A recent update in periodontal terminology includes a shift from the term “biotype”, replacing it with the term “phenotype”. Periodontal phenotype evaluation and diagnosis is possible when findings from both the clinical examination to establish the gingival phenotype are combined with assessment of the bone morphotype, commonly using Cone Bean Computed Tomography (CBCT) imaging technology. Such analysis is critical to treatment planning, particularly for interdisciplinary dentofacial therapy patients (IDT) whose treatment can often involve clinical interventions such as surgery, orthodontic tooth movement, and/or extensive restorative treatment. This paper highlights how this shift in terminology can also be considered an evolution of thought process, as phenotype offers a more comprehensive way to guide our planning at the foundational level, and offers an updated approach for diagnosing and treatment planning IDT patients. Being able to identify a patient with a seemingly intact periodontal phenotype that will become susceptible or deficient with planned intervention is critical. Until now, there has been no established protocol recommended for risk assessment regarding iatrogenic sequelae on the periodontium involving tooth movement. A systematic approach, Phenotype Driven Treatment Planning (PDTP), is introduced here, and an updated outcome of treatment termed optimized periodontal phenotype is suggested. Schlagwörter: Periodontal phenotype; surgical orthodontics; gingival recession; accelerated orthodontics; bone augmentation

Pterygoid implant placement has not been a common treatment modality to manage the atrophic posterior maxilla. This randomized, controlled clinical trial evaluated the accuracy of dynamic navigation using trace registration (TR) technology in pterygoid implant placement when compared to free-hand surgery. Partially edentulous patients requiring at least one pterygoid implant to rehabilitate the atrophic posterior maxilla were included. Implant accuracy (in a prosthetically directed context) and the relation of the placed implants to the greater palatine canal (GPC) were evaluated using EvaluNav to compare the preoperative CBCT plan with the postoperative CBCT implant location. Osseointegration success, mucosal thickness, implant length, time spent for surgical placement, and ease of prosthetic restorability via degree of multi-unit abutment angulation were assessed. A total of 63 pterygoid implants were placed (31 using TR, 32 using free-hand) in 39 partially edentulous patients. Mean deviations between the planned and actual position for TR-placed implants were 0.66 mm at the coronal level, 1.13 mm at the apical level, 0.67 mm in depth, and 2.64 degrees of angular deviation, compared to 1.54 mm, 2.73 mm, 1.17 mm, and 12.49 degrees, respectively, for free-hand implants. In relation to the GPC, TR implants were more accurate when compared to the presurgical plan and took less surgical time. The mean mucosal thickness measured for all implants was 5.41 mm. Most implants were 15 to 18 mm long, and most prostheses (92%) could be accommodated by a 17- or 30-degree multi-unit screw-retained abutment. TR implants had greater short-term osseointegration success rates than free-hand implants (100% vs 93.75%). Pterygoid implant surgery can be a predictable and successful modality for prosthetically directed implant rehabilitation in the atrophic posterior maxilla, is more accurate than free-hand surgery, and takes less time when using dynamic navigation via TR.

Trace registration is a new, alternative registration method for dynamic navigation implant surgery that eliminates the need for an artificial fiducial marker and stent to be present in the CBCT scan, substituting it with other high-contrast landmarks such as teeth, implants, or abutments. Clinical advantages include a streamlined, simplified workflow with fewer opportunities for error; elimination of presurgical steps associated with stent fabrication and imaging; and reduction in radiation risk. Sufficient high-contrast intraoral structures are a prerequisite for using this technique. This case series presents the trace registration protocol and workflow and reports on cases that demonstrate the application of this technology, including postoperative placement accuracy evaluation.

A technology called Trace Registration (TR) has been introduced to allow dynamic navigation of implant placement without the need for a thermoplastic stent. This study was undertaken in order to validate the accuracy of the TR protocol for dynamically guided implant surgery. A retrospective, observational, in vivo study was performed using dynamic navigation via the TR protocol. The preoperative cone beam computed tomography (CBCT) plan was superimposed and registered (aligned) with the postoperative CBCT scan to assess accuracy parameters. A total of 136 implants were placed in 59 partially edentulous arches. Mean deviation between the planned and actual position for all implants was 0.67 mm at the coronal level (entry point), 0.9 mm at the apical level, and 0.55 mm in depth, with an angle discrepancy of 2.50 degrees. Tracing 5 to 6 teeth tended to improve accuracy results compared to tracing 3 to 4 teeth. TR is as accurate as traditional registration and statically guided methods for implant surgery.

Purpose: To evaluate the in vivo accuracy of dental implants placed using a dynamic computer-aided dental implant (CAI) navigation system. The impact of various factors on accuracy was also analyzed. Materials and Methods: A retrospective in vivo study was performed during the period of October 2015 to December 2017. Data were obtained on all implants placed during this time frame. A chart review was conducted to identify the type of flap, number of implants placed, number of patients treated, and factors related to the description of edentulism (partial or complete). To evaluate accuracy outcomes, the preoperative cone beam computed tomography (CBCT) plan was volumetrically registered to a post-implant placement CBCT scan. Deviations between the planned and placed implant positions were analyzed. Data were statistically analyzed for factors that may affect the accuracy during usage. Results: Data were obtained on 231 implants placed in healed ridges using a flapless or minimal flap approach under dynamic guidance by a single surgeon. In the 89 arches operated on, 28 (125 implants) were fully edentulous. For all implants, the mean (SD) discrepancies were: 0.71 (0.40) mm for entry point (lateral) and 1.00 (0.49) mm at the apex (3D). The mean angle discrepancy was 2.26 degrees (1.62 degrees) from actual vs planned implant positions. The accuracy measurements for partially edentulous patients using a thermoplastic stent attachment and for fully edentulous patients using a mini-implant-based attachment were nearly identical. No significant accuracy differences were found between implant positions within the different sextants. Guided insertion of the implant itself reduced angular and apex location deviations. The accuracy of implant placement improved during the study period, with the mean entry point and apex deviation as well as overall angle discrepancy measured for the last 50 implants being better (0.59 mm, 0.85 mm, and 1.98 degrees, respectively) compared with the first 50 implants (0.94 mm, 1.19 mm, and 3.48 degrees, respectively). Conclusion: Dynamic surgical navigation is an accurate method for executing CBCT-based computer-aided implant surgery. In addition, an increased experience level of the surgeon with dynamic navigation appears to improve accuracy outcomes. Schlagwörter: computer-aided implantology, dental implant placement accuracy, dental navigation, dynamic guided implantology, dynamic navigation, static guided implantology

This case report describes a tissue-engineered reconstruction with recombinant human bone morphogenetic protein 2/acellular collagen sponge (rhBMP-2/ ACS) + cancellous allograft and space maintenance via Medpor Contain mesh in the treatment of a patient requiring maxillary and mandibular horizontal ridge augmentation to enable implant placement. The patient underwent a previously unsuccessful corticocancellous bone graft at these sites. Multiple and contiguous sites in the maxilla and in the mandibular anterior, demonstrating advanced lateral ridge deficiencies, were managed using a tissue engineering approach as an alternative to autogenous bone harvesting. Four maxillary and three mandibular implants were placed 9 and 10 months, respectively, after tissue engineering reconstruction, and all were functioning successfully after 24 months of follow-up. Histomorphometric analysis of a bone core obtained at the time of the maxillary implant placement demonstrated a mean of 76.1% new vital bone formation, 22.2% marrow/cells, and 1.7% residual graft tissue. Tissue engineering for lateral ridge augmentation with combination therapy requires further research to determine predictability and limitations.

Computer-aided design/computer-assisted manufacture (CAD/CAM) guides for surgery are becoming a widespread tool in implant dentistry. This study sought to evaluate the accuracy and precision of a new guided surgery system. Twenty-five patients were treated in eight centers, and a total of 117 implants were placed using CAD/CAM surgical guides supported by bone, mucosa, and/or teeth. A postoperative computed tomographic (CT) scan of each patient was taken and superimposed on a preoperative CT scan to evaluate any discrepancies between the planned and actual implant positions (apex and platform positions), as well as the implant tilt. Implant placement using bone- and mucosa-supported guides was found to be more precise compared to using guides supported by teeth or a combination of teeth and mucosa. However, the differences were not statistically significant. The accuracy of the guided surgery system is in line with the data found in the literature. Considering the mean positioning discrepancies between the planned and actual implant outcomes, clinicians are advised to maintain a safe distance between implants and anatomical structures of at least 2 mm. In immediate loading cases, relining a provisional prosthesis to compensate for any discrepancies between the virtual and clinical implant positions is recommended.

Pretreatment knowledge of crestal and radicular dentoalveolar zones and their associated thicknesses can improve risk assessment to meet esthetic and functional goals, particularly when discrepancies in anterior maxillary and mandibular arches exist and when an anterior protected articulation is to be achieved. This paper discusses a new classification of dentoalveolar bone phenotypes that differentiates the alveolar crestal zone from that of the radicular zone and classifies the thickness of facial bone at each compartment to aid in interdisciplinary dentofacial therapy risk assessment. The zone of crestal bone is defined as the region of the tooth alveolus measured from the cementoenamel junction (CEJ) to a point 4 mm apical. The dentoalveolar radicular zone is dependent upon the individual root length. It begins at a point 4 mm apical to the CEJ (base of the crestal zone) and extends the length of the tooth root. Dentoalveolar bone phenotype at both zones (crestal and remaining radicular alveolar aspect) can be categorized as either thick or thin. Thick is defined as >= 1 mm of facial bone width while thin is 1 mm.

The application of computed tomography (CT) and the use of computer software for dental implant therapy have significantly increased during the last several years. Dental implant positioning can be either "partially guided," where only osteotomy sites are prepared using sequential, removable surgical drilling guides (generated using computer software and through the process of stereolithography), or "totally guided," whereby one guide is used for osteotomy site preparation as well as implant delivery. Recently, the guided delivery of manufacturer-specific internalconnection implants has become available. Individualized protocols and specific instrumentation are employed under this approach to CT-based implant surgery. The purpose of this article is to expand on previous publications related to the use of prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Three case reports are presented where precision-guided CT-based surgery was employed and the immediate delivery of a dental prosthesis was facilitated.