A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth edentulous area: 3-year follow-up.

BACKGROUND: Traditionally, dental implants have been made from titanium or titanium alloys. Alternatively, zirconia-based ceramic implants have been developed with similar characteristics of functional strength and osseointegration. Ceramic implants offer advantages in certain settings, e.g. in patients who object to metal dental implants. The aim of this study was to investigate the mid-term (36 months) clinical performance of a ceramic monotype implant in single-tooth edentulous area. METHODS: This was a prospective, open-label, single-arm study in patients requiring implant rehabilitation in single-tooth edentulous area. Ceramic implants (PURE Ceramic Implant, Institut Straumann AG, Basel, Switzerland) with a diameter of 4.1 mm were placed following standard procedure and loaded with provisional and final prostheses after 3 and 6 months, respectively. Implant survival rate and implant success rate were evaluated and crestal bone levels were measured by analysing standardized radiographs during implant surgery and at 6, 12, 24 and 36 months. RESULTS: Forty-four patients received a study implant, of whom one patient withdrew consent after 3 months. With one implant lost during the first 6 months after surgery, the implant survival rate was 97.7% at 6 months. No further implants were lost over the following 30 months, and 3 patients were lost to follow-up during this time frame. This led to a survival rate of 97.5% at 36 months. Six months after implant surgery 93.0% of the implants were considered "successful", increasing to 97.6% at 12 months and remaining at this level at 24 months (95.1%) and 36 months (97.5%). Bone loss was most pronounced in the first half-year after implant surgery (0.88 ± 0.86 mm). By contrast, between 12 and 36 months the mean bone level remained stable (minimal gain of 0.06 [± 0.60] mm). Hence, the overall bone loss from implant surgery to 36 months was 0.97 (± 0.88) mm. CONCLUSIONS: In the follow-up period ceramic implants can achieve favourable clinical outcomes on a par with titanium implants. For instance, these implants can be recommended for patients who object to metal dental implants. However, longer term studies with different edentulous morphology need to confirm the present data. TRIAL REGISTRATION: Registered on www.clinicaltrials.gov : NCT02163395 .

A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth gaps.

INTRODUCTION: Dental implants have traditionally been made from titanium or its alloys, but recently full-ceramic implants have been developed with comparable osseointegration properties and functional strength properties to titanium. These ceramic implants may have advantages in certain patients and situations, for example, where esthetic outcomes are particularly important. OBJECTIVE: The objective of this investigation was to evaluate the performance of a newly developed full-ceramic ZrO2 monotype implant design (PURE Ceramic Implant; Institut Straumann AG, Basel, Switzerland) in single-tooth gaps in the maxilla and mandible. MATERIAL AND METHODS: This was a prospective, open-label, single-arm study in patients requiring implant rehabilitation in single-tooth gaps. Full-ceramic implants were placed, with provisional and final prostheses inserted after 3 and 6 months, respectively. Crestal bone level was measured at implant placement and after 6 and 12 months. Implant survival and success were evaluated after 6 and 12 months. Further evaluations are planned after 24 and 36 months. RESULTS: Forty-six patients were screened for potential study participation, of whom 44 (17 men and 27 women, mean age 48 ± 14 years) were recruited into the study. The majority of implants (90.9%) were placed in the maxilla. The implant survival and implant success rate after 12 months were 97.6%. A minor change of the mean bone level occurred between implant loading (final prosthesis insertion after 6 months) and 12 months (-0.14 mm) after initial bone remodeling was observed between implant placement and loading (-0.88 mm). CONCLUSIONS: The results indicated that monotype ceramic implants can achieve clinical outcomes comparable to published outcomes of equivalent titanium implants.

Perioperative Bromelain Therapy after Wisdom Teeth Extraction - A Randomized, Placebo-Controlled, Double-Blinded, Three-Armed, Cross-Over Dose-Finding Study.

Reduction in postoperative edema and inflammatory reactions is the key to the posttraumatic regeneration process. Use of bromelain is well established in this indication, but there is some controversy with regard to the optimal dosing of this drug. The aim of our study was therefore to investigate the efficacy of dosage-dependent therapy with bromelain in patients after wisdom teeth extraction by comparing the registered dosage 1000 FIP (Fédération Internationale Pharmaceutique) against higher dosages of 3000 FIP and 4500 FIP. A total of 75 patients were randomized to one of the three dosage arms, and 68 of these patients were finally analyzed in the modified intention-to-treat population. Patients involved underwent two surgery sessions: one study period being conducted under treatment with bromelain and the other with placebo. Postoperative swelling determined by a 3D face scanning system was defined as the primary endpoint; further efficacy parameters were maximum swelling, pain, difficulty in swallowing, and use of analgesics. A superiority of treatment with 3000 FIP and 4500 FIP versus 1000 FIP could not be demonstrated. The analysis of pooled bromelain treatments versus placebo did, however, show a clear trend in favor of bromelain for all assessments. Adverse events did not occur more frequently under bromelain therapy compared with placebo. This study thus clearly supports the clinical relevance of treatment of postoperative conditions with bromelain, and the recommended daily dose was sufficiently effective in this trial and indication. Copyright © 2016 John Wiley & Sons, Ltd.

Histological evaluation of different abutments in the posterior maxilla and mandible: an experimental study in humans.

OBJECTIVES: To histologically evaluate and compare the performance of healing abutments with either hydrophobic or hydrophilic surface properties in humans. MATERIALS AND METHODS: According to a parallel-group design, titanium implants placed in the posterior mandible and maxilla of 30 patients were randomly assigned to either (1) hydrophobic machined (M), (2) chemically modified hydrophilic (mod) acid etched (MA) titanium (Ti) (modMA1) or (3) modMA Ti- Zirconium alloy (modMA2) healing abutments and left to heal in a transmucosal position. At 8 weeks, the abutments and a limited soft tissue biopsy were harvested according to a standardized procedure and processed for histological analysis (primary outcomes: percentage epithelial- (EC) and subepithelial connective tissue contact (CTC) to the abutment surface). RESULTS: The surgical procedure was associated with an incomplete mucosal coverage of the study abutments in nine patients, and an unintentional submerged healing procedure in three patients. Per protocol analysis (18 patients) has pointed to an improved quantitative EC [modMA2 (53.45 ± 28.25) > modMA1 (32.25 ± 24.3) > M (23.15 ± 16.09)] and CTC [modMA2 (75.12 ± 43.22) > modMA1 (69.41 ± 46.74) > M (47.63 ± 19.28)] (%) to modMA surfaced abutments. CONCLUSIONS: It was concluded that modMA surfaces may have the potential to enhance soft tissue adhesion at the transmucosal aspect of titanium dental implants.

Dentin as a suitable bone substitute comparable to ß-TCP--an experimental study in mice.

Microvascular supply is of fundamental importance to the survival and integration of grafting. Since the autogenous bone is still the gold standard for osseous augmentation, the aim of this study was to analyze the initial osseous, angiogenic and inflammatory response and subsequent osseointegration after implantation of dentin and beta-tricalcium phosphate (ß-TCP) scaffolds into the calvaria chamber of balb/c mice comparing with bone. The vascularisation of perforated implants of dentin (n=8), ß-TCP (n=8) and isogenic calvarial bone (n=8) displaying pores similar in size and structure was analyzed in vivo using intravital fluorescence microscopy. In additional animals (n=24) the osseointegration of dentin, ß-TCP and bone implants was assessed by fluorochrome sequential labelling of growing bone for up to 12 weeks. Animals without implants served as controls. Intravital fluorescence microscopy revealed that implantation of bone substitutes caused an only mild inflammatory response. Comparable to isogenic bone both dentin and ß-TCP scaffolds were found nearly completely vascularized by day 22 and osseointegrated within 12 weeks. In conclusion, dentin and ß-TCP scaffolds are similar to isogenic bone in terms of inflammatory and neovascularization response, highlighting their potential utility in regeneration of bone defects.

Biomechanical evaluation of a microstructured zirconia implant by a removal torque comparison with a standard Ti-SLA implant.

OBJECTIVES: The purpose of this study was to evaluate the biomechanical bone tissue response to novel microstructured zirconia implants in comparison to sandblasted and acid-etched (SLA) titanium implants through the analysis of removal torque (RTQ) measurements. MATERIALS AND METHODS: Ti-SLA implants with a sandblasted, large-grit and acid-etched surface were compared with zirconia implants with an acid-etched surface. All implants had the same shape, a diameter of 4.1 mm and a length of 10 mm. A total of 136 implants were placed in the maxillae of 17 miniature pigs. Six animals were sacrificed after both 4 and 8 weeks and five animals were sacrificed after 12 weeks, thus providing a total of 102 implants for RTQ testing (34 implants were reserved for future histological analysis). The RTQ analysis was successfully performed, using a mixed model regression with P-values calculated using the nonparametric Brunner-Langer method, on 100 of the 102 implants, two were excluded from the analysis. RESULTS: The adjusted mean RTQ values for Ti-SLA implants were 131 Ncm (95% CI: 107-155) at 4 weeks, 128 Ncm (108-148) Ncm at 8 weeks, and 180 Ncm (153-207 Ncm) at 12 weeks of healing, whereas RTQ values for the zirconia implants were 110 Ncm (86-134), 97 Ncm (76-118) and 147 Ncm (121-174) at the corresponding time intervals. A comparison of the implant materials resulted in P-values of P = 0.114 at 4 weeks, P = 0.034 at 8 weeks and P = 0.105 at 12 weeks (significance set at P < 0.05). CONCLUSIONS: Within the limits of the present study, it could be confirmed that the biomechanical bone-tissue response of the investigated zirconia implants is non-inferior to that of the well-documented, roughened titanium surface, at each time point, within the set tolerance. There were no statistically significant differences between the two materials after a healing period of 4 and 12 weeks. The RTQ values of both implant types increased significantly from the 8-week to the 12-week time point.

Prospective Clinical Multicenter Study Evaluating the 5-Year Performance of Zirconia Implants in Single-Tooth Gaps.

PURPOSE: In recent years, ceramic implants made of zirconia have secured a niche position next to established titanium implants, due partly to new scientific findings and positive clinical experience with the handling of ceramic implants. The aim of this study was to assess the clinical and radiographic data for monotype ceramic implants that have remained in place for 60 months under masticatory loading. MATERIALS AND METHODS: In 2011, this prospective clinical study included patients with a single-tooth gap in the maxilla and mandible. Monotype ceramic implants (Straumann) were used according to a standard protocol. Provisional prostheses were placed after 3 months, followed by final prostheses 3 months later. Patients were invited for a 60-month follow-up. Implant survival was analyzed from lifetime data. Success rates and crestal bone levels were evaluated from implant placement to 6, 12, 36, and 60 months after surgery. RESULTS: From the initial 44 patients recruited, 36 were analyzable for the 60-month follow-up. With one implant lost before the 6-month followup, the survival rate after 60 months was 97.7%, and the mean survival time was 58.7 months. Sixty months after implant placement, the success rate was 97.2% (95% confidence interval = 84.6% to > 99.9%). Mean bone loss after 60 months was 0.99 (± 0.59) mm. CONCLUSION: After 60 months, monotype ceramic implants made of zirconia achieved success and survival rates comparable with those reported for titanium implants in selected patient populations. Ceramic implants can be used as an alternative to titanium implants at the request of patients and if specifically indicated, for example, due to titanium intolerance.

In vitro biomechanical comparison of the effect of pattern, inclination, and size of positional screws on load resistance for bilateral sagittal split osteotomy.

PURPOSE: The purpose of this in vitro investigation was to determine whether the pattern, angle of placement, or size of positional screws affected their ability to resist vertical loads resembling mastication in the bilateral sagittal split osteotomy system. MATERIALS AND METHODS: Standardized bone substitutes were secured with three 12- to 16 mm-long, 1.85-, 2.0-, 2.1-, and 2.4-mm outer diameter, self-tapping titanium screws (Synthes, Solothurn, Switzerland) in various patterns using a positional screw technique. These patterns included transbuccal triangular, intraoral triangular, and transbuccal linear patterns. The models were secured in a jig and subjected to vertical loads by a mechanical testing unit (1475 UPM; Zwick, Ulm, Germany) until failure. Loading test data analysis was based on peak load values resulting in mechanical deformation of the system (1-, 3-, and 5-mm displacement), maximal force, and stiffness (load/displacement slope curve) for each group. Means and standard deviations were derived and compared for statistical significance using univariate analysis of variance with a confidence level of 95% (P values < .05). RESULTS: The designed study demonstrated that 1.85- and 2.0-mm-diameter positional screws provided similar stability in all 3 setups. Three screws placed in an inverted L pattern at 90° (simulating a transbuccal approach) showed significantly higher resistance to vertical forces for advancement movements at 1-, 3-, and 5-mm displacement when compared with the inverted L group of screws placed at an angle (intraoral approach) or 3 screws in a linear pattern placed at 90° (transbuccal approach) (P < .01). CONCLUSIONS: Under the conditions tested in this in vitro study, differences in the load resistance of positional screws placed in a transbuccal or intraoral approach could be demonstrated depending on the fixation technique. The transbuccal group of 3 screws in an inverted L pattern showed significantly greater stability than the intraoral group of 3 screws placed in an inverted L pattern and the transbuccal group of 3 screws in a linear pattern. Resistance to vertical loads with 1.85-mm screws was similar to that with the standard 2.0-mm screws in all 3 setups. The results of this study suggest that the angle of screw placement (surgical approach) and pattern have a greater influence on the stability of the bilateral sagittal split osteotomy system than the screw size.

Forty sandwich osteotomies in atrophic mandibles: a retrospective study.

PURPOSE: The aim of the present retrospective study was to assess the suitability of segmental mandibular sandwich osteotomy combined with an interpositional autograft to meet the dimensional requirements of preimplant bone augmentation in cases of a severely atrophic mandible. PATIENTS AND METHODS: A total of 27 consecutive patients (6 men and 21 women) were included in the present study. The amount of bone gain was calculated using digital volume tomography before surgery and 3 months after bone augmentation. RESULTS: The postoperative course was uneventful for 18 patients. Temporary sensory disturbances were observed in 6 patients, with complete recovery after 3 to 12 weeks. Dehiscence of soft tissue closure occurred in 3 patients. The mean vertical gain was 3.41 mm (range 0.3 to 12). The mean horizontal gain was 3.08 mm (range 0.2 to 8.5). A total of 88 implants were placed in 40 surgical sites at 12 weeks after bone reconstruction. CONCLUSION: Segmental mandibular sandwich osteotomy is a suitable augmentation procedure in the mandible for the atrophic alveolar ridge and provides adequate height and transversal bone augmentation.

Bone augmentation after soft-tissue expansion using hydrogel expanders: effects on microcirculation and osseointegration.

OBJECTIVES: The success of bone augmentation, for example of the alveolar ridge, might be endangered by dehiscence of the soft tissue that covers the augmented bone. Soft-tissue coverage can be achieved without tension through pre-augmentation tissue expansion with hydrogel expanders. We used a periosteal chamber to study the influence of tissue expansion on microcirculation and osseointegration in an in vivo animal model. MATERIAL AND METHODS: Sixteen isogeneic Lewis rats were randomised into two groups. Additional eight animals served as donors of isogeneic bone grafts (Group 3, n=8). The bone grafts were harvested and implanted into Group 1 animals (n=8) (without tissue expansion) and Group 2 animals (after tissue expansion). In Group 2 (n=8), hydrogel expanders were inserted subperiosteally at the site to be augmented for 21 days. We used intravital microscopy to monitor microcirculation in vivo for 19 days after implantation. Specimens from both groups were evaluated histologically. RESULTS: During the entire study period, functional microvessel density in the region above the augmentation material was significantly higher after previous tissue expansion (P>0.05). Both groups showed physiological microcirculation around the augmentation material. Histology revealed bone osseointegration of the bone graft in the group with tissue expansion and the presence of connective and granulation tissue in the group without tissue expansion. CONCLUSIONS: Pre-augmentation soft-tissue expansion with hydrogel expanders leads to higher functional microvessel density in the tissue above the augmentation material and thus, to more rapid osseointegration. The use of hydrogel expanders appears to increase the probability of success, especially of pre-implant bone augmentation.

Microvascular response to the subperiosteal implantation of self-inflating hydrogel expanders.

PURPOSE: Excessive stretching of the overlying soft tissue often occurs during the attempt at primary closure after bone augmentation. Preliminary soft tissue expansion may prevent such perfusion disturbances caused by stretching. The purpose of this study was to investigate the effects of using self-inflating expanders at different rates to expand overlying soft tissue prior to the bone grafting procedure. MATERIALS AND METHODS: Two different hydrogel expanders with different inflation curves were used. For the experiments, 48 Lewis rats were divided into six groups of eight animals each. In four groups, the different expanders were implanted subperiosteally on the calvarium. In two of these groups, an observation window was implanted for intravital microscopy. In the other two groups, histologic analysis of the covering skin was performed. Intravital microscopy of the unexpanded periosteum and histologic analyses of unoperated rats served as control groups. RESULTS: Following implantation of the expanders, intravital microscopic examinations showed that, irrespective of the expansion curve, periosteal microcirculation had stopped completely without reperfusion within 14 days. Histologic analyses of the soft tissues, however, showed a well-vascularized connective tissue layer clinging to the expander. The microvessel density measured was significantly higher above slowly inflating expanders (91.2 ± 8.8 vessels/mm²) than above rapidly inflating expanders (48.4 ± 2.7 vessels/mm²) or unoperated periosteum (60.4 ± 4.8 vessels/mm²). CONCLUSIONS: Subperiosteal implantation of self-inflating expanders leads to complete ischemia of the periosteum. However, replacement of the periosteum by connective tissue takes place within 14 days; as a result of subcutaneous angiogenesis, this tissue may have a significantly higher microvessel density than healthy periosteum.

IL-1 polymorphism and periimplantitis. A literature review.

The most important factor leading to periimplantitis with bone loss appears to be an inflammatory process due to plaque accumulation. The object of this article was to present a review of the literature on a possible correlation between IL-1 polymorphism and periimplantitis. Research was carried out in the PUBMED and WEB OF KNOWLEDGE literature databases and 27 relevant articles were found. Of these articles, 4 groups of authors came to the conclusion that no correlation exists between IL-1 polymorphism and periimplantitis. In 5 articles by 4 groups of authors, the influence of IL-1 polymorphism on periimplantitis is unclear. 9 studies prove a correlation between IL-1 polymorphism and periimplantitis, and 6 studies also document a direct linkage between gene polymorphism and periimplantitis, if certain cofactors are present. IL-1 polymorphism is frequently connected with "noninfectious periimplant bone loss". Other studies prove that the inflammatory mediators and IL-1beta were significantly elevated in the gingival crevicular fluid (GCF) of infected implants. Many studies document that IL-1 polymorphism alone cannot be considered a risk factor for bone loss, but in combination with smoking, it is closely associated with periimplant bone loss. More studies are needed to discover possible correlations between IL-1 polymorphism and periimplantitis.

A new model for chronic in vivo analysis of the periosteal microcirculation.

OBJECTIVE: Microvascular perfusion is indispensable for the growth and remodulation of membrane bone. Trauma, inflammation and surgical interventions may alter periosteal perfusion. However, there is not much known about periosteal perfusion in membrane bones. Therefore, the aim of this study was to establish a new chronic model that permits the repeated in vivo analysis of the microcirculation of periosteum. METHODS: A circular skin island with a diameter of 6 mm was excised at the forehead of six Lewis rats. Then a newly developed chamber was implanted, containing a coverglass to protect the periosteum. Intravital microscopy (IVM) enables a quantitative analysis of periosteal microcirculation immediately as well as 3, 5 and 10 days after chamber implantation. At the end of the experiment the calvaria and periosteum were removed for histological examination. Six unoperated Lewis rats served as histological controls. RESULTS: The periosteal microcirculation remained stable over 10 days. The implantation of the chamber did not result in any substantial inflammatory response. The functional microvascular density was 131.2+/-19.3 cm/cm(2). The histological examinations revealed a regular anatomical structure of periosteum and bone including an intact interface. CONCLUSION: The presented model allows for the first time to conduct a repetitive, quantitative in vivo analysis of the periosteal microcirculation in membrane bone. Future studies may thus evaluate novel strategies to influence the periosteal perfusion.

Consequences of seeded cell type on vascularization of tissue engineering constructs in vivo.

Implantation of tissue engineering constructs is a promising technique to reconstruct injured tissue. However, after implantation the nutrition of the constructs is predominantly restricted to vascularization. Since cells possess distinct angiogenic potency, we herein assessed whether scaffold vitalization with different cell types improves scaffold vascularization. 32 male balb/c mice received a dorsal skinfold chamber. Angiogenesis, microhemodynamics, leukocyte-endothelial cell interaction and microvascular permeability induced in the host tissue after implantation of either collagen coated poly (L-lactide-co-glycolide) (PLGA) scaffolds (group 4), additionally seeded with osteoblast-like cells (OLCs, group 1), bone marrow mesenchymal stem cells (bmMSCs, group 2) or a combination of OLCs and bmMSCs (group 3) were analyzed repetitively over 14 days using intravital fluorescence microscopy. Apart from a weak inflammatory response in all groups, vascularization was found distinctly accelerated in vitalized scaffolds, indicated by a significantly increased microvascular density (day 6, group 1: 202+/-15 cm/cm(2), group 2: 202+/-12 cm/cm(2), group 3: 194+/-8 cm/cm(2)), when compared with controls (group 4: 72+/-5 cm/cm(2)). This acceleration was independent from the seeded cell type. Immunohistochemistry revealed in vivo VEGF expression in close vicinity to the seeded OLCs and bmMSCs. Therefore, the observed lack of cell type confined differences in the vascularization process suggests that the accelerated vascularization of vitalized scaffolds is VEGF-related rather than dependent on the potential of bmMSCs to differentiate into specific vascular cells.

Degeneration of retinal ganglion cells after optic nerve sheath fenestration in an experimental rat model.

BACKGROUND: Optic nerve sheath fenestration (ONSF) is a surgical procedure that is sometimes performed in patients with optic disc edema from increased intracranial pressure. The objective of this study was to assess the consequence of ONSF on optic nerve axons, retinal ganglion cells (RGCs), and retinal amacrine cells. METHODS: The optic nerves of 22 male Wistar rats were assigned to one of three groups. In Group 1 (n = 12), the rats underwent unilateral ONSF. In Group 2 (n = 10), the rat optic nerves were unilaterally exposed but were not operated on. Group 3 (n = 22) consisted of the optic nerves of Group 1 and Group 2 rats that were neither operated on nor exposed. Thirty days later, a cresyl violet staining method was used to assess the number and sizes of RGCs and amacrine cells. Optic nerve axons were assessed by means of glial fibrillary acidic protein (GFAP) immunoreactivity. RESULTS: ONSF was associated with a significant reduction (P < 0.05) in the number and size of RGCs and amacrine cells. Optic nerve axons were undisturbed. CONCLUSIONS: Although ONSF does not apparently injure the optic nerve axons, loss and shrinkage of RGCs is a caution when considering ONSF as a treatment.

Influence of different types of guns, projectiles, and propellants on patterns of injury to the viscerocranium.

PURPOSE: Gunshot injuries to the oral and craniomaxillofacial region vary with the type of gun used. Computed tomography (CT) is the standard diagnostic tool for assessing tissue damage in patients with gunshot injuries. Cone-beam computed tomography (CBCT) is a new imaging technique that has recently become available for clinical diagnosis. The objective of this study was to characterize injury patterns with a focus on gun types and identify the imaging modality that is best suited to assessing injuries caused by different gun types. PATIENTS AND METHODS: We present the cases of 14 patients who sustained gunshot injuries to the viscerocranium during the past 10 years. The injuries were caused by 8 basic combinations of handguns or long guns with soft lead core projectiles, partial or full metal-jacketed bullets, and different propellants. Diagnosis was based on clinical and radiological findings (including CT and CBCT). RESULTS: We found a direct correlation between the gun/projectile combination on the one hand and the diameter of the wound track, tissue contamination, and tissue destruction on the other. Entrance and exit wounds are indicative of certain gun/projectile combinations. High-density projectiles cause severe artifacts in CT, unlike CBCT, making it difficult to evaluate anatomic structures in close proximity to the projectile. CONCLUSIONS: Every gun/projectile combination is associated with a typical pattern of injury. Even in the absence of the offending projectile, it is thus possible to narrow down the likely gun and/or projectile. In the diagnostic imaging of injuries caused by high-density projectiles, CBCT is more suitable than CT.

Serratus anterior free flap in oral reconstruction.

PURPOSE: Perforating oral and maxillofacial defects frequently cause severe functional disorders. Microvascular free flaps like the radial forearm flap and the latissimus dorsi flap have been described to cover those defects; however, harvest of the radial forearm flap causes remarkable donor-site morbidity, while the latissimus dorsi flap often turns out to be too bulky. Therefore we introduce the serratus anterior muscle as a versatile and reliable microvascular flap to cover defects of both the floor of the mouth and the maxilla. PATIENTS AND METHODS: Between 2003 and 2007, 10 oral defects were reconstructed using the serratus anterior flap. In 5 of the cases, the defects were located at the hard palate and maxilla, while in the other cases they were located in the floor of the mouth. RESULTS: All of the patients were able to feed orally within the first week postoperatively. Donor-site morbidity was observed to be negligible not least because of the achievement of primary tension-free wound closure. Successful reconstruction could be observed in 8 of 10 patients. CONCLUSION: Although the serratus anterior muscle flap lacks an epithelial layer, this flap is not restricted to a subcutaneous placement. Due to rapid epithelialization, the serratus anterior muscle is even suitable for perforating intraoral defects.

Five-year retrospective study of mandibular fractures in Freiburg, Germany: incidence, etiology, treatment, and complications.

PURPOSE: To evaluate current trends in maxillofacial trauma, a retrospective review of mandibular fractures at a German university hospital was carried out. PATIENTS AND METHODS: In this retrospective study, records of 444 patients with mandibular fractures between 2000 and 2005 at the Department of Oral and Maxillofacial Surgery, University Hospital of Freiburg, Germany, were reviewed. A total of 444 patients presented with 696 mandibular fractures. RESULTS: Three hundred twenty-nine (74%) of the fractures occurred in male and 115 (26%) in female patients (2.9:1). One hundred forty-two fractures (32%) resulted from road traffic accidents, 126 from fights (28%), and 116 from falls (26%). Forty-four fractures were caused by sport accidents (10%) and 16 by pathologic fractures (4%). The mandibular condyle area was the most common fracture site, with 291 fractures (42%), followed by 144 fractures of the symphyseal and parasymphyseal area (21%) and 141 angle fractures (20%). Combined fractures were found in nearly half of the cases. Five hundred seventy-nine (83%) of patients with mandibular fractures were treated by surgical intervention, 117 (17%) of patients conservatively. Regarding the surgical treatment, 561 (65%) miniplates, 247 (29%) locking plates, and 51 (6%) lag screws were used. Complications, such as postoperative infections, abscesses, and osteomyelitis appeared in 66 (9%) cases. CONCLUSION: We concluded that osteosynthesis of mandibular fractures by miniplates and locking plates are both reliable.

Wound ballistics of injuries caused by handguns with different types of projectiles.

BACKGROUND: There are considerable differences in the shape and composition of military and civilian projectiles. MATERIALS AND METHODS: Five different projectiles with the same kinetic energy were fired into the heads of freshly sacrificed pigs (n=30) through the submental region in the occipital direction. Computed tomography (CT) and 3D face scans of the animal skulls were obtained before and after firing. The image data sets were fused and provided the basis for a quantitative analysis of destruction patterns. RESULTS: As a result of the destruction of the parietal bone at the potential exit site, there were significant volume difference between the Action 4 (6.45 +/- 3.42 ml) and the Hydra-Shok projectile (12.71 +/- 2.86 ml). The partial metal-jacketed projectile showed a minor increase in volume (4.89 +/- 1.47 ml) and a partial loss of soft projectile components. Radiology showed differences between the various projectiles in fragmentation and bone and soft-tissue destruction. CONCLUSIONS: Although the projectiles had the same kinetic energy, there were considerable differences in injury patterns between full metal-jacketed projectiles, which are the only projectiles permitted for military use under the Geneva Conventions, and the other investigated projectiles. These injuries present a major medical challenge to both first responders and surgeons.

Computer-assisted navigation in craniomaxillofacial tumors.

Surgical procedures in the head and neck region require a detailed knowledge of this region's complex anatomy. Anatomic changes due to tumor growth present special challenges for the surgeon. In addition to the clinical examination, which is still of fundamental importance, imaging procedures such as computer-aided surgical navigation technology are currently being used in the preoperative, intraoperative, and postoperative assessments of anatomic changes. For purposes of analysis, we have analyzed the application of navigation technology into 2 categories: 1) minimally invasive procedure and biopsy; and 2) resection of extensive tumors and reconstruction after tumor surgery. Navigation can make tumor surgery more reliable by specifying correct safety margins, protecting vital structures, and facilitating the reconstruction process.