[Oral appliances for obstructive sleep apnoea: What can we expect?] / Orthèses d'avancée mandibulaire et syndrome d'apnées-hypopnées obstructives du sommeil : qu'en attendre ? Revue de la littérature, comparaison par design.

INTRODUCTION: Mandibular appliances are a treatment option for obstructive sleep apnea. There are many designs, but in the literature they tend to be grouped into a single entity without considering that efficiency, tolerance, compliance, or side effects are inherent in the design of each of them. A more detailed literature review is therefore warranted for the reader who wants to understand the relative effectiveness of each appliance. STATE OF KNOWLEDGE: We conducted a literature search using the "oral appliance" and "obstructive sleep apnea" criteria on Pubmed, Embase and Cochrane. This allowed us to compare outcome parameters by appliance class and to highlight the rare studies comparing different appliances. CONCLUSIONS: Mandibular appliances are not a homogeneous entity. Common use includes only appliances designed for propulsion (with rods and jacks) and retention. However, the few comparative studies available do not identify which are the most effective types or the types with an optimal efficacy/tolerance ratio. PERSPECTIVES: Further appliance comparison studies are needed to determine the most effective type or with an optimal efficacy/tolerance ratio.

Free Radical Production, Inflammation and Apoptosis in Patients Treated With Titanium Mandibular Fixations-An Observational Study.

Despite high biocompatibility of titanium and its alloys, this metal causes various side effects in the human body. It is believed that titanium biomaterials may induce an innate/adaptive immune response. However, still little is known about changes caused by titanium mandible implants, particularly with regard to bone healing. The latest studies showed disturbances in the antioxidant barrier, increased oxidative/nitrosative stress, as well as mitochondrial abnormalities in the periosteum covering titanium mandible fixations; nevertheless, the impact of titanium implants on free radical production, inflammation, and mandible apoptosis are still unknown. Because severe inflammation and apoptosis are among the main factors responsible for disturbances in osteointegration as well as implant rejection, this study is the first to evaluate pro-oxidant enzymes, cytokines as well as pro- and anti-apoptotic proteins in the periosteum of patients with a broken jaw, treated with titanium miniplates and miniscrews. The study group consisted of 29 patients with double-sided fracture of the mandible body requiring surgical treatment. We found significantly higher activity of NADPH oxidase and xanthine oxidase as well as enhanced rate of free radical production in the periosteum of patients in the study group compared to the control group. The markers of inflammation [interleukin 1 (IL-1), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), transforming growth factor ß (TGF-ß) and ß-glucuronidase (GLU)] as well as apoptosis [Bax, Bax/Bcl-2 ratio, caspase-3 (CAS-3) and nitric oxide (NO)] were significantly elevated in periosteum covering titanium fixations compared to the control group. In the study group, we also demonstrated an increased content of titanium on the periosteum surface, which positively correlated with CAS-3 activity. The study led us to the conclusion that titanium mandible implants increase the production of pro-inflammatory cytokines, and enhance free radical generation in the periosteum covering titanium miniplates and miniscrews. Additionally, exposure to Ti6Al4V titanium alloy induces apoptosis in the mandible periosteum. However, no clinical signs of the said phenomena have been observed.

Foreign Body Giant Cell Reaction to a Proplast/Teflon Interpositional Implant: A Case Report and Literature Review.

After discectomy, interpositional implants (IPIs) are believed to provide temporomandibular joint stability and protect against degenerative joint space remodeling. Alloplastic IPIs gained popularity in the late 1970s because the practice showed early success without donor site morbidity. Unfortunately, these implants were subject to substantial fragmentation resulting in an exuberant foreign body giant cell response that progressively eroded adjacent structures. Most of these alloplastic implants were removed in the years following their recall by the US Food and Drug Administration in 1991, however some remained in circulation. This report describes a case of a failed Proplast/Teflon IPI 27 years after its placement. This case highlights the considerations for managing a patient with a Proplast/Teflon IPI and serves to remind providers that, although increasingly rare, these implants are still present and subject to delayed failure.

Adverse Local Tissue Responses to Failed Temporomandibular Joint Implants.

PURPOSE: The purpose of this study was to determine whether failed alloplastic temporomandibular joint replacement (TMJR) devices can elicit the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) reaction seen in some patients with metal-on-metal hip arthroplasties. MATERIALS AND METHODS: This study involved analysis of paraffin-embedded sections of peri-implant tissue from failed TMJ implant cases obtained from 3 independent sources. Hematoxylin and eosin staining, conventional and polarized light microscopy, back-scattered electron imaging, and energy-dispersive x-ray analysis were used. Immunohistochemical methods were used to identify T and B lymphocytes and macrophages. RESULTS: The total TMJR device specimens showed primary macrophage and lymphocytic responses similar to responses reported previously for failed total hip implants, including ALVAL. No chronic or acute inflammation was apparent in the failed hemiarthroplasty TMJR cases. CONCLUSION: In this limited preliminary study, the local tissue responses to the failed TMJR implants showed similar primary macrophage and lymphocyte responses to previously reported failed metal-on-metal and metal-on-polyethylene orthopedic total joint replacement devices. No such local inflammatory responses were seen with the failed TMJR hemiarthroplasty devices.

Antibacterial Effect of Bacteriocin Isolated From Lactobacillus Plantarum ATCC 8014 on Postoperative Infection of Mandibular Fracture In Vivo.

OBJECTIVE: The primary objective of this study was to verify the effects of bacteriocin in treatment of postoperative infection of mandibular fracture in vivo. METHODS: Eighty-two mice were inoculated intravenously with staphylococcal suspensions. Bacterial cultures were obtained from implants. Blood samples were collected at 1, 2, 4, 6, and 8 hours after the injection of bacteriocins. RESULTS: Bacteriocins have significant inhibitory effects on Staphylococcus aureus (P < 0.05) and there are significant differences interleukin (IL)-8 and IL-10 in serum (P < 0.05). CONCLUSIONS: Bacteriocin isolated from L plantarum may be one of promising ways to control postoperative infection of mandibular fracture in vivo.

Severe bone resorption in expanded polytetrafluoroethylene chin augmentation.

Expanded polytetrafluoroethylene implant is usually considered as a wonderful implant for chin cosmetic augmentation with no or less bone resorption compared with solid silicone implant. However, one severe bony erosion in expanded polytetrafluoroethylene chin augmentation was found in our clinical work. We consider that the possible reason about severe bone resorption in such situation is most relative to the mentalis muscle hyperactivity, rather than the kinds of materials. We also strongly advise that genioplasty is suitable for the cases with mentalis muscle hyperactivity caused by a dentofacial deformity.

Latissimus dorsi (LD) free flap and reconstruction plate used for extensive maxillo-mandibular reconstruction after tumour ablation.

PURPOSE: The purpose of this study was to consider the indications and evaluate the clinical advantages and disadvantages including, results and complications, of immediate reconstruction using a latissimus dorsi (LD) free flap and reconstruction plate (R-plate) in advanced oro-mandibular tumour resection. METHODS AND MATERIALS: Our cohort included 116 patients who underwent LD free flap and R-plate reconstruction. Flap survival, postoperative function, donor/recipient site complication and aesthetics were evaluated. RESULTS: Our series demonstrated a 99.1% flap survival rate. One case required a contralateral LD free flap reconstruction after the initial flap failed due to pedicle kinking. Twelve patients needed the plate to be removed and replaced (n=4, plate fracture; n=2, plate exposure) or definite reconstruction with free fibular flap and implant installation. Donor site complications included seroma accumulation, scarring, and discomfort of the shoulder girdle. The size of the skin paddle ranged from 6 × 10 cm to 12 × 18 cm (12 were double paddled).The facial contour was acceptable without sagging of the flap. The flap was tolerant to irradiation and was resistant to the exposure of the plate at the symphyseal arch. CONCLUSION: Our series of primary reconstruction with LD free flaps and R-plates showed the retention of mandibular function and the reconstruction of considerably large soft tissue can be achieved successfully. This reconstruction scheme can be indicated for large-volume defects in the oro-mandibular area when the area cannot be covered by a single osteocutaneous free flap, has undergone extensive oncologic resection for advanced or high recurrence rate malignancy and when immediate postoperative chemotherapy and/or irradiation is necessary.

Prototyped flexible grafting tray for reconstruction of mandibular defects.

In our previous studies, prototyped individual bone-grafting trays have been used to restore discontinuous mandibular defects. However, the attempts have shown that the trays have shielded the graft from stress, which caused considerable resorption of bone. To eliminate the shielding, we designed a flexible tray. Finite element analysis was used to compare the distribution of strain on the bone grafts that were placed in flexible and conventional trays. The analogue computation suggested that most of the strain on the graft in the flexible tray resulted in a beneficial mechanical environment, while in the conventional tray more than half of graft was in the lowest class of strain (disuse - <50 µstrains). Animal experiments were conducted on hybrid dogs, and the prototype flexible tray was used to carry particles of autologous cancellous iliac bone to reconstruct a 40 mm defect in the mandibular body. Sequential radionuclide bone imaging was used to monitor the bone metabolism. Animals were killed at 4, 12 and 24 weeks, and specimens processed for quantitative histological examination. The data from the flexible trays were compared with those from the conventional trays, as in our previous study. The results showed that bone metabolism was more active in the flexible tray than in the conventional tray during the early stages. There was increased bony adaptation in the flexible tray. These results indicate that the flexible tray can efficiently eliminate the shielding from stress, and allow more occlusive force to be conducted on to the bone graft, which results in better remodelling of the graft.

Silicone implant for chin augmentation mimicking a low-grade liposarcoma.

The silicone implant has been widely used in facial aesthetic surgery for chin augmentation. A case of a 71-year-old woman with a lesion in the anterior mandibular region detected by radiographies and suggestive of benign soft tissue tumor is presented. The patient denied previous surgical intervention in the mental area. A biopsy was performed and initially interpreted as low-grade liposarcoma. After an immunohistochemistry study showing CD-68-positive cells and complementary information regarding a silicone implant for chin augmentation, the definitive diagnosis was silicone granuloma. This case reinforces that silicone implant in the mandibular region can be misdiagnosed as malignant tumor and the correct diagnosis is heavily dependent on close collaboration between clinician and pathologist in order to avoid unnecessary surgical intervention.

Modular endoprosthesis for mandibular body reconstruction: a clinical, micro-CT and histologic evaluation in eight Macaca fascicularis.

This paper presents the results of an animal experiment, in which a modular endoprosthesis is tested to replace a resected part of the mandible. The prostheses were fixed with polymethacrylate (PMMA) cement into the medullar space of the stumps. Clinical, radiologic, micro-computed tomographic and histologic evaluations were made after 3 and 6 months on four Macaca fascicularis for each implantation time. The prosthesis had not loosened but there were some loose screws that had caused fistulas in three animals. The stems of the modules were stably fixed with PMMA cement, surrounded by a fibrous capsule with inflammatory cells. This capsule was thinner in the 6-month group and showed less inflammatory infiltrate compared with the 3-month group; this was not statistically significant. There was an increase in woven bone surrounding the modules after 6 months. After 3 months of implantation, there was a considerable inflammatory reaction in the soft tissues surrounding the module, which subsided over following 3 months. The results are encouraging, but a longer period of follow-up is required to assess its application in a clinical setting, and some design drawbacks need to be addressed.

Management of a patient with a failed transmandibular implant.

UNLABELLED: The Transmandibular Implant System (TMI) had been developed in order to provide a patient with a severely resorbed mandible with a stable and retensive implant-supported overdenture. Failure of the transmucosal posts may necessitate removal of the transmandibular implant in total and treatment with an implant-supported prosthesis. The purpose of this paper is to describe overcoming failure of a transmandibular implant without removal and synchronous placement of endosseous dental implants in the interforaminal region, providing an implant-retained overdenture to the patient. CLINICAL RELEVANCE: Transmandibular implants are rarely used nowadays and management of a failed transmandibular implant is reported even less often. Where bone height is adequate, dental implants may be placed in the anterior mandible, even when the failed transmandibular implant is not completely removed.

Reconstruction of large defects postmandibulectomy for oral cancer using plates and myocutaneous flaps: a long-term follow-up.

A series of 28 consecutive cases of mandibular reconstruction by means of reconstructive plates and myocutaneous flaps were reviewed. In all cases mandibular resection was indicated for treatment of squamous cell carcinoma of the oral cavity: 25 pelviglossomandibulectomies (resulting in large defects from the angle of the mandible), 2 Commando operations (resulting in lateral defects) and 1 anterior sectional mandibulectomy (resulting in an anterior defect). Tumour stages were T1-T2 (4 cases) and T3-T4 (24 cases). Success was defined as plate maintenance 6 months' postoperatively/postradiotherapy. The overall success rate was 32.2%. Lateral-centre-lateral (L-C-L) defects had 32% success, L (lateral) defects had 50% success and in the single case of a C (centre) defect, the plate was not maintained. Stainless steel reconstruction plates showed a similar success rate as titanium plates (30% versus 34%). In cases not submitted to radiotherapy there were more maintained plates than in cases that received radiotherapy (45.5% versus 23.6%). Reconstruction plates are not effective in bridging large defects of the resected mandible. Only in selected cases that are not eligible for microvascular free flaps should plates and myocutaneous flaps be considered as an option for mandibular reconstruction.

Removal of miniplates in maxillofacial surgery: a follow-up study.

PURPOSE: We sought to follow-up a cohort of patients who had miniplates (plates) inserted in the oral and maxillofacial region during a 13-month period over 4 years to study the incidence and factors associated with plate removal. PATIENTS AND METHODS: One hundred fifty-three patients had plates inserted in the oral and maxillofacial region in the Department of Oral & Maxillofacial Surgery, University Hospital Birmingham, UK, between November 1, 1998, and November 30, 1999. All 153 patients' records were revisited on or after October 31, 2002, giving a minimum follow-up of 3 years and a maximum of 4 years. RESULTS: During a period of 13 months (November 1, 1998 through November 30, 1999), 308 plates were inserted into 153 patients. A total of 32 plates were removed from 21 patients by October 31, 2002, (10.4%) over 4 years; 27 plates were removed from 16 patients for purely plate-related symptoms, with infection being the most common cause accounting for 16 plates (50%) in 9 patients. Symptoms necessitating plate removal occurred within 52 weeks after insertion in 16 patients, accounting for 23 of the plates removed (72%). The age of the patient at plate insertion may have some influence on plate removal but this was not significant. Seniority of the operator did not affect plate removal. CONCLUSION: Our experience with the removal of miniplates compares with previously published reports. Longitudinal follow-up at 4 years indicates that plate-related problems leading to removal are likely to occur in the first year after insertion.

[Retrospective analysis of 30 cases of mandibular ameloblastoma operated in the Ivory coast from 1992 to 2000]. / Etude rétrospective de 30 cas d'améloblastome mandibulaire opérés en Côte d'Ivoire de 1992 à 2000.

OBJECTIVE: We analyzed a retrospective series of 30 cases of ameloblastoma operated in the Ivory coast from 1992 to 2000. PATIENTS AND METHODS: The following techniques were used--temporary reconstructions via the endobuccal approach using a Peri prothesis in 27 cases and a resin coated Peri prosthesis in one;-- definitive reconstructions using iliac bone grafts in 3 cases and rib grafts in 14. These reconstructions were performed in a second operation via a cutaneous approach to replace the Peri prosthesis. Thirteen patients were lost to follow-up for this second phase. Mean follow-up ranged from 6 months to 13 months (mean 9.9 months). RESULTS: Satisfactory outcome was acchevied when mouth opening was greater than 10 mm and patients with an acceptable cosmetic result no longer complained of mastication or phonation problems. There were four postoperative infections after bone graft reconstruction (two of them were immediate reconstruction). The resin coated Peri prosthesis led to a skin ulceration. DISCUSSION: This study demonstrated the interest of mandibular reconstruction in undermedicalized countries where indications are dominated by reconstruction after resection for ameloblastoma. The large number of patients lost to follow-up before the second stage bone grafts points out the need for immediate reconstruction using autologous bone. Further study in a larger series would be needed to determine the cause of failure after immediate reconstruction.

[Displacement of the titanium endoprosthesis of the mandibular condyle process towards the middle cranial fossa and method for its repair]. / Smeshchenie titanovogo éndoproteza myshchelkovogo otrostka nizhnei cheliusti v storonu srednei cherepnoi iamki i sposob ego ustraneniia.

A clinical case is presented: endoprosthesis of the articular depression of the temporomandibular joint (TMJ) was used in the treatment of a patient with a complication which developed several years after insertion of an isolated endoprosthesis of the mandibular condylar process. This case is presented as a proof of the efficiency of a complete TMJ endoprosthesis.

Long-term functional outcome of mandibular reconstruction with stainless steel AO reconstruction plates.

Mandibular continuity defects are usually reconstructed with bone grafts. However, factors associated with the tumour and the patient can still be reasons to choose reconstruction plates. The aim of this study was to find out the results of mandibular reconstructions with stainless steel AO reconstruction plates after a long follow-up period. The records of 36 patients were reviewed for personal data and the history of disease, treatment and complications. Patients with failed reconstructions were compared with those in whom the procedure had been successful. Patients and surgeons gave their opinion on the functional and cosmetic results. The mean follow-up was 39 months (range 4-99); 4 patients were withdrawn because they developed early recurrent disease and in 17 patients the reconstruction failed. We found no significant differences between the successful and the failed group. Fourteen patients could be evaluated for functional outcome, 10 of whom were totally or satisfactorily rehabilitated. Therefore, stainless steel reconstruction plates can be used in patients when other options are inappropriate.

The fate of osseointegrated implants in patients following oral cancer surgery and mandibular reconstruction.

BACKGROUND: The feasibility of implant treatment in patients after oral ablative tumor surgery and defect reconstruction has not yet been investigated in terms of the requisite high standards of success assessment. A report on this topic must address not only implant survival but implant health, bone response, soft tissue health, failure pattern, and time of failure, as well. METHODS: From June 1990 through December 1997, 90 patients received 320 dental implants after oral tumor resection and immediate soft tissue reconstruction. Included in the study were 45 patients with 162 implants loaded for at least 1 year. Regular follow-up for 6 years consisted of detailed medical history and evaluation of periodontal parameters. Out of this population, 10 vascularized iliac bone grafts for mandibular reconstruction containing loaded implants were selectively evaluated for bone loss. RESULTS: The assessment of pocket probing depths, plaque accumulation, bleeding disposition, implant mobility by means of the Periotest method applied to the restoration type, horizontal and vertical (peri-implant) bone loss according to x-ray findings, causes and time of implant loss, and subjective statements offered results comparable to those found in healthy subjects examined with periodontal success parameters. CONCLUSION: Prosthetic restoration of patients after oral ablative tumor surgery followed by hard and soft tissue reconstruction can be achieved with dental implants with similar long-term efficacy as found in healthy subjects adhering to internationally established requirements.