammatory proteins was examined by semiquantitative reverse transcriptase-polymerase chain reaction. The synthesis of proinflammatory proteins was examined by Western blot analysis in cell extracts, followed by semiquantitative measurement of bands using densitometric analysis. Nitric oxide production was measured by Griess reaction, and prostaglandin E2 production was assessed by radioimmunoassays. The proteoglycan synthesis in chondrocytes was assessed by incorporation of Na2(35)SO4 in chondroitin sulfate proteoglycans. RESULTS: By exposing chondrocytes to CTS in the presence of TNFalpha in vitro, we showed that CTS is an effective antagonist of TNFalpha actions and acts as both an antiinflammatory signal and a reparative signal. CTS of low magnitude suppresses TNFalpha-induced mRNA expression of multiple proinflammatory proteins involved in catabolic responses, such as inducible nitric oxide synthase, cyclooxygenase 2, and collagenase. CTS also counteracts cartilage degradation by augmenting induction of tissue inhibitor of metalloproteinase 2. Additionally, CTS augments the reparative process via abrogation of TNFalpha-induced suppression of proteoglycan synthesis. Nonetheless, CTS acts on chondrocytes in a TNFalpha-dependent manner, since exposure of chondrocytes to CTS alone had no effect on these parameters. CONCLUSION: CTS of low magnitude acts as an effective antagonist of TNFalpha not only by inhibiting the TNFalpha-dependent induction of proinflammatory proteins upstream of mRNA transcription, but also by augmenting the proteoglycan synthesis that is inhibited by TNFalpha.

Animals↗

PubMed2001

Prevalence of cervical spine injuries in patients with facial trauma.

OBJECTIVE: Injuries to the spine may accompany facial trauma. By using a large computerized database the goal of this case control study was to assess the association between facial and cervical spine injuries among patients sustaining facial trauma. STUDY DESIGN: During a period of 4 years (1995 to 1998) 3083 patients, 10 years or older, with facial injuries were admitted to the University Hospital of Innsbruck's Department of Oral and Maxillofacial Surgery for facial trauma. Records were analyzed for cause of injury, age and gender distribution, frequency and type of injury, and frequency of cervical spine injuries in relation to facial trauma and concomitant injuries. Two hundred six (6.7%) of these patients had experienced a concomitant cervical spine injury (case group). All other patients (2877) were assigned to the control group of facial trauma only. RESULTS: Facial trauma patients with concomitant cervical spine injuries were significantly older (mean age, 42 vs 34 years); no difference existed for the female/male ratio of 30:70. Sports trauma was the main cause of facial trauma in the control group (37.4%), yet traffic accidents accounted for 43.7% of combined facial and cervical spine injuries in the case group. Central mid face fractures dominated in the case group and lateral mid face fractures in the control group. In the case group cervical spine fractures and dislocations occurred in 19.2%. None of them showed evidence of paralysis. Concomitant brain injuries occurred in 21.6% of the case group and 8.8% of the control group. For patients sustaining facial trauma, logistic regression analysis revealed reduced risks for additional cervical spine injuries in younger patients, female patients, absence of brain injury, and in patients with facial soft tissue lesions alone (58.2%) or dental trauma alone (77.5%). CONCLUSION: The results of this study underline the importance of proper clinical and computed tomographic evaluation in cases of facial fractures for recognition of additional cervical spine trauma. Detection of cervical spine trauma can be missed, especially when pain or symptoms from other parts of the body dominate. The typical patient with concomitant neck and facial trauma is male, 40 years old, and usually involved in a traffic accident.

Adolescent↗

PubMed2001

The incidence of combined facial and cervical spine injuries.

BACKGROUND: The association between facial and cervical spine injuries has been documented. However, only severe spinal injuries were included in previous analyses. It was the purpose of this study to evaluate the incidence of and risk factors for these injury combinations including the complete injury spectrum. METHODS: Between 1995 and 1997, 4,907 patients with cervical spine injuries were treated at our hospital. One hundred five (2.14%) of these patients had suffered a concomitant facial injury. This group was compared with the group of patients with cervical spine injury but without facial trauma. RESULTS: The majority of cases (98%) consisted of minor lesions to both regions. With increasing severity of cervical spine trauma, the risk for facial injury increased. Age and male gender represent significant (p < 0.05) risk factors for combined injuries. CONCLUSION: Patients sustaining cervical spine trauma have a small but real chance of injuring their face as well. The cervical spine must be examined carefully, whenever facial injuries are present.

Adolescent↗

PubMed2000

[Cytokine-induced nitric oxide production of joint cartilage cells in continuous passive movement. Anti-inflammatory effect of continuous passive movement on chondrocytes: in vitro study].

PURPOSE: The temporomandibular joint is a place of motion where release of proinflammatory cytokines like interleukin-1 beta (IL-1 beta) induces cartilage destruction via production of nitric oxide (NO). The purpose of this study was to evaluate the effects of continuous passive motion in the form of cyclic stretch on the synthesis of inducible nitric oxide synthase (iNOS). METHODS: Articular chondrocytes were harvested from rabbit cartilage slices and cultured in F12 medium supplemented with 10% fetal calf serum. Subsequently, cells (10(5)/ml per well) were transferred to Flexercell plates, grown to 90% confluency, and subjected to one of the following regimens: (1) no mechanical strain (10 Hz, 20% elongation rate); (2) rhIL-1 beta (1 ng/ml); (3) mechanical strain; (4) mechanical strain and rhIL-1 beta. The cells were exposed to cyclic stretch for 24 h. Thereafter, cells were trypsinized and centrifuged on microscope slides in a cytospin centrifuge. The presence of iNOS was determined by indirect immunoperoxidase staining using polyclonal rabbit anti-iNOS as primary antibodies, and goat anti-rabbit IgG conjugated with horseradish peroxidase (HRP) as secondary antibodies. Diaminobenzidine was used as substrate for HRP. Total NO production was spectrophotometrically measured in the supernatants of cultures using Greiss reaction. All experiments were done in triplicates and the statistical significance was analyzed by Student's t-test. RESULTS: Cells with treatment 1 and 3 did not exhibit presence of iNOS. IL-1 beta-treated cells in group 2 exhibited intense peroxidase staining. Cells in group 4 exposed to IL-1 and mechanical stress showed staining with considerably less intensity. Control cells treated with normal rabbit IgG as a primary antibody did not exhibit peroxidase staining. The data were further confirmed by measurement of statistically significant differences of NO levels in supernatants assessed in the four different treatment groups. CONCLUSION: Our findings suggest that continuous passive motion exerts anti-inflammatory effects on chondrocytes, downregulating the quantity of iNOS-positive cells. Since NO acts as an intracellular, transcellular, and cytotoxic molecule, it has a basic importance for proper post-traumatic and postoperative TMJ function as well as the course and therapy of inflammatory TMJ diseases.

Animals↗

PubMed2000

[Healing behavior and bone regeneration of maxillary osteotomies in the experimental rabbit model. Effect of osteosynthesis and guided bone regeneration].

PURPOSE: The development of fibrous nonunions following orthognathic surgery is thought to result from an interaction of biomechanical stress and the differential and more rapid migration of fibroblasts compared to osteoblasts into the wound site during healing. The present study was designed to test this hypothesis through the manipulation of guided tissue regeneration and osteotomy fixation techniques in an experimental rabbit model. MATERIALS AND METHODS: Bilateral critical size (4 mm) defects (n = 24) were produced in the maxillae of 12 adult New Zealand White rabbits. The maxillary segments were rigidly or nonrigidly fixed using bone microplates and screws or osteosynthetic wires. The defects were then covered with a resorbable collagen membrane or left uncovered. The rabbits were followed for 4 weeks with serial dorsoventral and lateral oblique cephalographs and the maxillae were then harvested for histological analysis. RESULTS: Radiographic and histomorphometric analysis revealed that rigidly fixed defects, covered with membrane, showed the most rapid and organized new bone formation. The rigidly fixed defects with membrane averaged approximately 40% more new bone in the osteotomy site than the rigidly fixed defects with no membrane. Nonrigidly fixed defects with no membrane also showed an ingrowth of fibroblasts and fibrous nonunions. CONCLUSION: These results suggest that an interaction between the decreased fibrous tissue ingrowth through guided tissue regeneration and osteotomy segment stability from rigid fixation prevented postoperative fibrous nonunions and facilitated new bone regeneration and osteotomy site healing in this rabbit model.

Animals↗

PubMed2000

Effect of arthrocentesis and hydraulic distension on the temporomandibular joint disk position.

OBJECTIVE: Recent studies have suggested arthrocentesis and hydraulic distension as an effective treatment modality in patients demonstrating clinical findings consistent with the diagnosis of disk displacement without reduction, normal range of motion thereby being restored and pain of the temporomandibular joint reduced. In view of the fact that only a few studies have been performed to verify the biologic concept of disk displacement without reduction as a diagnostic and therapeutic approach in patients with "closed-lock" symptoms, the purpose of this study was to investigate whether temporomandibular joint-related variable disk position might be linked to cessation of related signs and symptoms associated with the performance of arthrocentesis and hydraulic distension. STUDY DESIGN: The study compared 15 patients, each of whom was assigned a clinical unilateral temporomandibular joint-related diagnosis of internal derangement (ID) type III (disk displacement without reduction) in combination with capsulitis/synovitis. Clinical diagnoses were made according to the Clinical Diagnostic Criteria for Temporomandibular Disorders. Bilateral sagittal and coronal magnetic resonance images were obtained immediately preoperatively and at 2-month follow-up to establish the presence or absence of associated types of ID. Temporomandibular joint-related pain, level of function, and mandibular range of motion were assessed preoperatively and the data were compared with the respective 2-month follow-up findings. RESULTS: Comparison of the pretreatment temporomandibular joint side-related data revealed the temporomandibular joint side with an ID-III in combination with capsulitis/synovitis to be associated with significantly more magnetic resonance imaging diagnoses of ID than of an absence of ID (P <.001) and with significantly more disk displacement without reduction than disk displacement with reduction (P <.001). At the 2-month follow-up, clinical evaluation showed a significant reduction in temporomandibular joint-related pain during function (P <.001), a significant reduction in the prevalence of temporomandibular joint-related diagnoses of capsulitis/synovitis (P <.001) and ID-III (P <.01), and a significant increase in mandibular range of motion (P <.01). There was no change in the prevalence rates of associated temporomandibular joint side-related IDs. CONCLUSIONS: The results confirm the concept of disk displacement as a diagnostic approach but not as a therapeutic approach for patients presenting with signs and symptoms of unilateral ID-III in combination with capsulitis/synovitis. In terms of clinical decision-making in temporomandibular disorder-related instances of ID, magnetic resonance imaging may be used as a diagnostic method for identifying the diagnostic validity of the variable "disk-condyle relationship."

Adolescent↗

PubMed2000

Traumatic dental injuries and Alpine skiing.

The purpose of this study was to determine the occurrence and type of traumatic dental injuries after maxillofacial injuries as a result of Alpine skiing. During an 8-year period (from January 1991 to December 1998) 7600 patients with facial injuries were registered at the Department of Oral and Maxillofacial Surgery, University of Innsbruck, Austria. Of 784 patients with skiing-related facial injuries (524 males, 260 females) 326 (41.6%) sustained injuries to 639 teeth. The age groups predominantly affected were between 7 and 32 years. Luxation injuries occurred in 338 (53%) teeth, fractures accounted for 270 tooth injuries (42%), and only 35 (5%) were lost at the place of the accident. Of skiers with traumatic dental injuries 58% had concomitant soft tissue injuries, while 23.3% had associated facial bone fractures. The most common causes of injury were falls in 42% (329 patients) and collisions with other persons in 24.1% (189 patients). Being hit by one's own sports equipment (11%) was the third most common cause. Collisions with obstacles accounted for 9% and lift accidents for 5.6% of injuries. The probability of suffering dentoalveolar trauma during skiing varied depending on the injury mechanism. There was a 2-fold risk for dentoalveolar trauma when colliding with objects, a 3.5-fold risk when hit by one's own equipment and a 8.5-fold risk during lift accidents. Dental injuries occurred in about 2% of all injured skiers. Dental health professionals should be aware of the high incidence and the distribution of dental trauma and facial injuries caused by skiing.

Accidental Falls↗

PubMed2000

Histomorphology of rabbit thigh muscles: establishment of standard control values.

The thigh muscles of New Zealand White (NZW) rabbits are frequently used in experimental surgery, particularly for evaluation after reinnervation or ischaemia. Although histomorphometric analyses are regularly performed, morphological data for untreated thigh muscles in previously unoperated animals are not available. Specimens from the rectus femoris (RF), vastus medialis (VM) and adductor magnus (AM) muscles from both thighs were harvested in 7 untreated rabbits and were processed for histomorphometric evaluation. The right RF and VM were harvested in a further 5 rabbit hindlimbs after experimental denervation and reinnervation of the contralateral RF and subsequently processed for histomorphometric analysis. Muscle fibre type distribution, diameter and connective tissue content were evaluated on serial transverse cryosections reacted for ATPase and NADH tetrazolium reductase activity and statistical analysis was performed. In all untreated animals RF revealed the highest proportion of type I muscle fibres (right: 8.4+/-4%, left: 11.4+/-4.9%), whereas VM showed the highest percentage of IIa fibres (right: 31.9+/-5.5%, left: 28.3+/-7.8%) and AM the highest proportion of IIb/d fibres (right: 80.5+/-8.6%, left: 84.4+/-6.3%). Fibre type distribution and diameter in rabbits after contralateral experimental operations revealed a statistically significant difference from the data obtained in bilaterally untreated animals. Knowledge of the morphology of untreated muscles is fundamental to the understanding of changes induced by intervention to the ipsi and/or contralateral thigh muscles.

Analysis of Variance↗

PubMed2000

Growth factor and cytokine gene expression in mechanically strained human osteoblast-like cells: implications for distraction osteogenesis.

OBJECTIVE: An understanding of bone cellular biology is a basic necessity to understanding events such as distraction osteogenesis. The goal of this study was to determine the effect of continuous cyclic mechanical stretch as a fundamental event in distraction osteogenesis on the expression of 3 bone growth factors, transforming growth factor-beta 1 (TGF-beta1), insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (bFGF) and 2 cytokines, interleukin (IL)-1 (IL-1) and 6 (IL-6) in human osteoblast-like cells. MATERIAL AND METHODS: A human osteoblast-like cell line, SaOS-2, capable of forming a ground substance and mineralizing it, was maintained. Cells were transferred to 6-well plates with flexible silicon bottoms grown to confluence and either subjected to tensile stretch for different time intervals or used as the control group. RNA was isolated to conduct Northern blot analysis for the expression of 3 bone growth factors, transforming TGF-beta1, IGF-1, bFGF, and 2 cytokines, IL-1 and IL-6. RESULTS: After 8 hours, mRNA for TGF-beta1 and IGF-1 increased in the experimental group, whereas bFGF decreased but cytokines IL-1 and IL-6 were not affected. At 16 hours, TGF-beta1, IGF-1, and bFGF showed increased levels of mRNA; IL-6 showed a slight increase. After 24 hours, TGF-beta1, IGF-1, bFGF, and IL-6 had increased mRNA levels. IL-1beta did never show significant alterations in mRNA production as compared with the control. CONCLUSION: Tensile stretch on osteoblast-like cells alter local regulation of bone formation, increasing the expression of bone growth factors, whereas catabolic cytokines are unaffected. These findings suggest a direct effect of mechanical strain on osteoblasts and may be the driving factors of bone growth during distraction.

Blotting, Northern↗

PubMed2000

Temporomandibular joint pain: relationship to internal derangement type, osteoarthrosis, and synovial fluid mediator level of tumor necrosis factor-alpha.

OBJECTIVES: The purpose of this study was to investigate whether patients with temporomandibular joint (TMJ)-related pain classified as capsulitis/synovitis may be linked to magnetic resonance imaging (MRI) findings of internal derangement, osteoarthrosis, or the synovial fluid aspirate findings of tumor necrosis factor-alpha (TNF-alpha) level. STUDY DESIGN: The study comprised 23 patients with temporomandibular disorders (TMD), who had nonchronic pain (pain onset < or =6 months) and a unilateral TMJ-related diagnosis of capsulitis/synovitis. Bilateral sagittal and coronal magnetic resonance images were obtained to establish the presence or absence of internal derangement, osteoarthrosis, or both. TMJ synovial fluid aspirates were obtained from the pain and contralateral nonpain sides to determine the TNF-alpha level. RESULTS: Comparison of the TMJ side-related data showed a significant relationship between the clinical TMD diagnosis of capsulitis/synovitis and the MRI diagnoses of TMJ internal derangement (P =.002) and of TMJ internal derangement type (P =.04). The mean TNF-alpha level in synovial fluid aspirates from TMJs assigned a clinical TMD diagnosis of capsulitis/synovitis was significantly higher than in those obtained from contralateral nonpain sides (P =.001). There was no correlation between the clinical diagnosis of capsulitis/synovitis and the MRI diagnosis of TMJ osteoarthrosis (P =.13) or between the MRI diagnosis of TMJ osteoarthrosis and that of TMJ internal derangement (P =.70) or TMJ internal derangement type (P =.33). CONCLUSIONS: The results suggest that the TMJ pain condition of capsulitis/synovitis is related to TMJ-side specific MRI diagnoses of internal derangement and internal derangement type, and synovial fluid aspirate findings of TNF-alpha level. The data confirm the concept of elevated mediator level as a diagnostic approach for patients presenting with TMJ-related pain. MRI and synovial fluid aspirates may be used as diagnostic methods for evaluating TMJ-related pain conditions.

Adolescent↗

PubMed2000

Effect of temporomandibular joint arthrocentesis on synovial fluid mediator level of tumor necrosis factor-alpha: implications for treatment outcome.

Temporomandibular joint (TMJ) pain is a predominant sign and symptom in patients with temporomandibular disorder, and a common cause of chronic orofacial pain. Arthrocentesis of the upper joint space proved to be effective in reducing TMJ-related pain and reestablishing normal mandibular range of movement in patients diagnosed for a 'closed lock'. Using the therapeutic approach of arthrocentesis in TMJ-related instances of capsulitis/ synovitis (C/S) with a recency of first pain onset of < or =6 months, the purpose of the present study was to evaluate whether the TMJ-related variable synovial fluid (SF) level of TNF-alpha may be linked to the cessation of related signs and symptoms associated with the performance of arthrocentesis and hydraulic distension. In 23 patients with a specific temporomandibular disorder diagnosis of unilateral C/S with a recency of first pain onset of < or =6 months, TMJ SF aspirates were obtained from the pain and contralateral non-pain sides immediately before and after arthrocentesis. Visual analog scales were used for pre- and postoperative self-assessment of TMJ-related pain during function, while enzyme-linked immunosorbent assays were applied for measurement of the tumor necrosis factor-alpha (TNF-alpha) concentration. With a mean SF TNF-alpha level of 13.91 ng/ml associated with the pain side, and a mean SF TNF-alpha level of 7.73 ng/ml associated with the non-pain side, a statistically significant difference was found between the sample groups (P=0.001). Arthrocentesis led to a significant intraoperative decrease of the respective preoperative SF TNF-alpha levels, namely 61.64% (P=0.000) on the pain side and 89.50% (P=0.000) on the non-pain side, while reduction of TMJ-related pain during function was 73.17%, (P=0.000). Clinical evaluation showed a significant reduction in the prevalence of TMJ-related diagnoses of C/S (P<0.001). There was no change in the prevalence of associated TMJ-related diagnoses of internal derangement. In view of the fact that the described technique of TMJ SF analysis may be suggested as a valuable diagnostic method for the detection of biochemical SF events, the results of this study should encourage research in its potential uses so that it can become established as a reliable diagnostic approach. Further, the findings may support the concept of bilateral arthrocentesis to be effective in the treatment of patients with a unilateral specific TMD diagnosis of non-chronic C/S.

Adolescent↗

PubMed1999

Cyclic tensile stress exerts antiinflammatory actions on chondrocytes by inhibiting inducible nitric oxide synthase.

Continuous passive motion manifests therapeutic effects on inflamed articular joints by an as-yet-unknown mechanism. Here, we show that application of cyclic tensile stress (CTS) in vitro abrogates the catabolic effects of IL-1beta on chondrocytes. The effects of CTS are mediated by down-regulation of IL-1beta-dependent inducible NO production, and are directly attributed to the inhibition of inducible NO synthase (iNOS) mRNA expression and protein synthesis. The inhibition of iNOS induction by CTS is paralleled by abrogation of IL-1beta-induced down-regulation of proteoglycan synthesis. Furthermore, CTS inhibits iNOS expression and up-regulates proteoglycan synthesis at concentrations of IL-1beta frequently observed in inflamed arthritic joints, suggesting that the actions of CTS may be clinically relevant in suppressing the sustained effects of pathological levels of IL-1beta in vivo. These results are the first to demonstrate that mechanisms of the intracellular actions of CTS in IL-1beta-activated chondrocytes are mediated through inhibition of a key molecule in the signal transduction pathway that leads to iNOS expression.

Animals↗

PubMed1999

Multivitamin administration before ischemia reduces ischemia-reperfusion injury in rabbit skeletal muscle.

This study investigated the effect of a multivitamin preparation administered before ischemia or before reperfusion, on ischemia-reperfusion (I/R) injury of skeletal muscle. An in vivo hindlimb skeletal muscle I/R model (2.5 h/2 h) was carried out on adult New Zealand white rabbits. Animals used as I/R models were treated with a multivitamin preparation (0.4 ml/kg bw i.v. bolus), containing alpha-tocopherol, ascorbic acid, retinol, vitamin B complex, 30 min before starting ischemia (group MV(isc)) or 5 min before reperfusion (group MV(rep)) and compared to animals with I/R without treatment (group IR) and sham operated animals (group SHAM). Interstitial edema (muscle interfiber area, %MIFA) and changes in microvessel size (microvessel cross sectional area, MVCSA, microm(2)) were measured. Plasma malondialdehyde concentrations (MDA-TBA, nmol/ml) served as a measure of lipid peroxidation. After 2h of reperfusion, ischemia-reperfusion developed a significant microvascular constriction and an interstitial edema (IR, vs SHAM;P<< 0.01), but administration of antioxidative vitamins before the onset of ischemia reduced microvascular constriction and edema formation (P<< 0.05 vs IR group). In a similar manner, administration of vitamins before ischemia lowered plasma MDA-TBA levels as compared to the untreated group during reperfusion (p<< 0. 05). In animals treated with vitamins before reperfusion, the biochemical and morphological results showed no differences as compared to the untreated group. Antioxidative treatment with a multivitamin preparation exerted a beneficial effect on I/R injury of skeletal muscle when the aforementioned vitamins were administered before ischemia but not before the onset of reperfusion.

Animals↗

PubMed1999

Incidence of oral and maxillofacial skiing injuries due to different injury mechanisms.

PURPOSE: This study emphasizes the significance of maxillofacial injuries in skiing accidents, correlating injury mechanisms and patterns, by evaluating a large population of maxillofacial injuries over a 6-year period. PATIENTS AND METHODS: Between 1991 and 1996, of 5,623 patients showing oral and maxillofacial injuries, 1,859 were sports-related. Records of 579 patients with 882 incidents of oral and maxillofacial injury due to skiing were reviewed and analyzed according to age, sex, type of injury, cause of accident, location, and frequency of fractures. Additionally, the five main injury mechanisms were analyzed. RESULTS: The oral and maxillofacial injuries in 10.3% of all trauma patients, or 33% of all sports-related trauma patients, were due to skiing. A total of 310 patients (53.5%) had facial bone fractures, 236 patients (40.8%) suffered from dentoalveolar trauma, and 336 patients (58%) showed soft tissue injuries. Five major causes and mechanisms of injury existed, namely, 263 falls (45%); 135 collisions with other skiers (23%); 70 individuals struck by their own ski equipment (12%); 46 collisions against stationary objects (8%); and 34 lift-track accidents (6%). Sex distribution showed an overall male-to-female ratio of 1.9:1.0, but varied depending on the injury mechanism. The age distribution ranged from 2 to 81 years. CONCLUSION: The results of this study show the high incidence of oral and maxillofacial injuries due to skiing accidents. Depending on the mechanism of injury, different patterns occur. Facial bone fractures are more likely in collisions with other persons, falls, and collisions with stationary objects, whereas dentoalveolar trauma is more common when persons are struck by their own ski equipment, or when accidents on lift-tracks occur.

Accidental Falls↗

PubMed1999

Prevalence of dental trauma in 6000 patients with facial injuries: implications for prevention.

OBJECTIVE: In contrast to epidemiologic studies on facial injuries reporting on dental trauma, facial bone fractures with dentoalveolar injuries, or soft tissue injuries individually, the purpose of this study was to evaluate the overall place of dental trauma in facial injuries. This was a retrospective investigation of the impact of sport, work, violence, traffic, household, and play accidents in the relationships among dental trauma, facial trauma, and other concomitant trauma. Finally, preventive considerations are discussed. STUDY DESIGN: Six thousand patients registered at the University Hospital of Innsbruck's Department of Oral and Maxillofacial Surgery during a period of 6 years 4 months were admitted for dental trauma, facial trauma, or both. Records were analyzed for cause of injury, age, gender, monthly distribution, frequency, type of injury, and frequency of dental trauma in relation to facial injuries and concomitant injuries. RESULTS: The incidence of dental injuries with respect to the total number of facial injuries was as follows: 57.8% in play and household accidents, 50.1% in sports accidents, 38.6% in accidents at work, 35.8% in acts of violence, 34.2% in traffic accidents, and 31% in unspecified accidents. The overall incidence revealed was 48.25%. CONCLUSION: Our findings support the fact that in the mosaic of traumatic injuries, the frequencies of tooth trauma and its sequelae are underestimated and that such trauma and sequelae occur without a predictable pattern of intensity and extensiveness. Preventive approaches are the sole way to minimize the number of these injuries. Substantial progress made in treating facial and dental trauma in the last 2 decades only improves functional and esthetic outcomes among the population that has suffered dental injury.

Accident Prevention↗

PubMed1999

Facial injuries in skiing. A retrospective study of 549 cases.

In the last 2 decades, reports of skiing injuries have shown an increasing number of skiers with severe trauma. This article provides an account of a retrospective study of 549 patients with 1155 facial injuries sustained while skiing who received treatment at the Department of Oral and Maxillofacial Surgery at the University Hospital in Innsbruck, Austria between 1991 and 1996. The study was based on a questionnaire answered by the patients and on case report forms. Most of the patients were male (65.2%) and were aged between 3 and 81 years (average 28.4 years). A simple fall while skiing was the main type of accident (45.9%), followed by collisions with other people (23.5%). Injuries were classified into 1 of 3 groups: (i) lesions of the soft tissue (32.2% of all injuries); (ii) dentoalveolar traumas (24.3%); and (iii) fractures of facial bones (43.5%). Lacerations and haematomas were the most frequent lesions in patients with injuries to the soft tissues. The group of patients with dentoalveolar trauma mainly presented with fractures of tooth crowns. Fractures involving the mandible and the zygomatic bone were predominant in patients in the third group. Concomitant injuries mainly included injuries to the brain and skull fractures. Treatment was ambulatory, or by admission and surgery. We did not observe an increase in the number of skiing accidents causing facial injury in the last 5 years. Facial injuries represented 4% of all skiing injuries, a lower proportion than in other sports.

Accidental Falls↗

PubMed1999

Mountainbiking--a dangerous sport: comparison with bicycling on oral and maxillofacial trauma.

The popularity of bicycling is reflected in the number of cycling-related oral and maxillofacial injuries. Five hundred and sixty-two injured bicyclists (10.3% of all trauma patients) were registered at the Department of Oral and Maxillofacial Surgery, University of Innsbruck, Austria, between 1991 and 1996, accounting for 31% of all sports-related accidents and 48.4% of all traffic accidents. A review of the patient records revealed more severe injury profiles in sixty mountainbikers, with 55% facial bone fractures, 22% dentoalveolar trauma and 23% soft tissue injuries, compared to 502 street cyclists showing 50.8% dentoalveolar trauma, 34.5% facial bone fractures and 14% soft tissue lesions. The dominant fracture site in bicyclists was the zygoma (30.8%), whereas mountainbikers sustained an impressive 15.2% LeFort I, II and III fractures. Condyle fractures were more common in bicyclists, with 18.8% compared to 10.8% in mountainbikers. Reduction of facial injuries due to cycling-related accidents needs appropriate design of helmets with faceguards and compulsory helmet use for all cyclists, and particularly mountainbikers.

Accidental Falls↗