A rare low-grade myofibroblastic sarcoma in lower jaw with the resemblance to benign lesions.

BACKGROUND: Low-grade myofibroblastic sarcoma (LGMS) is a rare solid infiltrative soft tissue tumor with a predilection for the head and neck region. CASE PRESENTATION: We report the diagnostic steps of a fast-growing lesion of the lower left jaw in a 45-year-old otherwise healthy woman. A first biopsy and subsequent histopathological examination showed potential differentials of a benign myofibroma, benign nodular fasciitis or an LGMS. This diagnostic overlap was a challenge for the decision of the further treatment approach. The treatment consisted of a segmental en bloc resection of the mandible including the second premolar, first and second molar. Histopathological examination of the resected tumor confirmed an LGMS. CONCLUSION: The histopathologic resemblance of LGMS to a range of benign and reactive tumors may lead to misdiagnosis and mistreatment. The rarity of LGMS explains the lack of established treatment protocols. This case shows the importance of adequate clinical decisions, expertise in the histopathology of rare tumors and interdisciplinary exchange to achieve state-of-the-art patient management.

No apparent association between dental implants and mandibular fractures resulting from external forces.

OBJECTIVES: Dental implants are cylindrical metallic screws inserted into the jawbone to replace missing teeth. Their location may affect the pattern of fractures that occur as a result of the traumatic forces to the mandible. The aim of this study was to investigate possible influences of dental implants on the patterns of mandibular fractures triggered by external forces. MATERIAL AND METHODS: In this observational cross-sectional study, a total of 390 patients with mandibular fractures diagnosed between February 2016 and December 2020 were examined and the presence or absence of dental implants in the fracture gap was noted. Clinical and radiological data were analyzed in relation to the fracture line, the dental status, and the location of any implants. RESULTS: A total of 16 patients (4.1%) had previously placed dental implants in the mandible. Various fracture patterns were observed. Some yielded typical fracture lines located in the anatomically weak areas along the roots of the incisors, the mental foramina, and long-rooted molars. Occasionally, fracture lines were detected in combination with condylar fractures. Dental implants were not directly involved in any fracture line, except one. In that case, the fracture line extended from the alveolar process straight along the implant body, mimicking initial disintegration of the implant, with erosion of the surrounding bone. CONCLUSIONS: Once dental implants have osseointegrated, mandibular fractures are rarely projected along the implant surface. CLINICAL RELEVANCE: This observational retrospective cross-sectional study failed to associate mandibular fracture lines with the presence of dental implants.

What Are Possible Contributors to Associated Dental Injury in Mandibular Fractures?

PURPOSE: Among previous reports on dental injuries associated with mandibular fractures, there are few investigating the conditions under which dental injuries commonly occur. The aim of this study was to determine specific characteristics of mandibular fractures accompanied by dental injuries. METHODS: This retrospective cohort study included dentate patients with mandibular fractures treated at a tertiary trauma center between 2011 and 2019. The data were analyzed according to 2 outcome variables: patients with additional dental injuries and patients without. The predictor variables were patient age, sex, accident mechanism, number and location of mandibular fractures, and presence of submental lacerations. Odds ratios for the risk factors for dental injury were calculated in conjunction with descriptive statistics. Binary logistic regression analysis was also performed to identify the factors associated with dental injuries as dependent variables. RESULTS: Of 252 patients who had only mandibular fractures, 95 (37.7%) had associated dental injuries. In the group with dental injuries, 55.8% of mandibular fractures were caused by a fall (P = .003). Condyle fractures (77.9%) with dislocation (67.6%) and bilateral involvement (41.9%) were more common than in the group without dental injuries (P < .001). In patients with dental injuries, the incidence of 3 or more fractures (29.5%) was significantly higher than in the group without dental injuries. Dental injuries were more likely to occur in patients with concomitant submental lacerations (confidence interval (CI) 1.135-4.983, P = .02), and the risk of dental injury was significantly lower in the presence of angle fractures (CI 0.113-0.999, P = .045). CONCLUSIONS: A frontal impact involving the anterior part of the mandible is often associated with condyle and multiple mandibular fractures. This seems to be the typical mechanism for concomitant dental injuries. Submental laceration can be considered a prime sign of associated dental injuries.

Three-Dimensional Osteosynthesis Plates for the Surgical Treatment of Mandibular Fractures.

OBJECTIVES: Mandible fractures can be treated with different plate systems, that is, miniplates or three-dimensional (3D) plates. This systematic review describes the effectiveness and clinical outcomes of 3D plates used in fractures of the mandible and aims to critically evaluate its risks and benefits. MATERIALS AND METHODS: A comprehensive electronic search was conducted without date but with restriction to articles written in English. Studies in humans, including randomized or quasi-randomized controlled trials and retrospective studies, were included. The outcome parameters measured were number of patients, fracture classification, results, follow-up period, postoperative complications, and mean age of patients. Major complications were defined as those needing additional surgical intervention, for example, malocclusion, infection or plate fracture. Accordingly, complications not needing additional surgical intervention were defined as minor (ie, dehiscence, trismus). RESULTS: Guided by the PRISMA statement and the Cochrane Handbook for Systematic Reviews of Interventions, the authors identified 44 publications with a total of 1790 patients. Among the articles selected for the final review, there were 32 reported prospective studies, 12 reported retrospective studies. Regarding the evaluation of quality, 8 studies showed a low value of the risk of bias, 17 a moderate risk, and 19 a high risk. There were statistically significant advantages for 3D plates in mandibular fractures in terms of postoperative complications, for example, wound dehiscences or plate fracture. CONCLUSIONS: The 3D plate is an effective treatment modality for mandibular fractures, with low incidence of major complications, decreased length of operation time, and increased stability of osteosynthesis.

Single-visit chairside adjustment of a metal-acrylic resin implant-supported fixed complete dental prosthesis on an unloaded implant using a novel fixed attachment system: a case report.

BACKGROUND: Implant-supported prosthetic treatment options are reliable for elderly edentulous patients with systemic health problems. These patients often need cost- and time-efficient solutions to avoid complications. However, it is a challenge for clinicians to treat these patients without surgical interventions, placement of additional implants, or the need to renew existing prostheses. CASE PRESENTATION: A 75-year-old medically compromised caucasian male patient using multiple medications was referred for prosthetic rehabilitation of his edentulous maxilla after several implant failures. Because the patient's health was compromised, further surgical interventions were ruled out and the treatment was centered on the use of the remaining implants by placing a fixed attachment system and altering the existing prosthesis. The stepwise management of the patient's situation through the use of a new attachment system and adjustment of existing prosthesis is described in the present case report. CONCLUSIONS: Although implant therapy is not always contraindicated for medically compromised patients, it is preferable not to perform extensive surgeries to avoid complications. This clinical report describes an alternative, safe option based on a novel fixed attachment system to salvage an existing maxillary implant-supported fixed complete dental prosthesis of a patient with systemic health problems.

The impact of the size of bone substitute granules on macrophage and osteoblast behaviors in vitro.

OBJECTIVE: Bone substitute (BS) size might influence the clinical outcomes of guided bone regeneration (GBR) procedures. The aim of the present study was to investigate the influence of BS size on macrophage (Mφ) and osteoblast behaviors in vitro. MATERIALS AND METHODS: Two different granule sizes (S and M/L) were assessed for four different commercial BSs: deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate type 1 (BCP1), BCP type 2 (BCP2), and carbonate apatite (CO3Ap). The BSs were compared for their impacts on the cell viability and differentiation potential of THP-1-derived Mφs and human osteoblast-like Saos-2 cells. RESULTS: The smaller granules showed higher material volumes and surface areas than the larger granules. Significantly higher viability of Mφs and Saos-2 cells was observed with the DBBM_L-size granules than with the DBBM_S-size granules. Gene expression experiments in Mφs revealed few differences between the two sizes of each BS, although higher CD206 mRNA levels were observed in the BCP1_L group and the CO3Ap_M group than in the respective S-size groups on day 1. Only DBBM showed significantly higher mRNA levels of osteogenic markers, including Runx2 and osteocalcin, in Saos-2 cells in the S-size group than in the L-size group. CONCLUSIONS: The S-size and L-size DBBM granules exhibited clear differences in cell outcomes: cells cultured on the S-size granules exhibited lower cell viability, higher osteopromotive ability, and no noticeable Mφ polarization changes. CLINICAL RELEVANCE: A smaller granule size might be advantageous due to greater bone regeneration potential in the use of DBBM granules to treat defects.

Change of body composition, physical strength, and nutritional status of patients with mandibular fractures.

The aim was to determine changes in various parameters indicating physical conditions and nutritional status of patients during surgical and conservative treatment of mandibular fractures. A round by a nutrition support team was done once postoperatively for the surgical treatment group. For the conservative treatment group, three rounds were performed during the period of intermaxillary fixation. Data obtained from the rounds were compared between the groups. There were 29 patients surgically and 30 patients conservatively treated. A significant weight loss was observed in both groups postoperatively. The mean weight loss of the surgical treatment group measured at the postoperative round was 1.73 kg (SD ± 1.78) (P < 0.001) and that of the conservative treatment group at the third round was 2.74 kg (SD ± 2.35) (P < 0.001). During the entire treatment period, weight loss, body fat percentage, skeletal muscle percentage, grip strength and parameters indicating body composition and nutritional status of the conservative treatment group did not substantially differ from those of the surgical group. The influence of the conservative procedure on the nutritional condition of the patients seems to be limited and reversible at the end of the treatment. The weight loss observed here suggests that systematic nutrition support is necessary during both surgical and conservative treatment.

Clinical results of two different three-dimensional titanium plates in the treatment of condylar neck and base fractures: A retrospective study.

PURPOSE: The aim of this study was to examine two different types of three-dimensional plate for their suitability for the treatment of condylar neck and base fractures, and to evaluate the most frequent complications, while considering three different surgical approaches. MATERIALS AND METHODS: This retrospective study was conducted in patients who received two different types of three-dimensional plate for the treatment of condylar neck and base fractures, using three different surgical approaches, from January 2016 to December 2018. Medical records were obtained during an average follow-up period of 9 months after the traumatic event, with data collected on factors affecting success and failure of miniplates, clinical outcome parameters, and complications. RESULTS: A total of 43 fractures (38 patients) were examined. No differences were found between the two plate designs (mean = 0.093, SD = 0.294, p = 0.562). All fractures achieved complete bone healing, but in four cases, a revision operation had to be performed. No significant complications were found regardless of the surgical approaches chosen. There was no correlation between plate system (mean = 0.419, SD = 0.492, p = 0.497) or surgical access (mean = 0.163, SD = 0.432, p = 0.247) and the occurrence of facial nerve palsy found. Due to the extraoral approach used, permanent facial nerve palsy was reported in one case. With the intraoral approach, one case of transient facial paresis was observed. No facial palsy was observed in patients treated via a preauricular approach. CONCLUSION: Deltoid and trapezoid plates seem to perform equally in the treatment of condylar neck and base fractures.

Investigating the effect of antiseptic solution on the release of interleukin-6 and transforming growth factor beta 1 from human gingival fibroblasts using wound healing assays.

This in vitro study evaluated the effect of different antiseptics and different concentrations thereof in a model of wound healing using human gingival fibroblasts. The fibroblasts were rinsed with four different antiseptic solutions: sodium hypochlorite (HYP), hydrogen peroxide (H2O2), chlorhexidine digluconate (CHX), and benzalkonium chloride (BC). The effect on the release of interleukin-6 (IL-6) and transforming growth factor beta 1 (TGF-ß1) was investigated using enzyme-linked immunosorbent assays (ELISAs). In addition, the effects of the antiseptics on wound healing at 1, 12, 24, and 48 h were assessed through a wound healing assay. The viability of the fibroblasts rinsed with antiseptics was investigated with respect to the concentrations inhibiting cell growth by 50% (IC50), 25% (IC25), and ≤2% (IC2). A statistically significant increased release of IL-6 was obtained with BC IC25 and IC2 after 12, 24, and 48 h (P < 0.01). For TGF-ß1, no significant release was found for CHX IC2 after 24 and 48 h or for IC50 and IC25 after 12 h. There was no significant effect on wound healing capacity for CHX or for BC IC25 and IC2. This study demonstrated that antiseptic rinses of human gingival fibroblasts alter the release of IL-6 and TGF-ß1 and impact wound healing capacity, with both BC and CHX conferring neutral effects.

Changing trends in epidemiology and management of facial trauma in a Swiss geriatric population.

OBJECTIVE: To assess the prevalence and surgical treatment of facial fractures in a Swiss population aged 65 and over. BACKGROUND: The knowledge of the characteristics of geriatric trauma may help to prevent injuries and better allocate clinical resources for the management of multimorbid patients. MATERIAL AND METHODS: This study retrospectively evaluated a cohort of 181 patients who presented at the Bern University Hospital in Switzerland from May 2012 to September 2016. Data on age, gender, aetiology and type of trauma, treatment and complications, co-morbidities and associated injuries were obtained. RESULTS: Women were most frequently affected (55.2%). Mean age was 80 years. Zygomatic complex fractures were the most frequent type of fractures (37%), followed by isolated orbital fractures (27.6%). Falls were the most common cause of trauma (76.1%). Thirty-five per cent of all patients were taking anticoagulation or platelet aggregation medication. Hospitalisation was required in 88.4%, whereby 92.3% of the patients underwent surgical treatment. Surgery had to be performed immediately in three cases to treat compression of the optic nerve. Median hospital length of stay was 4 days, with 68% of patients returning to a domestic environment and 32% being transferred to another institution for further treatment. CONCLUSION: The most common cause of facial injuries is a fall while standing in a domestic environment. Midface fractures were the most common type of fractures.

Borreliosis-associated orofacial pain: A case report / Myoarthropathische Beschwerden als Manifestation einer frühen Neuroborreliose. Ein Fallbericht

Lyme borreliosis is a prevalent disease with a wide variety of clinical manifestations. However, only a few pertinent references are found in the dental literature. Considering the diversity of differential diagnoses, borreliosis-associated orofacial pain may be a challenge for treatment providers and patients alike. The aim of this case report is to emphasize the importance of a sound, structured medical history and assessment to identify severe cases early and to start interdisciplinary therapy if indicated.

Comparison of three block bone substitutes for bone regeneration: long-term observation in the beagle dog.

This study aimed to evaluate the impact of three types of block bone substitute material on bone formation and graft resorption in vivo. Standardized bone defects (n = 4 defects/animal) were created in the calvaria of nine dogs. Block bone substitutes made of deproteinized bovine bone mineral (DBBM), beta-tricalcium phosphate (ß-TCP) and a mixture alpha-TCP and hydroxyapatite (α-TCP/HA) were inserted into the bone defects. A fourth defect was left untreated (empty). All sites were covered with a collagenous membrane. Block biopsies were harvested at 3, 6 and 12 months post-implantation and analyzed by micro-CT and histology. Biomaterial absorption was minimal and incorporation within the defect margin was good for all biomaterials. However, ß-TCP demonstrated a relatively greater volume of new bone formation and less residual material volume when compared with DBBM and α-TCP/HA. Conversely, α-TCP/HA showed higher osteoconductive potential and a greater new bone area compared with the other two biomaterials. The block bone substitutes used in the present in vivo study showed advantageous in terms of maintenance of their original form in bony defect. However, the positive impact of all biomaterials on new bone formation and replacement of bone was minor even at 12 months. These findings indicate that block bone substitutes are not well suited to vertical bone augmentation. Further investigations are required to improve the insufficient new bone volume for promising clinical results.

Effect of Irrigation Time of Antiseptic Solutions on Bone Cell Viability and Growth Factor Release.

Antiseptic solutions are commonly utilized to treat local infection in the oral and maxillofacial region. However, surrounding vital bone is also exposed to antiseptic agents during irrigation and may have a potential negative impact on bone survival. The aim of the present study was therefore to investigate the effect of rinsing time with various antiseptic solutions on bone cell viability, as well as their subsequent release of growth factors important for bone regeneration. The bone samples collected from porcine mandible were rinsed in the following commonly utilized antiseptic solutions; povidone-iodine (0.5%), chlorhexidine digluconate (CHX, 0.2%), hydrogen peroxide (1%), and sodium hypochlorite (0.25%) for 1, 5, 10, 20, 30, or 60 minutes and assessed for cell viability and release of growth factors including vascular endothelial growth factor, transforming growth factor beta 1, bone morphogenetic protein 2, receptor activator of nuclear factor kappa-B ligand, and interleukin-1 beta by enzyme-linked immunosorbent assay. It was found in all the tested groups that the long exposure of any of the tested antiseptic solutions drastically promoted higher cell death. Sodium hypochlorite demonstrated the significantly highest cell death and at all time points. Interestingly, bone cell viability was highest in the CHX group post short-term rinsing of 1, 5, or 10 minutes when compared with the other 4 tested groups. A similar trend was also observed in subsequent growth factor release. The present study demonstrated that of the 4 tested antiseptic solutions, short-term CHX rinsing (ideally within 1 minute) favored bone cell viability and growth factor release. Clinical protocols should be adapted accordingly.

Osteosynthesis of partial rib osteotomy in a miniature pig model using human standard-sized magnesium plate/screw systems: Effect of cyclic deformation on implant integrity and bone healing.

Magnesium alloys are candidates for resorbable material in bone fixation. However, the degradation and performance of osteosynthesis plate/screw systems in vivo, under cyclic deformation, is unknown. We evaluated the outcomes of human standard-sized magnesium plate/screw systems with or without plasma-electrolytic surface modifications in a miniature pig rib model. Of a total of 14 minipigs, six were implanted with coated magnesium WE43 six-hole plates/screws, six received magnesium uncoated plates/screws, and two received titanium osteosynthesis systems. The performance of the plate/screw fixation system on partially osteotomized 7th ribs was compared with that on intact 9th ribs. Radiological examinations were performed in vivo at 1, 4 and 8 weeks and after euthanasia at 12 and 24 weeks. After euthanasia the bone blocks were analyzed by computed tomography (CT), microfocus computed tomography (micro-CT), histology and histomorphometry. Follow-up post-surgery showed no trouble with wound healing. In vivo radiological examinations showed higher amounts of gas formation above the uncoated magnesium plates fixed on the partially osteotomized and intact ribs. CT scans showed no broken plates or implant displacement. The micro-CT examination demonstrated better surrounding bone properties around the coated than the uncoated magnesium implants 12 weeks after surgery. No negative influence of magnesium degradation on bone healing was observed with histological examinations. Plastic deformation during surgery and cyclic deformation did not affect the integrity of the used magnesium plates. This study showed promising results for the further development of coated magnesium plate/screw systems for bone fixation.

In vivo degradation of a new concept of magnesium-based rivet-screws in the minipig mandibular bone.

Self-tapping of magnesium screws in hard bone may be a challenge due to the limited torsional strength of magnesium alloys in comparison with titanium. To avoid screw failure upon implantation, the new concept of a rivet-screw was applied to a WE43 magnesium alloy. Hollow cylinders with threads on the outside were expanded inside drill holes of minipig mandibles. During the expansion with a hexagonal mandrel, the threads engaged the surrounding bone and the inside of the screw transformed into a hexagonal screw drive to allow further screwing in or out of the implant. The in vivo degradation of the magnesium implants and the performance of the used coating were studied in a human standard-sized animal model. Four magnesium alloy rivet-screws were implanted in each mandible of 12 minipigs. Six animals received the plasmaelectrolytically coated magnesium alloy implants; another six received the uncoated magnesium alloy rivet-screws. Two further animals received one titanium rivet-screw each as control. In vivo radiologic examination was performed at one, four, and eight weeks. Euthanasia was performed for one group of seven animals (three animals with coated, three with uncoated magnesium alloy implants and one with titanium implant) at 12weeks and for the remaining seven animals at 24weeks. After euthanasia, micro-computed tomography and histological examination with histomorphometry were performed. Significantly less void formation as well as higher bone volume density (BV/TV) and bone-implant contact area (BIC) were measured around the coated implants compared to the uncoated ones. The surface coating was effective in delaying degradation despite plastic deformation. The results showed potential for further development of magnesium hollow coated screws for bone fixation.

Periosteum-Induced Bone Formation by Distraction Osteogenesis: Histologic and Microcomputed Tomography Analysis.

PURPOSE: Strains tending to pull the periosteum away from the bone are typically osteogenic. The aim of this study was to assess the influence of periosteum on de novo bone formation in a rat calvaria model of distraction osteogenesis. MATERIALS AND METHODS: A total of 28 rats were randomized in four experimental groups considering two treatment modalities. Periosteum was either left intact or completely excised. In half of the animals, the distraction plate was covered with a collagen membrane. All animals were subjected to a 7-day latency period and a 10-day distraction period. The samples were harvested after a 2-week consolidation period and analyzed histologically and by means of microcomputed tomography (micro-CT). RESULTS: New bone in all animals originated from the original bone surface. Two groups of animals with periosteum, with membrane (24.56 ± 5.26) and without membrane (21.83 ± 14.04), showed significantly more bone volume compared with groups without periosteum, with membrane (2.72 ± 1.08, P = .003) and without membrane (4.25 ± 2.33, P = .014). There were no significant differences between the four groups in bone mineral density. Groups pooled together for the presence of periosteum demonstrated significantly more bone volume (P < .001) and bone mineral density (P = .028) than groups without periosteum. No differences were found for groups pooled for the barrier membrane application. CONCLUSION: The periosteum plays an indispensable, but indirect role in the osteogenic process during periosteal distraction osteogenesis.

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.

In vivo degradation of magnesium plate/screw osteosynthesis implant systems: Soft and hard tissue response in a calvarial model in miniature pigs.

Biodegradable magnesium plate/screw osteosynthesis systems were implanted on the frontal bone of adult miniature pigs. The chosen implant geometries were based on existing titanium systems used for the treatment of facial fractures. The aim of this study was to evaluate the in vivo degradation and tissue response of the magnesium alloy WE43 with and without a plasma electrolytic surface coating. Of 14 animals, 6 received magnesium implants with surface modification (coated), 6 without surface modification (uncoated), and 2 titanium implants. Radiological examination of the skull was performed at 1, 4, and 8 weeks post-implantation. After euthanasia at 12 and 24 weeks, X-ray, computed tomography, and microfocus computed tomography analyses and histological and histomorphological examinations of the bone/implant blocks were performed. The results showed a good tolerance of the plate/screw system without wound healing disturbance. In the radiological examination, gas pocket formation was found mainly around the uncoated plates 4 weeks after surgery. The micro-CT and histological analyses showed significantly lower corrosion rates and increased bone density and bone implant contact area around the coated screws compared to the uncoated screws at both endpoints. This study shows promising results for the further development of coated magnesium implants for the osteosynthesis of the facial skeleton.

Comparison of two protocols of periosteal distraction osteogenesis in a rabbit calvaria model.

The regenerative pathways during periosteal distraction osteogenesis may be influenced by the local environment composed by cells, growth factors, nutrition and mechanical load. The aim of the present study was to evaluate the influence of two protocols of periosteal distraction on bone formation. Custom made distraction devices were surgically fixed onto the calvariae of 60 rabbits. After an initial healing period of 7 days, two groups of animals were submitted to distraction rates of 0.25 and 0.5 mm/24 h for 10 days, respectively. Six animals per group were sacrificed 10 (mid-distraction), 17 (end-distraction), 24 (1-week consolidation), 31 (2-week consolidation) and 77 days (2-month consolidation) after surgery. Newly formed bone was assessed by means of micro-CT and histologically. Expression of transcripts encoding tissue-specific genes (BMP-2, RUNX2, ACP5, SPARC, collagen I α1, collagen II α1 and SOX9) was analyzed by quantitative PCR. Two patterns of bone formation were observed, originating from the old bone surface in Group I and from the periosteum in Group II. Bone volume (BV) and bone mineral density (BMD) significantly increased up to the 2-month consolidation period within the groups (p < 0.05). Significantly more bone was observed in Group II compared to Group I at the 2-month consolidation period (p < 0.001). Expression of transcripts encoding osteogenic genes in bone depended on the time-point of observation (p < 0.05). Low level of transcripts reveals an indirect role of periosteum in the osteogenic process. Two protocols of periosteal distraction in the present model resulted in moderate differences in terms of bone formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1121-1131, 2016.

[Limited mouth opening - what now?]. / Eingeschränkte Mundöffnung – was nun?

This case report illustrates a rare complex of symptoms leading to limited mouth opening in a young woman. The 28-year old suffered from a progressively limited mouth opening over several years that finally resulted in restricted alimentation and made dental treatment impossible. Clinical findings suggest a structural alteration, including a hyperplastic mandibular angle and marked hypertrophy of the masseter muscle. Further radiologic investigations reveal a thickened aponeurosis of the masticatory muscles and hyperplastic coronoid processes that are not interfering with the zygomatic bone. Primary therapeutic options for such conditions are mainly surgical, including reduction of the masseter muscles volume and aponeurorectomy as well as bony reductions, such as coronoidectomy and mandibular angle reduction. With this treatment, the outcome and prognosis are good. Long-term results depend on concomitant physical therapy. A uniform nomenclature for this condition is yet lacking and propositions such as “masticatory muscle tendon-aponeurosis hyperplasia” have been made. However, knowledge of this condition and its typical clinical signs can make the diagnosis and treatment straightforward, thus leading to an improved quality of life of affected patients.