Comparison of off-the-shelf ß-tricalcium phosphate implants with novel resorbable 3D printed implants in mandible ramus of pigs.

Facial reconstructive surgery has already implemented the use of 3D printed Patient Specific Implants derived from CAD/CAM-based technologies as an alternative to preformed bone graft substitutes. 3D-printed patient-specific implants derived from CAD/CAM-based technologies are used in facial reconstructive surgery as an alternative to preformed bone graft substitutes. However, to minimize the invasiveness and long-term adverse effects of surgical interventions, the implant needs to exhibit exact fitting, porosity, density, and volume and be made from resorbable materials that allow ingrowth and formation of new bone tissue. Therefore, we present this pilot study using 3D-printed implants consisting of pure ß-TCP, produced using a novel technique that assures these properties. Eight pigs received 3D-printed truncated porous cone bone implants paired with either an off-the-shelve a chronOS (DePuy Synthes chronOS Vivify Preforms) preformed block (n = 4) or a no-implant void (n = 4) in a surgically created defect on each side of the angle of the mandible. After 6 months, CT data showed that all 3D-printed implants performed as well as did the off-the-shelve implants, with predicted osteointegration medially and laterally and with minimal gapping between the implants and native bone. The CT findings were confirmed by histological analysis that revealed that the 3D-printed implants together with the off-the-shelve implants were almost complete resorbed. Much of the resorbed volume had been replaced by vascularized compact bone, and fusion between newly formed bone and native bone was observed in all implants, further indicating that the 3D-printed implants and off-the-shelve implants performed equally well. Only soft tissue developed in the void control sites. Further studies are needed to confirm these initial findings.

Surgical accuracy of three-dimensional virtual planning: a pilot study of bimaxillary orthognathic procedures including maxillary segmentation.

This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation was analyzed in both superior and inferior maxillary repositioning. In addition, transverse surgical expansion was compared with the postsurgical expansion obtained. An overall, high degree of linear accuracy between planned and postsurgical outcomes was found, but with a large standard deviation. Rotational difference showed an increase in pitch, mainly affecting the maxilla. Segmentation had no significant influence on maxillary placement. However, a posterior movement was observed in inferior maxillary repositioning. A lack of transverse expansion was observed in the segmented maxilla independent of the degree of expansion.

High condylectomy for the treatment of mandibular condylar hyperplasia: a systematic review of the literature.

Mandibular condylar hyperplasia (MCH) is a rare, idiopathic disorder, which can cause both functional and aesthetic problems. MCH has often been described in the literature, but a comprehensive analysis of the current literature on MCH has not been undertaken. This study presents a systematic review analyzing the efficacy of high condylectomy in patients with MCH, with an emphasis on its role in the management of unilateral condylar hyperplasia. A systematic search of the current literature on high condylectomy was performed to find studies with sample sizes of more than five patients using a set of inclusion/exclusion criteria. The search terms revealed 664 studies, of which only 11 articles with a total of 289 patients were eligible for inclusion. Due to differences in the presentation of data, a meta-analysis was not conducted. High condylectomy appears to be a relevant surgical method to correct unilateral condylar hyperplasia. The current literature indicates large variations in terms of aetiology, use of diagnostic tools, and preferred time of intervention. Thus, further systematic studies are needed to determine which procedures offer the best aesthetic and functional results.

A prospective, single-centre study on patient outcomes following temporomandibular joint replacement using a custom-made Biomet TMJ prosthesis.

This study describes the clinical variables in 61 patients following total alloplastic temporomandibular joint reconstruction (TJR) in which the Biomet Microfixation Patient-Patient-Matched TMJ Implant was used. All patients were classified using the Wilkes classification. The visual analogue scale score for jaw pain intensity, the maximum inter-incisal opening (MIO), and the frequency of adverse events were recorded during follow-up; the mean follow-up was 14.2±8.6 months. Significant improvements were found in the MIO (P<0.0005), except at the 3-year follow-up. Additionally, a significant reduction in pain was observed both short and long term (P<0.0005). The incidence of adverse events was low (seven of the 81 alloplastic joints); two joints needed revision. TJR appears to be a relevant treatment option in patients with a broad range of temporomandibular joint disorders in whom none of the joint components are salvageable because of significant disease. Our patients gained an almost normal range of mouth opening and experienced a significant reduction in pain. Our results are promising, however TJR is associated with some side effects. TJR should be considered when less invasive procedures fail and a comprehensive presurgical work-up has been performed. Ongoing prospective studies are needed to consolidate the possible significant treatment outcomes.

Virtual planning in orthognathic surgery.

Numerous publications regarding virtual surgical planning protocols have been published, most reporting only one or two case reports to emphasize the hands-on planning. None have systematically reviewed the data published from clinical trials. This systematic review analyzes the precision and accuracy of three-dimensional (3D) virtual surgical planning of orthognathic procedures compared with the actual surgical outcome following orthognathic surgery reported in clinical trials. A systematic search of the current literature was conducted to identify clinical trials with a sample size of more than five patients, comparing the virtual surgical plan with the actual surgical outcome. Search terms revealed a total of 428 titles, out of which only seven articles were included, with a combined sample size of 149 patients. Data were presented in three different ways: intra-class correlation coefficient, 3D surface area with a difference <2mm, and linear and angular differences in three dimensions. Success criteria were set at 2mm mean difference in six articles; 125 of the 133 patients included in these articles were regarded as having had a successful outcome. Due to differences in the presentation of data, meta-analysis was not possible. Virtual planning appears to be an accurate and reproducible method for orthognathic treatment planning. A more uniform presentation of the data is necessary to allow the performance of a meta-analysis. Currently, the software system most often used for 3D virtual planning in clinical trials is SimPlant (Materialise). More independent clinical trials are needed to further validate the precision of virtual planning.

Mesenchymal stem cells in oral reconstructive surgery: a systematic review of the literature.

This study evaluated clinical outcomes following intraoperative use of adult mesenchymal stem cells (MSCs) in various oral reconstructive procedures. PubMed was searched without language restrictions from 2000 to 2011 using the search words stem cell, oral surgery, tissue engineering, sinus lift, bone regeneration and combinations of these. Inclusion criteria were intraoperative use of MSCs in the study design. Reference lists of the articles found were searched for other related studies. Eighteen clinical trials using MSCs for sinus augmentation were found: five case reports on the repair of large bony defects and six studies on ridge augmentation and healing of alveolar sockets after third molar extraction. The findings suggest that MSCs are capable of producing in vivo bone, re-establishing lost tissue and facilitating placement of dental implants. Use of MSCs would reduce patient morbidity because of a less stressful harvesting technique than that of autogenous bone. The majority of clinical trials indicate that MSCs can produce bone in vivo. However, a satisfactory outcome was not seen in all studies, and due to the diversity of study designs, a 'golden approach' cannot be determined. Before use of MSCs can be considered as a first-choice treatment, more predictable outcomes and better long-term prognoses need to be established. Conventional bone grafting remains the gold standard.