Reconstruction of the adult hemifacial microsomia patient with temporomandibular joint total joint prosthesis and orthognathic surgery

HFM patients' reconstruction has always been a challenge for maxillofacial surgeons, and numerous reconstructive techniques have been described. Surgical treatment depends on the patient's age and contemplates Temporomandibular Joint (TMJ) reconstruction in conjunction with orthognathic surgery, usually necessary following completion of growth to maximize the functional and esthetic results. Distraction osteogenesis had gained popularity as valid alternative in growing patients, but the two primary methods to reconstruct the TMJs involve the use of autogenous, using free or microvascular bone grafts, or alloplastic graft, but there is no widely accepted method

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): Guidelines for medical 3D printing and appropriateness for clinical scenarios

Este número da revista Cadernos de Estudos Sociais estava em organização quando fomos colhidos pela morte do sociólogo Ernesto Laclau. Seu falecimento em 13 de abril de 2014 surpreendeu a todos, e particularmente ao editor Joanildo Burity, que foi seu orientando de doutorado na University of Essex, Inglaterra, e que recentemente o trouxe à Fundação Joaquim Nabuco para uma palestra, permitindo que muitos pudessem dialogar com um dos grandes intelectuais latinoamericanos contemporâneos. Assim, buscamos fazer uma homenagem ao sociólogo argentino publicando uma entrevista inédita concedida durante a sua passagem pelo Recife, em 2013, encerrando essa revista com uma sessão especial sobre a sua trajetória

On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom-made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices

A Current Overview of Materials and Strategies for Potential Use in Maxillofacial Tissue Regeneration

Tissue regeneration is rapidly evolving to treat anomalies in the entire human body. The production of biodegradable, customizable scaffolds to achieve this clinical aim is dependent on the interdisciplinary collaboration among clinicians, bioengineers and materials scientists. While bone grafts and varying reconstructive procedures have been traditionally used for maxillofacial defects, the goal of this review is to provide insight on all materials involved in the progressing utilization of the tissue engineering approach to yield successful treatment outcomes for both hard and soft tissues. In vitro and in vivo studies that have demonstrated the restoration of bone and cartilage tissue with different scaffold material types, stem cells and growth factors show promise in regenerative treatment interventions for maxillofacial defects. The repair of the temporomandibular joint (TMJ) disc and mandibular bone were discussed extensively in the report, supported by evidence of regeneration of the same tissue types in different medical capacities. Furthermore, in addition to the thorough explanation of polymeric, ceramic, and composite scaffolds, this review includes the application of biodegradable metallic scaffolds for regeneration of hard tissue. The purpose of compiling all the relevant information in this review is to lay the foundation for future investigation in materials used in scaffold synthesis in the realm of oral and maxillofacial surgery

Comparative cone-beam computed tomography evaluation of the osseous morphology of the temporomandibular joint in temporomandibular dysfunction patients and asymptomatic individuals

We examined the bone components of the temporomandibular joint (TMJ) in asymptomatic individuals and patients with temporomandibular dysfunction (TMD) using cone-beam computed tomography (CBCT). Two hundred asymptomatic individuals and 200 patients with TMD were included in this study. Condyle position, eminence height, eminence inclination, condyle shape, and fossa shape were assessed on CBCT images of the 800 temporomandibular joints. The eminence inclination (P < 0.05), eminence height (P < 0.0001), mediolateral width of condyle (P < 0.0001), and anterior joint space (P < 0.0001) were significantly greater in male subjects compared with female subjects in both the asymptomatic group and TMD group. Comparisons of the asymptomatic group and TMD group revealed significant differences in the anterior joint space (P < 0.0001), ratio of anterior joint space to posterior joint space (P < 0.001), posterior joint space (P < 0.05), eminence inclination (P < 0.05), eminence height (P < 0.05), condyle shape (P < 0.0001), and fossa shape (P < 0.05). The present analyses suggest that a steeper articular eminence inclination may be risk factor for TMD. The presence of TMD was associated with the condyle position in the TMJ

Early Condylectomy: Biological Considerations

Objective: To describe the early treatment of two patients with unilateral condylar hyperplasia (UCH) diagnosis and therapeutic surgical protocol (early condylectomy) supported by the current biological knowledge about the development and repair of mandibular condyle cartilage (MCC). Methods: Review of the literature and two case description of the treatment. The two patients were girls, 12 and 13 year old. The follow up period was of 3 years. SPECT diagnostic, radiographic, photographic and tomographic images are presented. Results: The literature summarized provides biological basis favoring the early treatment of UCH. The two cases were treated with the same surgical protocol obtaining good esthetic and functional stable results. Discussion: The present literature review and clinical results provide biological basis to justify the practice of early condylectomy. Early intervention appears to be able to produce a successful outcome in terms of esthetic facial symmetry, avoiding dentoalveolar orthodontic compensations or additional orthognathic surgeries

Managing the variability of biomechanical characteristics before the preliminary design stage of a medical device

The very high level of requirements for certification procedures often limit research and development departments to innovate using increments and iterations during the design process for medical devices (MD). Instead of this semi-empirical approach, a structured procedure, a breakthrough innovation should be used when designing an articular MD (prosthesis, implant). The search for concepts can be based on functional analysis and producing behavioural models of the joint in its natural state and/or equipped with the prosthesis. This paper shows how anatomical variables can be managed and integrated using a modular design approach.This study has been realized under the two joint action projects PESSOA 14630YA and PTDC/EME-PME/112977

Functional Outcomes of Temporomandibular Joint Ankylosis Treatments: A 10-year cohort study

Introduction : Ankylosis of the temporomandibular joint (TMJ) is a disabling condition due to the fusion of joint to the base of skull and results in mouth opening limitation. Several surgical techniques have been described for treatment of this condition but no consensus has been reached. This study sought to assess the success of treatment with regard to long-term functional improvement and rate of complications in ankylosis patients during a 10-year period. Materials and Methods: Patients who underwent unilateral or bilateral condylectomy without joint reconstruction during 2001-2011 in the Maxillofacial Surgery Department of Shariati Hospital were evaluated in this historical cohort study. The patients were recalled to ensure the accuracy of information in their medical records and were clinically examined. Improvement in their joint function and rate of complications were evaluated. Data were analyzed using Wilcoxon Signed rank test, multivariate tests, Mauchly's sphericity test and McNemar’s test. Results: A total of 27 subjects (13 males and 14 females) with a mean age of 34.8 years and 6.1 years mean duration of follow-up were evaluated. The results of observation showed that trauma was the most common cause of ankylosis (63%). The most common type of ankyloses was fibrous (55.6%) and 55.6% of the patients had bilateral ankylosis. Maximum mouth opening (MMO), the amount of lateral movement and open bite significantly improved after the operation (P&lt;0.001). Frontal, zygomatic and buccal nerves had been injured in 4, 4 and 3 patients, respectively during the operation. Conclusion: Condylectomy without reconstruction significantly improves the TMJ function in patients with TMJ ankylosis with regard to MMO, the amount of lateral movement, maintenance of occlusion and the skeletal form