Nonvascularized bone grafting for mandibular reconstruction: myth or reality?

This retrospective study analyzes the long-term results and complications of mandibular reconstruction with nonvascularized bone grafts (NVBGs) and suggests refinements. A total of 166 patients underwent mandibular ablation and primary reconstruction between June 1990 and August 2009, of which 101 were NVBGs, 27 were vascularized bone grafts, and 38 were with functional plate reconstruction. Eighty-seven of 101 patients undergoing NVBG, having all records and followed up for a minimum of 12 months, were included in this study. The analysis criteria included site of defect, surgical approach, method of graft fixation, bony continuity and stability, presence or absence of infection, aesthetic and functional prosthetic rehabilitation, donor-site morbidity, and clinical and radiological changes in the reconstructed area.The overall success with NVBGs in our study was 77 (88.5%) of 87. We used ilium in 68 cases (78.16%), fibula in 16 cases (18.39%), and rib in 3 cases (3.44%). Ten cases (11.5%) showed complete failure due to infection (7 cases) and resorption (3 cases).Nonvascularized bone grafts could be used judiciously for reconstruction of selective mandibular resection defects where there is not much of soft tissue loss, or where 2-layer watertight closure can be achieved intraorally and extraorally. Where only a single-layer intraoral closure is anticipated, either additional soft tissue should be brought submucosally or there should not be extraoral-intraoral communication even during surgery. Also precise patient selection, surgical planning, and execution with meticulous nursing care are keys to success.     

Cranial bone grafting for orbital reconstruction: is it still the best?

A variety of etiologies may result in functional and aesthetic deficiencies requiring orbital reconstruction. These are discussed, as are some of the possible repair techniques. In the current study, a randomized, retrospective chart review of one surgeon's experience with orbital reconstruction using cranial bone grafts was performed. The results of the chart reviews are presented, including preoperative diagnosis, clinical signs and symptoms, and postoperative findings. This study allowed a comparison and contrast to be made between exogenous materials and autogenous bone for orbital reconstruction. The differences between cranial and iliac bone as autogenous sources of reconstructive material were examined. The study indicates that cranial bone grafting for reconstruction of the orbit remains the material of choice.     

Management of exposure of three-dimensional mandibular reconstructive plates in mandibular reconstruction： Report of 2 cases

Expmisure of three dimensionil mmdibuiar reconstnietive plate was a main complcation is clinical application ,which includ intaond expusure and exlsuoul exposure .This paper reporbed two typical cases with plate expostre und reviewed the litralmes in unaly in the canses of plate exposure and its preventive measures .     

Does osteoporosis increase marginal bone loss around dental implants in the posterior of the maxilla?

Osteoporosis is caused by an imbalance in bone remodelling. The aim of this study was to compare the marginal bone loss (MBL) around dental implants placed in the posterior maxilla between osteoporotic and non-osteoporotic female patients. This was a prospective cohort study. Female patients needing a dental implant restoration in the posterior maxilla were included. Dual-energy X-ray absorptiometry was performed and the T-score recorded. MBL was measured at 12 months after loading. The patients were assigned to one of two groups: group 1, osteoporotic (T-score ≥2.5); group 2, non-osteoporotic (T-score <2.5). In this study, osteoporosis was the primary predictor variable and MBL was the outcome variable. The mean MBL was compared between the two groups using an independent t-test. Pearson’s correlation test was applied to identify any correlation between the T-score and MBL. Ninety female patients were studied, 44 in group 1 and 46 in group 2. The mean MBL was 1.20 ± 0.29 mm in group 1 and 0.87 ± 0.15 in group 2; this difference in mean MBL was statistically significant (P = 0.001). There was a correlation between T-score and MBL (P = 0.001). Despite the correlation between T-score and MBL, this study did not provide enough evidence to prove any causal relationship between MBL and osteoporosis.     

Early bone resorption of free microvascular reanastomized bone grafts for mandibular reconstruction – A comparison of iliac crest and fibula grafts

ObjectivesPatients with continuous bone defects of the mandible after ablative tumor surgery need bony reconstruction for proper function and aesthetics. Free microvascular reanastomized bone grafts provide a clinically proven option for such patients, yet the optimal source of donor tissue has not yet been established. The aim of this study was to evaluate and compare the bone volume stability of vascularized bone grafts, particularly in the early highly resorptive phase, from the iliac crest (DCIA) and the fibula and to assess the implantologic rehabilitations.Materials and methodsThirty-six patients with mandibular continuity defects due to tumor resection were reconstructed by the use of vascularized bone grafts; 21 patients received DCIA flaps and 15 patients received a composite free fibular flap, depending on the size and location of the defect. Bone resorption was assessed using digital panographs. Radiographs were taken immediately after bone reconstruction, 6 months postoperatively, prior to implant surgery, and at prosthetic loading.ResultsAfter a mean observation period of 6 months, vertical bone resorption was 6.79% for the patients of the iliac crest group (DCIA), 10.20% after 11 months, and 12.58% after 17 months. Fibular grafts showed a bone resorption of 5.30% after a mean observation time of 6 months, 8.26% after 11 months, and 16.95% after 17 months. Eighteen patients received 71 implants for implant-retained dental reconstructions.ConclusionsMicrovascular reanastomized bone grafts represent a reliable treatment option for reconstruction in cases of large defects of the mandible, with low graft resorption in the early healing phase. Additionally, the compared grafts provide sufficient bone volume to permit implant rehabilitation.     

Donor site morbidity after reconstruction of alveolar bone defects with mandibular symphyseal bone grafts in cleft patients—111 consecutive patients

The aim of this study was to assess the objective and subjective morbidity after reconstruction of alveolar bone defects with mandibular symphyseal bone grafts in patients with cleft lip and palate. One hundred and eleven patients born between 1995 and 1999, who had undergone chin bone harvesting for alveolar cleft reconstruction in the period from 2000 through 2011, were included. A survey of medical records was conducted. Subjective morbidity after reconstruction was assessed using a questionnaire. Medical records revealed few postoperative incidents; 5.6% reported persistent sensory disturbances in the donor area. Postoperative pain averaged 3.6 ± 2.1 (scale 0–10). The overall satisfaction with the surgical result was 8.7 ± 1.7 (scale 0–10). This study revealed that chin bone harvesting for reconstruction of alveolar defects in patients with cleft lip and palate is a safe and predictable procedure, highly appreciated by the patients, and characterized by only minor postoperative incidents. Patients must be informed of the risk of sensory disturbances in the donor area.     

Treatment of the edentulous atrophic maxilla using zygomatic implants: evaluation of survival rates over 5–10 years

The aim of this retrospective observational cohort study was to analyse and report the 5–10-year survival rates of endosseous zygomatic implants used in the rehabilitation of the atrophic maxilla. Forty-three consecutive zygomatic implant placements in 25 patients were evaluated over a 5–10-year period. All zygomatic implant surgery was carried out under general anaesthesia. Nobel Biocare zygomatic machined-surface implants were used, and placement was undertaken using the modified sinus slot method. The main outcome measures and determinants for success were survival of the restored implants and the proportion of originally planned prostheses delivered to patients. Of the 25 patients treated, 12 were male and 13 were female; 19 were non-smokers, and the mean age at time of surgery was 64 years. Patients were treatment-planned for implant-retained bridgework, a removable prosthesis retained by fixed cast gold or milled titanium beams, or magnet-retained removable prostheses. A combination of zygomatic and conventional implants was used in all but one patient. In this study it was shown that the overall success rate for zygomatic implants was 86%, with six of the implants either failing to integrate or requiring removal due to persistent infection associated with the maxillary sinus. All patients received their planned prosthesis, although in six cases the method of retention required modification. This study illustrates that zygomatic implants are a successful and important treatment option when trying to restore the atrophic maxilla, with the potential to avoid additional augmentation/grafting procedures and resulting in a high long-term success rate.     

Two-stage distalization of the mental foramen to manage posterior mandibular vertical bone deficiency—a prospective observational study

Inferior alveolar nerve (IAN) transpositioning is a modality utilized to manage posterior mandibular vertical deficiency. Several complications have been reported including improper implant positioning, mandibular body fracture, and neurosensory disturbance. The aim of this prospective observational study was to introduce a two-stage mental foramen distalization technique to minimize the complications associated with IAN transpositioning. Ten patients with severely atrophied mandibular ridges were included. Cone beam computed tomography was ordered to accurately locate the position of the IAN and its incisive terminal branch before designing the outline of two cortical osteotomies anterior and posterior to the mental foramen. The osteotomies were created using a piezoelectric device, followed by separation and identification of the nerve. The incisive branch was severed to freely transpose the IAN. A new foramen was created far distally and the cortical windows were repositioned and fixed with two screws. Healing was uneventful for all patients. Neurosensory recovery was assessed by MRC scale. All cases showed full recovery within 6 weeks, except for two patients who showed complete recovery after 16 weeks. Four months postoperative, all patients showed complete consolidation of the cortical windows without any signs of failure implants were placed at the pre-planned surgical sites. Histomorphometric analysis of core biopsies from seven surgical sites showed bone area percentages ranging from 46% to 63%. The two-stage mental foramen distalization technique is a predictable and safer technique for IAN transpositioning specifically in cases of vertical bone deficiency associated with limited inter-arch space.     

Digitally designed,personalized bone cement spacer for staged TMJ and mandibular reconstruction — Introduction of a new technique

The aim of this paper is to introduce an innovative workflow for staged reconstruction of the mandible, including the temporomandibular joint (TMJ), using a temporary, patient-specific spacer. In cases of partial mandibular resection including disarticulation, sometimes needed to treat inflammatory bone disease, the spacer is intended to retain symmetry of the hard tissues, to preserve the soft tissues, and to act as a bactericidal agent. When complete healing of the affected surrounding tissues has occurred, final reconstruction using a patient-matched total TMJ endoprosthesis, in combination with an autogenous free bone flap, can be performed as a second-stage procedure. The crucial steps of the workflow are virtual surgical planning, manufacturing of a two-part silicone mold, and chairside manufacturing of the spacer using an established bone cement with gentamycin. The method was first introduced in two patients suffering from therapy-resistant chronic osteomyelitis. The presented protocol of staged surgery allows a much safer and predictable reconstruction compared with immediate reconstruction. The workflow also minimizes the potential risk of endoprosthesis infection — one of the major risks of implant failure.     

Can radiological examination of mandibular bone invasion accurately predict the need for mandibular resection in oral squamous cell carcinoma?

Bone invasion by oral squamous cell carcinoma necessitates jaw resection, with preoperative imaging ideally able to guide the resection. A retrospective review of 109 patients with oral squamous cell carcinoma who underwent mandibular resection was performed. Eighty-three had preoperative computed tomography (CT) imaging and 72 underwent magnetic resonance imaging (MRI). The presence of bone invasion on imaging was compared to histopathology. Bone invasion was detected in 44 of 109 resection specimens (40.4%) and was identified on CT in 31 of 83 cases (37.4%) and on MRI in 35 of 72 cases (48.6%). The sensitivity and specificity of CT for detecting bone invasion was 69.0% and 79.6%, respectively, while for MRI was 87.1% and 80.5%, respectively. Histological detection of bone invasion was associated with greater disease-specific mortality (P = 0.002), as was MRI detection of bone invasion (P = 0.027). CT detection was not significant (P = 0.240). Negative prediction of bone invasion was 95% accurate for both modalities in clinically non-invaded mandibles. Survival was reduced in patients who underwent marginal mandibular resection when bone invasion was detected histologically (33.3% vs. 70.5%, P = 0.277) and with CT, although this was not statistically significant. More data are required to determine whether more aggressive resection is warranted when bone invasion is detected preoperatively.     

The CAD–CAM technique for mandibular reconstruction: An 18 patients oncological case-series

BackgroundModern techniques for mandibular reconstruction, such as CAD–CAM, offer new solutions for planning of reconstructive surgery in relation to the aesthetic outcome and the prosthetic rehabilitation.MethodsCAD–CAM reconstruction procedures using vascularised bone free-flap transfers and surgical guides to cut the mandible and fibula were performed in 18 cases of neoplasms. The planned surgery was used to design and manufacture customised surgical devices.ResultsThe mean follow-up was 12 months. All patients, except one, are alive without disease at the time of writing. Reconstructive microvascular flap survival was 100%. No major or minor microvascular complication occurred. No donor site complication was observed.ConclusionsCAD–CAM technology is a very useful way to obtain the native morphology of the mandible, especially when both bi-dimensional and tri-dimensional defects occur. The reconstruction protocol presented offers several benefits and few disadvantages, which are discussed in the article.     

Is induced membrane technique effective in reconstruction of mandibular segmental bone defects? An experimental study

This study aimed to compare the effectiveness of different graft materials using induced membrane technique for reconstruction of mandibular segmental bone defects.New Zealand rabbits were used as the experimental animal. As first-stage surgical procedure, segmental bone defects were created at the lower border of the mandibula in all groups. Polymethylmethacrylate (PMMA) cement was inserted into the defects. After 6 weeks, PMMA cement was removed in all groups. In the Control group, defect areas were left empty. Defects were filled with autogenous graft in the Autograft group, xenograft in the Xenograft group, and a mixture of autogenous graft and xenograft in the Autograft + Xenograft group. Histopathological, stereological, and immunohistochemical analyses were performed.A total of 40 New Zealand rabbits were used. Rabbits were randomly divided into four subgroups as Control, Autograft, Xenograft and Autograft + Xenograft groups (n = 10). When the groups were compared in terms of newly formed bone tissue volumes, significant difference was found between the Control group and Autograft group, Xenograft group and Autograft + Xenograft group (p < 0.001, p < 0.001, p = 0.003). The results of immunohistochemical examination were consistent with this finding.Stereological and immunohistochemical results can be used as a justification to adopt the induced membrane technique on an experimental basis in humans when it comes to the reconstruction of small segmental mandibular defects.     

Does platelet-rich fibrin increase the stability of implants in the posterior of the maxilla? A split-mouth randomized clinical trial

The effect of platelet-rich fibrin (PRF) on bone healing around dental implants in areas of poor bone quality has not been studied. The aim of this study was to evaluate the stability of implants placed in the posterior maxilla, with or without the use of PRF, during the healing period. A split-mouth randomized clinical trial was performed. Twenty patients with missing teeth in the molar region of the maxilla, requiring bilateral implants, were included. PRF was used on one side (group 1); no PRF was used on the other (group 2). Implant stability was assessed by resonance frequency analysis (RFA) at 2, 4, and 6 weeks after placement. At 2 weeks, the mean ISQ was 60.60 ± 3.42 in group 1 and 58.25 ± 3.64 in group 2; at 4 weeks it was 70.30 ± 3.36 in group 1 and 67.15 ± 4.33 in group 2; at 6 weeks it was 78.45 ± 3.36 in group 1 and 76.15 ± 2.94 in group 2. Significant differences in RFA were found between the groups at 2 weeks (P = 0.04), 4 weeks (P = 0.014), and 6 weeks (P = 0.027) after placement. The study results suggest that the use of PRF may enhance the post-insertion stability of dental implants placed in the posterior maxilla during the healing period.     

Healing masseter entheses of mandibular reconstruction with autograft—Raman spectroscopic and histological study

Autogenous bone graft represents the gold standard for mandibular reconstruction. The authors used a beagle mandibular defect model and reconstructed with iliac crest and ulna graft. Healing masseter entheses were harvested 24 weeks after surgery and analyzed by histology and Raman microspectroscopy. The intensity ratio of 960/2940 was to document mineral-to-collagen ratio as degree of mineralization. Pearson correlation was used to evaluate the association between the intensity ratios of 960/2940 and the tendon-to-bone insertion site. In the normal control group (n = 4) and the experimental control group with detached masseter muscle (n = 4), the degree of mineralization at the insertion site increased linearly from tendon to bone. In the iliac graft (n = 4) and ulna graft groups (n = 4), healing entheses were far less mature than controls and a linear trend was not observed. There was no significant correlation between degree of mineralization and insertion site in the ulna group (r_spearman = 0.519, P > 0.001). These results indicate that transplanted bone plays a critical role in healing of entheses and healing enthesis to reconstructed mandible is inferior to normal. Raman spectroscopy provides quantitative information about different healing entheses and gives valuable insight into mechanical properties of entheses in functional mandibular reconstruction.     

Brånemark system implants in the posterior maxilla: clinical study of 660 implants followed for 5 to 12 years

Originally, osseointegrated implants were used principally in the anterior region of the mandible and maxilla, but use in the posterior segments of both arches is common today. The long-term success of implants placed in the posterior region, an environment of stronger forces and poorer bone quality, has not been thoroughly reviewed. The purpose of the present study was to review a large series of Br?nemark System implants placed in posterior maxillae (660 implants in 202 patients) that have been restored with fixed partial ceramometal restorations and followed for as long as 12 years after loading. Thirteen of the implants (2%) failed between placement and loading, 12 implants were lost between loading and the end of the first year, and 10 failed thereafter, 2 as the result of fractures at 3 and 4 years. The cumulative success rate is therefore 94.4% at 5 to 6 years and 93.4% after 10 years. The quality and quantity of bone appeared to have little influence on the success rate. Surgical techniques are particularly important to the success of osseointegrated implants placed in the posterior maxilla. With careful surgical planning and execution, a success rate of approximately 95% at 5 years can be achieved.     

SPECT bone scintigraphy for the assessment of condylar growth activity in mandibular asymmetry: is it accurate?

The comparison of serial radiographs and clinical photographs is considered the current accepted standard for the diagnosis of active condylar hyperplasia in patients with facial asymmetry. Single photon emission computed tomography (SPECT) has recently been proposed as an alternative method. SPECT can be interpreted using three reported methods absolute difference in uptake, uptake ratio, and relative uptake. SPECT findings were compared to those from serial comparisons of radiographs and clinical photographs taken at the time of SPECT and a year later; the sensitivities and specificities were determined. Two hundred patient scans were evaluated. Thirty-four patients showed active growth on serial growth assessment. On comparison with serial growth assessment, the sensitivity and specificity of the three methods ranged between 32.4% and 67.6%, and 36.1% and 78.3%, respectively. Analysis using receiver operating characteristic (ROC) curves revealed area under the curve (AUC) values of <0.58. The average age (mean ± standard deviation) of patients with active growth was 18.6 ± 2.8 years, and average growth in the anteroposterior, vertical, and transverse directions was 0.94 ± 0.91 mm, 0.88 ± 0.86 mm, and 1.4 ± 0.66 mm, respectively. With such low sensitivity and specificity values, it is not justifiable to use SPECT in place of serial growth assessment for the determination of condylar growth status.     

What is the best position for palatal implants? A CBCT study on bone volume in the growing maxilla

Clinical Oral Investigations - The objectives of the present study are the following: (a) to investigate limitations (bone height, proximity to nasopalatine nerve and roots) in juvenile patients,...