George A. Mandelaris

Emerging Regenerative Approaches for Periodontal Reconstruction: A Consensus Report From the AAP Regeneration Workshop

BACKGROUND Historically, periodontal regeneration has focused predominantly on bone substitutes and/or barrier membrane application to provide for defect fill and/or selected cell repopulation of the lesion. More recently, a number of technologies have evolved that can be viewed as emerging therapeutic approaches for periodontal regeneration, and these technologies were considered in the review paper and by the consensus group. The goal of this consensus report on emerging regenerative approaches for periodontal hard and soft tissue reconstruction was to develop a consensus document based on the accompanying review paper and on additional materials submitted before and at the consensus group session. METHODS The review paper was sent to all the consensus group participants in advance of the consensus conference. In addition and also before the conference, individual consensus group members submitted additional material for consideration by the group. At the conference, each consensus group participant introduced themselves and provided disclosure of any potential conflicts of interest. The review paper was briefly presented by two of the authors and discussed by the consensus group. A discussion of each of the following topics then occurred based on the content of the review: a general summary of the topic, implications for patient-reported outcomes, and suggested research priorities for the future. As each topic was discussed based on the review article, supplemental information was then added that the consensus group agreed on. Last, an updated reference list was created. RESULTS The application of protein and peptide therapy, cell-based therapy, genetic therapy, application of scaffolds, bone anabolics, and lasers were found to be emerging technologies for periodontal regeneration. Other approaches included the following: 1) therapies directed at the resolution of inflammation; 2) therapies that took into account the influence of the microbiome; 3) therapies involving the local regulation of phosphate and pyrophosphate metabolism; and 4) approaches directed at harnessing current therapies used for other purposes. The results indicate that, with most emerging technologies, the specific mechanisms of action are not well understood nor are the specific target cells identified. Patient-related outcomes were typically not addressed in the literature. Numerous recommendations can be made for future research priorities for both basic science and clinical application of emerging therapies. The need to emphasize the importance of regeneration of a functional periodontal organ system was noted. The predictability and efficacy of outcomes, as well as safety concerns and the cost-to-benefit ratio were also identified as key factors for emerging technologies. CONCLUSIONS A number of technologies appear viable as emerging regenerative approaches for periodontal hard and soft tissue regeneration and are expanding the potential of reconstructing the entire periodontal organ system. The cost-to-benefit ratio and safety issues are important considerations for any new emerging therapies. Clinical Recommendation: At this time, there is insufficient evidence on emerging periodontal regenerative technologies to warrant definitive clinical recommendations.

A randomized, controlled, multicentre clinical trial of post-extraction alveolar ridge preservation.

Abstract Aim To compare the effectiveness of two‐ridge preservation treatments. Materials and Methods Forty subjects with extraction sockets exhibiting substantial buccal dehiscences were enrolled and randomized across 10 standardized centres. Treatments were demineralized allograft plus reconstituted and cross‐linked collagen membrane (DFDBA + RECXC) or deproteinized bovine bone mineral with collagen plus native, bilayer collagen membrane (DBBMC + NBCM). Socket dimensions were recorded at baseline and 6 months. Wound closure and soft tissue inflammation were followed post‐operatively, and biopsies were retrieved for histomorphometric analysis at 6 months. Results Primary endpoint: at 6 months, extraction socket horizontal measures were significantly greater for DBBMC + NBCM (average 1.76 mm greater, p = 0.0256). Secondary and Exploratory endpoints: (1) lingual and buccal vertical bone changes were not significantly different between the two treatment modalities, (2) histomorphometric % new bone and % new bone + graft were not significantly different, but significantly more graft remnants remained for DBBMC; (3) at 1 month, incision line gaps were significantly greater and more incision lines remained open for DFDBA + RECXC; (4) higher inflammation at 1 week tended to correlate with lower ridge preservation results; and (5) deeper socket morphologies with thinner bony walls correlated with better ridge preservation. Thirty‐seven of 40 sites had sufficient ridge dimension for implant placement at 6 months; the remainder were DFDBA + RECXC sites. Conclusion DBBMC + NBCM provided better soft tissue healing and ridge preservation for implant placement. Deeper extraction sockets with higher and more intact bony walls responded more favourably to ridge preservation therapy.

Alternative Applications of Guided Surgery: Precise Outlining of the Lateral Window in Antral Sinus Bone Grafting

Computed tomography (CT) and the application of CT-based guided implant surgery allow clinicians to provide enhanced precision and accuracy in implant surgery. Because of the difficulty in transferring a patients often complex anatomic sinus configurations, as viewed on a preoperative CT scan, into precise osteotomy cuts at antral bone graft surgery, a prototype cutting guide was developed. The surgical guide was developed through the use of CT imaging, SimPlant module Oral and Maxillofacial Surgery computer software (Materialise Dental, Glen Burnie, MD), and the stereolithographic process to precisely position the lateral window, facilitating Schneiderian membrane elevation. This report demonstrates the step-by-step method to perform precise guided sinus window preparation using computer software and a stereolithographically generated surgical guide.

American Academy of Periodontology Best Evidence Consensus Statement on Selected Oral Applications for Cone-Beam Computed Tomography

BACKGROUND The American Academy of Periodontology (AAP) recently embarked on a Best Evidence Consensus (BEC) model of scientific inquiry to address questions of clinical importance in periodontology for which there is insufficient evidence to arrive at a definitive conclusion. This review addresses oral indications for use of cone-beam computed tomography (CBCT). METHODS To develop the BEC, the AAP convened a panel of experts with knowledge of CBCT and substantial experience in applying CBCT to a broad range of clinical scenarios that involve critical structures in the oral cavity. The panel examined a clinical scenario or treatment decision that would likely benefit from additional evidence and interpretation of evidence, performed a systematic review on the individual, debated the merits of published data and experiential information, developed a consensus report, and provided a clinical bottom line based on the best evidence available. RESULTS This BEC addressed the potential value and limitations of CBCT relative to specific applications in the management of patients requiring or being considered for the following clinical therapies: 1) placement of dental implants; 2) interdisciplinary dentofacial therapy involving orthodontic tooth movement in the management of malocclusion with associated risk on the supporting periodontal tissues (namely, dentoalveolar bone); and 3) management of periodontitis. CONCLUSION For each specific question addressed, there is a critical mass of evidence, but insufficient evidence to support broad conclusions or definitive clinical practice guidelines.

A classification system for crestal and radicular dentoalveolar bone phenotypes.

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.

Tissue engineering for lateral ridge augmentation with recombinant human bone morphogenetic protein 2 combination therapy: a case report.

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.

Cone-Beam Computed Tomography and Interdisciplinary Dentofacial Therapy: An American Academy of Periodontology Best Evidence Review Focusing on Risk Assessment of the Dentoalveolar Bone Changes Influenced by Tooth Movement

BACKGROUND The aim of this systematic review is to evaluate whether cone-beam computed tomography (CBCT) imaging can be used to assess dentoalveolar anatomy critical to the periodontist when determining risk assessment for patients undergoing orthodontic therapy using fixed or removable appliances. METHODS Both observational and interventional trials reporting on the use of CBCT imaging assessing the impact of orthodontic/dentofacial orthopedic treatment on periodontal tissues (i.e., alveolar bone) were included. Changes in the alveolar bone thickness and height around natural teeth as well as treatment costs were evaluated. MEDLINE (via PubMed) and EMBASE databases were searched for articles published in the English language, up to and including July 2016, and extracted data were organized into evidence tables. RESULTS Thirteen studies were included in this systematic review describing the positive or deleterious changes on the alveolar bone surrounding natural teeth undergoing orthodontic tooth movement or influenced by orthopedic forces through fixed appliances. Clinical recommendation summaries presenting the strengths and weaknesses of the evidence in terms of benefits and harms were generated. CONCLUSIONS CBCT imaging can improve the periodontal diagnostic acumen regarding alveolar bone alterations influenced by orthodontic tooth movement and can help determine risk assessment prior to such intervention. Clinicians are also better informed to determine risk assessment and develop preventative or plan interceptive periodontal augmentation (soft tissue and/or bone augmentation) therapies for patients undergoing orthodontic tooth movement. These considerations are recognized as being especially critical for treatment approaches in patients where buccal tooth movement (expansion) is planned in the anterior mandible or involving the maxillary premolars.

Restoration of the Anterior Segment in a Cleft Palate in Conjunction with Surgically Facilitated Orthodontic Therapy : An Interdisciplinary Approach

A 26-year-old woman was referred to a periodontal surgical practice for concerns related to gingival recession. After several consultations among the orthodontist, periodontist, and cosmetic/restorative dentist, she decided to have surgically facilitated orthodontic therapy as part of a collaborative, interdisciplinary treatment planning process to correct her constricted maxillary arch form, augment thin dentoalveolar facial bone, simultaneously with gaining root coverage as well as improving attached gingiva width and mucogingival thickness. As a consequence of changing the arch form, an improvement in the buccal corridor space was gained which optimized her smile display.