Implant Placement Using the Bone Ring Technique With and Without Membrane Placement: A Preclinical 12-Month Study in Dogs.

The bone ring technique is applied for vertical augmentation, in which the dental implant and autogenous block bone graft are simultaneously inserted. We investigated the healing of bone around implants placed simultaneously using the bone ring technique with and without membrane placement after a 12-month healing period. Vertical bone defects were created on both sides of the mandible of Beagle dogs. Implants were inserted into the defects through bone rings and fixed with membrane screws as healing caps. The augmented sites on one side of the mandible were covered with a collagen membrane. Samples were harvested 12 months after implantation and assessed histologically and by microcomputed tomography analysis. All implants remained throughout the healing period; however, except for 1 implant, they showed lost caps and/or exposure to the oral cavity. The implants had contact with newly formed bone despite frequent bone resorption. The surrounding bone appeared mature. The medians of bone volume and percentages of total bone area and bone-to-implant contact within the bone ring were slightly higher in the group with membrane placement than in that without membrane placement. Nevertheless, none of the evaluated parameters were significantly affected by the membrane placement. In the present model, soft tissue complication was frequent, and the membrane application did not reveal the effect at 12 months after implant placement using the bone ring technique. Sustained osseointegration and maturation of surrounding bone were observed in both groups after a 12-month healing period.

The Mandible Ameliorates Facial Allograft Rejection and Is Associated with the Development of Regulatory T Cells and Mixed Chimerism.

Vascularized composite allografts contain various tissue components and possess relative antigenicity, eliciting different degrees of alloimmune responses. To investigate the strategies for achieving facial allograft tolerance, we established a mouse hemiface transplant model, including the skin, muscle, mandible, mucosa, and vessels. However, the immunomodulatory effects of the mandible on facial allografts remain unclear. To understand the effects of the mandible on facial allograft survival, we compared the diversities of different facial allograft-elicited alloimmunity between a facial osteomyocutaneous allograft (OMC), including skin, muscle, oral mucosa, and vessels, and especially the mandible, and a myocutaneous allograft (MC) including the skin, muscle, oral mucosa, and vessels, but not the mandible. The different facial allografts of a BALB/c donor were transplanted into a heterotopic neck defect on fully major histocompatibility complex-mismatched C57BL/6 mice. The allogeneic OMC (Allo-OMC) group exhibited significant prolongation of facial allograft survival compared to the allogeneic MC group, both in the presence and absence of FK506 immunosuppressive drugs. With the use of FK506 monotherapy (2 mg/kg) for 21 days, the allo-OMC group, including the mandible, showed prolongation of facial allograft survival of up to 65 days, whereas the myocutaneous allograft, without the mandible, only survived for 34 days. The Allo-OMC group also displayed decreased lymphocyte infiltration into the facial allograft. Both groups showed similar percentages of B cells, T cells, natural killer cells, macrophages, and dendritic cells in the blood, spleen, and lymph nodes. However, a decrease in pro-inflammatory T helper 1 cells and an increase in anti-inflammatory regulatory T cells were observed in the blood and lymph nodes of the Allo-OMC group. Significantly increased percentages of donor immune cells were also observed in three lymphoid organs of the Allo-OMC group, suggesting mixed chimerism induction. These results indicated that the mandible has the potential to induce anti-inflammatory effects and mixed chimerism for prolonging facial allograft survival. The immunomodulatory understanding of the mandible could contribute to reducing the use of immunosuppressive regimens in clinical face allotransplantation including the mandible.

Local application of Usag-1 siRNA can promote tooth regeneration in Runx2-deficient mice.

Runt-related transcription factor 2 (Runx2)-deficient mice can be used to model congenital tooth agenesis in humans. Conversely, uterine sensitization-associated gene-1 (Usag-1)-deficient mice exhibit supernumerary tooth formation. Arrested tooth formation can be restored by crossing both knockout-mouse strains; however, it remains unclear whether topical inhibition of Usag-1 expression can enable the recovery of tooth formation in Runx2-deficient mice. Here, we tested whether inhibiting the topical expression of Usag-1 can reverse arrested tooth formation after Runx2 abrogation. The results showed that local application of Usag-1 Stealth small interfering RNA (siRNA) promoted tooth development following Runx2 siRNA-induced agenesis. Additionally, renal capsule transplantation of siRNA-loaded cationized, gelatin-treated mouse mandibles confirmed that cationized gelatin can serve as an effective drug-delivery system. We then performed renal capsule transplantation of wild-type and Runx2-knockout (KO) mouse mandibles, treated with Usag-1 siRNA, revealing that hindered tooth formation was rescued by Usag-1 knockdown. Furthermore, topically applied Usag-1 siRNA partially rescued arrested tooth development in Runx2-KO mice, demonstrating its potential for regenerating teeth in Runx2-deficient mice. Our findings have implications for developing topical treatments for congenital tooth agenesis.

Regeneración ósea con injertos intraorales: rama vs. mentón. Puesta al día / Bone regeneration with intraoral graft: ramus vs. chin. Updating

La utilización de injertos intraorales en bloque es una alternativa de tratamiento válida para la regeneración en anchura de defectos óseos maxilares y mandibulares. Sin embargo, actualmente no hay consenso entre los diferentes autores en la elección del mejor tipo de bloque intraoral a utilizar. Por ende, esta puesta al día busca comparar la ganancia ósea, la tasa de complicaciones postoperatorias y el éxito del injerto entre bloques autólogos de rama mandibular y mentón. La ganancia ósea alcanzada es similar en ambos bloques. No obstante, se podría deducir una mayor ganancia al utilizar bloques de la rama mandibular cuando son evaluados mediante CBCT. Además, la tasa de reabsorción ósea fue menor con los injertos de rama. La supervivencia de los implantes es equiparable con ambos tipos de injertos. Las complicaciones que tienen lugar, en orden de frecuencia, son las alteraciones sensoriales, las necrosis pulpares, dehiscencias y hemorragias; apareciendo con mayor frecuencia en los bloques de mentón. Además, el periodo de recuperación en las zonas de rama mandibular es más lento. De este modo, a la hora de la elección parece razonable individualizar el caso y tener en consideración aspectos como la morbilidad y el acceso a la zona donante. (AU)

The use of intraoral block grafts is a valid treatment alternative for the regeneration of maxillary and mandibular horizontal bone defects. However, there is currently no consensus among different authors on the choice of the best type of intraoral bone block to use. Therefore, this update seeks to compare bone gain, post-operative complication rate and grafting success between autologous mandibular ramus and chin bone block grafts. The bone gain achieved is similar in both block grafts. However, a higher gain can be observed by CBCT when using mandibular ramus blocks. In addition, the rate of bone resorption is lower with ramus grafts. Implant survival is comparable in both types of grafts. The complications that occur, in order of frequency, are sensory alterations, pulp necrosis, dehiscence and bleeding, appearing more frequently in chin blocks. In addition, the recovery period in the mandibular ramus areas is slower. Thus, when choosing, it seems reasonable to individualize the case and take into consideration aspects such as morbidity and access to the donor area. (AU)

Quantifying Free Fibula Flap Growth After Pediatric Mandibular Reconstruction.

INTRODUCTION: The free fibula flap (FFF) is a preferred option for adult mandibular reconstruction. Due to skeletal immaturity, its routine use in pediatric patients remains in question. Inconsistencies regarding the ability of the FFF to grow in concordance with the patients' natural growth currently exist in the literature. The purpose of this report is to quantify mandibular growth in a young patient undergoing partial hemi-mandibular reconstruction with a FFF utilizing advanced three-dimensional software. METHODS: A 2-year old underwent left hemi-mandibular reconstruction with a FFF following resection of a desmoid tumor. The condyle was preserved. Using 3D software, changes in mandibular growth and morphology were evaluated based on preoperative (2.1 years old) and postoperative (2.5 years and 5.2 years old) computed tomography imaging. RESULTS: Mandibular growth occurred throughout the mandible in both postoperative evaluations. Greatest growth was seen in the ramus height. Fibula growth was also seen when comparing measurements to the virtual surgical planning guide. A novel parts comparison analysis revealed the greatest growth potential occurred at the condyle. CONCLUSION: Providing an objective evaluation using 3D software, we have demonstrated growth throughout the reconstructed mandible, with greatest growth occurring at the preserved condyle. Despite scientific limitations of our study, the potential for mandibular growth appears to remain after FFF reconstruction, offering successful functional and cosmetic outcomes.

Teriparatide (recombinant parathyroid hormone 1-34) enhances bone allograft integration in a clinically relevant pig model of segmental mandibulectomy.

Massive craniofacial bone loss poses a clinical challenge to maxillofacial surgeons. Structural bone allografts are readily available at tissue banks but are rarely used due to a high failure rate. Previous studies showed that intermittent administration of recombinant parathyroid hormone (rPTH) enhanced integration of allografts in a murine model of calvarial bone defect. To evaluate its translational potential, the hypothesis that rPTH would enhance healing of a mandibular allograft in a clinically relevant large animal model of mandibulectomy was tested. Porcine bone allografts were implanted into a 5-cm-long continuous mandible bone defect in six adult Yucatan minipigs, which were randomized to daily intramuscular injections of rPTH (1.75 µg/kg) and placebo (n = 3). Blood tests were performed on Day 56 preoperation, Day 0 and on Day 56 postoperation. Eight weeks after the surgery, bone healing was analyzed using high-resolution X-ray imaging (Faxitron and micro computed tomography [CT]) and three-point bending biomechanical testing. The results showed a significant 2.6-fold rPTH-induced increase in bone formation (p = 0.02). Biomechanically, the yield failure properties of the healed mandibles were significantly higher in the rPTH group (yield load: p < 0.05; energy to yield: p < 0.01), and the post-yield displacement and energy were higher in the placebo group (p < 0.05), suggesting increased mineralized integration of the allograft in the rPTH group. In contrast to similar rPTH therapy studies in dogs, no signs of hypercalcemia, hyperphosphatemia, or inflammation were detected. Taken together, we provide initial evidence that rPTH treatment enhances mandibular allograft healing in a clinically relevant large animal model.

Full Facial Allotransplantation Including the Temporomandibular Joints: A Radiologic and Anatomical Cadaveric Study.

BACKGROUND: Facial allotransplantation including the temporomandibular joints may improve the functional outcomes in face transplant candidates who have lost or damaged this joint. METHODS: Linear and angular measurements were taken in 100 dry skulls and mandibles and in 100 three-dimensionally-reconstructed facial computed tomographic scans to determine the variability of the temporomandibular joint, glenoid fossa, and mandible. A vascular study was performed in six fresh cadaveric heads, followed by harvest of the face allograft in three heads. Next, four heads were used for mock transplantation (two donors and two recipients). The full facial allograft included four different segments: a Le Fort III, a mandibular tooth-bearing, and two condyle and temporomandibular joint-bearing segments. Statistical analysis was performed using SAS software. RESULTS: In only one-third of the skulls, the condylar shape was symmetric between right and left sides. There was a wide variability in the condylar coronal (range, 14.3 to 23.62 mm) and sagittal dimensions (range, 5.64 to 10.96 mm), medial intercondylar distance (range, 66.55 to 89.91 mm), and intercondylar angles (range, 85.27 to 166.94 degrees). This high variability persisted after stratification by sex, ethnicity, and age. The temporomandibular joint was harvested based on the branches of the superficial temporal and maxillary arteries. The design of the allograft allowed fixation of the two condyle and temporomandibular joint-bearing segments to the recipient skull base, preserving the articular disk-condyle-fossa relationship, and differences were adjusted at the bilateral sagittal split osteotomy sites. CONCLUSION: Procurement and transplantation of a temporomandibular joint-containing total face allograft is technically feasible in a cadaveric model.

Evaluation of bone availability for grafts in different donor sites, through computed tomography.

OBJECTIVE: To quantify the bone volume that can be safely withdrawn from 3 donor sites: (1) the mandibular symphysis, (2) the oblique mandibular line and (3) the skullcap. METHODOLOGY: For the symphysis, 200 tomographic exams were evaluated by the extension of the anterior loop of mental foramen, by the nerve, by the distance of the foramens, by the distance between the vestibular cortical and the lingual plates and by the distance between the apexes, or lower anterior teeth, and the mandibular base, using the "distance" tool of the I-CAT Vision, in the panoramic and parasagittal reformations. For the oblique line, 70 TCFC exams were analyzed retrospectively in panoramic and parasagittal reformations, evaluating the thickness of the vestibular cortical and the distance between the cortical and the mandibular canal. For the cranial bone, a hexagonal donor site located in parietal area was considered. RESULTS: The average dimensions of the bone blocks that can be safely removed from the region of the mandibular symphysis are: 32.27 mm in length, 4.87 mm in height and 4 mm in thickness, providing a volume of 628.61 mm3 available for grafting. In the oblique line, the available bone volume for grafting was 859.61 mm3. In the region of the cranial vault, multiplying the average bone thickness by the area of the hexagon, an average volume of 2,499 mm3 was obtained. CONCLUSIONS: Comparing the donor sites, the bone availability in the cranial vault is 3 times greater than in the mandibular posterior region, and at least 2 times greater than in the mandibular symphysis.

Evaluation of bone availability for grafts in different donor sites, through computed tomography

Abstract Objective To quantify the bone volume that can be safely withdrawn from 3 donor sites: (1) the mandibular symphysis, (2) the oblique mandibular line and (3) the skullcap. Methodology For the symphysis, 200 tomographic exams were evaluated by the extension of the anterior loop of mental foramen, by the nerve, by the distance of the foramens, by the distance between the vestibular cortical and the lingual plates and by the distance between the apexes, or lower anterior teeth, and the mandibular base, using the "distance" tool of the I-CAT Vision, in the panoramic and parasagittal reformations. For the oblique line, 70 TCFC exams were analyzed retrospectively in panoramic and parasagittal reformations, evaluating the thickness of the vestibular cortical and the distance between the cortical and the mandibular canal. For the cranial bone, a hexagonal donor site located in parietal area was considered. Results The average dimensions of the bone blocks that can be safely removed from the region of the mandibular symphysis are: 32.27 mm in length, 4.87 mm in height and 4 mm in thickness, providing a volume of 628.61 mm3 available for grafting. In the oblique line, the available bone volume for grafting was 859.61 mm3. In the region of the cranial vault, multiplying the average bone thickness by the area of the hexagon, an average volume of 2,499 mm3 was obtained. Conclusions Comparing the donor sites, the bone availability in the cranial vault is 3 times greater than in the mandibular posterior region, and at least 2 times greater than in the mandibular symphysis.

Assessing the accuracy of computer-planned osteotomy guided by stereolithographic template: A methodological framework applied to the mandibular bone harvesting.

Intraoral autologous bone grafting represents a preferential choice for alveolar reconstruction prior to dental implant placement. Bone block harvesting guided by a computer-planned lithographic template is a novel and promising technique for optimizing the volume of harvested material, while controlling the osteotomy 3D position with respect to delicate anatomical structures. We provide a quantitative framework to non-invasively estimate the accuracy of this technique. In the proposed framework, the planned osteotomy geometry was compared to the real outcome of the procedure, obtained by segmentation of post-procedural cone beam computed tomography data. The comparison required the rigid registration between pre and post-procedural mandibular models, which was automatically accomplished by minimizing the sum of squared distances via a stochastic multi-trial iterative closest point algorithm. Bone harvesting accuracy was quantified by calculating a set of angular and displacement errors between the planned and real planes which characterized the excision block. The application of the framework to four cases showed its capability to quantify the tolerance associated with computer-guided bone harvesting techniques with submillimetric accuracy (<0.4 mm), within the limits of native image resolution. The validation methodology proved suitable for defining the safety margins of osteotomy surgical planning.

A New Face Subunit Transplant Model in Mice, Containing Skin, Mandible, and Oral Mucosa for Future Face Vascularized Composite Allotransplantation Studies.

BACKGROUND: In immunologic research, mice have advantages over other animals, such as low costs, easy handling, suitable life cycle, and adequate laboratory resources. However, vascularized composite allotransplantation surgery using mice is not popular, partly because of technical difficulties and high mortality rates. The authors' goal was to demonstrate a face transplantation model in mice that includes skin, mandible, and oral mucosa. METHODS: The authors developed a new syngeneic face transplantation model composed of skin, mandible, teeth, and oral mucosa in C57BL/6 mice. The following assessment included measuring the length of the right incisor on the transplanted mandibles, computed tomographic scan in one mouse for mandibular structure evaluation, and histologic examination of different tissue samples in another mouse for viability evaluation. RESULTS: The authors performed five consecutive transplantations. The donor vessels were the common carotid artery (approximately equal to 0.4 mm) and the anterior facial vein (approximately equal to 0.2 mm), and the recipients were the common carotid artery and the posterior facial vein (approximately equal to 0.4 mm). The mean operative time was 80 minutes for the donor and 123 minutes for the recipient. There were neither flap failures nor animal deaths. The follow-up was 6 months. The right incisor of the transplant grew at different rates in all cases. Histologic samples showed viability in all tissues, including mandibular bone marrow. Computed tomography demonstrated normal structure of the transplanted bone. CONCLUSION: The authors' syngeneic partial face transplantation model in mice, which included skin, oral mucosa, and mandible with teeth, should be useful for future face allotransplantation research, as the myriad of tissues it provides, of different immunomodulatory functions, is similar to that in the clinical scenario.

The feasibility of rib grafts in long span mandibular defects reconstruction: A long term follow up.

AIMS: To evaluate the efficiency of reconstruction of long span mandibular defects using split rib bundle bone graft. MATERIALS AND METHODS: Six hundred patients with long span mandibular defects (more than 6 cm long), following resection of aggressive mandibular tumours, were reconstructed with split rib bundle bone graft technique. Immediate reconstruction was performed in all patients. A reconstruction plate was used to support the graft. Two ribs were harvested from the right side of the chest, split into four halves and used to restore the continuity of the mandible. The inclusion criterion was post-surgical mandibular bony defects without soft tissue deficiency. Defects with a history of previous or need of future irradiation were excluded. RESULTS: The appearance of the patients was accepted in 550 patients. Functional reconstruction was done in 320 patients by osseointegrated dental implants (after 15 months), and removable prosthesis in 150 patients. Infection was minor in 31 patients, moderate in 47 patients and severe in 42 patients. Partial loss of graft, up to 25%, due to moderate infection was reported. Total or near total loss of graft due to severe infection was corrected by reoperation six months later. CONCLUSIONS: This technique is simple, safe, and can be effectively used to reconstruct long-span mandibular defects with minimal complications in selected patients.

Maxillary Sinus Floor Augmentation With Autogenous Bone Graft From the Ascending Mandibular Ramus.

PURPOSE: The objective of the present study was to assess patient satisfaction and esthetic implant outcome 10 years after maxillary sinus floor augmentation with autogenous bone graft from the mandibular ramus. MATERIALS AND METHODS: Maxillary sinus floor augmentation with autogenous bone graft from the mandibular ramus was conducted in 48 consecutive patients from 2002 to 2006. Records and radiographs were retrospectively analyzed. Twenty-four patients including 34 sinus augmentation procedures and 37 implants were evaluated after 10 years. Subjective and professional evaluations of the final periimplant soft tissue, implant crown, and total implant treatment were conducted. RESULTS: The 10-year survival of suprastructures and implants was 84% and 100%, respectively. The patients were highly satisfied with the esthetic and implant treatment outcome expressed by scores >90 on the visual analog scale. Most implants were characterized by scores of 1 or 2, resulting in a mean pink esthetic score of 9 (maximum 14) and a white esthetic score of 8 (maximum 10). CONCLUSION: Maxillary sinus floor augmentation with autogenous bone graft is characterized by high long-term implant survival rate and patient satisfaction.

Stress distribution in mandibular donor site after harvesting bone grafts of various sizes from the ascending ramus of a dentate mandible by finite element analysis.

PURPOSE: Harvesting bone from the ascending ramus of the mandible is a common procedure. However, mandibular fracture may occur after grafting bone blocks. This study aimed to investigate the resulting force distribution of stress and strain in the mandibular donor site after harvesting bone grafts of different sizes and various loadings. METHODS: Finite element analysis was performed for virtual harvesting of bone blocks of nine different sizes between 15 × 20 and 25 × 30 mm and three different chewing loads (incisal, ipsilateral and contralateral). von Mises stress and first principal stress distributions were measured. RESULTS: von Mises stress was distributed between 35.01 (10 × 15 mm graft, incisal load) and 333.25 MPa (30 × 20 mm graft ipsilateral load), whereas first principal stress distributions were between 48.27 (10 × 15 mm graft, incisal load) and 414.69 MPa (30 × 20 mm graft ipsilateral load). In general, the least stress was observed with incisal load followed by ipsilateral load and finally contralateral load. The critical value of 133 MPa was found after removing almost all grafts with a width of 20 or 30 mm. CONCLUSIONS: Incisal loading led to less stress compared with contralateral and ipsilateral loads. Increasing graft size led to increasing weakness of the donor site. Graft width exerted a greater influence on stress development than its height. CLINICAL RELEVANCE: Ipsilateral chewing and increasing width of the bone graft result in maximum stress in the mandibular donor side, and critical values regarding to the possibility of fractures are already to expect from a graft size of 20 × 15 mm.

Anesthesia Considerations in Modified Osteo-odonto-keratoprosthesis.

PURPOSE: To elucidate anesthesia-related challenges in patients who underwent modified osteo-odonto-keratoprosthesis (MOOKP). DESIGN: Retrospective cohort study. METHODS: Medical records of consecutive patients who underwent MOOKP surgery between January 2007 and January 2015 were reviewed. Data including demographic details, systemic comorbidities, indications for MOOKP, and anesthesia techniques at various stages of MOOKP were collected and analyzed. RESULTS: A total of 74 patients (47 men, 27 women) were included in this study. The mean age of the patients was 29.7 ± 9.1 years. The most common indication for MOOKP was Stevens-Johnson syndrome (53%), followed by chemical burn (38%). In all stages of the MOOKP procedure, 94.6% of patients were American Society of Anesthesiologists (ASA) grade II, whereas 5.4% were ASA grade III. Mallampati score 1 was found in 79.7% of patients in stage 1A, 82.4% of patients in stage 1B + 1C, and 81.1% of patients in stage 2. Recovery grade of 10 was noted in all patients at all stages of the MOOKP procedure. Intubation in the second attempt was carried out in 8 patients and oral intubation in stage 1B + 1C was performed in 4 patients. Difficulty in intubation was noted in 3 patients in stage 1A, 4 patients in stage 1B + 1C, and 1 patient in stage 2. CONCLUSIONS: In patients undergoing MOOKP, a good preoperative anesthetic evaluation and intraoperative anesthesia plan before each stage could help in successful administration of anesthesia in these patients.

Use of a mandibular torus for autogenous grafting: a case report.

Conventional treatment for the management of 2- to 3-walled intrabony defects is the use of allograft or alloplasts. Autogenous grafts are the gold standard because of their osteogenic potential. Mandibular tori are an ideal site for harvesting bone because their excision causes no structural, esthetic, or functional compromise to the patient. This case report describes the use of an autogenous graft obtained from a mandibular torus. The graft was utilized, in particulate form, to fill an intrabony defect at the mandibular right central incisor. The mandibular torus provided sufficient graft material and eliminated the need for a second surgical site. A follow-up at 1 year revealed reduction in clinical attachment loss and complete resolution of tooth mobility.

The transient receptor potential cation channel subfamily V members 1 and 2, P2X purinoceptor 3 and calcitonin gene-related peptide in sensory neurons of the rat trigeminal ganglion, innervating the periosteum, masseter muscle and facial skin.

OBJECTIVE: Distribution of the transient receptor potential cation channel subfamily V members 1 (TRPV1) and 2 (TRPV2), and P2X purinoceptor 3 (P2 × 3) was investigated in rat trigeminal ganglion neurons innervating the periosteum, masseter muscle and facial skin. DESIGN: Double immunofluorescence method for TRPV1 and TRPV2 ion channels or ATP receptor P2 × 3 with calcitonin gene-related peptide (CGRP) was performed on trigeminal ganglion neurons retrogradely labeled from the mandibular periosteum, masseter muscle, or facial skin in 15 male Wistar rats. RESULTS: The cell size of periosteum neurons (mean ± S.D. = 810.7 ± 36.1 µ m2) was smaller than that of masseter muscle neurons (927.0 ± 75.6 µ m2), and larger than that of facial skin neurons (661.3 ± 82.2 µ m2). Periosteum neurons contained TRPV1- (26.7%), TRPV2- (47.1%) and P2 × 3-immunoreactivity (50.1%). Expression of TRPV2-immunoreactivity was more abundant among periosteum neurons than among facial skin neurons (16.1%). Regarding to TRPV1 and P2 × 3 expression, however, there was no significant difference between periosteum neurons and, masseter muscle and facial skin neurons. TRPV1- immunoreactive trigeminal ganglion neurons which innervated the periosteum, masseter muscle and facial skin mostly had small and medium-sized cell bodies, whereas TRPV2- and P2 × 3-immunoreactive trigeminal ganglion neurons innervating those tissues were of various cell body sizes. Approximately 20% of periosteum (19.2%), masseter muscle (19.2%) and facial skin (21.5%) neurons contained both TRPV1- and CGRP-immunoreactivity. Some periosteum neurons also co-expressed CGRP-immunoreactivity with TRPV2- (10.9%) or P2 × 3- immunoreactivity (11.1%). Distributions of perivascular and free nerve fibers containing CGRP and either TRPV1, TRPV2, or P2 × 3 were occasionally very similar in the mandibular periosteum. CONCLUSIONS: The present study indicated that trigeminal ganglion nociceptors innervating the periosteum as well as those innervating the masseter muscle and facial skin have vanilloid, acidic, thermal, mechanical and ATP sensors. In some periosteum neurons, CGRP may act as inflammatory mediator through activation of TRPV1, TRPV2 and P2 × 3.

Maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle.

BACKGROUND: Maxillary reconstruction using various pedicled and free-tissue transfer techniques with bone graft or without bone graft has some drawbacks. In this study, we demonstrate maxillary reconstruction using femoris rectus muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle through the modified lateral lip-submandibular approach. MATERIAL AND METHODS: Nine patients suffering from maxillary defects secondary to maxillary cancer ablation, who underwent maxillary reconstruction using rectus femoris muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle, were enrolled into this study between November 2015 and August 2017. RESULTS: All patients who underwent the maxillary reconstruction using femoris rectus muscle flap and sagittal mandibular ramus/coronoid process graft pedicled with temporalis muscle presented satisfactory postoperative function, with adequate mouth opening, optimal esthetic outcome and no restrictions on the diet. Every rectus femoris muscle flaps mucosalized well within five weeks. No donor site functional impairment or complications were observed. CONCLUSIONS: The technique is a feasible and acceptable technique for the maxillary reconstructions. It is safe, quick and simple to harvest. It also presents an optimal esthetic and satisfactory functional outcome with the advantage of low morbidity of the donor site. Combined with the three-dimension reconstruction, this technique can improve the postoperative outcomes.

Long-term stability of autologous bone graft of intraoral origin after lateral sinus floor elevation with simultaneous implant placement.

BACKGROUND: Lateral approach to maxillary sinus floor elevation (LSFE) with autologous bone grafts and simultaneous implant insertion is a widespread technique for prosthetic rehabilitation of the atrophic maxilla. PURPOSE: To analyze implant survival and autologous bone graft resorption after LSFE, in patients with at least 5 years follow-up. MATERIALS AND METHODS: Thirty-three patients (mean age 56 years, range 46-68 years) who had undergone LSFE with intraoral autologous bone graft from mandibular ramus and simultaneous implant insertion were included. A minimum of 5 years of follow-up was required. The total peri-implant bone height was measured at mesial and distal aspects of the implants immediately after surgery (T0) and after a period ranging from 5 to 11.5 years after surgery (mean 7.65 ± 1.80 years) (T1) on digital panoramic and periapical radiographs. Wilcoxon matched-pairs signed rank test was used to compare bone graft height at T0 and T1. The influence of patient-, surgery-, and implant-related factors on the outcomes was investigated. RESULTS: Of the 58 implants placed, no one was lost. All prostheses were in function, and no biological or mechanical complications occurred. The residual ridge height at the involved sites averaged 6.48 ± 1.72 mm. The mean bone height at grafted regions was 12.05 ± 2.47 mm at T0 and 12.13 ± 2.39 mm at T1 (not statistically significant). Marginal bone level change at T1 averaged -1.22 ± 1.60 mm. None of the evaluated factors significantly affected the results. CONCLUSION: Autologous bone grafts from intraoral donor sites display excellent volume stability over time that may contribute to optimal outcomes of the procedure.

Horizontal Maxillary Osteotomy Stability Using Mandibular Outer Cortex Bone Grafts in Patients With Cleft Lip and Palate.

OBJECTIVE: To investigate horizontal maxillary osteotomy stability after using bone grafts for the treatment of patients with unilateral cleft lip and palate (UCLP). DESIGN: Retrospective cohort study. SETTING: Plastic surgery hospital. PATIENTS: Fifty-eight patients with UCLP and maxillary hypoplasia requiring a maxillary Le Fort I advancement of 6 to 9 mm. INTERVENTIONS: The test group (TG) was comprised of 28 patients who underwent mandibular outer cortex bone grafting in the gaps created by a modified Le Fort I osteotomy. The control group (CG) was comprised of 30 patients who underwent a Le Fort I osteotomy without bone grafts. MAIN OUTCOME MEASURES: Maxillary horizontal advancement (recorded during the operation using a Vernier caliper) and horizontal relapse at 12 months after surgery (based on a manual cephalometric analysis of pre- and postoperative lateral teleradiographs). RESULTS: In the TG, the mean maxillary horizontal advancement was 7.13 ±â€Š0.7 mm (range: 6.01-8.23 mm), and the mean postoperative horizontal relapse was 25.07 ±â€Š6.64%. In the CG, the mean maxillary horizontal advancement was 6.90 ±â€Š0.55 mm (range: 6.05-7.39 mm), and the mean postoperative horizontal relapse was 24.89 ±â€Š4.25%. There were no significant between-group differences in the mean horizontal relapses. CONCLUSION: The use of mandibular outer cortex bone grafts as physical barriers in patients with UCLP does not increase postoperative stability when the maxillary advancement is 6 to 9 mm.