Scope and limitations of methods of mandibular reconstruction: a long-term follow-up

Non-vascularised fibular bone graft after vascular crisis: compensation for the failure of vascularised fibular free flaps

After reconstruction of a segmental mandibular defect with a fibular free flap, a vascular crisis can be detected clinically and a "no-flow" phenomenon found during re-exploration. Traditional methods used to solve this include removal of the failed flap and delayed mandibular reconstruction, or restoration of the defect with a functional reconstruction plate or contralateral fibular free flap. Our aim therefore was to investigate under what circumstances it is feasible to use a non-vascularised fibular bone graft (NVFB) as a free bone graft after the failure of a vascularised fibular free flap. From 1 January 2010-31 December 2014, 10 patients who had NVFB after failure of a fibular free flap were included in the study. All patients were treated at the Peking University School and Hospital of Stomatology. NVFB were preserved successfully without infection in all 10 cases, and follow-up imaging showed that it had incorporated well with the residual mandible, the basic function and facial aesthetics of which were maintained. In conclusion we have identified that by precise selection of patients, detailed preoperative planning, and meticulous postoperative care, NVFB can be used as a "rescue" technique after failure of a fibular free flap, and can successfully restore the segmental mandibular defect and facial contour.

Mandibular Condyle Reconstruction With Fibula Free-Tissue Transfer: The Role of the Masseter Muscle

BACKGROUND

Free fibula flap is an option for primary restoration after disarticulation mandibular resection, though literature on technique refinements is scarce. The authors hypothesized that inset of the masseter, the key mandibular elevator muscle, at the reconstructed mandible may optimize functional recovery.

METHODS

All patients undergoing reconstruction of mandibulectomy-condylectomy defect (January 2009 to January 2014) by means of a fibular flap were prospectively studied. The neocondyle was formed by the distal portion of the fibula and placed directly into the glenoid fossa with preservation of the temporomandibular disc. The deep portion of the masseter was inset at the angle of the reconstructed mandible.Condylar position was postoperatively evaluated by panoramic radiographs. Patients self-evaluated speech, chewing, swallowing, and facial appearance.

RESULTS

Two patients had immediate and 3 delayed reconstruction involving condyle ramus body, in the study period. During a mean follow-up of 32 months, 4 patients had satisfactory occlusion, 1 patient had an open-bite deformity, but was able to masticate solid food and maintain an oral diet. Although no significant condyle dislocation was recorded, 2 patients had slight ipsilateral deviation on mouth opening. Nevertheless, cosmesis was satisfactory and all patients maintained intelligible speech. Functional score was 13.6 ± 1.14 and facial appearance score was 4 ± 0.7.

CONCLUSION

The free fibula transfers with direct seating of the fibula into the condylar fossa followed by masseter muscle reinsertion provides acceptable functional reconstruction of the mandibulectomy-condylectomy defect.

The fitting accuracy of pre-bend reconstruction plates and their impact on the temporomandibular joint

BACKGROUND

Various causes for bone defects of the lower jaw have been described. As a result, patients often suffer from compromised aesthetics and a loss of, or reduction in, important physiological functions, such as swallowing, breathing, and speaking. A change in the shape of the lower jaw can impair the natural occlusion and leads to an atypical or modified position of the temporomandibular joint. Titanium reconstruction plates are the standard approach to jaw reconstruction, and are used for temporary bridging of a jaw defect or fixation of a bone graft. Conventionally these plates are intraoperatively adjusted to the mandible by the surgeon. Computer-aided manufacturing, computer-aided design, and rapid prototyping have gained increasing importance in the field of medicine, as they allow the production of individual models of the lower jaw, with the possibility of preoperatively bending the reconstruction plates. In this retrospective study, the accuracy of pre-bent titanium plates and their effect on the temporomandibular joint situation in comparison with intraoperatively curved plates will be discussed.

MATERIALS AND METHODS

Patients who attended our department for lower jaw reconstruction between March 2013 and February 2015 were included in this retrospective study. Within that time 20 patients were treated with pre-bent reconstruction plates (group 1). 20 comparable patients were selected with reconstruction and conventional intraoperative bending (group 2). To evaluate the accuracy of the plates and the condylar position, postoperative cone beam computed tomograms and computed tomograms were used to assess the bone-plate distance at 12 defined points and four angles in axial reconstruction. The results were compared, statistically evaluated, and discussed.

RESULTS

Regarding the maximum bone-plate distances and the sum of distances, there was a significant difference between the accuracy of the pre-bent and the conventionally bent reconstruction plates (p = 0.022, p = 0.048). Regarding the condylar position, there was no significant difference between both methods (p = 0.867).

CONCLUSION

The results of this study show that a better fitting accuracy can be achieved using pre-bent plates. Preparation of the plates proves to be advantageous and meaningful, especially in complex bone defects and deformations of the lower jaw. Nevertheless, concerning the position of the temporomandibular joint, no significant difference could be ascertained between the shown methods, contradicting several studies.

The prosthetic rehabilitation of a patient with a lateral postsurgical defect using a 2-piece magnet-retained facial prosthesis: A clinical report

Nonsurgical prosthetic interventions are often proposed after repeated grafts have failed to restore irradiated facial defects. This report describes a facial prosthetic reconstruction following ablative surgery for a sizable facial tumor by using a novel custom-made magnet-bearing substructure, which connected with an exposed part of the mandibular reconstruction plate. The defect involved the entire left lower part of the face and angle of the mentum. This reconstructive technique, together with an added surface texture with hair-like silicone strands, effectively addressed the cosmetic needs of the patient. Magnetic anchorage to an exposed reconstruction plate could be considered an option for retaining facial prostheses. The biomechanical aspects of loading and retention should be addressed before considering this prosthetic option.

Surgical site infections following oral cavity cancer resection and reconstruction is a risk factor for plate exposure

Background

Plate-related complications following head and neck cancer ablation and reconstruction remains a challenging problem often requiring further management and reconstructive surgeries. We aim to identify an association between surgical site infections (SSI) and plate exposure.

Methods

A retrospective study between 1997 and 2014 was performed to study the association between postoperative SSI and plate exposures. Eligible patients included those with a history of oral squamous cell carcinoma who underwent surgical resection, neck dissection, and free tissue reconstruction. Demographic and treatment related information was collected. SSI were classified based on CDC definition and previously published literature. Univariable analysis on demographic factors, smoking history, diabetes, radiation, surgical and hardware related factors; while multivariable analysis on SSI, plate height, segmental mandibulectomy defects and radiation were conducted such as using cox proportional hazard models.

Results

Three hundred sixty-five patients were identified and included in our study. The mean age of the study group was 59.2 (+/−13.8), with a predominance of male patients (61.9%). 10.7% of our patient cohort had diabetes, and another 63.8% had post-operative radiation therapy. Patients with SSI were more likely to have plate exposure (25 vs. 6.4%, p <0.001). Post-operative SSI, mandibulectomy defects, and plate profile/thickness were associated with plate exposure on univariable analysis (OR = 5.72, p < 0.001; OR = 2.56, p = 0.014; OR = 1.44, p = 0.003 respectively) and multivariable analysis (OR = 5.13, p < 0.001; OR = 1.36, p = 0.017; OR = 2.58, p = 0.02 respectively).

Conclusion

Surgical site infections are associated with higher rates of plate exposure. Plate exposure may require multiple procedures to manage and occasionally free flap reconstruction.

Mandibular Reconstruction: Overview

INTRODUCTION

Mandibular reconstruction has changed significantly over the years and continues to evolve with the introduction of newer technologies and techniques.

PURPOSE

This article reviews the history of oromandibular reconstruction, biomechanics of mandible, summarizes the reconstruction options available for mandible with defect classification, goals in reconstruction, the various donor sites, current reconstructive options, dental rehabilitation and persistent associated problems.

SUMMARY

Oromandibular reconstruction, although a challenge for the head and neck reconstructive surgeon, is now reliable and highly successful with excellent long-term functional and aesthetic outcomes with the use of autogenous bone grafts and current reconstructive options. The ideal reconstruction would provide a solid arch to articulate with the upper jaw, restoring swallowing speech, mastication, and esthetics. Autogenous vascularized bone grafts in combination with microsurgical techniques have revolutionized mandibular reconstruction in oral cancer surgery. Current trends in mandibular reconstruction aim to achieve reestablishment of a viable mandible of proper form and maxillary mandibular relationship while decreasing the need for invasive autogenous graft procurement. However the optimal reconstruction of mandibular defects is still controversial in regards to reconstructive options which include the donor site selection, timing of surgery and method of reconstruction.

Customized mandibular reconstruction plates improve mechanical performance in a mandibular reconstruction model

The purpose of this paper was to analyze the biomechanical performance of customized mandibular reconstruction plates with optimized strength. The best locations for increasing bar widths were determined with a sensitivity analysis. Standard and customized plates were mounted on mandible models and mechanically tested. Maximum stress in the plate could be reduced from 573 to 393 MPa (−31%) by increasing bar widths. The median fatigue limit was significantly greater (p < 0.001) for customized plates (650 ± 27 N) than for standard plates (475 ± 27 N). Increasing bar widths at case-specific locations was an effective strategy for increasing plate fatigue performance.

Three-Dimensional Planning in Maxillofacial Fracture Surgery: Computer-Aided Design/Computer-Aided Manufacture Surgical Splints by Integrating Cone Beam Computerized Tomography Images Into Multislice Computerized Tomography Images

This study aimed to evaluate an innovative workflow for maxillofacial fracture surgery planning and surgical splint designing. The maxillofacial multislice computerized tomography (MSCT) data and dental cone beam computerized tomography (CBCT) data both were obtained from 40 normal adults and 58 adults who suffered fractures. The each part of the CBCT dentition image was registered into MSCT image by the use of the iterative closest point algorithm. Volume evaluation of the virtual splints that were designed by the registered MSCT images and MSCT images of the same object was performed. Eighteen patients (group 1) were operated without any splint. Twenty-one (group 2) and 19 patients (group 3) used the splints designed according to the MSCT images and registered MSCT images, respectively. The authors' results showed that the mean errors between the 2 models ranged from 0.53 to 0.92 mm and the RMS errors ranged from 0.38 to 0.69 mm in fracture patients. The mean errors between the 2 models ranged from 0.47 to 0.85 mm and the RMS errors ranged from 0.33 to 0.71 mm in normal adults. 72.22% patients in group 1 recovered occlusion. 85.71% patients in group 2, and 94.73% patients in group 3 reconstructed occlusion. There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients (P <0.05). The MSCT images based splints' volume was statistically significantly distinct from the registered MSCT splints' volume in normal adults (P <0.05). There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients and normal adults (P <0.05). The occlusion recovery rate of group 3 was better than that of group 1 and group 2. The way of integrating CBCT images into MSCT images for splints designing was feasible. The volume of the splints designed by MSCT images tended to be smaller than the splints designed by the integrated MSCT images. The patients operated with splints tended to regain occlusion. The patients who were operated with the splints which were designed according to registered MSCT images tended to get occlusal recovered.

Autogenous non-vascularized bone graft in segmental mandibular reconstruction: a systematic review

The restoration of mandibular bone defects with non-vascularized bone grafts depends on the diagnosis, anatomical site, extent of the defect, and the patient's age, as well as the surgeon's experience. The aim of this study was to perform a systematic literature review on mandibular reconstruction for segmental mandibular bone defects using non-vascularized bone grafts to answer the following question: Is there scientific evidence to support the use of this technique? The initial literature search in PubMed, Scopus, and Cochrane databases identified 862 articles. Of these, 25 were included in the final review. These articles encompassed 926 procedures with non-vascularized bone grafts; 76.1% were from the iliac crest. Benign tumours were the major cause of these defects (56.8%), and 44.7% of defects were located in the lateral mandibular area. Although this technique showed a high occurrence of complications (290 in 873 patients, some with more than one complication), these did not account for treatment failure. The restoration of bone defects due to malignant tumours treated with radiation therapy had lower success rates, and these appear to be a contraindication for the technique. Although standardized randomized controlled clinical studies are needed to obtain better clinical evidence for treatment choices in general, the use of non-vascularized bone grafts for mandibular reconstruction showed an 87.6% success rate in this review.

Reconstruction of Continuity Defects of the Mandible with Non-vascularized Bone Grafts. Systematic Literature Review

BACKGROUND

The use of NVBG for mandibular defects seems to be gradually giving way for more advanced reconstructive techniques but it has the advantages of shorter operating time and lesser amount of blood loss. The aim of this study was to review the available data on the success and failure rates of use of NVBG and factors associated with failure.

METHOD

Studies published from 1978 to 2014 regarding the use of NVBG were searched. Most important information was graft success and failure outcomes. Information on graft success with particular focus on large defects was extracted and the quality of papers was rated. Defects > 6cm were considered long defects.

RESULTS

Twenty publications were included in this review. The quality of the studies was low and there was high heterogeneity. All articles reported high graft success rates ranging from 67 to 100%. Success in defects > 6cm was considerable, the range was 72-100%. Three main factors were associated with failure; these were defect length, fixation method and infection. Infection contributed the highest complication rate which was 48.2%.

CONCLUSION

NVBG seems to be appropriate for mandible reconstruction when there is vascular recipient bed and sufficient soft tissue cover and mucosal lining are achievable.

Reconstruction plates used in the surgery for mandibular discontinuity defect

OBJECTIVES

The purpose of this study was to analyze the survival rate of reconstruction plates that were used to correct mandibular discontinuity defects.

MATERIALS AND METHODS

We analyzed clinical and radiological data of 36 patients. Only discontinuous mandibular defect cases were included in the study. Reconstruction plate survival rate was analyzed according to age, gender, location of defect, defect size, and whether the patient underwent a bone graft procedure, coronoidectomy, and/or postoperative radiation therapy (RT).

RESULTS

Plate-related complications developed in 8 patients, 7 of which underwent plate removal. No significant differences were found in plate survival rate according to age, gender, location of defect, defect size, or whether a bone graft procedure was performed. However, there were differences in the plate survival rate that depended on whether the patient underwent coronoidectomy or postoperative RT. In the early stages (9.25±5.10 months), plate fracture was the most common complication, but in the later stages (35.75±17.00 months), screw loosening was the most common complication.

CONCLUSION

It is important to establish the time-related risk of complications such as plate fracture or screw loosening. Coronoidectomy should be considered in most cases to prevent complications. Postoperative RT can affect the survival rate and hazard rate after a reconstruction plate is fitted.

Predictive factors for premature loss of Martin 2.7 mandibular reconstruction plates

Mandibular reconstruction with a plate, with or without a vascularised free (bone) flap, is commonly used to treat patients with a segmental mandibular defect. Common complications are loosening of the osteosynthesis screws, malposition, intraoral or extraoral exposure, or infection. To define prognostic factors for premature loss of such plates and improve future planning, we designed a retrospective study of all patients operated on between 2005 and 2011 for reconstruction of a mandibular segmental defect with a reconstruction plate with or without a free vascularised (bone) flap. Prognostic factors collected from medical records were the patient's age, sex, and American Society of Anesthesiologists (ASA) grade; treatment with radiotherapy; whether they had diabetes or smoked; the site of the mandibular defect; whether there was a dental occlusion; the number of screws used on each side, and the use of a free vascularised (bone) flap; and whether the diagnosis was of oral cancer, benign tumour, or trauma. One hundred patients were included, 79 with oral cancer, 19 with benign tumours, and 2 with trauma. In 20 patients the Martin 2.7 reconstruction plate failed. Diabetes and smoking were significant prognostic factors for premature loss of the reconstruction plate with a hazard ratio of 2.95 (95% CI 1.068-8.172), p value=0.04, for diabetes, and 2.42 (95% CI 1.006-5.824), p value=0.05, for smoking. Smokers and diabetic patients have a higher risk of failure after mandibular reconstruction with a 2.7 reconstruction plate.

Initial Experience With rhBMP-2 Delivered in a Compressive Resistant Matrix for Mandibular Reconstruction in 5 Dogs

OBJECTIVE

To document cumulative initial experience and long-term follow-up of the use of rhBMP-2/CRM for reconstruction of large mandibular defects (≥5 cm) in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 5).

METHODS

Medical records (October 1999-April 2011) of dogs that had mandibular reconstruction for defects/resections of ≥5 cm using rhBMP-2/CRM were reviewed. Signalment, preoperative assessment/rationale for mandibular reconstruction, surgical methods, postoperative assessment of the reconstruction (evaluation of occlusion), and complications were recorded. A definitive histologic diagnosis was obtained in dogs that had mandibular resection for mass removal. Long-term complications were determined. A minimum time frame of 2-year in-hospital follow-up was required for case inclusion.

RESULTS

Mandibular reconstruction was successfully performed in all dogs' defects where gaps of 5-9 cm were bridged. Surgical reconstruction rapidly restored cosmetic appearance and function. All dogs healed with new bone formation across the gap. New bone formation was present within the defects as early as 2 weeks after surgery based on palpation, and new bone formation bridging the gap was documented radiographically by 16 weeks. Minor complications occurred in all dogs in the early postoperative period, and included early firm swelling and gingival dehiscence in 1 dog; late plate exposure in 3 dogs; and exuberant/cystic bone formation in 2 dogs (related to concentration/formulation of rhBMP-2/CRM). Two dogs had minor long-term complications of late plate exposure and a non-vital canine tooth; the plates and the affected canine tooth were removed. Long-term in-hospital follow-up was 5.3 years (range, 2-12.5 years); further long-term telephone follow-up was 6.3 years (range, 2-12.5 years). All owners were pleased with the outcome and would repeat the surgery again under similar circumstances.

CONCLUSION

The efficacy and success of this mandibular reconstruction technique, using rhBMP-2/CRM with plate fixation, was demonstrated with bridging of large mandibular defects regardless of the underlying cause, and with excellent cosmetic and functional results. Complications were common, but considered minor and easily treated. The complications encountered revealed the importance of tailoring the use of BMPs and fixation methods to this specific anatomic location and indication.

Outcome of microvascular free flaps in a high-volume training centre

PURPOSE

Microvascular free tissue transfer allows major ablative defects following oncologic surgical and traumatic reasons to be reliably reconstructed in the head and neck region. A retrospective analysis of the microvascular flap procedures which were performed within one year in a high volume training centre was performed.

PATIENTS AND METHODS

The microvascular free flap procedures of the year 2011 were reviewed and followed up until the 31st December 2012. The type and indication of the reconstructive procedure, operation time, operating team, experience and level of training of the surgeons involved, postoperative IMC (intermediate care unit) and/or ICU (intensive care unit) time, inpatient time, flap revisions, further postoperative complications, preoperative and postoperative radiation of the patients, the placement of dental implants were studied.

RESULTS

From 1st of January 2011 to 31st of December, 2011, the data of 101 patients with 103 microvascular free flap procedures were analysed of which 72% (84 flaps) were harvested by residents. The patients ranged in age from 14 to 89 years (mean age 59 years, 71 males and 40 females). The mean operation time was 591 min with the longest operation times for scapular flaps (744 min) and the shortest operation times for ALT flaps (455 min). Mean inpatient time was 34.2 days with a minimal time for the fibular flaps of 27.2 days and a maximum of 45.7 days for the latissimus dorsi flaps. 24 flaps (23.3%) in total had to be revised with bleeding being the main cause of immediate revisions (41.7% of all revisions). 5 flaps (4.85% of all flaps) were lost despite a revision procedure meaning a successful revision rate in 79.2% of all revisions.

CONCLUSION

Microvascular reconstruction procedures are safe and should be considered as standard procedures for reconstruction of large defects especially in high volume training centres. Intensive flap monitoring and early revisions maximize the flap outcome.

Biomechanical analysis of a curvilinear distractor device for correcting mandibular symphyseal defects

PURPOSE

The local mechanical environment is a determinant of successful transport disc distraction osteogenesis. This study assessed the biomechanics of a curvilinear distractor device for correcting mandibular symphyseal defects.

MATERIALS AND METHODS

The finite element method was used to analyze an intact mandible, mandibular distractor bodies with different rail thicknesses (4, 6, 8, and 10 mm), and mandibular distractor bodies with rails and auxiliary lingual brackets.

RESULTS

Rail thickness was positively correlated with maximum von Mises stress in the distractor and negatively correlated with maximum displacement of the mandibular distractor bodies. The maximum von Mises stress occurred at the junction of the rails and fixed arms. It also exceeded the yield strength of the titanium material. Compared with the maximum displacement of the intact mandible, that of the mandibular distractor bodies was visibly increased.

CONCLUSION

An auxiliary lingual bracket can effectively decrease stress in such devices and displacement of mandibular distractor bodies. Rail fixation alone cannot achieve stability for distraction osteogenesis. Using an auxiliary lingual bracket effectively prevents distractor breakage and exposure.

Reconstruction of acquired oromandibular defects

Acquired defects of the mandible resulting from trauma, infection, osteoradionecrosis, and ablative surgery of the oral cavity and lower face are particularly debilitating. Familiarity with mandibular and cervical anatomy is crucial in achieving mandibular reconstruction. The surgeon must evaluate which components of the hard and soft tissue are missing in selecting a method of reconstruction. Complexity of mandibular reconstruction ranges from simple rigid internal fixation to microvascular free tissue transfer, depending on defect- and patient-related factors. Modern techniques for microvascular tissue transfer provide a wide array of reconstructive options that can be tailored to patients' specific needs.

Alloplastic mandibular reconstruction: a systematic review and meta-analysis of the current century case series

BACKGROUND

Alloplastic mandibular reconstruction remains insufficiently predictable, with no systematic reviews to assess its scope and limitations.

METHODS

The PubMed, CINAHL, EMBASE, and Web of Science databases were searched for English study reports, published in the current century, of mere alloplastic surgical reconstruction of mandibular ablative defects.

RESULTS

In 14 articles, there were 944 patients, with a median age of 58.7 years (interquartile range, 53.2 to 62 years); 58.7 percent (interquartile range, 66.7 to 78.6 percent) were male. Cases of squamous cell carcinoma per study constituted 93.5 percent (interquartile range, 81.5 to 100 percent). Defects were mostly lateral (Boyd classification) (60.5 percent; interquartile range, 56.2 to 62 percent) and received mostly conventional bridging plates (in 64.3 percent of the studies) and pedicled flaps (45.3 percent; interquartile range, 37.1 to 58.3 percent); 60.7 percent (interquartile range, 53.5 to 58.8 percent) received adjuvant therapy. At 32-month follow-up, the complication and failure rates were 40.1 percent (interquartile range, 26.7 to 58.6 percent) and 30.8 percent (interquartile range, 11.7 to 48.1 percent), respectively. The overall survival rate was 55 percent (interquartile range, 27.8 to 74 percent). Radiotherapy seemed to be a relative risk factor for complications (1.387; p = 0.014) and plate loss (1.585; p = 0.006). Crossing the midline seemed to be a relative risk factor for plate exposure (1.533; p = 0.000) and overall complications (1.385; p = 0.002).

CONCLUSIONS

The results should be generalized cautiously. Alloplastic reconstructive surgery faces a remarkable lack of evidence. Relatively high complication and failure rates are areas of further concern.

Carbon plate shows even distribution of stress, decreases screw loosening, and increases recovery of preoperative daily feed intake amount in a rabbit model of mandibular continuity defects

INTRODUCTION

The aim of this study was to compare a carbon plate (CP) and a titanium mandibular reconstruction plate (TMRP) in finite element analysis and an animal model.

MATERIALS AND METHODS

Twelve rabbits were used for this experiment. After a mandible continuity defect was created, either a CP or a TMRP was used for mandibular reconstruction. Postoperatively, daily feed intake amount (DFIA) was measured for 4 weeks. Radiographic images were also acquired to evaluate screw loosening. For the analysis of the stress distribution, a simple continuity defect model was used, and finite element analysis was performed.

RESULTS

The CP group had 0.80 ± 0.45 lost screws in an animal during the 4 weeks postoperative observation; however, the TMRP group had 1.86 ± 0.69 lost screws (p = 0.014). Overall, the 5 out of 5 of rabbits in the CP group and 3 out of 7 in the TMRP group exhibited preoperative levels of DFIA during the 4 week observation (p = 0.038). The finite element analysis showed that the stress was more evenly distributed in the CP than in the TMRP model.

CONCLUSIONS

The CP group showed decreased screw loosening and increased recovery of preoperative DFIA compared to the TMRP group in a rabbit model of mandibular continuity defects. Perfect adaptation of CP during the operation could not be achieved in spite of reshaping to the mandibular curvature. This disadvantage of the CP system can be overcome by the prefabricated technique using a prototype model.

The promotion of mandibular defect healing by the targeting of S1P receptors and the recruitment of alternatively activated macrophages

Endogenous signals originating at the site of injury are involved in the paracrine recruitment, proliferation, and differentiation of circulating progenitor and diverse inflammatory cell types. Here, we investigate a strategy to exploit endogenous cell recruitment mechanisms to regenerate injured bone by local targeting and activation of sphingosine-1-phosphate (S1P) receptors. A mandibular defect model was selected for evaluating regeneration of bone following trauma or congenital disease. The particular challenges of mandibular reconstruction are inherent in the complex anatomy and function of the bone given that the area is highly vascularized and in close proximity to muscle. Nanofibers composed of poly(DL-lactide-co-glycolide) (PLAGA) and polycaprolactone (PCL) were used to delivery FTY720, a targeted agonist of S1P receptors 1 and 3. In vitro culture of bone progenitor cells on drug-loaded constructs significantly enhanced SDF1α mediated chemotaxis of bone marrow mononuclear cells. In vivo results show that local delivery of FTY720 from composite nanofibers enhanced blood vessel ingrowth and increased recruitment of M2 alternatively activated macrophages, leading to significant osseous tissue ingrowth into critical sized defects after 12 weeks of treatment. These results demonstrate that local activation of S1P receptors is a regenerative cue resulting in recruitment of wound healing or anti-inflammatory macrophages and bone healing. Use of such small molecule therapy can provide an alternative to biological factors for the clinical treatment of critical size craniofacial defects.

Reconstruction of mandibular defects

Defects requiring reconstruction in the mandible are commonly encountered and may result from resection of benign or malignant lesions, trauma, or osteoradionecrosis. Mandibular defects can be classified according to location and extent, as well as involvement of mucosa, skin, and tongue. Vascularized bone flaps, in general, provide the best functional and aesthetic outcome, with the fibula flap remaining the gold standard for mandible reconstruction. In this review, we discuss classification and approach to reconstruction of mandibular defects. We also elaborate upon four commonly used free osteocutaneous flaps, inclusive of fibula, iliac crest, scapula, and radial forearm. Finally, we discuss indications and use of osseointegrated implants as well as recent advances in mandibular reconstruction.

Full length articles published in BJOMS during 2010-11--an analysis by sub-specialty and study type

Full length articles such as prospective and retrospective studies, case series, laboratory-based research and reviews form the majority of papers published in the British Journal of Oral and Maxillofacial Surgery (BJOMS). We were interested to evaluate the breakdown of these types of articles both by sub-specialty and the type of study as well as the proportion that are written by UK colleagues compared to overseas authors over a 2 year period (2010-11). A total of 191 full length articles across all sub-specialties of our discipline were published, with 107 papers (56%) coming from UK authors. There were proportionately more oncology papers arising from the UK than overseas (60 and 30% of total respectively) while the opposite was found for cleft/deformity studies (10% and 22%). There was only one laboratory-based study published from the UK compared with 27 papers from overseas. The number of quality papers being submitted to the Journal continues to increase, and the type of article being published between UK and overseas probably reflects different practices and case-loads amongst colleagues. The relatively few UK laboratory based studies published in BJOMS compared to overseas authors are most likely due to authors seeking the most prestigious journals possible for their work.

Application of CAD/CAM-assisted technique with surgical treatment in reconstruction of the mandible

OBJECTIVE

The purpose of this clinical study was to explore the optimal method of reconstruct mandible defects individually and immediately.

STUDY DESIGN

Three-dimensional model simulation technique and vascularized fibular osteomyocutaneous flap were used to repair 15 cases of mandible defects, which were caused by ameloblastoma. A three-dimensional computed tomography (CT) images were converted to a virtual model using CAD software and the 3-dimensional (3D) simulated resin models of skeleton and fibula were used to design the osteotomies, bone segment replacement and titanium mesh shaping preoperatively.

RESULTS

Fibula flaps were alive and no complication occurred. The patients were satisfied with the results both esthetically and functionally.

CONCLUSIONS

This preliminarily clinical study and case demonstrated that CAD/CAM-assisted technique with surgical treatment offers an individual anatomical reconstruction of the mandible in ameloblastoma patients. The procedures guarantee intraoperatively an exact placement of the preformed mesh even for precise reconstruction of extensive mandible defects.

What are we reading? A study of downloaded and cited articles from the British Journal of Oral and Maxillofacial Surgery in 2010

A large number of papers related to oral and maxillofacial surgery are published in many specialist journals. With the ever-increasing use of the internet it is easy to download them as part of a journal subscription on a fee per paper basis, or in some cases for free. Online access to the British Journal of Oral and Maxillofacial Surgery (BJOMS) is free to British Association (BAOMS) members with a $30 fee per paper download for non-members. Many colleagues use the online version of the journal, and this provides valuable information about downloading trends. Other data on articles that have been cited in subsequent publications are also readily available, and they form the basis for the calculation of a journal's impact factor. We evaluated the top 50 downloaded papers from the BJOMS website in 2010 to ascertain which articles were being read online. We also obtained data on the number of citations for papers published in 2009-2010 to see whether these papers were similar to the articles being downloaded. In 2010 there were over 360000 downloaded articles. The most popular papers were leading articles, reviews, and full length articles; only one short communication featured in the top 50 downloads. The papers most cited in subsequent publications were full length articles and leading articles or reviews, which represent 80% of the total citations of the 50 papers. Ten papers were in both the top 50 downloaded and most cited lists. We discuss the implications of this study for the journal and our readers.

Mandibular reconstruction using AO/ASIF stainless steel reconstruction plate: a retrospective study of 36 cases

AIM

The study was aimed at esthetic and functional results as well as patient tolerance after reconstruction with reconstruction plate. The follow-up ranged from 1 to 4 years.

MATERIALS AND METHODS

A retrospective study of 36 patients who had mandibular reconstruction with AO/ASIF stainless steel reconstruction plates after oncologic resection was evaluated. The indications and postoperative outcomes were studied.

RESULTS

At the end of study, 24 of 36 patients (67%) still had the plate in place. Around three (8%) plates were fractured. Nine (25%) plates got exposed leading to surgical intervention. Surgical results were satisfying, particularly when looking at delayed healing or long-term tolerance. Esthetic (79% rated results as good or acceptable) and functional results of this reconstruction were satisfying.

CONCLUSION

We conclude by saying that reconstruction plate provides a solution for safe and rapid mandibular reconstruction for patients with poor prognosis or poor condition. This method also preserves the possibility of secondary reconstruction.

CLINICAL SIGNIFICANCE

The reconstruction plate may be a good clinical choice for safe and rapid mandibular reconstruction.