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.

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.

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.

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.

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.

Is a black eye a useful sign of facial fractures in patients with minor head injuries? A retrospective analysis in a level I trauma centre over 10 years.

Orbital blunt trauma is common, and the diagnosis of a fracture should be made by computed tomographic (CT) scan. However, this will expose patients to ionising radiation. Our objective was to identify clinical predictors of orbital fracture, in particular the presence of a black eye, to minimise unnecessary exposure to radiation. A 10-year retrospective study was made of the medical records of all patients with minor head trauma who presented with one or two black eyes to our emergency department between May 2000 and April 2010. Each of the patients had a CT scan, was over 16 years old, and had a Glasgow Coma Score (GCS) of 13-15. The primary outcome was whether the black eye was a valuable predictor of a fracture. Accompanying clinical signs were considered as a secondary outcome. A total of 1676 patients (mean (SD) age 51 (22) years) and minor head trauma with either one or two black eyes were included. In 1144 the CT scan showed a fracture of the maxillofacial skeleton, which gave an incidence of 68.3% in whom a black eye was the obvious symptom. Specificity for facial fractures was particularly high for other clinical signs, such as diminished skin sensation (specificity 96.4%), diplopia or occulomotility disorders (89.3%), fracture steps (99.8%), epistaxis (95.5%), subconjunctival haemorrhage (90.4%), and emphysema (99.6%). Sensitivity for the same signs ranged from 10.8% to 22.2%. The most striking fact was that 68.3% of all patients with a black eye had an underlying fracture. We therefore conclude that a CT scan should be recommended for every patient with minor head injury who presents with a black eye.

The role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomised, double-blind, placebo-controlled pilot clinical study. Part 3: Le Fort and zygomatic fractures in 94 patients.

The aim of this study was to evaluate the difference between the effect of a 5-day and a 1-day postoperative course of antibiotics on the incidence of infection after midfacial fractures. A total of 98 patients with displaced Le Fort or zygomatic fractures that required operation were randomly assigned into 2 groups, both of which were given amoxicillin/clavulanic acid 1.2g intravenously every 8h from the time of admission until 24h postoperatively. The 5-day group was then given amoxicillin/clavulanic acid 625 mg orally 8-hourly for another 4 days. The 1-day group was given placebo orally at the same time points. Patients were followed up 1, 2, 4, 6, and 12 weeks, and 6 months, postoperatively. The development of an infection of the wound was the primary end point. Ninety-four of the 98 patients completed the study. Two of the 45 patients in the 5-day group (4%) and 2/49 in the 1-day group (4%) developed postoperative wound infections. One in each group had a purulent infection, while the others had only wound breakdown. Two patients of the 5-day group and one in the 1-day group developed rashes on the trunk. There were no significant differences in the incidence of infection or side effects between the groups. In midfacial fractures a 1-day course of antibiotics postoperatively is as effective in preventing infective complications as a 5-day regimen.

The role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomized, double-blind, placebo-controlled pilot clinical study. Part 2: Mandibular fractures in 59 patients.

The aim of this study was to evaluate the difference between a 5-day and a 1-day postoperative course of antibiotic on the incidence of infection after mandibular fractures involving the alveolus. Sixty-two patients with fractures of the mandible involving the dentoalveolar region were randomly assigned to 2 groups, both of which were given amoxicillin/clavulanic acid 1.2 g intravenously every 8 h from admission until 24 h postoperatively. The 5-day group were then given amoxicillin/clavulanic acid 625 mg orally every 8 h for another 4 days. The 1-day group was given an oral placebo at the same intervals. Follow-up appointments were 1, 2, 4, 6, 12 weeks and 6 months postoperatively. Development of an infection was the primary end point. Fifty-nine of the 62 patients completed this study. Six of the 30 patients in the 5-day group (20%) and 6 out of the 29 in the 1-day group (21%) developed local wound infections. Three of the 6 in the 1-day group developed purulent discharge and swelling. One patient in the 5-day group developed a rash on the trunk. There were no significant differences in the incidence of infection or side effects between the groups. In fractures of the mandible involving the alveolus, a 1-day postoperative course of antibiotic is as effective in preventing infective complications as a 5-day regimen.

Severe destruction of the temporomandibular joint with complete resorption of the condyle associated with synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome.

The synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome consists of a combination of inflammatory bone disorders and dermatologic pathology. Bone lesions as a form of diffuse sclerosing osteomyelitis in the mandible occur in the posterior body and ramus. Bone lesions rarely spread to the temporomandibular joint (TMJ) where ankylosis may result. Herein we present an unusual case of SAPHO syndrome with TMJ involvement in which severe destruction of the TMJ occurred. We observed an extension of the invasive soft tissue lesion into the infratemporal fossa from the TMJ with complete resorption of the condyle. In contrast to other previously reported cases, in our case the condyle was strongly suspected as the primary site of the bone lesion with subsequent extension to the ramus and infratemporal fossa. The destructive nature and related symptoms resembled a malignant tumor.

The role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomised, double-blind, placebo-controlled pilot clinical study. Part 1: orbital fractures in 62 patients.

The aim of this study was to evaluate the difference between the effects of a 5-day and a 1-day course of antibiotics on the incidence of postoperative infection after displaced fractures of the orbit. A total of 62 patients with orbital blow-out fractures were randomly assigned to two groups, both of which were given amoxicillin/clavulanic acid 1.2g intravenously every 8h from the time of admission to 24h postoperatively. The 5-day group were then given amoxicillin/clavulanic acid 625 mg orally every 8h for 4 further days. The 1-day group were given placebo orally at the same time intervals. Follow up appointments were 1, 2, 4, 6, and 12 weeks, and 6 months, postoperatively. An infection in the orbital region was the primary end point. Sixty of the 62 patients completed the study. Two of the 29 patients in the 5-day group (6.8%) and 1/31 patients in the 1-day group (3.2%) developed local infections. In the 5-day group 1 patient developed diarrhoea. In the 1-day group 1 patient developed a rash on the trunk. There were no significant differences in the incidence of infection or side effects between the groups. We conclude that in displaced orbital fractures a postoperative 1-day course of antibiotics is as effective in preventing infective complications as a 5-day regimen.

Analysis of new bone formation induced by periosteal distraction in a rat calvarium model.

BACKGROUND: A controlled, gradual distraction of the periosteum is expected to result in the formation of new bone. PURPOSE: This study was designed to estimate the possibility of new bone formation by periosteal distraction in a rat calvarium model. MATERIAL AND METHODS: Sixteen animals were subjected to a 7-day latency period and distraction rate at 0.4 mm/24 hours for 10 days. Two experimental groups with seven rats each were killed at 10 and 20 days of consolidation period and analyzed by means of microcomputed tomography, histologically and histomorphometry. RESULTS: In the central regions underneath the disk device, signs of both bone apposition and bone resorption were observed. Peripheral to the disc, new bone was consistently observed. This new bone was up to two and three times thicker than the original bone after a 10- and 20-day consolidation period, respectively. Signs of ongoing woven bone formation indicated that the stimulus for new bone formation was still present. There were no statistically significant differences regarding bone density, bone volume, and total bone height between the two groups. CONCLUSION: The periosteal distraction model in the rat calvarium can stimulate the formation of considerable amounts of new bone.

Alveolar bone grafting in association with polyostotic fibrous dysplasia and bisphosphonate-induced abnormal bone turnover in a bilateral cleft lip and palate patient: a case report.

A case is presented of extensive alveolar bone grafting in a patient with bilateral cleft lip and palate and polyostotic fibrous dysplasia. The patient previously underwent bisphosphonate therapy. Because of an abnormal and often decreased bone turnover caused by the fibrous dysplasia and the bisphosphonate therapy, bone grafting in such a patient poses several potential difficulties. In addition, the histomorphometric analysis of the bone grafts showed markedly decreased bone turnover. However, alveolar bone grafting using the iliac crest was performed successfully. Sufficient occlusion was achieved by postoperative low-loading orthodontic treatment.