Biomaterials in temporomandibular joint replacement: current status and future perspectives – a narrative review

The alloplastic total temporomandibular joint (TMJ) prosthesis has a long history, with many different materials and designs used. While several of these materials have proven valuable over time, many others have not been suitable for implantation, resulting in failure and the need for explantation of the implant. Because of the failure of several of these systems, the use of alloplastic prostheses has reduced dramatically, despite their advantages over autogenous restoration. The aim of this narrative review is to discuss the criteria that must be met by a biomaterial in order for it to be considered suitable for implantation, as well as the common complications that can occur. Currently used materials are highlighted, as well as potential future materials that might prove better suitable for implantation. Several surface modification techniques are proposed as an alternative to the materials used in current TMJ prosthesis systems.status: publishe

Long-term prospective study of an orthodontic bone anchor

Purpose: (1) To determine whether immediate loading of orthodontic bone anchors (OBAs) generates more failures than delayed loading and (2) to evaluate the impact of different variables on the success rate of the use of OBAs as temporary anchorage devices in orthodontic treatment. Materials and Methods: In a prospective registry, consecutive patients were treated with OBAs by one experienced maxillofacial surgeon. An independent evaluator compared and analyzed different prospectively determined parameters: gender, age (young [< 16 years] versus mature 16 years]), time of loading (delayed versus immediate), jaw, location, fixation screw length, complications, and orthodontic indications. Success with the OBA was defined as the capacity to maintain anchorage throughout treatment. Premature removal of an OBA because of infection, serious mobility, or persistent pain was considered a failure. Fisher exact tests for analysis of associations between the categorical variables, with the patient as independent variable, were performed. Success and complications were evaluated using multivariate logistic regression. Results: Sixty-one patients (37 male, 24 female) were treated with 106 OBAs over a 5-year period (2001 to 2006). The reported success rate in this study was 88.3%. In seven patients (11.7%) an OBA was removed prematurely. Age, gender, time of loading, jaw, and location did not influence the failure rate. In 25% of patients, at least one screw failure was noted. A statistically higher screw failure rate was noted in female patients, and the younger group presented more complications than the mature group. Conclusion: According to the results of this study, OBAs are a reliable means to obtain absolute orthodontic anchorage. Immediate loading of an OBA did not generate more failures than delayed loading. Age, jaw, and position did not seem to play important roles in success. Age and gender were important parameters in fixation screw failure rate

Unicoronal suture autotransplantation in the rabbit

Introduction: Our hypothesis was that a neurocranial suture autograft will, when shielded from dura, grow and be incorporated into the calvarium. Methods: Growth was monitored by marker separation in three isohistogenic groups of rabbits, between postnatal days 9 and 90. In order to simulate increased neurocapsular expansion force, the left-sided coronal suture of a group of 20 rabbits was immobilised with a resorbable suture on gestational day 25. The other group of 10 rabbits was sham-operated. On postnatal day 9, 10 of the experimental rabbits underwent transplantation of the suture contralateral to the defect resulting from extirpation of the immobilised suture. The transplant was shielded from dural influence by a platinum foil. Results: The growth of the immobilised coronal sutures was severely impaired, and also that of the contralateral unicoronal sutures to a lesser extent. A significant catch-up of growth occurred in the transplanted unicoronal sutures. Overgrowth occurred at the donor sites. Conclusion: The results allow us to consider suture transplantation combined with endosteal dura stripping in craniosynostosis surgery

A systematic review on soft-to-hard tissue ratios in orthognathic surgery part II: Chin procedures.

Precise soft-to-hard tissue ratios in orthofacial chin procedures are not well established. The aim of this study was to determine useful soft-to-hard tissue ratios for planning the magnitude of sliding genioplasty (chin osteotomy), osseous chin recontouring and alloplastic chin augmentation.info:eu-repo/semantics/publishe

Options for the nasal repair of non-syndromic unilateral Tessier no. 2 and 3 facial clefts

Background: Non-syndromic Tessier no. 2 and 3 facial clefts primarily affect the nasal complex. The anatomy of such clefts is such that the ala of the nose has a cleft. Repairing the ala presents some challenges to the surgeon, especially to correct the shape and missing tissue. Various techniques have been considered to repair these cleft defects. Aim: We present two surgical options to repair such facial clefts. Materials and Methods: A nasal dorsum rotational flap was used to treat patients with Tessier no. 2 clefts. This is a local flap that uses tissue from the dorsal surface of the nose. The advantage of this flap design is that it helps move the displaced ala of a Tessier no. 2 cleft into its normal position. A forehead-eyelid-nasal transposition flap design was used to treat patients with Tessier no. 3 clefts. This flap design includes three prongs that are rotated downward. A forehead flap is rotated into the area above the eyelid, the flap from above the eyelid is rotated to infra-orbital area and the flap from the infraorbital area that includes the free nasal ala of the cleft is rotated into place. Results and Conclusions: These two flap designs show good results and can be used to augment the treatment options for repairing Tessier no. 2 and 3 facial clefts

Preferences of AP position of the straight Caucasian facial profile

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Titanium surface modifications and their soft-tissue interface on nonkeratinized soft tissues-A systematic review (Review)

In this systematic review, the authors explored the surface aspects of various titanium (Ti) or Ti alloy medical implants, examining the interface formed between the implant and surrounding nonkeratinized soft tissues (periosteum, muscles, tendons, fat, cicatrix, or dura mater). A comprehensive search undertaken in July 2019 used strict keywords in relevant electronic databases to identify relevant studies. Based on the authors' inclusion criteria (restricted to in vivo studies), 19 of 651 publications qualified, all pertaining to animal models. The syrcle's risk of bias tool for animal studies was applied at study level. Given the broad nature of the reported results and the many different parameters measured, the articles under scrutiny were assigned to five research subgroups according to their surface modification types: mechanical surface modifications, oxidative processes (e.g., acid etching, anodization, microarc oxidation), sol-gel derived titania (TiO2) coatings, biofunctionalized surfaces, and a subgroup for other modifications. The primary outcome was a liquid space at the interface (e.g., seroma formation) that was reported in six studies. Machining Ti implants to a roughness between Ra = 0.5 and 1.0 μm was shown to induce soft-tissue adhesion. Smoother surfaces, with the exception of acid polished and anodized Ti (Ra = 0.2 μm), prevented soft-tissue adhesion. A fibroblast growth factor 2 apatite composite coating promoted soft-tissue attachment via Sharpey-like fibers. In theory, this implant-soft tissue interface could be nearly perfect.status: publishe