Patrick J. Louis

Reconstruction of the Maxilla and Mandible With Particulate Bone Graft and Titanium Mesh for Implant Placement

PURPOSE The purpose of the study was to evaluate the magnitude of ridge augmentation with titanium mesh, overall graft success, anatomic location of ridge defects and their relationship to mesh exposure. MATERIALS AND METHODS This retrospective study evaluated 44 patients who received mandibular or maxillary reconstruction with autogenous particulate bone graft and titanium mesh for the purpose of implant placement. Autogenous bone graft was harvested from the iliac crest, tibia, and mandibular symphysis. A total of 45 sites were included in the study. Average augmentation bone heights were measured and compared. Statistical analysis was done with ANOVA and Students t test. Histomorphometric analysis was performed on the soft tissue specimen found between the mesh and the bone graft. RESULTS Twenty-nine sites underwent mandibular reconstruction and 16 underwent maxillary reconstruction. The mean augmentation in partial maxillary defects was 11.33 +/- 1.56 mm, and in complete maxillary augmentation, the height achieved was 14.3 +/- 1.39 mm. In the mandible, mean increase in height for partial defects was 14 +/- 1.42 mm and for complete augmentation it was 13.71 +/- 1.14 mm. The mean augmentation for all sites was 13.7 mm (12.8 mm in the maxilla and 13.9 mm in the mandible). A total of 82 implants were placed in the maxilla and 92 implants were placed in the mandible. In the maxillary group, 7 sites had exposure of the titanium mesh and 16 sites were exposed in the mandible. The success of the bone grafting procedure was 97.72%. CONCLUSIONS Porous titanium mesh is a reliable containment system used for reconstruction of the maxilla and the mandible. This material tolerates exposure very well and gives predictable results.

Long-term skeletal stability after rigid fixation of Le Fort I osteotomies with advancements

The purpose of this retrospective study was to evaluate relapse, comparing large and small maxillary advancements with four-plate rigid fixation and without bone grafting. All patients had obstructive sleep apnea, and underwent bimaxillary surgery. Standardized cephalometric analysis by two separate examiners was performed on serial radiographs of 20 patients immediately before surgery, and at 1 week and at least 6 months postoperatively (mean 18.5 months). The group was divided into three subsets to determine whether the magnitude of maxillary advancement correlated with the magnitude of relapse. In group 1 (< or = 6 mm, n = 4), the average advancement was 4.7 +/- 0.8 mm, with a mean relapse of 0 +/- 0.6 mm. In group 2 (7-9 mm, n = 9), the average advancement was 8.2 mm +/- 0.9, with a mean relapse of 0.7 +/- 1.5 mm. In group 3 (> or = 10 mm, n = 7), the mean advancement was 12.3 +/- 2.8 mm, with a mean relapse of 1.9 +/- 1.8 mm. There was no statistical difference in the measured relapse among the groups.

Barrier membranes used for ridge augmentation: is there an optimal pore size?

PURPOSE To identify the optimal pore size of barrier membranes for successful alveolar ridge reconstruction procedures, to determine if cortical perforations have any effect on bone regeneration, and to reiterate that bone graft containment is an important parameter for successful regeneration. MATERIALS AND METHODS This was a prospective, randomized, controlled study performed on hound dogs. Corticocancellous tibial bone grafting was performed to the lateral border of the mandible and protected with barrier membranes (meshes). The experiment analyzed three different pore sized meshes, compared with controls without the mesh. Two meshes (macroporous and microporous) were made of titanium, and one was a resorbable mesh. Meshes were preformed into the shape of a cube with one face open. Each side of the cube measured approximately 10 mm. Cubes were open-faced on one side, to facilitate packing of the graft material. The dogs received bilateral ramus grafts. Cortical perforations were created on the left ramus of all the dogs and compared with the right side, which did not have perforations. The dogs were randomly divided into 3 groups and sacrificed at intervals of 1, 2, and 4 months. Before sacrifice, all dogs received 2 doses of tetracycline as a marker for new bone formation. Histomorphometry was performed by using Bioquant image-analysis software. Areas of new bone and soft tissue were measured. The rate of mineral apposition was also calculated. All values obtained via histomorphometry were statistically analyzed with a t test. RESULTS Thirty-one experimental sites were evaluated. The amount of new bone growth into the macroporous mesh was significantly higher than in the other groups. The mean area of new bone formation in large and small meshes was 66.26 +/- 13.78 mm(2) and 52.82 +/- 24.75 mm(2), respectively. In the resorbable mesh group, the mean area of new bone formed was 46.76 +/- 21.22 mm(2). The amount of new bone formed in the control group was 29.80 +/- 9.35 mm(2). There was no significant difference in amount of bone formation between left and right sides (P = .3172). Resorbable meshes had significant soft tissue ingrowth (23.47 mm(2)) compared with macroporous mesh (16.96 mm(2)) and microporous mesh (22.29 mm(2)). Controls had the least amount of soft tissue ingrowth (9.41 mm(2)). Mineral apposition rate was found to be higher in the resorbable group (2.41 microm/day), and the rate was lowest (1.09 microm/day) in the large pore mesh group. CONCLUSION Macroporous membranes facilitated greater bone regeneration compared with microporous and resorbable membranes. Macroporous mesh also prevented significant soft tissue ingrowth compared with other meshes. Containment of a bone graft is the most critical parameter in successful bone regeneration. Cortical perforations did not have any effect on the quantity of regenerated bone. Further research should be directed toward identifying a critical pore size and manufacturing a reliable mesh that would prevent excessive soft tissue ingrowth in ridge augmentation procedures.

Vertical Ridge Augmentation Using Titanium Mesh

With tooth loss, there is increased bone loss of the alveolus. In some cases alveolar bone loss can be severe. Severe bone loss may cause difficulty for patients wearing a conventional prosthesis or being restored with dental implants. Severe alveolar bone loss can result in malnutrition, poor self-esteem, multiple dental visits for failed prosthesis, and jaw fracture. In many cases, patients with loss of alveolar bone height or width may require reconstructive procedures. Vertical ridge augmentation remains a challenge in the reconstruction of the atrophic maxilla and mandible. The main problem arises from the need to expand the soft-tissue envelope and achieve the proper bony architecture. Techniques that have been developed to solve or circumvent this problem include onlay bone grafting with particulate bone graft, block bone graft, barrier techniques with permanent or resorbable membranes, distraction osteogenesis, vascularized ridge splitting techniques, sinus lifts, nerve repositioning techniques, short implants, and angled implants. All of these techniques have advantages and disadvantages. This article focuses on augmentation procedures using titanium mesh, which acts as a barrier and physical support of the soft tissue over the bone graft.

Review and recommendations for the prevention, management, and treatment of postoperative and postdischarge nausea and vomiting

Patients have rated severe nausea to be worse than postoperative pain. The overall incidence of postoperative nausea and vomiting (PONV) is 25%-30% and can lead to delayed discharge and unanticipated hospital admission. After outpatient surgery, the overall incidence of postdischarge nausea has been reported to be 17% and of vomiting 8%, higher than nausea and vomiting reported during the procedure or recovery. Patients who experienced postdischarge nausea and vomiting (PDNV) were unable to resume normal daily activities as quickly. This paper addresses the frequency, pathophysiology and patient perception of PONV and PDNV and reviews antiemetics and adjunctive medications used for the prevention, management, and treatment of PONV and PDNV. For each, the indication, mechanism of action, adverse effects, drug interactions, and implications for oral surgery and outpatient sedation are provided. Because many antiemetics are available for prevention, management, and treatment of PONV and PDNV, optimal medication choices are important for each procedure and patient.

Revisiting the supraforaminal horizontal oblique osteotomy of the mandible.

PURPOSE Today, the most common orthognathic procedure for correction of mandibular deformities is the bilateral sagittal split osteotomy, also called sagittal ramus osteotomy. Permanent injury to the mandibular nerve (V3) is one of the main complications, with a reported incidence between 5% and 30%. Orthognathic surgery using sagittal ramus osteotomy of the mandible as the procedure of choice should be re-evaluated because of the complexity and the relatively high risk of damage to the inferior alveolar nerve. Surgical techniques that allow for accurate condylar positioning with a lower risk of inferior alveolar nerve injury should be considered. The aim of this study is to present a retrospective case series using the previously described horizontal osteotomy of the mandibular rami along with modern-day technical advances that make this procedure safe, reliable, and reproducible. MATERIALS AND METHODS We performed a modified approach to the supraforaminal horizontal oblique osteotomy of the mandible with a condylar positioning device, endoscopy, and a surgical navigation system. This technique was performed in 17 consecutive patients. Postoperatively, we measured the amount of surgical movement of the mandible, monitored the mandibular nerve, and evaluated bone healing during removal of the osteosynthesis plates. RESULTS In all 17 treated patients there was uneventful wound healing, and no patient had permanent nerve alteration. The mean movement of the mandible was 7.48 mm (SD, 2.1 mm), with a range from 3.0 to 10.5 mm. The mean follow-up was 19 months. The main purpose of the surgical navigation was the translation of the planned osteotomy line from the computed tomography scan to the surgical site during the operation. This was performed to prevent a large gap between the bone segments at the osteotomy site. CONCLUSION The supraforaminal approach with a condylar positioning device appears to be an appropriate way to prevent injury to the inferior alveolar nerve during orthognathic surgery of the mandible while maintaining centric positioning of the condyle and obtaining good bony union.

Surgical navigation in reconstruction.

Navigational systems are paramount in solving todays traffic dilemmas, and have important applications in the human body. Current imaging must be diagnostic and is often dictated by the radiologist, but it is up to the surgeon to consider surgical procedures and to decide in which case surgical navigation (SN) has advantages. Knowledge of the surgical capabilities of SN is indispensable. The aims of this article are to support real-time image-guided SN, present routine and advanced cases with precise preoperative planning, and show the scientific capabilities of SN.

Use of recombinant bone morphogenetic protein 2 in free flap reconstruction for osteonecrosis of the mandible.

PURPOSE Osteoradionecrosis of the mandible is a debilitating consequence of radiation therapy for head-and-neck malignancy. It can result in pain, bone exposure, fistula formation, and pathologic fracture. Recombinant human bone morphogenetic protein 2 (rhBMP-2) has shown promise in reconstruction of bone defects. The purpose of this study is to determine whether the addition of rhBMP-2 at the union of vascularized bone and native bone improves surgical outcomes in patients with osteonecrosis of the mandible. MATERIALS AND METHODS This study was a retrospective analysis of patients who were treated between 2006 and 2010 for osteonecrosis of the mandible. Patients requiring definitive reconstruction after failure of a course of conservative management were included. Patients were divided into 2 cohorts depending on whether rhBMP-2 was used during the reconstruction. The primary outcome measure was defined as stable mandibular union. RESULTS Seventeen patients were included. The development of malunion was similar in both groups (13% for rhBMP-2 group vs 11% for non-rhBMP-2 group). Infectious complications were similar between the groups (25% in rhBMP-2 group vs 56% in non-rhBMP-2 group, P = .33). The rates of hardware removal were similar for the 2 groups (33% in non-rhBMP-2 group vs 25% in rhBMP-2 group, P = .10). No cancer recurrences were observed in patients receiving rhBMP-2. CONCLUSIONS The use of rhBMP-2 is safe in free flap reconstruction of the mandible, but its ability to significantly improve patient outcomes, as measured by rates of malunion, reoperation, or infection, is still unknown.

Bone Grafting the Mandible

Many bone grafting techniques have been used to reconstruct the partially dentate and edentulous mandible. This article discusses the various bone grafting techniques to reconstruct mandibular defects. Also included are issues such as whether autogenous bone is necessary for reconstruction of the mandibular ridge and the importance of membranes.

Reconstruction of acquired temporomandibular joint defects.

Various conditions are responsible for the development of acquired temporomandibular joint (TMJ) defects, the reconstruction of which represents a unique challenge, as the TMJ plays an important role in the functioning of the jaw including mastication, deglutition, and phonation. Autogenous reconstructions such as costochondral or sternoclavicular joint graft continue to be the best option in children, owing to their ability to transfer a growth center. In adults, alloplastic reconstructions are a safe and predictable option. Vascularized tissue transfers have also become a popular and reliable way to restore these defects.