A Novel Approach to Bone Reconstruction: The Wafer Technique.

This study presents a novel technique based on guided bone regeneration and onlay grafts for three-dimensional bone augmentation. This two-stage technique uses an autogenous cortical bone plate and collagen membranes to form a barrier containing a mixture of deproteinized bovine bone matrix, autologous blood, and bone grafted from intraoral sites. Five patients were treated. At 6 months postsurgery, a mean increase in bone volume of 1,062 mm³ was shown. Mean maximum linear augmentation was 3.65 mm. Histologic analysis of the regenerated areas revealed the presence of compact newly formed bone with no sign of inflammation. A total of 13 implants were placed. The patients were satisfied, and complications were not observed.

Evaluation of Masticatory Efficiency and QoL Improvements After Prosthetic Rehabilitation of Mandibular Cancer Patients Reconstructed with a Fibula Free Flap.

PURPOSE: The purpose of this noninferiority study was to determine whether removable or implant-supported fixed dental prostheses restored patients' abilities to preoperative levels after cancer removal in the mandible. MATERIALS AND METHODS: Ten patients who had undergone mandibular resection to remove cancer and subsequent reconstruction with microvascularized free fibula flaps were examined in this study. Five patients were rehabilitated with removable prostheses and five received implant-supported fixed prostheses. Health-related quality of life was evaluated using the Head and Neck (H&N30) questionnaire. Kruskal-Wallis nonparametric analysis of variance and Tamhane's T2 test were used to analyze results in comparison with a control group composed of 10 subjects with Class I natural dentition. RESULTS: Masticatory efficiency among the three groups of patients differed significantly (P=.003); in particular, that of the patients who received removable prostheses was not inferior to that of the control subjects (P=.019). Analysis of responses to the Head and Neck module of the Quality of Life Questionnaire showed no significant difference between patients with fixed dentures and patients with removable dentures. CONCLUSIONS: There is no apparent difference in quality of life between patients using implant-supported fixed prostheses and those using removable prostheses. Regarding masticatory efficiency, when feasible, the use of implant-supported fixed prostheses is recommended in patients who have undergone free fibula flap surgery, although the removable prostheses also were not inferior in patients who underwent no surgery.

Fence technique for localized three-dimensional bone augmentation: a technical description and case reports.

This study presents a novel bone reconstructive technique based on guided bone regeneration for localized three-dimensional hard tissue augmentation. This two-stage technique utilized a titanium osteosynthesis plate and a collagen membrane to form a physical barrier resembling a fence that contains bone graft biomaterial composed of a combination of deproteinized bovine bone matrix and autologous bone grafted from intraoral sites. Six patients were treated. At 6 months postsurgery, an increase in bone volume of 953 mm³ was shown. Mean maximum linear augmentation in the vertical direction was 6.75 mm. Histologic analysis of the regenerated area revealed the presence of compact newly formed bone with no sign of inflammation. A total of 13 implants were placed. Peri-implant marginal bone level was 0.94 mm at implant placement and 1.30 mm after 6 months. The patients were satisfied with the procedure and no complications were observed.

Computer-aided design and computer-aided manufacturing cutting guides and customized titanium plates are useful in upper maxilla waferless repositioning.

PURPOSE: The purpose of the present study was to develop a computer-aided design (CAD) and computer-aided manufacturing (CAM) technique that enabled fabrication of surgical cutting guides and titanium fixation plates that would allow the upper maxilla to be repositioned correctly without a surgical splint in orthognathic patients. MATERIALS AND METHODS: Ten patients were recruited. A complete CAD-CAM workflow for orthognathic surgery has 3 steps: 1) virtual planning of the surgical treatment, 2) CAD-CAM and 3-dimensional printing of customized surgical devices (surgical cutting guide and titanium fixation plates), and 3) computer-aided surgery. Upper maxilla repositioning was performed in a waferless manner using a CAD-CAM device: the surgical cutting guide was used during surgery to pilot the osteotomy line that had been planned preoperatively at the computer and the custom-made fixation titanium plates allowed desired repositioning of the maxilla. RESULTS: To evaluate the reproducibility of this CAD-CAM orthognathic surgical method, the virtually planned and actually achieved positions of the upper maxilla were compared. Overlap errors using a threshold value smaller than 2 mm were evaluated, and the frequency of such errors was used as a measurement of accuracy. By this definition, the accuracy was 100% in 7 patients (range in all patients, 62 to 100%; median, 92.7%). CONCLUSION: These results tend to confirm that the use of CAD-CAM cutting guides and customized titanium plates for upper maxilla repositioning represents a promising method for the accurate reproduction of preoperative virtual planning without the use of surgical splints.

Accuracy of fibular sectioning and insertion into a rapid-prototyped bone plate, for mandibular reconstruction using CAD-CAM technology.

Modern techniques of mandibular reconstruction, such as CAD-CAM technology and rapid prototyping, offer new means by which reconstructive surgery can be planned to optimise aesthetic outcomes and prosthetic rehabilitation. The high degree of accuracy afforded by these approaches is principally attributable to high-precision fibular sectioning and insertion of the bone into a customised bone plate. CAD-CAM mandibular reconstruction procedures using vascularised bone free-flap transfers were performed on 10 patients with benign or malignant neoplasms. Five were not treated with the aid of CAD-CAM technology, and served as the control group. Five were scheduled for maxillofacial surgery using surgical cutting guides and customised bone plates. A generalised linear model for linear measures was used to compare the accuracy of reconstruction between the two groups. A difference, even though not significant, in the lateral shift of the mesial and distal positions of the fibular units was evident between groups. CAD-CAM-generated fibular surgical guides afford improved accuracy when used to restore native anatomy, especially in the context of mandibular arch restoration, and both operating room time and related costs are reduced during fibular sectioning.

Technical aspects of prosthetically guided maxillofacial surgery of the mandible. A pilot test study.

A test of the accuracy in transferring the virtual data into the surgical environment was carried out. Differences between the virtually planned and the actual position during surgery of the rapid prototyped guides and the bone plates were investigated. The accuracy of the method was evaluated in terms of the precision of cuts in the mandible, the final positions of the rami and condyles, and the sectioning precision of the fibula. The guide position presented a mean value dislocation of 0.6 mm in the right side and of 4.1 mm in the left side; the cut line of the mandible presented an angular deviation of 2.9° (right) and of 17.5° (left). The right condyle was positioned 2.5 ± 0.05 mm more medial than native position, and the left condyle 5.2 ± 0.05 mm medial. The total length was 0.3 ± 0.05 mm short of the virtually projected length at the inferior margin of the mandible and 1.9 ± 0.05 mm longer than projected at the superior margin. The Prosthetically Guided Maxillofacial Surgery (PGMS) is a viable way to improve the precision of mandibular reconstruction using a fibula free flap.

The CAD-CAM technique for mandibular reconstruction: an 18 patients oncological case-series.

BACKGROUND: Modern 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. METHODS: CAD-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. RESULTS: The 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. CONCLUSIONS: CAD-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.

Prosthetically guided maxillofacial surgery: evaluation of the accuracy of a surgical guide and custom-made bone plate in oncology patients after mandibular reconstruction.

BACKGROUND: The aim of the present study was to evaluate the accuracy of prosthetically guided maxillofacial surgery in reconstructing the mandible with a free vascularized flap using custom-made bone plates and a surgical guide to cut the mandible and fibula. METHODS: The surgical protocol was applied in a study group of seven consecutive mandibular-reconstructed patients who were compared with a control group treated using the standard preplating technique on stereolithographic models (indirect computer-aided design/computer-aided manufacturing method). The precision of both surgical techniques (prosthetically guided maxillofacial surgery and indirect computer-aided design/computer-aided manufacturing procedure) was evaluated by comparing preoperative and postoperative computed tomographic data and assessment of specific landmarks. RESULTS: With regard to midline deviation, no significant difference was documented between the test and control groups. With regard to mandibular angle shift, only one left angle shift on the lateral plane showed a statistically significant difference between the groups. With regard to angular deviation of the body axis, the data showed a significant difference in the arch deviation. All patients in the control group registered greater than 8 degrees of deviation, determining a facial contracture of the external profile at the lower margin of the mandible. With regard to condylar position, the postoperative condylar position was better in the test group than in the control group, although no significant difference was detected. CONCLUSIONS: The new protocol for mandibular reconstruction using computer-aided design/computer-aided manufacturing prosthetically guided maxillofacial surgery to construct custom-made guides and plates may represent a viable method of reproducing the patient's anatomical contour, giving the surgeon better procedural control and reducing procedure time. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Fence technique: guided bone regeneration for extensive three-dimensional augmentation.

This report describes a novel bone reconstructive technique based on guided bone regeneration for extensive three-dimensional hard tissue augmentation. This two-stage technique utilizes bioresorbable osteosynthesis plates, pins, and collagen membranes that form a physical barrier resembling a fence, which contains the bone graft biomaterials composed of a combination of deproteinized bovine bone matrix and autologous bone grafted from intraoral sites. This technique can result in significant bone regeneration with minimal patient discomfort. Four case reports are presented. Histologic analysis of specimens shows the presence of mature bone. This procedure yields favorable results for bone formation, implant placement, and patient satisfaction.

CAD/CAM guided secondary mandibular reconstruction of a discontinuity defect after ablative cancer surgery.

A surgical guide is projected to aid the repositioning of the mandibular segments in their original locations, and a reconstruction bone plate is provided to support the fibula free flap. Computer-aided mandibular reconstruction involves three steps: virtual surgical planning, CAD/CAM and rapid-prototyping procedures for the design and manufacture of the customised surgical device and surgery. The duration of the reconstructive phase (<1.5 h intraoperative time) was reduced in comparison with traditional secondary mandibular reconstruction. The bone plate permitted the maximal restoration of the original facial and mandibular contours and the more precise positioning of the residual mandibular ramus in comparison with conventional procedures. No complication was noted during the mean follow-up period of 12 months. The protocol presented in this paper offers some benefits: 1) The virtual environment permitted ideal preoperative planning of mandibular segment repositioning in secondary reconstruction; 2) Intraoperative time was not consumed by approximate and repeated bone plate modelling; 3) Using CT data obtained before primary surgery, the reconstruction bone plate was designed using the original external cortical bone as a template to reproduce the ideal mandibular contour; 4) Prototyped resin models of the bone defect allowed the surgeon to train preoperatively by simulating the surgery.

Chondroma of the mandibular condyle-relapse of a rare benign chondroid tumour after 5 years' follow-up: case report.

Chondroma of the mandibular condyle is rare and its signs and symptoms can mimic those of patients with more common disorders of facial asymmetry or dysfunction of the temporomandibular joint (TMJ). We report a case of chondroma of the mandibular condyle that presented as temporomandibular pain with malocclusion, and which relapsed 5 years after the initial treatment. To our knowledge only 7 cases of chondroma of the mandibular condyle have been reported in the last 70 years. This case is the eighth.

Simulation-guided navigation: a new approach to improve intraoperative three-dimensional reproducibility during orthognathic surgery.

Because of the recent development of three-dimensional technology, computer software is increasingly being used for diagnosis, analysis, data documentation, and surgical planning for orthognathic surgery. Currently, the typical method to reposition jaws in the correct and planned location is based on the use of surgical splints, which have a quite high level of imprecision. The most important differences between planned and achieved maxillary movements are in the vertical and rotational positioning. Several methods have been described for intraoperative maxillary control, but none of these procedures is satisfactory. We present a new method to transfer individualized three-dimensional virtual planning of the patient using a navigation system in the operating room to improve reproducibility of the simulation. We enrolled 10 patients with dentofacial deformities from November 2008 to May 2009. All patients were studied and treated according to the following steps: cone-beam computed tomography data acquisition, virtual simulation of the surgical procedure, surgery with intraoperative navigation, and validation through reproducibility evaluation. We found 86.5% mean preoperative surgical plan reproducibility with the assistance of simulation-guided navigation compared with 80% mean reproducibility obtained in our previous group, in which no intraoperative navigation was performed. According to these results, we can assume that simulation-guided navigation would be a helpful procedure during orthognathic surgery to improve reproducibility of the preoperative virtual surgical planning.

Oromandibular reconstruction using a fibula osteocutaneous free flap: four different "preplating" techniques.

BACKGROUND: The aim of oromandibular reconstruction following a partially or fully extended resection is to recreate the normal morphology with a mandibular profile as similar as possible to the original and to restore oral function. Oromandibular reconstruction can be performed with fibula osteocutaneous free flaps combined with the preplating technique. The authors report their experience using the preplating technique for oromandibular reconstruction. METHODS: Four different methods can be used to mold the titanium plate that will be used in reconstruction against the existing mandible before resection. The preplating technique was used in 18 patients between 1998 and 2003. In eight patients, the external cortical bone of the mandible was spared by the tumor and the vestibular preplating technique was used. In one patient, the internal cortical bone was unaffected and the lingual preplating technique was used. When the tumor affected both the internal and external cortical bones, the double preplating technique was adopted in eight cases and Luhr's approach was used in one case. RESULTS: A good cosmetic appearance was obtained through the accurate reconstruction of the inferior mandibular border. Mandible continuity was restored, and the masticatory and oral muscles were anchored to the titanium plate, resulting in good occlusal and functional rehabilitation. CONCLUSION: The preplating technique combined with a fibula microvascular free flap is a useful, predictable method for oromandibular reconstruction.