Prevalence and distribution of deep caries and abscess formation in children who required emergency dental general anaesthesia. A retrospective analysis.

AIM: The aim of this study was the assessment of prevalence, distribution, and treatment of deep caries and odontogenic abscess formation in children who received emergency dental general anaesthesia (DGA) at the University Hospital of Cranio-Maxillofacial and Oral Surgery of Innsbruck, Austria. MATERIALS AND METHODS: The study population was composed of 1,184 consecutive cases of emergency DGA from January 2008 to June 2014, in patients ?16 years who had presented with odontogenic pain and/or swelling. Under DGA, the tooth causative for the acute pain, and all teeth with deep caries had been routinely removed. From patient files, demographic data, abscess location and therapy, and the number of teeth extracted under DGA were recorded and analysed by means of descriptive statistics. RESULTS: In 549 cases (46.4%) (mean age 5.29±2.39 years), an abscess formation was recorded; 90.5% of all abscesses were submucous, and 9.5% affected fascial spaces. Decayed primary molars and maxillary primary incisors and canines were most often causative for abscess formation. Drainage was in most cases performed by tooth extraction with/without an intraoral incision under antibiotic therapy. Per case, a mean of 5.91±4.04 primary teeth were extracted. In 77 individuals (mean age 9.83± 2.59), a mean of 1.92±1.02 permanent first molars were extracted. CONCLUSION: In the study population, prevalence of deep caries and abscess formation was alarmingly high. In consideration of the medical risks and high efforts immanent in DGA, educational measures should address parents in order to raise awareness of their responsibility for their children´s health.

Complications related to midfacial fractures: operative versus non-surgical treatment.

The treatment of midfacial fractures depends on the dislocation of the fracture and patient-related limitations. Surgical treatment risks iatrogenic complications. In 740 patients with midfacial fractures, the age, sex, fracture type, concomitant injuries, cause of accident and the decision to use operative or non-surgical treatment were recorded. Follow-up was performed 6 and 12 months after the injury. In 41% the fractures were isolated; they were multiple in 59%. Initially, hypaesthesia of the infraorbital nerve was present in 10% of the single and 16% of the multiple fracture patients. Surgical treatment was performed in 57% of the single and in 75% of the multiple fracture patients. Women underwent surgical treatment considerably less frequently than men. After 6 and 12 months, significantly more complications were present in the surgically treated cohort. Nerve disturbances and 'meteorosensitivity' were most prominent. These results, together with previous findings, indicate that there is a need for prospective clinical investigations that fulfil the criteria of evidence-based medicine to generate guidelines for decision making in trauma surgery. In the meantime, the decision to use surgical treatment for midfacial fractures has to be made carefully.

The impact of ageing on cranio-maxillofacial trauma-a comparative investigation.

The number of patients older than 65 is increasing in developed societies. The impact of age on injuries and their outcome has been well documented in several fields of traumatology. Data on a broad cohort suffering from oral and maxillofacial injuries are missing. In this study, the data of 12,572 such patients were collected, of which 11,798 were younger and 774 were older than 65 years. With increasing age the risk of a domestic accident increased. The accident mechanism in elderly people was most frequently a fall (72%) or was not reproducible (12%). There was a significant difference between groups regarding concomitant injuries. Additional neurological symptoms occurred in 26% of the older and 15% of the younger patients (P<0.001). Until the age of 65 the risk of concomitant neurological injury increases. Injuries in the older patients mainly affected the soft tissue and midface. No statistical differences in surgical postoperative complications were observed. Due to the changing face of society, the treatment of elderly people is of high relevance. To enable an independent life after trauma, pre- and post-therapeutic care is of major importance. These data support surgical treatment of all patients, regardless of age, driven by general health condition whenever possible.

The effects of guided tissue regeneration (GTR) on modified Le Fort I osteotomy healing in rabbits.

Osteogenesis following surgery depends on the osteoblasts at the wound site. Fibrous nonunions may be the result of differential and rapid migration of fibroblasts compared to osteoblasts into the wound. The present study was designed to test this hypothesis through the use of guided tissue regeneration (GTR) in a rabbit model. Bilateral, Le Fort I osteotomies (n=20) were produced in the maxillae of 10 New Zealand White rabbits. The segments were advanced 6mm and rigidly fixed using microplates and screws. One side was covered with a resorbable collagen membrane or left uncovered. Rabbits were followed for four weeks with radiographs and the maxillae were harvested for histology. Cephalometry revealed that membrane-covered defects had significantly (P<0.01) reduced defect area (by approximately 70%) compared to uncovered defects. Histologically, membrane-covered defects showed more organized osteogenesis and less fibrous tissue than uncovered defects. Histomorphometry revealed that membrane covered defects had significantly (P<0.05) reduced defect areas (by approximately 20%) compared to uncovered defects. While findings suggest that GTR can facilitate osseous wound healing in Le Fort I osteotomies, results also caution against relying exclusively on two-dimensional radiography to assess bony wound healing in lieu of three-dimensional imaging and evaluations.

[Dentoalveolar trauma. Analysis of 4763 patients with 6237 injuries in 10 years]. / Dentoalveoläre Traumen. Analyse von 4763 Patienten mit 6237 Verletzungen in 10 Jahren.

PURPOSE: The purpose of this study was to evaluate the overall place of dental trauma in facial injuries. This was a retrospective investigation based on the analysis of a large amount of dentoalveolar injuries over a 10-year period. PATIENTS AND METHODS: Between 1991 and 2000, 4763 of 9543 patients suffering from oral and maxillofacial injuries, sustained dentoalveolar trauma. Records of 6237 different dental injury patterns were reviewed according to the five main injury mechanisms: age, sex, type of injury, cause of accident, and frequency of dentoalveolar trauma. They were statistically analyzed using frequency distribution, chi-square test, t-test, Mann-Whitney U test, Kolmogorov-Smirnov test, and logistic regression analysis. RESULTS: Household and play (2117), sports (1533), traffic accidents (438), acts of violence (426), and work-related accidents (201) were noted. A total of 4763 patients had 2988 subluxations, 2356 showed crown fractures, 444 had avulsions, 176 root fractures, 154 intrusions, and 119 patients suffered from concussions. This number of patients accounts for the prevalence of 49.9% for dentoalveolar trauma among all facial injuries. CONCLUSION: Only the analysis of a large number of injuries reveals the risk of suffering from dentoalveolar trauma. Due to this fact, preventive methods can be recommended and demanded more effectively.

Diagnostic quality of dynamic high-resolution ultrasonography of the TMJ--a pilot study.

The aim of this study was to compare sensitivity, specificity, accuracy and positive and negative predictive value for high-resolution ultrasonography (HR-US) in diagnosing degenerative changes, effusion and disk displacement using magnetic resonance imaging (MRI) as a reference. Over a period of 6 months, 100 patients with TMJ disorders (200 TMJs) were investigated by an experienced radiologist with HR-US and magnetic resonance imaging (MRI). The MRI investigation showed degenerative changes in 190 joints (95%), while an effusion was found in 59 (29.5%) joints. At closed-mouth position a disc dislocation was found in 138 joints (69%) and in maximum-mouth-opening position disc dislocation was diagnosed in 76 joints (38%). In the determination of degenerative changes HR-US showed a sensitivity of 94%, a specificity of 100% and an accuracy of 94%. In the detection of effusion HR-US yielded a sensitivity of 81%, a specificity of 100% and an accuracy of 95%. In the determination of disk displacement at closed-mouth position HR-US showed a sensitivity, specificity and an accuracy of 92% each. At maximum-mouth-opening position HR-US reached a sensitivity of 86%, a specificity of 91% and an accuracy of 90%. The results of the current study imply that HR-US is a valuable diagnostic imaging method of the TMJ which can be used as an alternative method to a MRI-investigation, but is yet not able to replace it. Further studies have to be done to reduce false-negative results.

Maxillofacial fractures masking traumatic intracranial hemorrhages.

Maxillofacial trauma may mask intracranial injuries prompting intensive care treatment. The purpose of this study was to identify whether craniofacial fracture patterns predispose patients with maxillofacial fractures to different types of intracranial hemorrhages. Within 7 years, 6649 patients with craniomaxillofacial injuries were admitted for treatment. The charts of the patients were analyzed according to age, sex, cause and mechanism of injury, type and location of facial injury, and intracranial trauma; 2195 sustained maxillofacial fractures. Statistical analyses were followed by logistic regression analyses for the four main types of intracranial hemorrhage to determine the impact of the different maxillofacial fractures. Intracranial hemorrhages in 212 patients (9.7%) occurred as epidural (2.5%), subdural (4.3%), subarachnoid (5.3%), and intracerebral hemorrhages (6.3%). Le Fort, orbit, nose, zygoma, and maxillary fractures increased the risk for accompanying intracranial hemorrhage by two- to fourfold (P < 0.05). Basal skull fractures caused a multiplication of the risk up to 17-fold, while fractures of the cranial vault were associated with a risk up to 14-fold. Nearly 10% of patients with craniomaxillofacial fractures sustain intracranial hemorrhages requiring frequently immediate neurosurgical intervention. Those patients, suffering from central midface fractures and skull base fractures, are prone to highly significant elevated risks of intracranial hemorrhage.

Placental growth from the first to the second trimester of pregnancy in SGA-foetuses and pre-eclamptic pregnancies compared to normal foetuses.

The aim of this study was to determine placental growth between 12-22 weeks in normal pregnancies compared to pregnancies complicated by foetal SGA and maternal pre-eclampsia (PE). The placentae of 1199 women were measured 3D sonographically at 12, 16 and 22 weeks of gestation. Placental volume growth was then calculated. Neonatal birthweight, birth centile and the occurrence of pre-eclampsia were recorded in every woman and correlated with placental growth (four groups: normals, SGA, PE, SGA+PE). SGA-placentae are already smaller at 12 weeks but then develop in a similar way to normal placentae. PE placentae are slightly, but significantly, larger at 12 weeks, grow rapidly until 16 weeks and then stop growing normally between 16 and 22 weeks. If SGA goes together with PE, both placental volume (PV) at 12 weeks as well as growth is reduced significantly. Nevertheless, placental growth between week 12 and 22 is too heterogeneous to justify using this method as a clinical tool, but it can provide new information on placental physiology underlying unfavourable obstetric outcomes.

Maxillofacial trauma due to work-related accidents.

Even though numerous reports on maxillofacial trauma exist, only a few give detailed information about work-related maxillofacial injuries. The purpose of this study was to reveal the significance of maxillofacial injuries related to accidents occurring at work by evaluating a large number of patients with maxillofacial injuries over a 9-year period. Out of the 8704 trauma patients treated between 1991 and 1999 in the Department of Oral and Maxillofacial Surgery at the University of Innsbruck, Austria, 463 (5.4%) were injured at work. All charts were reviewed and analyzed according to age, gender, cause of accident, occupation, type of injury, location and frequency of fractures. The highest incidence of maxillofacial injury was found among construction workers (a total of 124 patients, 26.8%), followed by craftsmen (102 patients, 22.0%) and office employees (69 patients, 14.9%). The sex distribution showed an overall male-to-female ratio of 11.8:1 and those in the age group most affected were between 20 and 29 years of age. The most frequent cause of injury was a blow in 48.4%, followed by falls and falls over obstacles, accounting for 27.9% and 7.1%, respectively. Of all trauma, 45.4% (210 persons) sustained 423 maxillofacial fractures, 31.7% (147 patients) suffered 232 dento-alveolar injuries, and 21.2% (98 people) showed 430 soft-tissue injuries. One-fifth (20.7%) of all patients displayed concomitant injuries with cerebral and cranial trauma being the most common. The probability of sustaining maxillofacial trauma at work is correlated to the nature of the occupation. Individuals (mostly men) using tools or machines at work are exposed to a much higher risk of work-related maxillofacial trauma.

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.

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.

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.

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.

Interaction of strain and interleukin-1 in articular cartilage: effects on proteoglycan synthesis in chondrocytes.

In temporomandibular joint disorders, the release of proinflammatory cytokines such as interleukin-1 (IL-1) initiates an inflammatory process disrupting cartilage homeostasis, ultimately leading to cartilage destruction. Additionally, mechanical stimuli affect articular chondrocyte metabolism. While articular chondrocytes generate nitric oxide (NO) in the presence of IL-1 proteoglycan synthesis is consecutively suppressed. The purpose of this study was to assess the effects of proinflammatory cytokines and mechanical strain in the form of cyclic tensile stretch on proteoglycan synthesis in chondrocytes, as compared to the NO competitive inhibitor L-N-monomethyl arginine (LMA), and to assess whether this effect is secondarily related to the activity of growth factors such as transforming growth factor beta (TGF-beta). Lapine articular chondrocytes were exposed to one of four different treatment regimens: no cyclic tensile stretch, IL-1, cyclic tensile stretch, or IL-1 plus cyclic tensile stretch. NO production was determined as medium nitrite accumulation. TGF-beta-bioactivity in chondrocyte conditioned medium was measured with the mink-lung epithelial cell bioassay. Proteoglycan synthesis was measured as the incorporation of 35-[S]-sodium sulfate into macromolecules separated from unincorporated label by gel filtration on PD-10 columns. In resting chondrocyte cultures, only baseline levels of NO were measured and the application of stretch for 24 h did not affect NO production. Addition of IL-1 provoked a large increase in NO synthesis which was abrogated in the presence of LMA. Application of stretch decreased the IL-1 induced NO synthesis, but did not modify the effect of LMA (being a competitive inhibitor of the inducible NO synthase) inhibiting IL-1 induced NO production. Glucosaminoglycan production was noted as proteoglycan synthesis showing almost no effect of cyclic stretch alone in comparison to the control condition, which correlates with the missing NO production in control and stretch conditions. Addition of IL-1 strongly inhibited proteoglycan synthesis, which was partly restored in the presence of LMA. However, cyclic stretch acted as a stronger restorer of proteoglycan synthesis in IL-1 treated conditions in the absence, and even more in the presence, of LMA. It was concluded that motion in the form of cyclic tensile stretch is a remarkable anti-inflammatory stimulus reversing the IL-1 induced suppression of proteoglycan synthesis in chondrocytes. These findings have therapeutic implications for the treatment of temporomandibular joint disorders, supporting early onset of postoperative and post-traumatic continuous passive motion therapy.

[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]. / Zytokininduzierte Stickstoffmonoxidproduktion von Gelenkknorpelzellen unter kontinuierlicher passiver Bewegung. Antientzündlicher Effekt von kontinuierlicher passiver Bewegung auf Chondrozyten: In-vitro-Nachweis.

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.

[Healing behavior and bone regeneration of maxillary osteotomies in the experimental rabbit model. Effect of osteosynthesis and guided bone regeneration]. / Heilungsverhalten und Knochenregeneration von maxillären Osteotomien im experimentellen Kaninchenmodell. Effekte von Osteosynthesen und gesteuerter Knochenregeneration.

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.

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.

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.

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.