Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Auricular Prostheses-Systematic Review.

This systematic review was aimed at gathering the clinical and technical applications of CAD/CAM technology for craniofacial implant placement and processing of auricular prostheses based on clinical cases. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, an electronic data search was performed. Human clinical studies utilizing digital planning, designing, and printing systems for craniofacial implant placement and processing of auricular prostheses for prosthetic rehabilitation of auricular defects were included. Following a data search, a total of 36 clinical human studies were included, which were digitally planned and executed through various virtual software to rehabilitate auricular defects. Preoperative data were collected mainly through computed tomography scans (CT scans) (55 cases); meanwhile, the most common laser scanners were the 3dMDface System (3dMD LLC, Atlanta, Georgia, USA) (6 cases) and the 3 Shape scanner (3 Shape, Copenhagen, Denmark) (6 cases). The most common digital design software are Mimics Software (Mimics Innovation Suite, Materialize, Leuven, Belgium) (18 cases), Freeform software (Freeform, NC, USA) (13 cases), and 3 Shape software (3 Shape, Copenhagen, Denmark) (12 cases). Surgical templates were designed and utilized in 35 cases to place 88 craniofacial implants in auricular defect areas. The most common craniofacial implants were Vistafix craniofacial implants (Entific Medical Systems, Goteborg, Sweden) in 22 cases. A surgical navigation system was used to place 20 craniofacial implants in the mastoid bone. Digital applications of CAD/CAM technology include, but are not limited to, study models, mirrored replicas of intact ears, molds, retentive attachments, customized implants, substructures, and silicone prostheses. The included studies demonstrated a predictable clinical outcome, reduced the patient's visits, and completed the prosthetic rehabilitation in reasonable time and at reasonable cost. However, equipment costs and trained technical staff were highlighted as possible limitations to the use of CAD/CAM systems.

The epidemiology and management of odontomas: a European multicenter study.

INTRODUCTION: Odontoma is the most commonly diagnosed odontogenic tumor of the oral cavity. The objective of the present study was to assess the demographic variables, patterns, diagnostic features, and management issues of odontomas treated at several European departments of maxillofacial and oral surgery. MATERIALS AND METHODS: This study was conducted at 8 European departments of oral surgery between January 1, 2004, and December 31, 2018. Only patients with odontomas were included. The following data were recorded for each patient: gender, age, comorbidities, site, size of odontomas, radiographic features, type of odontoma, treatment of odontomas, treatment of associated teeth, complications, and recurrence. RESULTS: A total of 127 patients (70 male and 57 female patients) with odontomas were included. The mean age was 22 years; 71 odontomas were found in the mandible, whereas 56 in the maxilla. In the mandible, the most frequently involved subsite was the parasymphysis, while in the maxilla, the most common subsite was the upper incisor region. The mean size of included odontomas was 15.3 mm. On the whole, 62 complex odontomas, 50 compound odontomas, and 15 mixed-type odontomas were observed. Complete excision of the odontomas was performed in 121 patients. In 24 patients, the extraction of deciduous teeth was performed, and in 43 patients, one or more permanent teeth were removed. Finally, in 9 patients, a partial excision of the odontoma was performed. Recurrence was observed in 4 cases out of 127 patients. CONCLUSIONS: Dental practitioners should be aware of the distinct clinical and radiographic features of odontoma in order to perform an appropriate and early diagnosis. Conventional radiography, such as panoramic radiograph, is often sufficient technique for a diagnosis after clinical suspicion or for an incidental diagnosis to prevent later complications, such as impaction or failure of eruption of teeth.

Imaging of odontogenic keratocysts: a pictorial review.

INTRODUCTION: The aim of the present article was to review and depict the main radiological features of odontogenic keratocysts (OKCs), thus helping the differential diagnoses from other odontogenic cysts and neoplasms. EVIDENCE ACQUISITION: A review of articles published between January 2000 and October 2020 using Medline and the MeSH Term "odontogenic keratocyst" in combination with the following terms "imaging," "radiology," "panoramic radiograph," and "computed tomography," was performed. EVIDENCE SYNTHESIS: Radiographically, OKCs are well-defined unilocular or multilocular radiolucencies bounded by corticated margins. Most lesions are unilocular; instead, multilocular OKCs represent about the 30% of cases, mainly involving the posterior mandible. When, particularly in large lesions, OKCs display a multilocular presentation with adjacent satellite cysts (daughter cysts) a "soap-bubble appearance" can be recognized. DISCUSSION: Panoramic radiograph and CT still play an important role in the diagnosis and treatment planning of OKCs. Unfortunately, it may not be easy to differentiate OKCs from other odontogenic lesions, especially when they are small and unilocular. CONCLUSIONS: Histopathological findings are still necessary to obtain a definitive diagnosis.

The epidemiology and management of odontogenic keratocysts (OKCs): A European multicenter study.

The objective of the present study was to assess the epidemiology including demographic variables, diagnostic features, and the management of odontogenic keratocyst (OKCs) at several European departments of maxillofacial and oral surgery. This study is based on a systematic computer-assisted database that allowed the recording of data from treated OKCs. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, treatment of OKCs, length of hospital stay, complications, recurrence, management and complications of eventual recurrence. A total of 405 patients, 249 male and 156 female, with 415 OKCs (407 sporadic and 8 syndromic lesions) were included in the study: 320 lesions were found in the mandible, whereas 95 were found in the maxilla. In the mandible, the most frequently involved subsite was the angle, whereas in the maxilla it was the molar region. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 204 OKCs (recurrence rate, 9%). Decompression without residual cystectomy (recurrence rate, 66%), marsupialization with residual enucleation with the use of Carnoy's solution (recurrence rate, 50%), decompression with residual cystectomy (recurrence rate, 43%), and simple enucleation (recurrence rate, 24%) were the treatment options with the highest recurrence rates. An appropriate management of odontogenic keratocysts should be individualized, taking into consideration clinical and radiological findings, as well as patients' age and comorbidities.

Systematic Review of Clinical Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Orbital Prostheses.

This systematic review was aimed at gathering technical and clinical applications of CAD/CAM technology for the preoperative planning of craniofacial implants placement, designing of molds and substructures and fabrication of orbital prostheses. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, an electronic search was executed. Human studies that utilized digital planning systems for the prosthetic rehabilitation of orbital defects were included. A total of 16 studies of 30 clinical cases, which were virtually planned through various digital planning and designing software, were included. The most common preoperative data required for digital planning were CT scans in 15 cases, the 3DSS-STD-II scanning system in 5 cases, an Artec Color 3D scanner in 3 cases and a NextEngine Desktop 3D laser scanner in 2 cases. Meanwhile, the digital designing software were Ease Orbital Implant Planning EOIPlan software in eight cases, Geomagic software in eight cases, Simplant software in four cases and Artec Studio 12 Professional in three cases. Surgical templates were fabricated for 12 cases to place 41 craniofacial implants in the orbital defect area. An image-guided surgical navigation system was utilized for the placement of five orbital implants in two cases. Digital designing and printing systems were reported for the preoperative planning of craniofacial implants placement, designing of molds and substructures and fabrication of orbital prostheses. The studies concluded that the digital planning, designing and fabrication of orbital prostheses reduce the clinical and laboratory times, reduces patient visits and provide a satisfactory outcome; however, technical skills and equipment costs are posing limitations on the use of these digital systems.

The epidemiology and management of ameloblastomas: A European multicenter study.

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

Long-term outcomes of implant-based dental rehabilitation in head and neck cancer patients after reconstruction with the free vascularized fibula flap.

The study aimed at evaluating, comprehensively, implant-based dental rehabilitation in head and neck cancer patients after maxillofacial reconstruction with a vascularized free fibula flap (FFF). Data were obtained by retrospectively reviewing the medical records of patients treated in Amsterdam UMC-VU Medical Center. Dental implant survival and implant success according to the Albrektsson criteria were analyzed. Additionally, prosthetic-related outcomes were studied, with a focus on functional dental rehabilitation. In total, 161 implants were placed in FFFs, with a mean follow-up of 4.9 years (range 0.2-23.4). Implant survival was 55.3% in irradiated FFFs and 96% in non-irradiated FFFs. Significant predictors for implant failure were tobacco use and irradiation of the FFF. Implant success was 40.4% in irradiated FFFs and 61.4% in non-irradiated FFFs, mainly due to implant failure and non-functional implants. Implant-based dental rehabilitation was started 45 times in 42 patients, out of 161 FFF reconstructions (27.9%). Thirty-seven patients completed the dental rehabilitation, 29 of whom achieved functional rehabilitation. Irradiation of the FFF negatively influenced attainment of functional rehabilitation. For patients with functional rehabilitation, the body mass index varied at different timepoints: FFF reconstruction, 24.6; dental implantation 23.5; and after placing dental prosthesis, 23.9. Functional implant-based dental rehabilitation, if started, can be achieved in the majority of head and neck cancer patients after FFF reconstruction. Actively smoking patients with an irradiated FFF should be clearly informed about the increased risk for implant and prosthetic treatment failure.

Systematic Review of Clinical Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Nasal Prostheses.

The aim of this systematic review was to gather the clinical and laboratory applications of CAD/CAM technology for preoperative planning, designing of an attachment system, and manufacturing of nasal prostheses. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, an electronic search was carried out. Only human clinical studies involving digital planning for the rehabilitation of facial defects were included. A total of 21 studies were included with 23 patients, which were virtually planned through different planning software. The most common preoperative data for digital planning were CT scans in nine cases, CBCT in six cases, and laser scans in six cases. The reported planning softwares were Mimics in six cases, Geomagic Studio software in six cases, ZBrush in four cases, and Freeform plus software in four cases. Ten surgical templates were designed and printed to place 36 implants after digital planning, while post-operative assessment was done in two cases to check the accuracy of planned implants. Digital 3D planning software was reported for presurgical planning and craniofacial implants placement, fabrication of molds, designing of implants, designing of retentive attachments, and printing of silicone prostheses. Digital technology has been claimed to reduce the clinical and laboratory time; however, the equipment cost is still one of the limitations.

Accuracy of Computer-Assisted Surgery in Maxillary Reconstruction: A Systematic Review.

Computer-assisted surgery (CAS) in maxillary reconstruction has proven its value regarding more predictable postoperative results. However, the accuracy evaluation methods differ between studies, and no meta-analysis has been performed yet. A systematic review was performed in the PubMed, Embase, and Cochrane Library databases, using a Patient, Intervention, Comparison and Outcome (PICO) method: (P) patients in need of maxillary reconstruction using free osteocutaneous tissue transfer, (I) reconstructed according to a virtual plan in CAS software, (C) compared to the actual postoperative result, and (O) postoperatively measured by a quantitative accuracy assessment) search strategy, and was reported according to the PRISMA statement. We reviewed all of the studies that quantitatively assessed the accuracy of maxillary reconstructions using CAS. Twelve studies matched the inclusion criteria, reporting 67 maxillary reconstructions. All of the included studies compared postoperative 3D models to preoperative 3D models (revised to the virtual plan). The postoperative accuracy measurements mainly focused on the position of the fibular bony segments. Only approximate comparisons of postoperative accuracy between studies were feasible because of small differences in the postoperative measurement methods; the accuracy of the bony segment positioning ranged between 0.44 mm and 7.8 mm, and between 2.90° and 6.96°. A postoperative evaluation guideline to create uniformity in evaluation methods needs to be considered so as to allow for valid comparisons of postoperative results and to facilitate meta-analyses in the future. With the proper validation of the postoperative results, future research might explore more definitive evidence regarding the management and superiority of CAS in maxillary and midface reconstruction.

Collaboration Around Rare Bone Diseases Leads to the Unique Organizational Incentive of the Amsterdam Bone Center.

In the field of rare bone diseases in particular, a broad care team of specialists embedded in multidisciplinary clinical and research environment is essential to generate new therapeutic solutions and approaches to care. Collaboration among clinical and research departments within a University Medical Center is often difficult to establish, and may be hindered by competition and non-equivalent cooperation inherent in a hierarchical structure. Here we describe the "collaborative organizational model" of the Amsterdam Bone Center (ABC), which emerged from and benefited the rare bone disease team. This team is often confronted with pathologically complex and under-investigated diseases. We describe the benefits of this model that still guarantees the autonomy of each team member, but combines and focuses our collective expertise on a clear shared goal, enabling us to capture synergistic and innovative opportunities for the patient, while avoiding self-interest and possible harmful competition.

Polymethyl Methacrylate in Patient-Specific Implants: Description of a New Three-Dimension Technique.

Polymethyl methacrylate (PMMA), an easily moldable and economical synthetic resin, has been used since the 1940s. In addition, PMMA has good mechanical properties and is one of the most biocompatible alloplastic materials currently available. The PMMA can serve as a spacer and as a delivery vehicle for antibiotics. Prior studies have indicated that no significant differences in infection rates exist between autologous and acrylic cranioplasty. Although inexpensive, the free-hand cranioplasty technique often yields unsatisfactory cosmetic results. In the present study, the application of a recently developed, economic modality for the perioperative application, and molding of PMMA to ensure a precise fit in 16 patients using computer-aided design, computer-aided manufacturing, and rapid prototyping was described.The mean defect size was 102.0 ±â€Š26.4 cm. The mean volume of PMMA required to perform the cranioplasty procedure was 51 mL. The cost of PMMA was approximately 6 Euro (&OV0556;) per mL. The costs of fabricating the implants varied from 119.8 &OV0556; to 1632.0 &OV0556; with a mean of 326.4 &OV0556; ±â€Š371.6. None of the implants required removal during the follow-up period.

Finite element analysis of 6 large PMMA skull reconstructions: A multi-criteria evaluation approach.

In this study 6 pre-operative designs for PMMA based reconstructions of cranial defects were evaluated for their mechanical robustness using finite element modeling. Clinical experience and engineering principles were employed to create multiple plan options, which were subsequently computationally analyzed for mechanically relevant parameters under 50N loads: stress, strain and deformation in various components of the assembly. The factors assessed were: defect size, location and shape. The major variable in the cranioplasty assembly design was the arrangement of the fixation plates. An additional study variable introduced was the location of the 50N load within the implant area. It was found that in smaller defects, it was simpler to design a symmetric distribution of plates and under limited variability in load location it was possible to design an optimal for expected loads. However, for very large defects with complex shapes, the variability in the load locations introduces complications to the intuitive design of the optimal assembly. The study shows that it can be beneficial to incorporate multi design computational analyses to decide upon the most optimal plan for a clinical case.

Structural and mechanical implications of PMMA implant shape and interface geometry in cranioplasty--A finite element study.

This computational study investigates the effect of shape (defect contour curvature) and bone-implant interface (osteotomy angle) on the stress distribution within PMMA skull implants. Using finite element methodology, 15 configurations--combinations of simplified synthetic geometric shapes (circular, square, triangular, irregular) and interface angulations--were simulated under 50N static loads. Furthermore, the implant fixation devices were modelled and analysed in detail. Negative osteotomy configurations demonstrated the largest stresses in the implant (275 MPa), fixation devices (1258 MPa) and bone strains (0.04). The circular implant with zero and positive osteotomy performed well with maximum observed magnitudes of--implant stress (1.2 MPa and 1.2 MPa), fixation device stress (11.2 MPa and 2.2 MPa), bone strain (0.218e-3 and 0.750e-4). The results suggest that the preparation of defect sites is a critical procedure. Of the greatest importance is the angle at which the edges of the defect are sawed. If under an external load, the implant has no support from the interface and the stresses are transferred to the fixation devices. This can endanger their material integrity and lead to unphysiological strains in the adjacent bone, potentially compromising the bone morphology required for anchoring. These factors can ultimately weaken the stability of the entire implant assembly.

Porous polyethylene implants in facial reconstruction: Outcome and complications.

The aim of the present study was to assess the indications, results and complications of patients treated with porous polyethylene (Medpor(®)) implants in the Department of Oral and Maxillofacial Surgery of VU Medical Centre, Amsterdam over 17 years. A total of 69 high-density porous polyethylene implants (Medpor(®) Biomaterial; Porex Surgical, Newman, GA) were used in forty patients (22 males, 18 females). All patients were analysed for gender, age, diagnosis, indications for surgery, follow-up period and postoperative complications. A mean age of 34.1 years was observed. The main reason for implant surgery was post-traumatic functional impairment (27.5%). Most implants were placed at the mandibular angel and the orbital floor. Unsatisfactory appearance scored the highest in postoperative complications (10.1%) followed by infection rate (7.2%). Comparing the number of implants placed over the years and the incidence of complications, makes the overall complications rate of porous polyethylene very low. A consensus about antibiotic prophylaxis is needed. The objective measurements in patient satisfaction and proper implant design would be of great use.