Die FAMI-Schraube für die temporäre intermaxillare Fixation

The aim of this study was to demonstrate the suitability of the FAMI screw (fixation and adaptation in mandibular injuries) for maxillomandibular fixation in the maxillofacial area in orthognathic and trauma surgery. This FAMI screw was used in 28 patients for maxillomandibular fixation with wiring or elastics. The screw is inserted into the labial or buccal surfaces of the alveolar process without predrilling. Adequate intermaxillary fixation with balanced occlusion was created intraoperatively in all patients. In comparison with conventional splinting methods, this technique was far less time-consuming. The use of the FAMI screw has the advantage of being quick and simple, particularly if only a brief period of maxillomandibular immobilization is planned. Furthermore, the risk to the surgeon of sustaining a puncture injury from wire ligatures is distinctly reduced. Screws can be removed without local anesthesia. The above-mentioned method is minimally traumatic, effective, timesaving, and hence inexpensive. It can be used for maxillomandibular immobilization in dentate as well as in edentulous patients.     

Magnetic Field Interactions of Orthodontic Wires during Magnetic Resonance Imaging (MRI) at 1.5 Tesla

AbstractBackground: Orthodontic appliances pose a potential risk during magnetic resonance imaging (MRI) due to forces on metallic objects within the static magnetic field of MRI systems. The aim of the present investigation was to measure forces on orthodontic wires caused by the static magnetic field of a 1.5-Tesla MRI system, and to assess the safety hazards associated with these forces.Materials and Methods: Thirty-two different orthodontic wires (21 arch wires, eight ligature wires and three retainer wires) were investigated in a 1.5-Tesla MRI system (Magnetom Symphony, Siemens Medical Solutions, Erlangen, Germany). The translational forces were measured using the deflection angle test (ASTM F2052-02); rotational forces were assessed on a 5-point qualitative scale.Results and Conclusion: All retainer wires and the steel arch wires (the Noninium^® arch wire being the exception) were subjected to considerable rotational and translational forces within the MRI system’s magnetic field. Translational forces were from 9.1- to 27.6-times as high as gravitational forces on these objects. Steel ligature wires and arch wires made of cobalt chromium, titanium molybdenum, nickel-titanium, and brass alloys showed no or negligible forces within the magnetic field. The translational and rotational forces within the MRI magnetic field should pose no risk to carefully-ligated arch wires. Steel retainer wire bonds should be checked to ensure secure attachment prior to an MRI investigation.* both authors share first authorship     

Erythema multiforme: a review and contrast from Stevens-Johnson syndrome/toxic epidermal necrolysis

Erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis are separate diseases. Recent evidence suggests that they have different etiologies and require different treatments. This article provides an overview of the two conditions with emphasis on the differences between them. An outline of the diagnosis and management of the diseases is included.     

Preemptive rofecoxib and dexamethasone for prevention of pain and trismus following third molar surgery *

Objective The goal of this preliminary randomized prospective clinical trial was to compare the analgesic efficacy and the reduction in trismus of preoperative rofecoxib, intraoperative dexamethasone, and both rofecoxib and dexamethasone following third molar extraction surgery. Study design Thirty-five subjects requiring surgical removal of at least 1 partial bony impacted mandibular third molar were invited to participate in this double-blind and double-dummy placebo-controlled clinical trial. Subjects were randomly assigned into 1 of 4 treatment groups: (1) placebo po preoperatively and placebo IV intraoperatively; (2) rofecoxib 50 mg po preoperatively and placebo IV intraoperatively; (3) placebo po preoperatively and dexamethasone10 mg IV intraoperatively; and (4) rofecoxib 50 mg po preoperatively and dexamethasone 10 mg IV intraoperatively. Subjects completed a diary assessing postoperative pain onset and intensity using categorical and visual analogue scales. Interincisal opening was assessed 1, 2, 3, and 7 days postoperatively using a Therabite ruler. Results This randomized controlled clinical trial enrolled 35 subjects. Two subjects did not meet the inclusion criteria and 4 did not return completed diaries. The mean age of the remaining 29 subjects (11 males, 18 females) was 22.8 years (+/- 0.6 year). The active treatments tended to delay the need for initial pain medication. When compared to other active treatments and to placebo, the combination of preoperative rofecoxib and intraoperative dexamethasone significantly reduced initial pain intensity ( P < .05). Baseline interincisal opening was 52.6 mm (+/- 6.2). The greatest decrease in interincisal opening was 43.3% for the placebo group at 24 hours. Preoperative rofecoxib alone showed a decrease in interincisal opening of 42.3% ( P = ns) at 24 hours. Intraoperative dexamethasone alone showed a decrease in the interincisal opening of 24.1% of baseline ( P < .05 vs placebo). The group receiving the combination of rofecoxib and dexamethasone showed a decrease in interincisal opening of 23.7% of baseline ( P < .05 vs placebo). Conclusions The results of this trial indicate that the use of intraoperative dexamethasone is an effective therapeutic strategy for limiting trismus following surgical removal of impacted third molars. The combination of preoperative rofecoxib 50 mg and intraoperative dexamethasone 10 mg was most effective in minimizing pain and trismus following third molar surgery.     

Preoperative radiochemotherapy and radical resection for stages II to IV oral and oropharyngeal cancer: grade of regression as crucial prognostic factor

The purpose of this study was to assess the prognostic value of histological response to preoperative radiochemotherapy in an established multimodal therapy concept for advanced oral and oropharyngeal cancer. Two hundred and twenty-two patients who underwent preoperative radiochemotherapy (RCT: 50 Gy, mitomycin C and fluorouracil) and radical surgery were retrospectively evaluated. Resected tumours of all patients were histologically analysed and response to RCT was classified in histopathological grades of regression (RG). In a multivariate statistical analysis, RG was compared with established factors regarding their predictive value for overall and disease-specific survival. The 5-year overall survival probability in the different groups of histopathological regression grades were: RG1 (no vital tumour): 73.4%, RG2 (minimal tumour remnants encompassing less than 5%): 72.1%, RG3 (5-50% vital tumour cells): 41.9%, RG4 (more than 50% vital tumour): 37.9%. For disease-specific survival probability no significant differences were found between both groups of "responders" (RG1 and RG2) nor between "non-responders" (RG3 and RG4), whereas responders and non-responders differed significantly from each other (log-rank test; p < 0.001). T-classification, N-classification and disease stage, histological grading, tumour site, age, and sex had less prognostic value than RG in a Cox regression model. In the neoadjuvant multimodal therapy concept, histological response to preoperative RCT is a crucial prognostic factor even when surgical R0-resection is accomplished. Thus, non-responders have to be regarded as high-risk patients for recurrence and may benefit from further therapy.     

Intracanal temperature rise evaluation during the usage of the System B: replication of intracanal anatomy

AIM: To evaluate and determine intracanal temperature rises at 2 and 4 mm from the working length (WL) necessary to obtain proper replication of intracanal anatomy with gutta-percha (GP) using the System B heat source during vertical condensation. METHODOLOGY: A split-tooth model was prepared and artificial shallow depressions were cut in the buccal canal wall 2 and 4 mm from the WL. At the same level on the palatal wall holes were drilled to adapt two thermocouples. The canal was filled using GP in a vertical condensation technique by placing the System B plugger at 2 and 4 mm from the WL in groups A and B, respectively. Two control groups in which no GP was used were carried out placing the plugger 2 and 4 mm from the WL (groups A.c and B.c, respectively) and activating the heat source. Recording of temperature rise was carried out during the filling procedure for groups A and B and during activation for control groups A.c and B.c; the highest temperatures were recorded. After each filling was completed, 3 min were allowed for the GP to cool and the model divided to reveal the filling. Images of the GP were taken with a CCD camera to evaluate the presence of replication of artificial round depressions. In control groups, the temperature was recorded for 20 s after a 3 s activation of the heat source. The rise in temperature was compared between the groups individually at each level (2 or 4 mm) and statistically analysed using one-way anova and Fisher PLSD tests at 5% of significance level (P < 0.05). RESULTS: Mean temperature rises of 14 +/- 3 and 12 +/- 2 degrees C at 2 and 4 mm from the WL, respectively, were observed in group A fillings, and 4 +/- 1 and 6 +/- 1 degrees C at 2 and 4 mm, respectively, in group B fillings. Recordings at 2 mm showed significantly (P < 0.05) higher temperature rises with group A.c when compared with groups B and B.c. Replication of intracanal anatomy with GP was always found in group A fillings at both levels but only 4 mm from the WL in group B fillings. CONCLUSIONS: Positioning the plugger close to WL and a temperature rise of 6 degrees C were necessary to obtain replication of intracanal anatomy. A mean temperature rise of 4 degrees C at 2 mm from WL (group B) resulted in no replication of intracanal anatomy. Further studies simulating clinical conditions are necessary.     

Dendritic-NK cell interactions in P. gingivalis-specific responses

Patients with localized aggressive periodontitis have type-1 cytokines in gingival crevicular fluid and high titers of IFN-gamma-dependent IgG2 reactive with P. gingivalis in gingival crevicular fluid and serum. Localized aggressive periodontitis monocytes spontaneously differentiate into dendritic cells that can stimulate IFN-gamma production by NK cells. These relationships prompted the hypothesis that P. gingivalis-dendritic cell-NK cell interactions might promote type-1 cytokine responses. Although P. gingivalis is not a potent inducer of Th1 responses, it stimulated strong IL-12 responses by monocyte-derived dendritic cells in the presence of IFN-gamma, and IFN-gamma was produced by NK cells within 24 hrs in the presence of dendritic cells. Anti-P. gingivalis IgG2 responses were enhanced by dendritic cells, and removal of NK cells reduced IFN-gamma- and P. gingivalis-specific IgG2. Thus, P. gingivalis-dendritic cell-NK cell interactions apparently resulted in reciprocal stimulation and increased type-1 cytokine production by both dendritic cells and NK cells, and increased P. gingivalis-specific IgG2.     

Double-blind study on materials testing with applied kinesiology

Applied Kinesiology (AK) is a scientifically unproven method used in complementary medicine to recognize the (in)tolerance of dental materials. Test-retest reliability of AK was examined. The working hypothesis was the assumption that the reliability of AK would not exceed random chance. Two dentists qualified in AK examined 112 volunteers to determine individual (in)tolerance toward two dental composite materials. After the first examination, 31 subjects were excluded from further testing. At the end of the open test phase, 34 of 81 participants had been classified as "tolerant", and seven as "intolerant" to both materials. The remaining 40 individuals showed a combination of either tolerant (to material I)/intolerant (to material II), or the reverse (n = 20 each). Retrieval rate was tested under blind conditions. In 14 cases, the results of the open and blinded tests matched, whereas in 26 cases they did not (95% confidence interval, 21%-52%; p = 0.98). This outcome confirmed our working hypothesis.     

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial

BACKGROUND: Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. METHODS: Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. RESULTS: CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. CONCLUSIONS: To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.     

Assessing the competency of University of Malaya dental graduates: employers' and graduates' perceptions

A survey was conducted to assess competencies of dental graduates of the Faculty of Dentistry, University of Malaya, as perceived by the graduates and their employers, based on the five-year undergraduate curriculum introduced in 1995. All senior dental officers in the Ministry of Health (MOH), representing employers, and all 164 dental graduates of the years 2000, 2001, and 2002 were sent a self-administered questionnaire covering eight areas of competency. The respondents had to rate these areas on a scale of 1 (very poor) to 4 (very good). The responses for each area were then dichotomized into poor (1 and 2) and good (3 and 4). If less than 60 percent of the respondents rated an area as good, then it was categorized as needing attention; 60-69 percent as satisfactory; and 70 percent and above as excellent. One hundred and six graduates (64.6 percent) and twenty-nine employers (96.7 percent) responded; of the graduates, 73.6 percent were working in the MOH and 22.6 percent in private practice. About 57.1 percent of employers reported that at least five graduates have worked under them. Graduates (85.7 percent) and employers (83.3 percent) agreed that graduates have excellent skills in communication. Although all graduates perceived their competency to be excellent in the four areas (treatment planning; community-based skills; management, administrative skills, and personal management; and professional development skills), employers felt that these are the areas that are of concern and needed attention. In conclusion, whilst generally the graduates' level of competency in almost all areas is acceptable or good, there are areas of concern that need to be addressed to further improve the five-year curriculum at the University of Malaya.