Comparison of two surgical techniques (HOO vs. BSSO) for mandibular osteotomies in orthognathic surgery-a 10-year retrospective study.

PURPOSE: To retrospectively compare the high-angled sagittal split osteotomy (HOO) and the bilateral sagittal split osteotomy (BSSO) for the correction of skeletal dysgnathias regarding intra- and postoperative complications. METHODS: The electronic medical records of all patients treated with an orthognathic surgery at the Department for Oral, Maxillofacial and Facial Plastic Surgery, University Hospital Frankfurt, Germany, between the years 2009 and 2019 were retrospectively reviewed. RESULTS: Two hundred ninety-one patients were included. The overall complication rates were 19.78% (BSSO) compared to 12.5% (HOO) (p = 0.14). Significant differences were found regarding the operation time (HOO < BSSO, p = 0.02), material failure (HOO > BSSO, p = 0.04), and early recurrence requiring revision surgery (HOO < BSSO, p = 0.002). The use of a ramus plate significantly reduced the risk of plate failure (2.8% < 13.6%, p = 0.05). More bad splits (p = 0.08) and early sensory disorders (p = 0.07) occurred in the BSSO group. CONCLUSION: The HOO presents a possible alternative to the BSSO since newly developed osteosynthesis material significantly reduces the risk of material failure. The BSSO is accompanied by higher risks of developing complications like a bad split and sensory disorders but, however, remains the standard for large anterior-posterior transpositions of the mandible.

Do the stages of orthodontic-surgical treatment affect patients' quality of life and self-esteem?

The orthodontic-surgical treatment comprises different stages from diagnosis to final soft tissue accommodation, but there are no data regarding the patient's perception during these phases. This study aimed to investigate the impact of these stages on quality of life and self-esteem of patients with dentofacial deformity. Patients were divided into 4 groups according to the treatment stage: initial orthodontic pre-treatment (1), one week before surgery (2), three months after surgery (3), and after the removal of the orthodontic appliance (4) (n = 20 / group). They filled the following questionnaires: Oral Health Impact Profile (OHIP-14), Orthognathic Quality of Life Questionnaire (OQLQ) and Rosenberg Self-Esteem Scale (RSES). Data were evaluated by Kruskal-Wallis test. Differences among groups were noticed in all evaluated scales (p = 0.001 for all). No statistically significant differences between patients in groups 1 and 2 (OHIP, OQLQ, and RSES, p >0.05 for all), while patients at group 4 presented different scores in all questionnaires compared to 1, 2, and 3 (p < 0.05 for all), irrespective of the type of dentofacial deformity (p > 0.05). The results indicate that dental decompensation stage did not negatively affect patient's confidence and well-being. Despite the improvement noticed few months after the orthognathic surgery, the main impact on patient's quality of life and self-esteem was evidenced after the removal of the orthodontic appliance. We highlight the important role of counselling patients to discuss all the treatment stages to clarify patients' subjective expectations before any intervention is carried out.

Piezoelectric versus conventional techniques for orthognathic surgery: Systematic review and meta-analysis.

PURPOSE: A systematic review and meta-analysis of the advantages and disadvantages of the piezo surgery comparing with conventional osteotomy in orthognathic surgery. METHODS: We conducted this systemic review in accordance with the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. We searched for relevant studies in the PubMed/MEDLINE, Embase databases, Lilacs, Scopus and Science Direct to identify prospective and retrospective studies, compare patient outcomes (intraoperative blood loss, operative time, neurosensory disturbance) after performing orthognathic surgery by conventional saw or piezo-electric device. According to pool individual results we used the mean difference (MD) with the 95% confidence interval (95% CI). RESULTS: Among three studies that used conventional saw and three studies used piezo-electric device and nine studies used both techniques, the operative time required to perform orthognathic standard procedures was longer using piezo-electric device compared to conventional saw. The results showed that during using the conventional saw to perform orthognathic surgery the amount of the blood loss was higher than the amount while using piezo-electric device (MD -140.4 mL; P = 0.29). based on the studies that evaluated neurosensory disturbance, after 3 months and 6 months respectively, neurosensory disturbance was seen in 23.8% and 23.4% of patient who underwent conventional osteotomy versus 4.3% and 2.4% of the patients who underwent surgery in which piezo surgery was used. Our meta-analysis showed difference in neurosensory disturbance between piezo-surgery and conventional surgery at 3 months (MD -19.5; P = 0.11) and 6 months (MD -21; P = 0.5) postoperatively. CONCLUSION: Piezo-electric device enabled lower blood loss and higher nerve integrity rates in outcomes according to the complications that associated with orthognathic surgery.

Changes in admission laboratory tests in patients with maxillofacial fractures and the influence of dento-alveolar trauma.

BACKGROUND/AIM: There are few studies in the literature evaluating possible alterations in laboratory tests in patients with maxillofacial fractures. The aim of this study was to analyze the changes in admission laboratory tests of patients with maxillofacial fractures with indications for surgical treatment, including the influence of dento-alveolar trauma. MATERIAL AND METHODS: Data from complete blood counts, blood coagulation tests, blood chemistries, and urinalysis results were obtained. The occurrence of concomitant dento-alveolar trauma was noted. The medical records were also re-evaluated later to verify the treatment outcome and the occurrence of complications. Statistical analyses were performed using the likelihood-ratio test to verify significant changes in the evaluated parameters (P ≤ .050). RESULTS: There was a prevalence of males (78%) with a mean age of 35.9 years. Lower erythrocyte counts, hemoglobin levels, and/or hematocrit were observed in males with associated fractures and with simultaneous dento-alveolar fractures. Higher mean neutrophil, segmented neutrophil, and lymphocyte counts were observed in patients with simultaneous dento-alveolar trauma. A higher mean activated partial thromboplastin time (aPTT) ratio was also observed. Lower potassium levels were observed for patients in the fourth decade of life. Higher leukocyte counts not associated with trauma were observed in the urinalysis results of females and in the group of patients aged 20 or younger. Verification of treatment outcome showed two cases of infections and two cases that needed re-operation after mandible fractures. These four cases showed no significant changes in laboratory tests regarding the predisposition for complications. CONCLUSION: Patients with maxillofacial fractures had neutrophilia, increased aPTT, and non-traumatic leukocyturia. There was an influence of associated fractures and dento-alveolar trauma on the decrease in red blood cell parameters, neutrophilia, and lymphocytosis and of age on hypokalemia.

Longitudinal evaluation of the effects of low-power laser phototherapy on mandibular movements, pain, and edema after orthognathic surgery.

The aim of this study was to longitudinally evaluate mandibular movements, pain, and edema in patients who underwent low-power laser (LPL) phototherapy after bimaxillary orthognathic surgery. A double-blind, randomized, controlled clinical trial was conducted using 30 patients, who were divided into a study group (n = 15) and control group (n = 15). The former group received postoperative LPL (3 J/cm2, 808 nm, and 100 mW) and the latter group received placebo LPL phototherapy. Over a period of 60 days, these groups were evaluated for: mandibular movements - opening, laterality, and protrusion; pain - visual analogue scale; and edema - measured between cephalometric points. The study group showed significantly better jaw opening (p = 0.009), laterality (p = 0.036), and protrusion (p = 0.029) after 2 weeks in most comparisons. The study group showed significantly less postoperative pain (p < 0.001) in most comparisons, and they recovered from pain earlier than the control group. There was a reduction in edema, with no statistically significant difference for most measurements. As observed in most analyses, there were increases in values for all mandibular movements, no significant differences in the occurrence of edema, and decreases in the occurrence of pain.

Current concepts in cleft care: A multicenter analysis.

The current surgical techniques used in cleft repair are well established, but different centers use different approaches. To determine the best treatment for patients, a multi-center comparative study is required. In this study, we surveyed all craniofacial departments registered with the German Society of Maxillofacial Surgery to determine which cleft repair techniques are currently in use. Our findings revealed much variation in cleft repair between different centers. Although most centers did use a two-stage approach, the operative techniques and timing of lip and palate closure were different in every center. This shows that a retrospective comparative analysis of patient outcome between the participating centers is not possible and illustrates the need for prospective comparative studies to establish the optimal technique for reconstructive cleft surgery.

Comparison of a 2.0-mm locking system with conventional 2.0- and 2.4-mm systems in the treatment of mandibular fractures: a randomized controlled trial.

PURPOSE: A comparative study of the use of the 2.0-mm locking fixation system with conventional systems in the treatment of mandibular fractures was performed. METHODS: For this study, 87 consecutive patients with 112 mandibular fractures were randomized to receive either 2.0-mm locking plates (n = 45) or conventional 2.0- or 2.4-mm plates (n = 42) and had a minimum follow-up of 6 months. Fractures were classified based on the degree of displacement and complexity. Statistical analyses were used to verify possible differences between the groups when separately compared unfavourable and favourable cases (p ≤ 0.050). RESULTS: Despite randomization, systemic diseases were more frequent in the 2.0-mm locking group in favourable cases. Substance abuse occurred predominantly in the 2.0-mm locking group, in unfavourable and favourable fractures. There were more cases of complex fractures in the conventional group in unfavourable cases. One case involving a major postoperative complication occurred in the locking group (2.2%) and three cases occurred in the conventional group (7.1%) but with no significant difference between groups. In this study, there were no major differences between conventional and locking 2.0-mm locking systems with regard to the outcome of treated mandibular fractures, showing that both are adequate as long as the criteria of their indication and requirements for installation are met. CONCLUSIONS: It was concluded that the 2.0-mm locking fixation system can replace conventional systems in the treatment of mandibular fractures; in addition, this approach was effective in the treatment of unfavourable fractures that typically require the 2.4-mm conventional system.

Self-drilling and self-tapping miniscrews for osteosynthesis fixture after LeFort I osteotomy: An ex vivo trial for primary stability and a randomized clinical study.

BACKGROUND: Self-drilling osteosynthesis screws (SDS) have a potential higher primary stability together with clinical advantages such as less time effort compared to self-tapping screws (STS). The aims of the study were to compare the primary stability of SDS and STS ex vivo and to analyze of the time-saving effect in vivo. MATERIALS AND METHODS: Ex vivo, both screws were placed in porcine bone. Torque was measured for insertion and removal. Four specimens were kept in bone for histologic bone-to-implant-contact examination. In vivo, 49 patients who received orthognathic surgery in the maxilla were included in 2 centers. In a split-mouth design, the time for osteosynthesis fixation and perioperative events were recorded. RESULTS: Ex vivo, insertion and removal torque measurements were higher for SDS, especially in dense bone. Histologic imaging on the exemplary-stained specimens showed higher bone contact and compressed bone matrix for SDS in all bone densities. In vivo, the mean osteosynthesis time in both centers was 5.5 min (±3.03) for SDS and 5.5 min (±2.37) for STS. Separate analysis showed that center I was faster with STS and center II with SDS. Although, in center I a higher rate of failed primary stability of SDS compared to STS was documented. CONCLUSIONS: SDS showed a partially higher primary stability ex vivo, especially in dense bone. The timesaving effect of SDS is less pronounced than expected, but technically SDS might be favorable where drilling is difficult or even impossible.

Biological performance of cell-encapsulated methacrylated gellan gum-based hydrogels for nucleus pulposus regeneration.

Limitations of current treatments for intervertebral disc (IVD) degeneration have promoted interest in the development of tissue-engineering approaches. Injectable hydrogels loaded with cells can be used as a substitute material for the inner IVD part, the nucleus pulposus (NP), and provide an opportunity for minimally invasive treatment of IVD degeneration. The NP is populated by chondrocyte-like cells; therefore, chondrocytes and mesenchymal stem cells (MSCs), stimulated to differentiate along the chondrogenic lineage, could be used to promote NP regeneration. In this study, the in vitro and in vivo response of human bone marrow-derived MSCs and nasal chondrocytes (NCs) to modified gellan gum-based hydrogels was investigated. Both ionic- (iGG-MA) and photo-crosslinked (phGG-MA) methacrylated gellan gum hydrogels show no cytotoxicity in extraction assays with MSCs and NCs. Furthermore, the materials do not induce pro-inflammatory responses in endothelial cells. Moreover, MSCs and NCs can be encapsulated into the hydrogels and remain viable for at least 2 weeks, although apoptosis is observed in phGG-MA. Importantly, encapsulated MSCs and NCs show signs of in vivo chondrogenesis in a subcutaneous implantation of iGG-MA. Altogether, the data endorse the potential use of modified gellan gum-based hydrogel as a suitable material in NP tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.

Moving the mandible in orthognathic surgery - A multicenter analysis.

Orthognathic surgery has always been a classical focus of maxillofacial surgery. Since more than 100 years, various surgical techniques for mandibular repositioning have been developed and clinically tested. Since the establishment of plate and screw osteosynthesis, orthognathic surgery became more stable and safe. Nowadays, different surgical methods for mobilising the mandible are existing. This international multicenter analysis (n = 51 hospitals) is providing first evidence based data for the current use of different surgical methods. The dominating techniques were Obwegeser/dal Pont (61%) followed by Hunsuck/Epker (37%) and Perthes/Schlössmann (29%). The main osteosynthesis materials were plates (82%), bicortical screws (23.5%), or a combination of both (5.9%). 47% of all centers reported to use several surgical methods at the same time, depending on the anatomical problem and the surgeon's preference. This shows that different surgical methods seem to work as comparable, safe, and reliable procedures in everydays clinical practise. On this basis, further prospective studies could evaluate possible advantages for our patients.

Poly(γ-Glutamic Acid) as an Exogenous Promoter of Chondrogenic Differentiation of Human Mesenchymal Stem/Stromal Cells.

Cartilage damage and/or aging effects can cause constant pain, which limits the patient's quality of life. Although different strategies have been proposed to enhance the limited regenerative capacity of cartilage tissue, the full production of native and functional cartilaginous extracellular matrix (ECM) has not yet been achieved. Poly(γ-glutamic acid) (γ-PGA), a naturally occurring polyamino acid, biodegradable into glutamate residues, has been explored for tissue regeneration. In this work, γ-PGA's ability to support the production of cartilaginous ECM by human bone marrow mesenchymal stem/stromal cells (MSCs) and nasal chondrocytes (NCs) was investigated. MSC and NC pellets were cultured in basal medium (BM), chondrogenic medium (CM), and CM-γ-PGA-supplemented medium (CM+γ-PGA) over a period of 21 days. Pellet size/shape was monitored with time. At 14 and 21 days of culture, the presence of sulfated glycosaminoglycans (sGAGs), type II collagen (Col II), Sox-9, aggrecan, type XI collagen (Col XI), type X collagen (Col X), calcium deposits, and type I collagen (Col I) was analyzed. After excluding γ-PGA's cytotoxicity, earlier cell condensation, higher sGAG content, Col II, Sox-9 (day 14), aggrecan, and Col X (day 14) production was observed in γ-PGA-supplemented MSC cultures, with no signs of mineralization or Col I. These effects were not evident with NCs. However, Sox-9 (at day 14) and Col X (at days 14 and 21) were increased, decreased, or absent, respectively. Overall, γ-PGA improved chondrogenic differentiation of MSCs, increasing ECM production earlier in culture. It is proposed that γ-PGA incorporation in novel biomaterials has a beneficial impact on future approaches for cartilage regeneration.

Perspectives of patients about bioabsorbable internal fixation for maxillofacial fractures.

PURPOSE: Resorbable/bioabsorbable internal fixation provides effective treatment for maxillofacial fractures and avoids the need for metal hardware removal. We evaluated the initial knowledge, attitudes, subjective demand, and treatment satisfaction of patients concerning bioabsorbable osteofixation for maxillofacial trauma. MATERIALS AND METHODS: From May 2007 to October 2009, there were 71 patients (63 males and 8 females; mean age: 35 ± 15 years) included in this prospective study. The patients completed preoperative and postoperative (4-6 weeks and 1 year) questionnaires. RESULTS: After receiving information, 70 patients (99%) preferred resorbable/bioabsorbable bone fixation, usually because they preferred to avoid a second operation to remove metal hardware (67 patients [94%]). The higher cost of resorbable/bioabsorbable bone fixation was believed and justified by 41 patients (58%) and not justified by 30 patients (42%). No adverse events were reported by 27 of 34 patients (79%) at 4-6 weeks and by 14 of 21 patients (67%) at 1 year after surgery. Most patients were very satisfied with the outcome of surgery. CONCLUSION: Patients who have maxillofacial trauma have a high frequency of preference and high satisfaction with resorbable/bioabsorbable than metal osteofixation. Literature review showed increased activity in research and publication worldwide about resorbable bone fixation, suggesting that there may be increased patient demand for resorbable bone fixation in the future.

Intraoperative condyle positioning by sonographic monitoring in orthognathic surgery verified by MRI.

OBJECTIVE: Repositioning of the jaw in orthognathic surgery must produce precise and stable long-term results; an effective and practical method of intraoperative condyle positioning is required to achieve this. Most traditional methods, such as manual positioning or positioning plates do not permit intraoperative monitoring of the temporomandibular joint (TMJ) position. This study evaluates the results of intraoperative, sonographically-monitored joint positioning, comparing preoperative and postoperative MRI scans. PATIENTS AND METHODS: Of the 97 patients who were originally assessed (53 female, average age 29 ± 10.93; and 44 male, average age 28 ± 9.25), 21 had incomplete data sets and were excluded, leaving 76 evaluable patients. MRIs were performed preoperatively between 2 days and 100 weeks (median 30.5 days), and postoperatively between 12 and 96 weeks (median 150 days). Condyle positioning, intercondylar distance, and disc degeneration and dislocation were compared in preoperative and postoperative MRIs, and differentiated by Angle class on horizontal, axial and sagittal scans. Condyle to fossa distances were measured on parasagittal images from 0° (the vertical sagittal plane), 45° anteriorly and 45° posteriorly. The intercondylar distances between the condylar head midpoints were measured on axial sections. Two-sided t-tests (α < 0.05) were used for comparisons within classes; the interclass correlation was performed using univariate ANOVA and linear correlation for paired sample correlation settings. RESULTS: In 27 Angle class II cases, the anterior distance of both condyles increased on average 0.3 ± 1.0 mm, the posterior position decreased 0.1 ± 1.2 mm, and the vertical position decreased 0.2 ± 1.1 mm postoperatively. In 47 Angle class III cases the anterior distance of both condyles increased on average 0.3 ± 0.8 mm, the posterior 0.1 ± 0.8 mm and the vertical distance 0.1 ± 0.8 mm postoperatively. All alterations of the condyle-fossa relation were non-significant except for the anterior distance in Angle class ІІІ (p = 0.02). Alterations of the disc position and disc degeneration were non-significant in class II. In class ІІІ, the disc degeneration deteriorated slightly on the left side (p = 0.02). Intercondylar distance increased 1 ± 5.5 mm in class ІІ and decreased by 1 ± 5.5 mm in class ІІІ postoperatively, alterations were non-significant. CONCLUSION: Sonography is a non-invasive, comfortable, fast, economical and effective intraoperative method of condyle positioning. The results of the present study support this statement because the degree of disc degeneration and luxation remained unaltered and the condyle position did not change significantly. Prospective randomized comparison to manual positioning is in preparation and will be conducted in the near future.

TRAP-Positive Multinucleated Giant Cells Are Foreign Body Giant Cells Rather Than Osteoclasts: Results From a Split-Mouth Study in Humans.

This study compared the material-specific tissue response to the synthetic, hydroxyapatite-based bone substitute material NanoBone (NB) with that of the xenogeneic, bovine-based bone substitute material Bio-Oss (BO). The sinus cavities of 14 human patients were augmented with NB and BO in a split-mouth design. Six months after augmentation, bone biopsies were extracted for histological and histomorphometric investigation prior to dental implant insertion. The following were evaluated: the cellular inflammatory pattern, the induction of multinucleated giant cells, vascularization, the relative amounts of newly formed bone, connective tissue, and the remaining bone substitute material. NB granules were well integrated in the peri-implant tissue and were surrounded by newly formed bone tissue. Multinucleated giant cells were visible on the surfaces of the remaining granules. BO granules were integrated into the newly formed bone tissue, which originated from active osteoblasts on their surface. Histomorphometric analysis showed a significantly higher number of multinucleated giant cells and blood vessels in the NB group compared to the BO group. No statistical differences were observed in regard to connective tissue, remaining bone substitute, and newly formed bone. The results of this study highlight the different cellular reactions to synthetic and xenogeneic bone substitute materials. The significantly higher number of multinucleated giant cells within the NB implantation bed seems to have no effect on its biodegradation. Accordingly, the multinucleated giant cells observed within the NB implantation bed have characteristics more similar to those of foreign body giant cells than to those of osteoclasts.

Transoral vs. extraoral approach in the treatment of condylar neck fractures.

PURPOSE: The aim of this study was to assess a non-endoscopic transoral versus extraoral technique in the open reduction and internal fixation of displaced or dislocated fractures of the condylar neck. MATERIAL AND METHODS: A total of 104 patients, treated from 2007 to 2012 with 114 class II or class IV fractures according to Spiessl and Schroll were included in this study. Facial nerve function, scarring, pain and functional clinical parameters, such as protrusion, mediotrusion and maximum interincisal distance, were judged clinically (at 21 ± 12.1 months); repositioning and reossification were measured upon preoperative, postoperative and follow-up (at 8.8 ± 7 months) radiographs. Patient satisfaction was evaluated using the OHIP-G 14 questionnaire. RESULTS: In all, 36 patients (35%) with 43 fractures (38%) presented for clinical follow-up. Both treatment groups showed clinically and radiologically comparable results. Scarring was obvious in all extraorally treated patients, and hypertrophic scars occurred in four class IV cases (24%). One class IV patient (6%) had a persistent facial nerve palsy; temporary pareses were more frequent (n = 4; 24%). CONCLUSION: The transoral approach did not jeopardize facial nerve function, and extraoral scars were avoided. Repositioning and fixation results and the frequency of revision operations were comparable. The transoral approach can be recommended generally in class II and class IV cases.

Benefit of piezoosteotomy in cranioplasties for craniosynostosis correction versus conventional saw-and-chisel osteotomy: a pilot study.

OBJECTIVE: Pilot study evaluation of the benefit of piezoosteotomy in cranioplasty of craniosynostoses, based on clinical data. DESIGN: Retrospective case-control study. SETTING: Universitarian institution. PATIENTS: Craniosynostosis patients (n = 19) operated upon conventionally with a craniotome and microsaw versus 19 patients operated upon with a piezoosteotomy and a craniotome. INTERVENTION: Piezoosteotomy of the supraorbital "bandeau" and osteotomies on part of the parietal and occipital regions versus conventional saw-and-chisel osteotomy. MAIN OUTCOME MEASURES: Perioperative age, weight, laboratory parameters, transfusion and infusion requirements, operation time, and blood loss. RESULTS: The intraoperative erythrocyte concentrate transfusion and noncolloidal infusions were comparable (P = .15; P = .56). The fresh frozen plasma transfusion was significantly higher (P = .03); possibly, the anesthesiologist's reaction was secondary to the higher irrigation-fluid accumulation in the aspiration bag during piezoosteotomy. The postoperative erythrocyte concentrate transfusion rate was significantly lower (P = .01) as a result of local hemostasis in piezoosteotomy. The fresh frozen plasma transfusion and noncolloidal infusion volumes were nonsignificantly lower (P = .27; P = .85). Operation time was slightly shorter with a smaller standard deviation (P = .09), due to a lower rate of dural lacerations and consecutive repair; patients in the study group were on the intensive care unit half a day less (P = .73) than those in the control group. C-reactive protein was significantly lower preoperatively (P = .00) and on the operation day (P = .01) and nonsignificant postoperatively (P = .81); hematocrit was postoperatively higher (P = .23). Thrombocytes were preoperatively lower and postoperatively higher, both nonsignificant (P = .29; P = .52). CONCLUSIONS: Piezoosteotomy appears to be less traumatic than conventional saw-and-chisel osteotomy by the evaluated parameters. The main study limitation is its nonrandomized retrospective design; results should be confirmed by a randomized controlled trial.

Introduction of craniomaxillofacial surgery as a component of medical student training in general surgery.

PURPOSE: This study provides an overview of the objective structured clinical examination (OSCE) in concept, determination of task difficulty, execution, and evaluation by students and examiners. METHODS: During a 4-semester study period, 507 medical students completed a practical skills training (PST) course and subsequently participated in a 16-station OSCE, which contained 2 craniomaxillofacial surgical (CMS) stations covering the following key tasks: craniofacial examination and facial trauma fracture management. The students were rated using dedicated checklists. The students subjectively evaluated the PST and the OSCE using anonymous evaluation forms. RESULTS: Students rated the PST and OSCE as "very positive." The CMS OSCE stations were rated as having good task difficulty (74.05 ± 1.78% average task fulfilment for the examination and 74.45 ± 3.40% for the management station). With no changes to the examination station, no significant improvement of performance occurred over the entire investigation period (P = .787). In contrast, students improved slightly at the management station (P = .308). The CMS stations showed high selectivity and were representative in the overall context of the OSCE; improvement of selectivity increased from 0.259 ± 0.088 to 0.465 ± 0.109. CONCLUSION: CMS was successfully implemented in the general surgical training for medical students, with an initial PST and a final OSCE concordant with the literature. The CMS implementation effectively trained and fairly evaluated clinical skills. Although an OSCE consumes time and resources, this addition proved feasible and valuable, even with large numbers of students, and students expressed a high level of satisfaction with the training.

Advanced platelet-rich fibrin: a new concept for cell-based tissue engineering by means of inflammatory cells.

Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.

Treatment of malar and midfacial fractures with osteoconductive forged unsintered hydroxyapatite and poly-L-lactide composite internal fixation devices.

PURPOSE: To evaluate the internal fixation of malar and midfacial fractures, long-term results, and biocompatibility of osteoconductive internal fixation devices composed of a forged composite of unsintered hydroxyapatite and poly-L-lactide (F-u-HA/PLLA). MATERIALS AND METHODS: From January 2006 to June 2010, 29 patients (24 males and 5 females; age 33 ± 15 years) were included in the present prospective study. The fracture type was malar in 24 patients, midfacial in 5, isolated orbital floor blowout in 2, and frontal sinus, cranial base in 2 patients. The fractures were fixed with internal fixation devices; these were plates and screws composed of F-u-HA/PLLA. The 24 patients with malar fractures were treated with a single 4-hole L-plate or a straight plate at the infrazygomatic crest. RESULTS: All fractures with internal fixation using devices composed of F-u-HA/PLLA healed well. All malar and midfacial fractures had satisfactory long-term stability. The follow-up examinations at 12 to 67 months after surgery showed that most patients had no complaints, although 2 patients (15%) had a foreign body reaction that was treated by implant removal, with complete symptom resolution. At 5 years after fracture fixation, 2 patients had ultrasound and 2 had radiographic evidence of residual material. An exemplar biopsy showed direct bone growth into the material. CONCLUSIONS: In patients with malar and midfacial fractures, hardware composed of the F-u-HA/PLLA composite provided reliable and satisfactory internal fixation, intraoperative handling, long-term stability, and biocompatibility. Direct bone growth into the material could be histopathologically exemplified, in contrast to previous polymer fixations that were resorbed and surrounded by a connective tissue layer. This finding indicates that long-term F-u-HA/PLLA residual material will be included into the remodeled bone, which was confirmed on long-term follow-up radiographs.

Segmental stability in orthognathic surgery: hydroxyapatite/Poly-l-lactide osteoconductive composite versus titanium miniplate osteosyntheses.

Hydroxyapatite was included into F-u-HA/PLLA (unsintered hydroxyapatite - Poly l-lactide) composite osteosynthesis material for its documented osteoconductive capacity. This study investigates segmental retention capacities and outcome stability using F-u-HA/PLLA composite osteosyntheses in orthognathic surgery. Of fifty patients in total, 25 patients were osteofixated with F-u-HA/PLLA osteoconductive bioabsorbable osteosyntheses and compared to a group of 25 patients treated with titanium miniplates. The F-u-HA/PLLA group included 14 maxillary advancements, 4 setbacks, 13 impactions, 5 elongations at A-point; the titanium group included 20 maxillary advancements, 2 setbacks, 11 impactions and 11 elongations. In the mandible the F-u-HA/PLLA group included 13 advancements at B-point, 11 setbacks, 16 clockwise rotations and 8 counterclockwise rotations at the Gonial angle (Ar-Go-Gn); the titanium group included 9 mandibular advancements, 5 setbacks, 8 clockwise rotations and 6 counterclockwise rotations at Ar-Go-Gn. Segmental stability and relapse were assessed comparing preoperative, postoperative and follow-up roentgen cephalometrics at 22 ± 11 months on average in F-u-HA/PLLA cases, 24 ± 22 months on average in the titanium group. All absolute operative movements were nonsignificant in the F-u-HA/PLLA cases compared to the titanium osteosynthesis cases. Relapses were nonsignificant but there was greater vertical relapse in maxillary impactions with titanium osteosyntheses. Throughout this study, F-u-HA/PLLA composite osteosyntheses appeared as stable as titanium miniplates. It can therefore be concluded, although from a limited number of patients, that the investigated osteoconductive osteosynthesis can be used in a similar way to titanium miniplates in orthognathic surgery. Compared to earlier studies using other bioabsorbable polymers in the literature, F-u-HA/PLLA proved to be more stable in segmental retention.