Mandibular Fracture Healing Research Articles

The Effect of Local Rosuvastatin on Mandibular Fracture Healing.

Mandibular fracture is the most common injury seen in facial fractures and plays an important role for oral and maxillofacial surgery department. The purpose of this study is to investigate the potential of the local administration of rosuvastatin (RSV) on mandibular fracture healing in rats. Thirty-two rats were divided into 4 groups: group C-14 (control), group R-14, group C-28 (control), and group R-28. A unilateral standard vertical osteotomy was performed right side of the mandibula extending from the tooth to the mandibular basis for each animal. In groups C-14 and C-28 sterile saline treated absorbable collogen sponge was applied to the fracture area, in groups R-14 and R-28 absorbable collogen sponge with saline solution containing 1 mg RSV was applied to the fracture area. Animals in groups C-14 and R-14 were euthanized on the 14th day, groups C-28 and R-28 were euthanized on the 28th day after operation. Stereologic analyses were performed. New bone area and connective tissue volumes were measured. Stereologic analysis showed that group R-14 had significantly more new bone at 2 weeks compared with group C-14. Connective tissue volumes were also significantly higher in R-14. New bone and connective tissue volume differences were not statistically significant between groups C-28 and R-28. Locally administered RSV enhances early bone regeneration on mandibular fracture in rats.

The effect of nerve growth factor on the expression of BMP-2 in the healing of rabbits' mandibular fracture with partial nerve injury

Objective:To observe the effect of NGF on the expression of BMP-2 in rabbit model and explore the molecular mechanism of NGF which might promote the healing of mandibular fracture with nerve injury. Method:The 48 New-Zealand white rabbits were randomly divided into the experimental group (mandibular fracture+to cut off the nerve bundle+NGF by GS), the control group (mandibular fracture+to cut off the nerve bundle+NS by GS), the blank group (mandibular fracture+to cut off the nerve bundle) and the full-set group (mandibular fracture+retains the nerve bundle). After 2 weeks, 4 weeks, 6 weeks and 8 weeks, 3 rabbits were sacrificed in each group for HE staining and RT-PCR, respectively. Result:HE staining showed the osteogenesis phenomenon: the experimental group was clearer than control group, the full-set group was clearer than the blank group and the control group is similarly to the blank group. RT-PCR results revealed that there was a statistically significance in the early stage. The expression of BMP-2 peaked in 2 weeks and decreased later with time. Conclusion:The local application of NGF can prompt BMP-2 expression in the early stages of the mandibular fracture with partial nerve injury healing and this may be one of the molecular mechanisms.

A comparative study on evaluation of role of 1.5 mm microplates and 2.0 mm standard miniplates in management of mandibular fractures using bite force as indicator of recommendation.

Aims and Objectives:To compare the maximum voluntary bite force generated at different periods during mandibular fracture healing using miniplates and microplates as means of rigid internal fixation.Materials and Methods:Maximum voluntary bite force was recorded in healthy young individuals of different age group from either gender. Patients suffering from symphyseal and parasymphyseal and body fractures were selected and randomly treated using miniplate and microplate osteosynthesis by open reduction and rigid internal fixation. Postoperative bite forces at intervals of 1st, 2nd, 4th, and 6th week were recorded and compared with control group.Observations and Results:It was noticed that bite forces were significantly reduced in the study groups in comparison to control group and at different intervals of treatment. There was a progressive improvement in the bite force with passage of time. There was no statistical significance in the observed bite force in both the study groups at different intervals of assessment.Conclusion:1.5 mm microplates provide adequate stability comparable to miniplates for the treatment of fractured mandible and should be preferred over miniplates. We further suggest that bite forces should be considered for the assessment of clinical union of bone as well as studies pertaining to selection of hardware for rigid internal fixation.

An Evaluation of the Effect of Therapeutic Ultrasound on Healing of Mandibular Fracture.

The mandible is the most frequently fractured bone in maxillofacial trauma, the treatment of which consists of reduction and fixation of dislocated fragments by open or closed approach. Innovative techniques toward reducing the period of the postoperative intermaxillary fixation (IMF) are being researched. A relatively unknown treatment that may have an effect on fracture healing is ultrasound. Recent clinical trials have shown that low-intensity pulsed ultrasound (LIPUS) has a positive effect on bone healing. The aim of this study was to evaluate the effect of LIPUS on healing by its application in fresh, minimally displaced or undisplaced mandibular fracture in young and healthy individuals. A total of 28 healthy patients were selected randomly from the outpatient department needing treatment of mandibular fractures. They were then randomly allocated to either of the following two groups-experimental group and study group. After IMF, patients in experimental group received pulsed ultrasound signals with frequency of 1 MHz, with temporal and spatial intensity of 1.5 W/cm(2), pulsed wave for 5 minutes on every alternate day for 24 days, whereas patients in control group received no therapy except IMF. Radiographic density at the fracture zone was assessed from the radiograph by Emago (Emago, Amsterdam, Netherlands) Image Analysis software before IMF then at 1st to 5th weeks post-IMF. The amount of clinical mobility between fracture fragments was assessed by digital manipulation of fractured fragment with the help of periodontal pocket depth measuring probe in millimeters at pre-IMF and after 3 weeks. Pain was objectively measured using a visual analogue scale at weekly interval. The data collected were subjected to unpaired "t" test. The experimental group showed significant improvement in radiographic density compared with control group at 3- and 5-week interval; pain perception was significantly reduced in experimental group compared with study group in the subsequent weeks. No significant difference was found in clinical mobility between fracture fragments at 3-week interval. The present study provides a basis for application of therapeutic controlled ultrasound as an effective treatment modality to accelerate healing of fresh, minimally displaced mandibular fracture.

Effect of 2100 MHz mobile phone radiation on healing of mandibular fractures: an experimental study in rabbits

ABSTRACTFractures in the maxillofacial region are among the most frequent incidences in patients exposed to trauma. The aim of this study was to evaluate the effect of 2100 MHz electromagnetic radiation on the healing of mandibular fractures in rabbits. The study was carried out on 12 mature male New Zealand rabbits. After producing a left mandibular osteotomy, the fracture was repaired by using a plate screw. The rabbits were divided into two groups – control and experimental. The experimental group was exposed for 3 h daily to a 2100 MHz radiofrequency (RF) for 28 d. Biomechanical, histopathological and radiological tests were performed during the healing of the mandibular bone. According to the biomechanical tests, the energy absorption capacity, toughness and maximum strength of the mandibular bone were increased compared to the control group (6.84 vs. 2.57, 0.135 vs. 0.041 and 22.21 vs. 10.32, respectively). No significant differences between the two groups were found during the radiological assessment. However, the histopathological examination revealed that the fracture healing score was higher in the experimental group when compared to the control group (8.0 vs. 2.75, respectively). In conclusion, the results of this study showed that a 2100 MHz RF radiation positively affected fracture healing.

Low-intensity pulsed ultrasound enhances bone morphogenetic protein expression of human mandibular fracture haematoma-derived cells

We previously demonstrated that human mandibular fracture haematoma-derived cells (MHCs) play an important role in mandibular fracture healing and that low-intensity pulsed ultrasound (LIPUS) accelerates this effect by stimulating various osteogenic cytokines. In the present study, we investigated how LIPUS affects the expression of bone morphogenetic proteins (BMPs), which are also known to have the ability to induce bone formation. MHCs were isolated from human mandibular fracture haematomas and the cells were divided into two groups: a LIPUS (+) group and a LIPUS (−) group, both of which were cultured in osteogenic medium. LIPUS was applied to the LIPUS (+) group 20min a day for 4, 8, 14, and 20 days (1.5MHz, 30mW/cm2). Real-time PCR and immunofluorescence studies were carried out to determine the expression of BMP-2, 4, and 7. Compared to the LIPUS (−) group, gene expression levels were significantly increased in the LIPUS (+) group for BMP-2 on day 20 (67.38±26.59 vs. 11.52±3.42, P<0.001), for BMP-4 on days 14 (45.12±11.06 vs. 9.20±2.88, P=0.045) and 20 (40.96±24.81 vs. 3.22±1.53, P=0.035), and for BMP-7 on day 8 (48.11±35.36 vs. 7.03±3.96, P=0.034). These findings suggest that BMP-2, 4, and 7 may be mediated by LIPUS therapy during the bone repair process.

Evaluation of the effectiveness of early or delayed treatment upon healing of mandibular fractures: A retrospective study.

Objectives:This study was aimed to assess the impacts of delay treatment of mandibular fracture and its complications. In addition risk variables related such as time to repair, fracture types, substance abuse, causes, surgical management, muddling or complications and duration of clinic stay were also evaluated.Materials and Methods:The data of patients attending the Newcastle General Hospital, UK for the management of mandibular fractures were probed. This retrospective clinical trial conducted over 6 months, included 91 patients attending trauma operating theatre during weekdays or weekends. Data were analyzed for time to admission and treatment and its relationships to various factors using SPSS version 20 (SPSS Inc., Chicago, IL).Results:Time to treatment from the point of admission was 31.50 ± 3.83 h during week days that has been significantly more for patients attending the hospital at weekends or nights. Similar trend was observed for total summative time from the incident to treatment analysis.Conclusions:This investigation has demonstrated that the rate of infection and postoperative complications following surgical treatment of mandible fractures can be eased off by reducing the waiting time from presentation to the emergency and to the operating theater.

The effect of methotrexate on the bone healing of mandibular condylar process fracture: An experimental study in rats

BackgroundMethotrexate (MTX) is an anti-metabolite used in rheumatology and oncology. High doses are indicated for oncological treatment, whereas low doses are indicated for chronic inflammatory diseases. This study evaluated the effect of two MTX treatment schedules on the bone healing of the temporomandibular joint fracture in rats. MethodsSeventy-five adult male Wistar rats were used to generate an experimental unilateral medially rotated condylar fracture model that allows an evaluation of bone healing and the articular structures. The animals were subdivided into three groups that each received one of the following treatments intraperitoneally: saline (1 mL/week), low-dose MTX (3 mg/kg/week) and high-dose MTX (30 mg/kg). The histological study comprised fracture site and temporomandibular joint evaluations and bone neoformation was evaluated by histomorphometric analysis. A biochemical parameter of bone formation was also assessed. ResultsWhen compared with saline, high-dose MTX delayed bone fracture repairs. In this latter group, after 90 days, the histological analysis revealed atrophy of the fibrocartilage and the presence of fibrous tissue in the joint space. The histomorphometric analysis revealed diminished bone neoformation. The alkaline phosphatase levels also decreased after MTX treatment. ConclusionIt was concluded that high-dose MTX impaired mandibular condyle repair and induced degenerative articular changes.

Herbal remedies for mandibular fracture healing.

Purpose:When a bone is fractured it is usually necessary to employ a mechanical means to reduce and maintain the fragments in position. However, healing of the fracture is governed by biological principles, with which the mechanical measures must be coordinated to the end, such that a satisfactory bony union and restoration of form and function are obtained. We have studied the effect of Cissus quadrangularis (Harjor) and Ocimum sanctum (Tulsi), in the healing of mandibular fractures.Materials and Methods:A total of 29 cases having a fracture in the body of the mandible were included in the study and divided into three groups. Groups A and B were treated with Ocimum sanctum and Cissus quadrangularis, respectively, and fracture healing was assessed with biochemical markers and the bite force. Group C was the control group.Results:The period of immobilization was the lowest in the Group A followed by Group B. A significant increase in alkaline phosphatase and serum calcium was seen in Group B. The tensile strength in terms of the biting force was the maximum in cases of Group B.Conclusion:We conclude that Cissus quadrangularis and Ocimum sanctum help in fracture healing, and use of such traditional drugs will be a breakthrough in the management and early mobilization of facial fractures.

Amifostine Protects Vascularity and Improves Union in a Model of Irradiated Mandibular Fracture Healing

Pathologic fractures of the mandible can be devastating to cancer patients and are due in large part to the pernicious effects of irradiation on bone vascularity. The authors' aim was to ascertain whether amifostine, a radioprotective drug, will preserve vascularity and improve bone healing in a murine model of irradiated mandibular fracture repair. Rats were randomized into three groups: nonirradiated fracture (n = 9), irradiation/fracture (n = 5), and amifostine/irradiation/fracture (n = 7). Animals in the irradiation groups underwent a human equivalent dose of radiation directed at the left hemimandible. Animals treated in the amifostine group received amifostine concomitantly with radiation. All animals underwent unilateral left mandibular osteotomy with external fixation set to a 2.1-mm fracture gap. Fracture healing was allowed for 40 days before perfusion with Microfil. Vascular radiomorphometrics were quantified with micro-computed tomography. When compared with the irradiated/fractured group, amifostine treatment more than doubled the rate of fracture unions to 57 percent. Amifostine treatment also resulted in an increase in vessel number (123 percent; p < 0.05) and a corresponding decrease in vessel separation (55.5 percent; p < 0.05) there was no statistical difference in the vascularity metrics between the amifostine/irradiation/fracture group and the nonirradiated/fracture group. Amifostine prophylaxis during radiation maintains mandibular vascularity at levels observed in nonirradiated fracture specimens, corresponding to improved unions. These results set the stage for clinical exploration of this targeted therapy alone and in combination with other treatments, to mitigate the effects of irradiation on bone healing and fracture repair.

Effect of ageing on healing of bilateral mandibular condyle fractures in a rat model

To examine the hypothesis that conservative treatment is applicable to younger patients with bilateral mandibular condylar fractures, we studied the effect of ageing on the healing of bilateral mandibular condylar fractures in a rat model. Male Sprague–Dawley rats aged 3, 6, and 36 weeks (n=25/cohort, total n=75) were divided into a fracture group (n=12) and a sham control group (n=12); one rat from each cohort was used as a normal unoperated control. Cell proliferation was evaluated using the bromodeoxyuridine (BrdU) labelling index (LI). Osteochondrogenesis was assessed by the expression of Indian hedgehog (Ihh), type X collagen, and osteocalcin in the condylar head. Condylar fracture healing was found to be delayed by ageing. BrdU LI values in the fracture groups were higher in younger rats than in older rats at 8 weeks after fracture. The number of Ihh-positive cells in the fracture groups increased significantly up to 2 weeks after fracture, and then gradually decreased until 8 weeks after fracture. The findings of this study support the clinical concept of conservative treatment of bilateral condylar fractures in younger patients, but functional issues regarding ramus height and its consequences on occlusion have not been tested in this study.

The osteogenic activity of human mandibular fracture haematoma-derived cells is stimulated by low-intensity pulsed ultrasound in vitro

Low intensity pulsed ultrasound (LIPUS) stimulation is a clinically established treatment method used to accelerate long bone fracture healing; however, this method is currently not applied to mandibular fractures. In this study, we investigated the effects of LIPUS on human mandibular fracture haematoma-derived cells (MHCs) in order to explore the possibility of applying LIPUS treatment to mandibular fractures. MHCs were isolated from five patients. The cells were divided into two groups: (1) LIPUS (+) group: MHCs cultured in osteogenic medium with LIPUS treatment; and (2) LIPUS (−) group: MHCs cultured in osteogenic medium without LIPUS treatment. The osteogenic differentiation potential and proliferation of the MHCs were compared between the two groups. The waveform used was equal to the wave conditions of a clinical fracture healing system. The gene expression levels of ALP, OC, Runx2, OSX, OPN, and PTH-R1 and mineralization were increased in the LIPUS (+) group compared to the LIPUS (−) group. There were no significant differences in cell proliferation between the two groups. These findings demonstrate the significant effects of LIPUS on the osteogenic differentiation of MHCs. This study provides significant evidence for the potential usefulness of the clinical application of LIPUS to accelerate mandibular fracture healing.

The Effects of Zoledronic Acid on Mandibular Fracture Healing in an Osteoporotic Model

The aim of this study was to evaluate the effect of zoledronic acid (ZA) in the ovariectomized rat on mandibular fracture. Corpus osteotomies were performed on the mandible of ovariectomized rats. Miniplates were placed on these rats, which were randomly divided into 4 groups. After 7 days, groups 3 and 4 were injected with 0.1 mg/kg ZA. Groups 1 and 2 were control groups, so they were injected 0.1 mg/kg saline solution. Animals in groups 1 and 3 were killed at 4 weeks, whereas groups 2 and 4 were killed 8 weeks after operation. The new bone volume of the fracture gap was examined stereologically. Although the difference was not statistically significant compared with the other groups (groups 1 and 3), more bone formation was found in ZA-treated groups (groups 2 and 4) (P < 0.05).

Effect of Extracorporeal Shock Waves on Subcondylar Mandibular Fractures

The purpose of this pilot study was to evaluate the effects of extracorporeal shock wave therapy on healing of subcondylar mandibular fracture in rats. Unilateral subcondylar fracture in 20 Wistar albino rats was used as a fracture model. Each rat was anesthetized 1 day after surgery, and extracorporeal shock wave therapy was performed. On the 21st day after surgery, animals were killed. Mandibles were dissected, all soft tissues were removed after sacrifice, and fractured and nonfractured hemimandibles were obtained from each rat. Histologic analyses were performed by a single pathologist blinded to the samples. The specimens' mean score in bone fracture healing was 7 (1.09) (range, 6-9) in group 1 and 2.57 (1.62) (range, 1-6) in group 2. With respect to the specimens' bone fracture healing score, there was a statistically significant difference between the 2 groups. As a result, our study showed that extracorporeal shock wave therapy accelerated the improvement of fractures in experimentally induced subcondylar mandibular fracture in the rat mandible. We believe that reducing the duration of improvement in subcondylar mandibular fractures by intermaxillary fixation along with extracorporeal shock wave theraphy would contribute to preventing complications such as ankylosis, fibrosis, and hypomobility occuring because of prolonged fixation.

Does Traumatic Brain Injury Result in Accelerated Mandibular Fracture Healing?

To investigate the occurrence of accelerated bone healing evidenced by early callus formation in patients with mandibular fractures and traumatic brain injury (TBI). A retrospective cohort study was performed in patients who presented for mandibular fracture evaluation and management over a 6-year period. Subjects eligible for the study included those who underwent a computed tomographic examination of the mandible more than 2 weeks after the injury and had not undergone surgery with rigid internal fixation. TBI was used as the predictor variable. Time to callus formation as detected on computed tomographic scans was recorded as the primary outcome variable. Other variables considered included age, gender, coma duration, and fracture distribution. Appropriate statistical analyses were performed to determine the influencing factors. Forty-five patients with mandibular fractures (24 with severe TBI and 21 without TBI) were retrospectively analyzed. Twelve patients with TBI and 6 without TBI exhibited a visible callus on their computed tomographic scans. Statistical analysis showed no significant differences in age, gender, examination time, and fracture distribution between the groups. Cox proportional hazards regression analysis indicated a positive correlation of time to callus formation with TBI and coma duration but not with age, gender, and fracture distribution. These findings suggest that patients with severe TBI and mandibular fractures exhibit increased fracture healing as evidenced by early callus formation. A more exhaustive study is required to advance the understanding of this phenomenon and provide additional clinical significance.

Application of ultrasonic inspection in monitoring dynamic healing of mandibular fracture in rabbit model

ObjectiveTo investigate the feasibility of ultrasonic diagnosis for monitoring fracture healing. MethodsThirty rabbit models with fraction of mandible body were established by surgically removing partial lower jawbone. At the 1st, 2nd, 4th, 6th, 8th and 12th week after the operation, they were examined by X-ray and ultrasound, respectively. All detection results were scored according to a generally accepted standard. Spearman rank correlation analysis was conducted to explore the relationship between the results of the two inspection methods. ResultsIn each healing stage, the results of the ultrasonic inspection were basically consistent with those of the X-ray examination, as supported by a Spearman rank correlation coefficient of 0.892 (P<0.001). ConclusionsNon-invasive ultrasonic inspection can be used instead of X-ray examination to monitor and diagnose fracture healing.

Successful repair of mandibular symphyseal fracture in a Dog

Introduction fracture. Therefore, it was decided to repair the fracture with wiring. Mandibular symphyseal fractures are the most common in the cat accounting for 73% of jaw fractures in this species [1], while fractures in the premolar region are most common in the dog accounting for 31% of mandibular fractures. Vehicular trauma being the most common cause and most patients are young, having a mean age of 3 year [2] and almost 50% of affected dogs are less than one year of age [3]. Most jaw fractures are open with varying degrees of contamination and infection. The complication rate of treatment for jaw fractures however, is high at 34%. Nearly 2/3 of those complications involved dental malocclusion or osteomyelitis [1]. The healing of most mandibular fractures is rapid enough [4] and generally heal without a large callus [5]. Since there are a few Figure-1. Symphyseal fracture of mandible case reports, successful repair of mandibular symphyseal fractures in a dog is reported. Treatment and Discussion

The use of Portland cement in the repair of mandibular fractures in rats

To evaluate the bone healing of mandibular fractures following the use of Portland cement. Thirty-two male Wistar rats were divided into control and experimental groups. In the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. In the experimental group the rats had the mandibular fracture reduced and maintained with the Portland cement. The animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. The following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. A weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). From the histological point of view, with a margin of error (5.0%) the only two significant differences (p <0.05) recorded in the variables were "Material deployed" and "Bone resorption" during the evaluations at 7 and 21 days, respectively. The Portland cement served to promote bone healing.

Mandibular Hematoma Cells as a Potential Reservoir for Osteoprogenitor Cells in Fractures

We hypothesized that cells within the mandibular fracture hematoma played an important role in mandibular fracture healing. The objective of this study was to analyze cells in human mandibular fracture hematoma. We isolated and analyzed human mandibular fracture hematoma cells (MHCs) and investigated whether MHCs had multilineage mesenchymal differentiation capacity in vitro, similar to bone marrow stromal cells (BMSCs). Cell-surface markers showed that the adherent MHCs expressed mesenchymal stem cell-related markers, namely CD29, CD44, CD105, and CD166, while lacking hematopoietic markers CD14, CD34, CD45, and CD133. The proliferative potential, osteogenic potential, and adipogenic potential of MHCs were comparable to those of BMSCs. In contrast, the chondrogenic potential of MHCs was inferior to that of BMSCs. The role of the mandibular fracture hematoma could be as a presumptive local reservoir for osteogenic progenitors and thus contribute to intramembranous bone healing. Our findings may provide new insights into the mechanism of intramembranous bone healing in membranous bone fractures.

The management of unstable oblique infected mandibular fractures with a 2.3 mm mandibular osteosynthesis reconstruction bone plate

This study is aimed to evaluate the efficacy of 2.3 mm reconstruction bone plates in the treatment of unstable infected mandibular fractures. Material The study included 32 patients with unstable oblique infected mandibular fractures (23 males and 9 females), with a mean age of 33 years. The patients were divided into two groups. Group 1 were treated with an osteosynthesis plate (with at least 3 screws on each side of fracture sites) applied to the mandibular fracture site, while in group 2 the bone plate was applied (2 screws on each side of fracture sites) with maxillomandibular fixation (MMF). Clinical and radiographic examinations were carefully assessed preoperatively and postoperatively at follow-up intervals of 1, 2, 6, 12 months. Postoperative complications in terms of dysocclusion, wound dehiscence and neurosensory disturbances were examined. Result Postoperative clinical and radiographic results showed that group 1 had quicker bone generation and more precise anatomical alignment of fracture sites than with those in group 2. All patients showed no evidence of infection, plate fracture or exposure, malunion, osteomyelitis, neurosensory disturbances, or dental injury. Conclusion The 2.3 mm reconstruction bone plates provide excellent stability and healing of the unstable infected mandibular fractures provided that the fracture site is fixed by at least 3 screws on each side of the fracture sites.