Oral Frenum Composition and Clinical Implications in Bone Regeneration: A Review

Successful bone augmentation relies on primary wound closure. The labial frenum is a soft tissue that connects the lip to the alveolar mucosa or gingiva. However, the frenum may exert biomechanical forces to the wound edge, causing wound instability. The aim of this study is to review the frenum composition and classifications and to understand the significance of the frenum in wound stability upon bone regeneration. Together with a manual search, an electronic search was conducted through three online databases on studies published until September 2022. A total of 300 articles were identified, and 9 studies were included in this review. Two of the included studies discovered that 35% to 37.5% of the labial frenum had muscle fibers. Other studies showed that the labial frenum was mainly composed of connective tissue with elastic fibers. There are two widely used classifications for the frenum based on its morphology and attachment position. No studies specifically evaluated the impact of the frenum on bone regeneration, but the frenum location intercorrelated with the amount of keratinized tissue, which could influence wound stability. A modified frenum classification for the edentulous ridge and a decision diagram to manage the frenum is proposed for research and evidence-based practice.

Ultrasound-based jawbone surface quality evaluation after alveolar ridge preservation

BACKGROUND

Bone readiness for implant placement is typically evaluated by bone quality/density on 2-dimensional radiographs and cone beam computed tomography at an arbitrary time between 3 and 6 months after tooth extraction and alveolar ridge preservation (ARP). The aim of this study is to investigate if high-frequency ultrasound (US) can classify bone readiness in humans, using micro-CT as a reference standard to obtain bone mineral density (BMD) and bone volume fraction (BVTV) of healed sockets receiving ARP in humans.

METHODS

A total of 27 bone cores were harvested during the implant surgery from 24 patients who received prior extraction with ARP. US images were taken immediately before the implant surgery at a site co-registered with the tissue biopsy collection location, made possible with a specially designed guide, and then classified into 3 tiers using B-mode image criteria (1) favorable, (2) questionable, and (3) unfavorable. Bone mineral density (hydroxyapatite) and BVTV were obtained from micro-CT as the gold standard.

RESULTS

Hydroxyapatite and BVTV were evaluated within the projected US slice plane and thresholded to favorable (>2200 mg/cm3; >0.45 mm3/mm3), questionable (1500-2200 mg/cm3; 0.4-0.45 mm3/mm3), and unfavorable (<1500 mg/cm3; <0.4 mm3/mm3). The present US B-mode classification inversely scales with BMD. Regression analysis showed a significant relation between US classification and BMD as well as BVTV. T-test analysis demonstrated a significant correlation between US reader scores and the gold standard. When comparing Tier 1 with the combination of Tier 2 and 3, US achieved a significant group differentiation relative to mean BMD (p = 0.004, true positive 66.7%, false positive 0%, true negative 100%, false negative 33.3%, specificity 100%, sensitivity 66.7%, receiver operating characteristics area under the curve 0.86). Similar results were found between US-derived tiers and BVTV.

CONCLUSION

Preliminary data suggest US could classify jawbone surface quality that correlates with BMD/BVTV and serve as the basis for future development of US-based socket healing evaluation after ARP.

Quantitative Ultrasound for Periodontal Soft Tissue Characterization

Periodontal diseases affect 45.9\% of adults aged 30 or older in the United States. Current diagnostic methods for clinical assessment of these diseases are visual examination and bleeding on probing that are subjective, qualitative, and/or invasive. Thus, there is a critical need for research on noninvasive modalities for periodontal tissue characterization. Quantitative Ultrasound (QUS) has shown promising results in noninvasive characterization of various soft tissues; however, it has not been used in periodontics. This study is among initial investigations into the application of QUS for periodontal tissue characterization in the literature. Here, QUS analysis of oral soft tissues (alveolar mucosa and gingiva) is performed in an in vivo animal study including 10 swine. US scanning was performed at the first molar of all four oral quadrants, resulting in a total of 40 scans. We investigated first order speckle statistics of oral tissues by using the two-parameter Burr (power-law b and scale factor l) and Nakagami models (shape factor m and scale factor $\alpha$). Parametric imaging of these parameters was created using a sliding kernel method sweeping regions of interest with a kernel size of 10 wavelengths from a phantom study. Results showed that the difference between gingiva and alveolar mucosa were statistically significant using Burr and Nakagami parameters ($p-value<0.0001$). The Burr b and Nakagami m were higher in gingiva while the Burr l and Nakagami {$\alpha$} were higher in alveolar mucosa. Findings from QUS analyses agreed with observation from histology that showed denser stains for gingiva. Linear classifications of these tissues using 2D parameter spaces of the Burr and Nakagami models resulted in a segmentation accuracy of 93.51\% and 90.91\%, respectively. We propose that QUS holds promising potentials as an augmented tool for disease diagnosis in periodontology.

Considerations for Selecting Root Coverage Techniques in the Anterior Mandible

The anterior mandible is the most challenging anatomical site for performing periodontal plastic surgeries. Increased demands for optimal root coverage and esthetic outcomes contribute to the development of pedicle flap-based surgical solutions, in contrast to the predominantly used free gingival graft. The aims of this study were to (1) summarize the current literature to identify the mostused techniques, indications, and their efficacy, and (2) provide a decision table for surgeons to navigate through the selection of appropriate techniques. Four main approaches were identified: free gingival graft, lateral sliding, tunneling, and coronally advanced flap. The flap approaches are mostly combined with a connective tissue graft. The decision table considers the patient's chief complaint, local anatomical factors, and technique sensitivity. The table provides a framework for supporting an evidence-based selection of surgical techniques and for studying novel methods to achieve predictable root coverage in the anterior mandible.

Role of upfront autologous transplant for peripheral T-cell lymphoma patients achieving a complete remission with first-line therapy: a systematic review and meta-analysis

There is currently no consensus on the role of upfront autologous transplantation (ASCT) for patients with peripheral T-cell lymphomas (PTCL), especially in patients achieving first complete remission (CR1) following chemotherapy, and data in the literature is conflicting. A systematic review and meta-analysis was performed to address this question. We searched key databases from January 2000 to February 2022. Six prospective and eleven retrospective studies were included among 2959 unique records. Median follow up in these studies ranged from 22 to 94 months. There was a trend towards benefit in PFS (HR = 0.80, 95% CI 0.62-1.05, p = 0.11) and OS (HR = 0.79, 95% CI 0.57-1.09, p = 0.15) in the ASCT compared to chemotherapy only group. Importantly, in transplant eligible patients in CR1, a significant benefit was demonstrated in both OS (HR = 0.59, 95% CI 0.36-0.95, p = 0.03) and PFS (HR = 0.61, 95% CI 0.47-0.81, p = 0.0004) in the ASCT group. Amongst the nodal PTCL subgroups, ASCT showed a significant PFS benefit for the AITL subgroup (HR = 0.43, 95% CI 0.20-0.94, p < 0.03) but not PTCL-NOS or ALK-ve ALCL subgroups. Our findings support upfront ASCT for transplant eligible PTCL patients achieving CR1 post chemotherapy. In particular, patients with AITL exhibited a significantly better PFS after upfront ASCT.

Ridge augmentation planning, wound healing evaluation, and peri-implant tissue phenotype assessment with ultrasonography: A case report

BACKGROUND

Ridge regeneration for implant therapy requires comprehensive site evaluation and wound healing monitoring. This case report aimed to demonstrate ultrasound (US) can image soft and hard tissues for surgical planning and assess longitudinal outcomes.

METHODS AND RESULTS

US was used in a patient planned for ridge augmentation to evaluate soft tissue thickness, location of muscle attachment, and hard tissue defect features presurgically. US were obtained at 1, 2.5, and 5 months afterward to assess tissue healing. Preoperatively, US showed ∼2.5 mm and ∼0.8 mm soft tissue thickness on the facial and lingual sides, respectively. The crestal bone width was ∼2 mm, with severe facial bone deficiency and high muscle attachment. US showed wound approximation and ridge width gain to 4.5 and 4.0 mm at 1 and 5 months, respectively. US tissue perfusion increased to ∼two-fold and ∼4-fold at 1 and 2.5 months and reduced below the baseline at 5 months. An implant with simultaneous bone augmentation was performed accordingly. Tissue phenotype around the implant was measured on US images at 1-year visit.

CONCLUSIONS

This case report demonstrated that US parameters could be valuable for planning and wound healing outcome assessment of ridge augmentation in clinical as well as research settings.

KEY POINTS

Why is this case new information? Novel high-resolution, chairside ultrasound was proposed to facilitate treatment planning and wound healing outcome assessment of ridge augmentation in clinical as well as research settings. What are the keys to successful use of this technology? Proper training in imaging acquisition and interpretation Adhere to high-level disinfection protocol Patient education and explanation What are the primary limitations to success in using this technology? Investment in this technology Learning curve in imaging acquisition and reading Insurance reimbursement strategy.

A systematic review of oral wound healing indices

Wound healing monitoring for abnormality identification and intervention is crucial to securing a successful surgical outcome. Indices have been used to summarize the degree of healing. Given the increasing frequency of regenerative procedures which preserve dentition and implant stability, and the higher esthetic demands, an appraisal of the available indices is needed to identify the current knowledge gap. This study aimed to systematically review published oral wound healing indices and scores.

MATERIALS AND METHODS

A complete literature electronic search in 5 databases was conducted by two reviewers. A combination of keywords related to oral wound healing was used.

RESULTS

A total of 11 articles were included in the evaluation of various procedures (conventional periodontal procedures, guided tissue regeneration, soft tissue reconstruction procedures, and tooth extractions), at different time points (1 day to 12 weeks), with a focus on diverse clinical signs and symptoms. Frequently evaluated parameters included wound dehiscence/epithelialization (91%), tissue color (redness) (73%), suppuration (55%), swelling/edema (55%), and hemostasis (55%). Other less commonly used parameters include esthetics-related and patient-centered outcomes.

CONCLUSION

The available indices evaluate a diverse group of subjective clinical signs and symptoms to estimate the underlying biological healing events and assess the degree of clinical success. The majority of the included indices are not validated. Quantitative and objective subclinical parameters including blood perfusion, biomaterial stability, and completeness of epithelialization, are needed for customized wound healing care and better outcome prediction.

Ultrasonography-Derived Elasticity Estimation of Live Porcine Oral Mucosa

OBJECTIVES

To investigate the biomechanical properties of porcine oral tissues with in vivo ultrasonography and to compare the difference between oral alveolar mucosa and gingival tissue concerning compressional and tensile mechanical strain.

MATERIALS AND METHODS

Sinclair minipigs (6 females and 4 males, 6 to 18 months of age) were anesthetized for ultrasonography. In vivo high-frequency tissue harmonic ultrasound (12/24 MHz) cine-loops were obtained while inducing mechanical tissue stress (0 to 1 N). Post-processing strain analysis was performed in a cardiac speckle tracking software (EchoInsight®). Region of interest (ROI) was placed for gingival and alveolar mucosa tissues for longitudinal (compressional) and tensile strain analyses. A calibrated gel pad was employed to determine the absolute force (pressure) for the measured tissue strain response function. The resulting elasticity data was statistically analyzed using custom Matlab scripts.

RESULTS

In total, 38 sonography cine-loops around the third premolars were included in the investigation. The longitudinal strain of alveolar mucosaε AM L was found to be significantly (P < .05) larger than that of gingivaε G L . Across the measured force range,ε AM L  ~ 1.7 × ε G L . Significant differences between alveolar mucosa and gingiva tissues were found for all forces. The tensile strain of the alveolar mucosaε AM T was found to be ~2 × ε G T (on the epithelial surface of the gingiva). Both were statistically significantly different for forces exceeding ~0.08 N. At depth, that is, 500 and 1000 μm below the epithelial surface, the gingiva was found to have less ability to stretch contrary to the alveolar mucosa. Gingival tissue at 500 μm depth has significantly less tensile strain than at its surface and more than at 1000 μm depth. In contrast, the tensile strain of alveolar mucosa is largely independent of depth.

CONCLUSION

Ultrasonography can reveal significant differences in oral alveolar mucosal and gingival elastic properties, such as compressional and tensile strain. Under minute forces equivalent to 10 to 40 g, these differences can be observed. As dental ultrasound is a chairside, and noninvasive modality, obtaining real-time images might soon find clinical utility as a new diagnostic tool for the objective and quantitative assessment of periodontal and peri-implant soft tissues in clinical and research realms. As ultrasound is a safe modality with no known bioeffects, longitudinal monitoring of areas of concern would be particularly attractive.

Review of Intraoral Vasculature and Implications on Incision Designs of Periodontal and Implant Surgeries

Currently, the incision design for periodontal and implant surgeries is mainly based on the surgeon's personal preference. The primary aim of this study is to review the intricate periodontal microvascular system and to illustrate the potential impact of commonly applied flap designs on the integrity of this system. A complete literature electronic search resulted in 37 relevant articles. The maxillary, facial, and lingual arteries supply the microvasculature system, including the supraperiosteal, intraligamental, and intraosseous arterioles. These arterioles have their own territories yet are extensively interconnected. The impact of common papilla management techniques are discussed, including tunneling; papilla base, incision, and preservation; and flap-releasing incisions. Flap design can impact reperfusion and blood inflow in the early healing phase, which eventually influences wound closure probability, healing speed, surgical predictability, tissue volume change, and postoperative morbidity. Future studies on the three-dimensional distribution of microvasculature and clinical impact of various flap designs on tissue reperfusion can lead to evidence-based incision selection and improved wound-healing outcomes.

Life satisfaction and peace of mind among dentists: a cross-sectional study

OBJECTIVES

This study sought to identify the factors associated with the life satisfaction and peace of mind (PoM) of dentists not in full-time clinical training.

MATERIALS AND METHODS

Cross-sectional questionnaires were distributed to dentists in Taiwan to collect their life satisfaction, PoM, sociodemographic data, and dental career-related characteristics. Life satisfaction was measured using a 5-item Satisfaction with Life Scale. PoM was measured using a 7-item Peace of Mind Scale. Descriptive statistics and multiple linear regression models were estimated to explore potential associations between the two scales and the examined factors.

RESULTS

A total of 1196 dentists (45.6% female; mean age = 44.12) completed the questionnaires. The response rate of completed questionnaires from email invitations was 32.9%. On multivariable analysis, life satisfaction and PoM were associated with age (b = 0.008 in both), better perceived health (b = 0.262 and 0.308, respectively), family interaction (b = 0.264 and 0.207, respectively), and friend relationships (b = 0.076 and 0.091, respectively). Being married (b = 0.191), being specialized (b = 0.127), working in private practice, and spending 10 to 39 h per week with patients (b = 0.101 to 0.162) were associated with a higher level of life satisfaction but not PoM.

CONCLUSIONS

Specialists working in private practice without working overtime were associated with better life satisfaction. However, the dentists' health and relationships with family were more related to their subjective well-being than their professional achievements.

CLINICAL RELEVANCE

Our findings can help policymakers increase awareness of the well-being of general dentists and those in academia or hospitals to promote their mental health.

Doppler ultrasonographic evaluation of tissue revascularization following connective tissue graft at implant sites

AIM

To assess the Doppler ultrasonographic tissue perfusion at dental implant sites augmented with connective tissue graft (CTG) using coronally advanced flap (CAF) or tunnel technique (TUN).

MATERIALS AND METHODS

Twenty-eight patients presenting with isolated healthy peri-implant soft-tissue dehiscence (PSTD) were included in this randomized clinical trial. PSTDs were treated with either CAF + CTG or TUN + CTG. Ultrasound scans were taken at baseline, 1 week, 1 month, 6 months and 12 months. Tissue perfusion at the mid-facial, mesial and distal aspects of the implant sites was assessed by colour Doppler velocity (CDV) and power Doppler imaging (PDI). Early vascularization of the graft and the flap at 1 week and at 1 month were evaluated via dynamic tissue perfusion measurements (DTPMs), including flow intensity (FI), mean perfusion relief intensity (pRI) and mean perfused area (pA).

RESULTS

Regression analysis did not reveal significant differences in terms of mid-facial CDV and PDI changes between CAF and TUN over 12 months (p > .05), while significant differences between the two groups were observed at the interproximal areas (p < .001 for both CDV and PDI changes). Higher early DTPMs were observed at the TUN-treated sites in terms of mean FI of the graft (p = .027) and mean FI (p = .024) and pRI of the flap (p = .031) compared with CAF-treated sites at 1 week. Assessment of the FI direction showed that CTG perfusion at 1 week and at 1 month mainly occurred from the flap towards the implant/bone. Early tissue perfusion outcomes were found to be associated with the 12-month mean PSTD coverage and mucosal thickness gain.

CONCLUSIONS

Doppler ultrasonography shows tissue perfusion changes occurring at implant sites augmented with CTG. The main differences in tissue perfusion between CAF and TUN were observed at the interproximal sites, with early perfusion associated with clinical and volumetric outcomes at 12 months.

A Narrative Review on Oral Mucosa Biomechanics and Clinical Implications of Periodontal and Implant-related Regenerative Procedures

Healing outcomes of periodontal and implant-related regenerative procedures are closely related to wound stability, which is partially determined by biomechanical properties and behaviors of oral mucosal tissues. Studies on soft tissue behaviors under biomechanical forces in oral regeneration models are scarce. The aims of this review article are to (1) contrast the microstructural differences between the attached gingiva (AM) and lining (LM) mucosa, (2) evaluate biomechanical behaviors of the two mucosal types,and (3) relate residual flap tension to the prevalence of wound opening after regenerative procedures. Results: Compositional and structural differences between the AM and LM explain the biomechanical property differences between AM and LM. Wound destabilizers, including tissue recoil stemming from its viscoelastic property, muscle pull, and inflammatory edema created after the flap releasing procedure for primary wound closure interfere with wound stability. Residual flap tension <0.05 N is a prerequisite for sustained wound closure. Tissues under stress can exert negative cellular changes, resulting in necrosis and wound dehiscence. Conclusion: Biomechanical properties and the variations between AM and LM dictate the degree of wound stability. Efforts should be made to reduce the negative impact of the potential destabilizers to optimize wound stability.

Anatomy-driven complexity classification for soft-tissue tunneling procedures

BACKGROUND

The tunnel technique (TUN) preserves the integrity of the papilla by creating envelope flaps that allow for the insertion of a connective tissue graft, and/or biomaterials.

METHODS

(1) A comprehensive overview of tunneling flap procedures in the treatment of gingival recessions (GRs) for soft tissue coverage is presented and (2) A classification system for soft and hard tissue anatomy of GR sites which may aid the clinician in determining the surgical complexity is being introduced.

RESULTS

A novel clinical classification system is proposed to illustrate complexity levels determined by soft and hard tissue anatomy of GR sites such as the mucogingival junction proximity to the gingival margin, bone morphotype, and mucosal margin thickness.

CONCLUSIONS

TUN is highly effective in treating single/multiple GRs. Its limitations are related to variability in surgical site anatomy and operator expertise. A classification system based on anatomical soft and hard tissue variations has been proposed to help identify complexity levels encountered during tunneling procedures.

KEY POINTS

Site-related factors directly impact the surgical variables related to tissue trauma, flap tension, soft tissue management, muscle pull, and wound stability during the healing of gingival recessions (GRs). The achievement of expedited and favorable wound healing is crucial to obtaining quantitative and qualitative success in the treatment of GR and the long-term stability of root coverage. A classification system based on anatomical soft and hard tissue variations has been proposed to facilitate tunneling procedures while respecting surgical principles.

Operating microscope-assisted reconstructive strategy for peri-implantitis: A case series report

BACKGROUND

Treating peri-implantitis with reconstructive means has been largely unpredictable due to access limitations for surface decontamination, unfavorable bony topography, difficulty in achieving wound stability, and inferior soft tissue qualities. A microsurgical approach with the use of the operating microscope (OM) that provides adjustable higher magnification (∼5-30 times) and coaxial illumination, coupled with the use of microsurgical instruments, may overcome, or alleviate some of the abovementioned obstacles, resulting in more predictable outcomes.

METHODS

Three patients received reconstructive therapy for correcting peri-implant defects under OM in private practice settings. After precise incisions to preserve soft tissue volume, the flaps were dissected prudently from underlying granulomatous tissues, which were subsequently removed, followed by controlled flap releasing under ∼10-15x magnification. Surface decontamination was performed using a piezoelectric ultrasonic device, air polishing, and hand instruments at ∼30x magnification. The biomaterial selections were dehydrated human de-epithelialized amnion-chorion membrane with mineralized allograft particulates in two cases and xenografts in one case, based on the surgeons' preference. Wound closure followed the non-submerged approach.

RESULTS

These cases demonstrated uneventful soft tissue healing, favorable radiographic bone fill, and disease resolution with follow-ups ranging from 2 to 4 years.

CONCLUSIONS

Preliminary data suggest encouraging outcomes after the microsurgical approach following biological as well as biomechanical principles for peri-implant defect reconstruction.

Preliminary Experience in Transducer Preparation for Intraoral Imaging

Intraoral scanning must meet a stringent infection control standard because of contact with the oral mucosa. A preparation protocol is thus presented for increased inquiries about intraoral scanning requirements. Materials required for such a preparation include: a single-use bubble-free gel packet, a gel standoff pad, and a transducer probe cover. Postscan reprocessing of the ultrasound transducer requires high-level disinfection. Examples for proper and improper use are provided as well as limitations of this preparation protocol and recommendations for future development. This guidance meets the current infection control standard and may guide the user to obtain consistent ultrasound image quality.

Overview of Ultrasound in Dentistry for Advancing Research Methodology and Patient Care Quality with Emphasis on Periodontal/Peri-implant Applications

BACKGROUND

Ultrasound is a non-invasive, cross-sectional imaging technique emerging in dentistry. It is an adjunct tool for diagnosing pathologies in the oral cavity that overcomes some limitations of current methodologies, including direct clinical examination, 2D radiographs, and cone beam computerized tomography. Increasing demand for soft tissue imaging has led to continuous improvements on transducer miniaturization and spatial resolution. The aims of this study are (1) to create a comprehensive overview of the current literature of ultrasonic imaging relating to dentistry, and (2) to provide a view onto investigations with immediate, intermediate, and long-term impact in periodontology and implantology.

METHODS

A rapid literature review was performed using two broad searches conducted in the PubMed database, yielding 576 and 757 citations, respectively. A rating was established within a citation software (EndNote) using a 5-star classification. The broad search with 757 citations allowed for high sensitivity whereas the subsequent rating added specificity.

RESULTS

A critical review of the clinical applications of ultrasound in dentistry was provided with a focus on applications in periodontology and implantology. The role of ultrasound as a developing dental diagnostic tool was reviewed. Specific uses such as soft and hard tissue imaging, longitudinal monitoring, as well as anatomic and physiological evaluation were discussed.

CONCLUSIONS

Future efforts should be directed towards the transition of ultrasonography from a research tool to a clinical tool. Moreover, a dedicated effort is needed to introduce ultrasonic imaging to dental education and the dental community to ultimately improve the quality of patient care.

Coronally advanced flap versus tunnel technique for the treatment of peri-implant soft tissue dehiscences with the connective tissue graft: A randomized, controlled clinical trial

AIM

To evaluate the efficacy of coronally advanced flap (CAF) versus tunnel technique (TUN) in covering isolated mid-facial peri-implant soft tissue dehiscences (PSTDs).

MATERIALS AND METHODS

Twenty-eight participants presenting with isolated non-molar implants exhibiting PSTDs were enrolled and randomized to receive either CAF or TUN, both with a connective tissue graft (CTG). The primary outcome of the study was the percentage of mean PSTD coverage at 12 months. Secondary endpoints included the frequency of complete PSTD coverage, changes in keratinized mucosa width (KMW) and horizontal mucosal thickness (MT), as assessed with transgingival probing, 3D optical scanning and ultrasonography, professional aesthetic evaluation and patient-reported outcome measures (PROMs).

RESULTS

At 12 months, the mean PSTD coverage of the CAF and TUN groups was 90.23% and 59.76%, respectively (p = .03). CAF-treated sites showed a substantially higher frequency of complete PSTD coverage (p = .07), together with significantly greater gain of KMW (p = .01), increase in MT (p = .02), volumetric gain (p < .01) and professional aesthetic outcomes (p = .01). Both interventions showed an improvement in patient-reported aesthetics and a reduction of the anxiety related to the appearance of the implant compared to baseline, with the CAF group obtaining significantly higher scores (p = .03 for both PROMs).

CONCLUSIONS

CAF + CTG resulted in superior PSTD coverage outcomes, greater gain in KMW and MT, and better PROMs than TUN + CTG for the treatment of isolated PSTDs (ClinicalTrials.gov NCT03498911).

Coronally Advanced Flap with Xenogeneic Collagen Matrix for the Treatment of Gingival Recessions at Sites Presenting with Cervical Restorations or Noncarious Cervical Lesions: A Clinical and Ultrasonographic Study

The aim of this prospective study was to evaluate the efficacy of a cross-linked xenogeneic volume-stable collagen matrix (CCM) in treating gingival recessions (GRs) at teeth presenting with cervical restorations or noncarious cervical lesions (NCCLs). Fifteen patients with esthetic concerns for multiple sites with GRs and cervical restorations were consecutively enrolled. The sites were treated with a coronally advanced flap (CAF) design in combination with a CCM. When present, the previous restoration was removed, and the cementoenamel junction was reconstructed with a composite material. The CCM was stabilized on the root surface(s) previously occupied by the restoration. The CAF was sutured to completely cover the graft. Clinical measurements and intraoral digital and ultrasonographic scans were collected at baseline and at 3 and 6 months postsurgery. Limited postoperative discomfort was reported by patients during the healing. The mean root coverage at 6 months was 74.81%. Average increases in gingival thickness of 0.43 mm and 0.52 mm were observed when measured with ultrasonography 1.5 mm and 3 mm apical to the gingival margin, respectively (P < .05). Relatively high patient-reported satisfaction and esthetics were associated with the treatment outcomes. The treatment resulted in a significant reduction in dental hypersensitivity (mean: 33 VAS points). The present study demonstrated that CAF + CCM is an effective approach for treating GRs at sites with cervical restorations or NCCLs. Int J Periodontics Restorative Dent 2023;43:147-154. doi: 10.11607/prd.6448.

Intrasocket reactive tissue: The state of current knowledge

This review focuses on intrasocket reactive tissue and its impact on extraction socket healing. It summarises the current knowledge about intrasocket reactive tissue from a histopathological and biological perspective and discusses the mechanisms by which residual intrasocket reactive tissue can have a positive or negative effect on healing. Additionally, it provides an overview of the various hand and rotary instruments that are currently used for intrasocket reactive tissue debridement. The review also discusses preserving intrasocket reactive tissue as a socket sealing material and the benefits this may offer. It presents clinical cases where either removal or preservation of intrasocket reactive tissue was adopted following extraction and prior to alveolar ridge preservation. Future studies are needed to investigate the suggested beneficial effects of intrasocket reactive tissue on socket healing outcomes.

Ultrasonography on the non-living. Current approaches

The vast majority of clinicians associate diagnostic ultrasound with a tool that is designed for the living patient. However, it is of course possible to apply this imaging technology to evaluate the recently deceased patient for postmortem diagnosis, or even just examine postmortem tissue. We describe several cases in which ultrasound-enabled providers obtain answers in postmortem examinations and discuss potential future strategies and applications. In addition, we will also illustrate the use of sonography in minimally invasive post-mortem tissue sampling (MITS), an approach that can be used in post-mortem minimally invasive autopsies as well as for establishing ultrasound diagnostic parameters in new medical fields such as periodontal and dental implant specialties.

Ultrasound insonation angle and scanning imaging modes for imaging dental implant structures: A benchtop study

INTRODUCTION

High frequency ultrasound has shown as a promising imaging modality to evaluate peri-implant tissues. It is not known if the ultrasound imaging settings might influence ultrasound's ability to differentiate implant structures. The aim of this benchtop study was to evaluate the dependence of ultrasound on imaging angles and modes to measure implant geometry-related parameters.

METHODS

A clinical ultrasound scanner (ZS3, Mindray) with an intraoral probe (L30-8) offering combinations of harmonic and compound imaging modes was employed for imaging 16 abutments and 4 implants. The samples were mounted to a micro-positioning system in a water tank, which allowed a range of -30 to 30-degree imaging angles in 5-degree increment between the probe and samples. The abutment angle, implant thread pitch and depth were measured on ultrasound, compared to the reference readings. The errors were computed as a function of the image angles and modes. All samples were replicated 3 times for 3 image modes and 11 image angles, thus resulting in 2,340 images.

RESULTS

The mean errors of ultrasound to estimate 16 abutment angles, compared to the reference values, were between -1.8 to 2.7 degrees. The root mean squared error (RMSE) ranged from 1.5 to 4.6 degrees. Ultrasound significantly overestimated the thread pitch by 26.1 μm to 36.2 μm. The error in thread depth measurements were in a range of -50.5 μm to 39.6 μm, respectively. The RMSE of thread pitch and depth of the tested 4 implants was in a range of 34.7 to 56.9 μm and 51.0 to 101.8 μm, respectively. In most samples, these errors were independent of the image angle and modes.

CONCLUSIONS

Within the limitations of this study, high-frequency ultrasound was feasible in imaging abutments and implant fixtures independent of scanning angle within ±30° of normal incidence and for compounding and non-compounding-based imaging modes.

Radiographic protrusion of dental implants in the maxillary sinus and nasal fossae: A multidisciplinary consensus utilising the modified Delphi method

The aim of the present study was to generate an international and multidisciplinary consensus on the clinical management of implant protrusion into the maxillary sinuses and nasal fossae. A total of 31 experts participated, 23 of whom were experts in implantology (periodontologists, maxillofacial surgeons and implantologists), 6 were otolaryngologists and 2 were radiologists. All the participants were informed of the current scientific knowledge on the topic based on a systematic search of the literature. A list of statements was created and divided into three surveys: one for all participants, one for implant providers and radiologists and one for otolaryngologists and radiologists. A consensus was reached on 15 out of 17 statements. According to the participants, osseointegrated implants protruding radiographically into the maxillary sinus or nasal fossae require as much monitoring and maintenance as implants fully covered by bone. In the event of symptoms of sinusitis, collaboration between implant providers and otolaryngologists is required. Implant removal should be considered only after pharmacological and surgical management of sinusitis have failed.

Comparative Assessment of Flap-Advancing Techniques in an Ex Vivo Cadaverous Porcine Model

PURPOSE

Since flap advancement is a prerequisite for tension-free primary closure and successful regenerative procedures, the aim of this study was to test the efficacy of six surgical approaches for flap advancement in an ex vivo porcine model.

MATERIALS AND METHODS

A total of 60 fresh mandibles from pigs were randomized into one of six groups: (1) trapezoidal full-thickness flap design with two vertical releasing incisions (control), (2) trapezoidal flap with linear periosteal scoring, (3) mucosal detachment technique, (4) mucosal detachment with horizontal extension, (5) mucosal detachment with horizontal and vertical extension, and (6) mucosal detachment with horizontal vertical and cutback extension. Coronal advancement of the flap was recorded as the primary variable; the surface area of exposed mucosa and the tear strength were recorded as secondary variables.

RESULTS

Homogeneity existed among groups for preoperative keratinized tissue width and tissue thickness. Mucosal detachment with horizontal, vertical, and, cutback extensions achieved the highest amount of advancement. All remaining groups achieved a statistically higher advancement compared with the trapezoidal full-thickness flap (control). Pairwise comparison demonstrated statistical significance between any two groups (P < .001). A positive correlation was noted between exposed mucosa and flap advancement; the advancement increased 0.62 mm for each 10 mm2 of increase in the exposed mucosal surface. Strength at tear stress was the highest in the trapezoidal full-thickness flap (control) and mucosal detachment with horizontal-vertical-cutback incisions (P < .001).

CONCLUSION

Coronal flap advancement was maximized in the mucosal detachment techniques and positively correlated with the area of exposed mucosa.

Agreement in measurements of ultrasonography-derived periodontal diagnostic parameters among multiple raters: A diagnostic accuracy study

OBJECTIVE

The aim of this study was to investigate the reproducibility of measurements of ultrasound-derived periodontal diagnostic parameters (PDPs) among raters.

STUDY DESIGN

Periodontists with various degrees of ultrasound experience were invited to measure 3 PDPs: soft tissue height (STH), soft tissue thickness (STT), and crestal bone thickness (CBT) on 37 human periodontal ultrasound scans acquired at the midfacial site of non-molar maxillary teeth. After an online training session and a 2-week calibration exercise, intraclass correlation coefficients (ICCs) were estimated with mixed linear regression models. The interrater mean absolute differences (MADs) were calculated among the raters and between the raters and a reference standard examiner.

RESULTS

Thirteen raters participated in the study. MADs among the 13 raters were 0.18 mm (STH), 0.16 mm (STT), and 0.12 mm (CBT). ICC values for STH, STT, and CBT were 0.83, 0.77, and 0.76, respectively. The MADs between the raters and the reference standard were 0.23 mm (STH), 0.19 mm (STT), and 0.14 mm (CBT). Survey results showed that ultrasound has diagnostic value and is generally easy to learn.

CONCLUSIONS

Within the limitations of this study, good agreement was observed among ultrasound learners with various degrees of experience when measuring ultrasound-derived PDPs.

Multi-class deep learning segmentation and automated measurements in periodontal sonograms of a porcine model

OBJECTIVES

Ultrasound emerges as a complement to cone-beam computed tomography in dentistry, but struggles with artifacts like reverberation and shadowing. This study seeks to help novice users recognize soft tissue, bone, and crown of a dental sonogram, and automate soft tissue height (STH) measurement using deep learning.

METHODS

In this retrospective study, 627 frames from 111 independent cine loops of mandibular and maxillary premolar and incisors collected from our porcine model (N = 8) were labeled by a reader. 274 premolar sonograms, including data augmentation, were used to train a multi class segmentation model. The model was evaluated against several test sets, including premolar of the same breed (n = 74, Yucatan) and premolar of a different breed (n = 120, Sinclair). We further proposed a rule-based algorithm to automate STH measurements using predicted segmentation masks.

RESULTS

The model reached a Dice similarity coefficient of 90.7±4.39%, 89.4±4.63%, and 83.7±10.5% for soft tissue, bone, and crown segmentation, respectively on the first test set (n = 74), and 90.0±7.16%, 78.6±13.2%, and 62.6±17.7% on the second test set (n = 120). The automated STH measurements have a mean difference (95% confidence interval) of -0.22 mm (-1.4, 0.95), a limit of agreement of 1.2 mm, and a minimum ICC of 0.915 (0.857, 0.948) when compared to expert annotation.

CONCLUSION

This work demonstrates the potential use of deep learning in identifying periodontal structures on sonograms and obtaining diagnostic periodontal dimensions.

Ultrasonographic evaluation of edentulous crestal bone topography: A proof-of-principle retrospective study

OBJECTIVE

Edentulous crestal bone ridge assessment, an essential task for planning of implant and bone regenerative procedures, is performed through radiographs. Ultrasonography, providing point of care and cross-sectional images without radiation, could be an adjunct for this purpose. The aim was to investigate the feasibility of ultrasound (US) in assessing bone ridge width (BRW) and crestal bone surface quality (CBSQ) compared with cone beam computed tomography (CBCT).

STUDY DESIGN

Records of patients who were planned for implant placement in at least 1 healed edentulous ridge space with available CBCT and US images were included. The BRWs at 1, 2, and 3 mm from the crest were measured and compared. The CBSQ agreement evaluated using a 3-tier grading system was calculated.

RESULTS

A total of 45 sites were included. The mean correlation of BRW was 0.97. The mean BRW differences ranged from 0.048 mm (95% confidence interval, -0.69 to 0.78 mm) at the 1-mm level to 0.18 mm (95% confidence interval, -0.92 to 1.3 mm) at the 3-mm level. There was a 91% agreement in CBSQ between the 2 methods.

CONCLUSIONS

Preliminary data with a limited clinical sample size suggested that US is feasible in evaluating crestal BRW and surface quality assessment compared with CBCT.

Intraoral scanning reduces procedure time and improves patient comfort in fixed prosthodontics and implant dentistry: a systematic review

OBJECTIVES

The primary aim of this systematic review was to evaluate whether intraoral scanning (IOS) is able to reduce working time and improve patient-reported outcome measures (PROMs) compared to conventional impression (CI) techniques, taking into account the size of the scanned area. The secondary aim was to verify the effectiveness of IOS procedures based on available prosthodontic outcomes.

MATERIALS AND METHODS

Electronic and manual literature searches were performed to collect evidence concerning the outcomes of IOS and CI performed during the treatment of partially and complete edentulous patients for tooth- or implant-supported restorations. Qualitative analysis was conducted to evaluate the time efficiency and PROMs produced by the two different techniques. Clinical prosthodontic outcomes were analyzed among the included studies when available.

RESULTS

Seventeen studies (9 randomized controlled trials and 8 prospective clinical studies) were selected for qualitative synthesis. The 17 included studies provided data from 430 IOS and 370 CI performed in 437 patients. A total of 7 different IOS systems and their various updated versions were used for digital impressions. The results demonstrated that IOS was overall faster than CI independent of whether quadrant or complete-arch scanning was utilized, regardless of the nature of the restoration (tooth or implant supported). IOS was generally preferred over CI regardless of the size of the scanned area and nature of the restoration (tooth- or implant-supported). Similar prosthodontic outcomes were reported for workflows implementing CI and IOS.

CONCLUSIONS

Within the limitations of this systematic review, IOS is faster than CI, independent of whether a quadrant or complete arch scan is conducted. IOS can improve the patient experience measured by overall preference and comfort and is able to provide reliable prosthodontic outcomes.

CLINICAL RELEVANCE

Reduced procedure working time associated with the use of IOS can improve clinical efficiency and the patient experience during impression procedures. Patient-reported outcome measures (PROMs) are an essential component of evidence-based dental practice as they allow the evaluation of therapeutic modalities from the perspective of the patient. IOS is generally preferred by patients over conventional impressions.

Prevalence and risk indicators of midfacial peri-implant soft tissue dehiscence at single site in the esthetic zone: A cross-sectional clinical and ultrasonographic study

BACKGROUND

Esthetic complications of dental implants in the esthetic zone can have a major negative impact on patients' quality of life and perception of implant therapy. The aim of the present study was to evaluate the prevalence of peri-implant soft tissue dehiscence (PSTD) and the clinical and ultrasonographic risk indicators for this condition.

METHODS

Subjects with one or more healthy single dental implants in the esthetic area were identified and recruited. Clinical and ultrasonographic measurements, including PSTD class and subclass, pocket depth, keratinized mucosa width (KMW), mucosal thickness (MT) at 1 mm and 3 mm, buccal bone distance (BBD) and buccal bone thickness, were evaluated in healthy implants and implants with PSTD.

RESULTS

153 subjects with a total of 176 dental implants were included. The prevalence of PSTD was 54.2% and 56.8% on a patient and implant level, respectively. The most frequent type of PSTD was the one characterized by having both an implant-supported crown longer than the clinical crown of the homologous tooth and a visible abutment/implant fixture exposed to the oral cavity. The multi-variate analysis showed that the presence of an adjacent implant, a longer time of the implant in function, limited MT, reduced KMW and increased BBD were significantly associated with the presence of a PSTD.

CONCLUSIONS

PSTDs are common findings in the esthetic region. Several risk indicators for this condition, such as presence of an adjacent implant, increased time in function of the implant, higher BBD, lower KMW and MT were identified. This article is protected by copyright. All rights reserved.

Personalized and Defect-Specific Antibiotic-Laden Scaffolds for Periodontal Infection Ablation

Periodontitis compromises the integrity and function of tooth-supporting structures. Although therapeutic approaches have been offered, predictable regeneration of periodontal tissues remains intangible, particularly in anatomically complex defects. In this work, personalized and defect-specific antibiotic-laden polymeric scaffolds containing metronidazole (MET), tetracycline (TCH), or their combination (MET/TCH) were created via electrospinning. An initial screening of the synthesized fibers comprising chemo-morphological analyses, cytocompatibility assessment, and antimicrobial validation against periodontopathogens was accomplished to determine the cell-friendly and anti-infective nature of the scaffolds. According to the cytocompatibility and antimicrobial data, the 1:3 MET/TCH formulation was used to obtain three-dimensional defect-specific scaffolds to treat periodontally compromised three-wall osseous defects in rats. Inflammatory cell response and new bone formation were assessed by histology. Micro-computerized tomography was performed to assess bone loss in the furcation area at 2 and 6 weeks post implantation. Chemo-morphological and cell compatibility analyses confirmed the synthesis of cytocompatible antibiotic-laden fibers with antimicrobial action. Importantly, the 1:3 MET/TCH defect-specific scaffolds led to increased new bone formation, lower bone loss, and reduced inflammatory response when compared to antibiotic-free scaffolds. Altogether, our results suggest that the fabrication of defect-specific antibiotic-laden scaffolds holds great potential toward the development of personalized (i.e., patient-specific medication) scaffolds to ablate infection while affording regenerative properties.

Implant Placement with Palatal Access Flap (PAF) for Facial Tissue Preservation in the Esthetic Zone: A Retrospective Case Series

Conventional crestal and intrasulcular incisions followed by full-thickness flap reflection may inevitably induce surgical trauma, resulting in facial contour reduction, mucosal recession, and interdental papilla loss. Flapless implant surgery is the most conservative approach; however, it might create undetectable bone fenestration/dehiscence and subsequent complications. The present clinical study introduces a modified and minimally invasive approach, the palatal access flap (PAF), for placing implants in the esthetic zone. Preliminary data of 15 consecutive cases demonstrated clinically negligible soft tissue contour changes when pre- and postoperative 3D model scans were compared. The PAF technique could be a surgical solution, especially for patients with a high esthetic risk, to maintain facial and interproximal tissue contours for the implant site and adjacent teeth.

Multivariate outcome evaluation of furcation-involved molars treated with non-surgical mechanical therapy alone or combined with open flap debridement: A retrospective study

BACKGROUND

This retrospective study assessed the effect of non-surgical and surgical mechanical therapy for furcation-involved molars.

METHODS

Furcation defects treated and followed for at least 1 year were selected. Data relative to the clinical outcomes were recorded. The immediate (3- to 6-month) clinical outcomes and the long-term survival of the treated molars were assessed. The potential variables influencing the treatment outcomes through multi-level regression analysis, and Cox Proportional-Hazards Models were also analyzed.

RESULTS

One hundred and eighty-four molars were included with an average follow-up of 7.52 years. At the 3- to 6-month re-evaluation 1.39 ± 0.99 mm pocket depth reduction, 0.88 ± 1.29 mm clinical attachment gain, and a 0.51 ± 1.13 mm increase in recession was observed. The 5- and 10-year survival rates were 88.3% and 61.3%, respectively. The horizontal and vertical extent of furcation involvement, baseline probing depth, mucoperiosteal flap elevation, and the frequency of supportive periodontal therapy influenced the clinical outcomes and tooth survival.

CONCLUSION

Non-surgical and surgical mechanical root debridement is a viable treatment for the management of furcation involved molars with shallow horizontal and vertical components.

Maintenance visit regularity has a different impact on periodontitis-related tooth loss depending on patient staging and grading

AIM

To assess whether maintenance variables have a differential effect on tooth loss due to periodontitis (TLP) based on staging and grading.

MATERIALS AND METHODS

Patients treated for periodontitis for a minimum of ≥10 years follow-up were included and categorized according to their stage and grade at baseline. Impact of number, regularity, and pattern of supportive periodontal therapy visits (SPT) on TLP was explored by dividing teeth into test (5 year time periods prior to TLP events) and control groups (random 5 year periods without tooth loss).

RESULTS

The regularity of maintenance visits, but not the overall quantity, had a significant impact on risk of TLP and showed higher importance as staging and grading increased (larger impact for stages III/IV and grade C). The minimum threshold of visits below which the risk of TLP was equivalent to that of the control group was one visit every 7.4 months for stages I-II, 6.7 months for stage III-IV, 7.2 months for grade B and 6.7 months for grade C. This frequency should be increased for former and current smokers, diabetics and elderly patients. Stage III and IV patients who skip more than 1 year of maintenance in a 5 year period have an increased risk of TLP (OR = 2.55) compared to those only miss 1 year. A similar trend was noted for grade C patients, but not for stages I/II or grades A/B.

CONCLUSIONS

Lack of SPT regularity and missing multiple years of maintenance had a larger influence on risk of TLP for higher-level staging and grading.

Comprehensive peri-implant tissue evaluation with ultrasonography and cone-beam computed tomography: A pilot study

OBJECTIVES

The aim of the present study was to explore the feasibility of ultrasonography (US) for clinical imaging of peri-implant tissues.

MATERIAL AND METHODS

Patients with ≥1 implant, a cone-beam computed tomography (CBCT) scan, an US scan, and clinical photographs taken during the surgery were included. The crestal bone thickness (CBT) and facial bone level (FBL) were measured on both US and CBCT modalities, and direct FBL measurements were also made on clinical images. US measurements were compared with CBCT and direct readings.

RESULTS

A total of eight implants from four patients were included. For FBL measurements, US and direct (r2 = 0.95) as well as US and CBCT (r2 = 0.85) were highly correlated, whereas CBCT correlated satisfactorily with the direct reading (r2 = 0.75). In one implant without facial bone, CBCT was not able to measure CBT and FBL accurately. The estimated bias for CBT readings was 0.17 ± 0.23 mm (p = .10) between US and CBCT. US blood flow imaging was successfully recorded and showed a wide dynamic range among patients with different degrees of clinical inflammation.

CONCLUSION

US is a feasible method to evaluate peri-implant facial crestal bone dimensions. Additional US features, for example, functional blood flow imaging, may be useful to estimate the extent and severity of inflammation.

Efficacy of microsurgery and comparison to macrosurgery for gingival recession treatment: a systematic review with meta-analysis

OBJECTIVES

Microsurgical principles, techniques, and armamentarium have made significant contributions to the periodontal plastic surgery. The present meta-analysis aimed to investigate the overall efficacy of microsurgery on root coverage, and its clinical outcomes when compared to traditional macrosurgery.

MATERIAL AND METHODS

Electronic searches on PubMed, Embase, and CINAHL were used to retrieve prospective clinical trials. Primary outcomes were the mean root coverage (mRC) and probability of achieving complete root coverage (cRC), with secondary outcomes as other periodontal parameters and patient-reported outcome measures (PROMs).

RESULTS

Nineteen studies were included in the quantitative analysis. Microsurgery was estimated to achieve 83.3% mRC and 69.3% cRC. From a subgroup of 9 comparative studies, it was estimated microsurgery increased mRC by 6.6% (p<0.001) and cRC by 27.9% (p<0.01) compared to macrosurgical control treatments. Operating microscope (OM) yielded a significantly 6.7% higher mRC than the control group (p=0.002), while using loupes showed 6.16% increase in mRC with a borderline significance (p=0.09). OM and loupes-only had a 31.05% (p=0.001) and 25.54% (p=0.001) increases in achieving cRC compared to control, respectively. As for PROMs, microsurgery reduced postoperative pain (p<0.001) and enhanced esthetics (p= 0.05).

CONCLUSIONS

Microsurgery significantly improved mean root coverage, probability of achieving complete root coverage, esthetics, and post-surgical recovery. Microsurgery enhances not only subclinical healing but also clinical outcomes, possibly owing to its minimally invasive approach and surgical precision.

CLINICAL RELEVANCE

Periodontal plastic microsurgery is minimally invasive, inducing less surgical trauma and ultimately resulting in improved clinical outcomes, patient's satisfaction, and quality of life.

Potential of Using an Implant Fixture as a Ridge Expander for Minor Ridge Augmentation: An Ex Vivo Randomized Controlled Study

To place implants with minimal trauma is what the patient and clinician are seeking. Hence, the aim of this study was to quantify the potential of using an implant fixture as a ridge expander in an underprepared osteotomy. Thirty-eight edentulous sites in 12 human cadaver jaws with ridge widths ranging from 4 to 6 mm and with type 3 or type 4 bone density were randomly assigned into 2 groups. In the ridge expansion group (RE), each osteotomy was drilled to a width of 2.8 mm and depth of 11.5 mm. In the non-ridge expansion (NE) control group, each osteotomy was drilled to a width of to 3.4 mm and depth of 11.5 mm. A 3.7 mm × 11.5 mm tapered implant was inserted into each site. The ridge width before (RW1) and after (RW2) implant placement as well as the buccal plate thickness (BPT) post-insertion were measured and analyzed. In the RE group, the average RW1 and RW2 were 4.69 ± 0.45 mm and 5.54 ± 0.35 mm, respectively, corresponding to a statistically significant ridge expansion of 0.85 mm (P < .01). In the NE group, no ridge width gain was observed (RW1: 4.79 ± 0.40 mm, RW2: 4.88 ± 0.42 mm). Compared to NE, RE resulted in a statistically greater BPT (1.08 ± 0.28 mm after RE vs 0.71 ± 0.37 mm after NE, P < .001). Our study determined that it was physically possible to widen a ridge by an average of 0.85 mm by osteotomy underprepation in ridge with type 3 or type 4 bone density, which effectively turned the implant upon insertion into a ridge expander. The physiological consequences of this method of ridge expansion in a living person must be established before drawing further conclusions about its clinical indications or efficacy.

Ultrasonographic tissue perfusion analysis at implant and palatal donor sites following soft tissue augmentation: A clinical pilot study

AIM

To describe the application of power Doppler Ultrasonography (US) for evaluating blood flow at implant and palatal donor sites following soft tissue augmentation with the connective tissue graft (CTG).

MATERIALS AND METHODS

Five patients exhibiting a peri-implant soft tissue dehiscence received treatment with a coronally advanced flap and corresponding CTG. Power Doppler US was used for assessing blood volume at baseline, 1 week, 1 month, 6 months and 12 months post-surgery for assessing blood-flow dynamics at the implant and palatal donor sites. The speed-weighted and power-weighted colour pixel density (CPPD) were computed from colour velocity (CV) and colour power (CP), respectively.

RESULTS

A mean increase in CV of 199.25% was observed at the midfacial region of the implant sites after 1 week compared to baseline. CV and CP were increased in all sites at 1 week and 1 month. At 6 and 12 months, the mean CV appeared lower than baseline at the implant sites. CCPD was increased at the palatal donor sites and at the great palatine foramen areas at the 1-week and 1-month post-operative evaluations.

CONCLUSIONS

Power Doppler US is a non-invasive and valuable tool for estimating tissue perfusion and CPPD variation during different phases of intra-oral soft tissue graft healing.

Facial mucosal level of single immediately placed implants with either immediate provisionalization or delayed restoration: An intermediate-term study

BACKGROUND

Immediately placed single implants with either immediate provisionalization (test) or delayed restoration (control) were followed for up to 1 year in our previous randomized clinical trial. Peri-implant tissues continue to remodel after implants are in function. Therefore, the primary aim of this study was to evaluate the facial mucosal level changes in the intermediate term between the two groups and to study potential factors influencing the mucosal level change.

METHODS

Patients who had already completed the previous clinical trial by receiving a single immediately placed implant were re-invited to this study. The facial mucosal level as well as the other peri-implant hard and soft tissue dimensions and conditions were measured clinically, radiographically and with ultrasound. These data were compared between the test and control implants. The mucosal level change as the function of the final crown contour, measured as the abutment-crown angle (ACA), was estimated with a linear regression model.

RESULTS

Twenty-eight patients (n of test/control = 16/12) with a mean 30-month follow-up were recruited. The mean mucosal level change was -0.38 mm (control) and 0.06 mm (test), without statistical difference between the two groups. The other clinical, radiographic, and ultrasound parameters were not statistically different. ACA was statistically significant associated with the recession (P = 0.02). The estimate effect was 0.25 mm per 10° increase (adjusted R²  = 0.18; 95% CI, 0.02 to 0.49 mm). After adjusting for vertical implant position, implant abutment angle and the group, the effect became borderline significant (P = 0.09).

CONCLUSIONS

Peri-implant tissues, including the mucosal level change of immediately placed implants with either immediate provisionalization or delayed restoration remained stable and did not differ between the groups in the intermediate term. The final crown angle, influenced by implant position and abutment angle, might be associated with mucosal margin level change.

Amnion-Chorion Membrane in Open-Wound Approach for Localized Horizontal Ridge Augmentation: A Case Series Report

INTRODUCTION

Guided bone augmentation often requires extensive releasing of the mucoperiosteal flap to achieve primary wound closure, an invasive procedure that can compromise the keratinized tissue volume and increase patient morbidity. Amnion-chorion membranes have been used to actively promote healing in chronic open-wound situations in the medical field, suggesting that they could be used in a similar manner in the oral cavity.The ability to use open-wound healing techniques for guided bone regeneration would allow clinicians to avoid invasive procedures that cause additional tissue trauma at the surgical site.

CASE SERIES

Amnion-chorion membranes were applied over the bone grafting material augmenting localized horizontal ridge defects, and a gap between the flaps was left intentionally during healing. Minor flap releasing procedures were performed in these cases, which demonstrated uneventful soft tissue healing, good volume of bone regeneration and preserved keratinized tissue.

CONCLUSIONS

Preliminary clinical outcomes suggested contained minor horizontal ridge defects may be treated satisfactorily in a controlled, open-wound healing manner that reduces surgical trauma, chair time, and patient morbidity.

Impact of mucosal phenotype on marginal bone levels around tissue level implants: A prospective controlled trial

BACKGROUND

The aim of this 1-year prospective clinical trial was to compare clinical parameters and marginal bone levels (MBLs) around tissue level implants with a partially smooth collar between patients with thin (≤2 mm) and thick (>2 mm) vertical mucosal phenotypes.

METHODS

Thirty patients needing a single dental implant were recruited and allocated to thin (n = 14) or thick (n = 16) phenotype groups. Post-restoration, clinical (probing depth, recession, width of keratinized mucosa, bleeding on probing, suppuration, implant mobility, plaque index, and gingival index) and radiographic bone level measurements were recorded at different timepoints for 1 year.

RESULTS

Twenty-six patients (13 per group) completed the 1-year examination. No implants were lost (100% survival rate). There were no significant differences (P >0.05) between thin and thick vertical mucosal phenotypes for any clinical parameter or for the radiographic MBL.

CONCLUSIONS

Tissue level implants at 1 year of function placed in thin vertical mucosa achieved similar clinical parameters and radiographic MBLs as those in thick tissue. The formation of the peri-implant supracrestal tissue height plays a key role in MBL than mucosal thickness in tissue level implant.

Does a fully digital workflow improve the accuracy of computer-assisted implant surgery in partially edentulous patients? A systematic review of clinical trials

BACKGROUND

Accurate implant placement is essential in reducing post-treatment complications and in ensuring a successful treatment outcome.

PURPOSE

To compare the accuracy of fully-guided static computer-assisted implant surgery (s-CAIS) using partially- and fully-digital workflows.

MATERIALS AND METHODS

Electronic and manual literature searches were performed to collect evidence concerning the accuracy of fully-guided s-CAIS procedures utilizing tooth-supported guides. Quantitative analysis was conducted to evaluate the accuracy of partially- and fully-digital workflows, and survival rates and complications were qualitatively analyzed.

RESULTS

Thirteen studies, including 6 randomized controlled trials and 7 prospective clinical studies, were selected for quantitative and qualitative synthesis. A total of 669 implants in 325 patients using s-CAIS were available for review. Meta-analysis of the accuracy revealed a total mean angular deviation of 2.68° (95% CI: 2.32°-3.03°); mean global coronal deviation of 1.03 mm (95% CI: 0.88-1.18 mm); mean global apical deviation of 1.33 mm (95% CI: 1.17-1.50 mm); and mean depth deviation of 0.59 mm (95% CI: 0.46-0.70 mm). Minimal differences were found between the two different workflows. Few complications were reported, and survival rates were between 97.8% to 100% (range of follow-up: 12 to 24 months) in the available studies.

CONCLUSION

Similar accuracy is obtained when implants are placed in partially edentulous patients using fully-guided s-CAIS, independently of the workflow utilized.

0882 Local Deformation Analysis of Lateral Cephalogram for Childhood OSA Classification

Introduction

Craniofacial profile is one of the anatomical causes of obstructive sleep apnea (OSA). Cephalometry provides information on patients’ skeletal structures and soft tissues. Traditional cephalometric analysis focuses on linear distances, angles, ratios and area of specific variables. Its classification power is often disappointed. In this study, a novel approach to cephalometric analysis using local deformation information was carried out to assess its efficacy in OSA classification.

Methods

This study was a retrospective analysis based on 60 case-control pairs who were Chinese children recruited for sleep studies in the Prince of Wales Hospital, with accessible lateral cephalometry and polysomnography (PSG) data. Local deformation technique was adopted to derive 1215 deformations from 15 manual landmarking on each cephalogram. In addition, three linear distances (hyoid bone to mandibular plane, hyoid bone to posterior pharyngeal wall, and minimal distance between tongue base and posterior pharyngeal wall) were measured from each cephalogram. A total of 1218 information features were obtained per subject. Classification models were built with an equal ratio between OSA and non-OSA groups (defined by OAHI≥1 and OAHI&lt;1 respectively). Forty pairs were used as training data and twenty pairs were used as testing data.

Results

Three model settings which used all 1218 cephalometric features, 800 features, and 500 features were tested. The accuracy for the three settings were 67.5% (sensitivity: 70%, specificity: 65%), 87.5% (sensitivity: 90%, specificity: 85%), and 92.5% (sensitivity: 95%, specificity: 90%) respectively. Apart from the three distances, the 500 topmost discriminative features were predominantly landmarks around the nasal cavity.

Conclusion

A new approach to cephalometric analysis using local deformation information can provide additional details on each cephalogram, hence, achieving better classification. The classification models using 500 features yielded the highest accuracy among the three settings. This setting could benefit most from the comprehensive comparison while avoiding overfitting.

Support

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Life satisfaction of Taiwanese dental graduates received residencies in the U.S.: a cross-sectional study

BACKGROUND

Each year, more than 200 international dental graduates start U.S. specialty trainings to become specialists. It is unknown if their life satisfaction is associated with any dental career-related factor before residencies (e.g. dental school class rank, research experience, or private practice experience) and after residencies (e.g. staying in the U.S., teaching status, workplace, or board certification). This cross-sectional study aimed to identify these potential factors by surveying Taiwanese dental graduates who pursued U.S. residencies.

METHODS

Life satisfaction was measured with a structured questionnaire, Satisfaction With Life Scale (SWLS), which includes five statements on a 5-point Likert scale. Online surveys were sent out to 290 Taiwanese dental graduates who were known to pursue U.S. residencies. T-test, one way analysis of variance, and multivariable adjusted generalized linear model (GLM) were used to assess the differences of mean SWLS scores from different variables.

RESULTS

Surveys were completed by 158 dentists. Mean SWLS score of 125 specialists was higher (p = 0.0007) than the score of 33 residents. For the 125 specialists, multivariable adjusted GLM demonstrated better life satisfaction was positively associated with multiple independent factors, such as having research experience, being ranked in the top 26 ~ 50% of the class in dental school, starting U.S. residency within 4 years after dental school, starting residency before year 1996, and specializing in endodontics (vs. periodontics). Life satisfaction was not associated with any factors after residency (e.g. staying in the U.S. afterwards, teaching status, or workplace), but better mean life satisfaction score was significantly associated with being American specialty board certified (p < 0.001) for the specialists in the 26 ~ 75% of their class in dental school. For the 33 residents, better mean life satisfaction score was associated with better dental school class rank in both bivariate (p = 0.020) and multivariable adjusted GLM (p = 0.004) analyses.

CONCLUSIONS

The life satisfaction of Taiwanese dental graduates pursuing U.S. residencies might be associated with some professional factors, such as research experience, dental school class rank, residency timing, specialty type, and specialty board certification. We hope our results may provide some objective information on making career decisions for international dental graduates/students who are preparing for U.S. residency.

Ultrasonography for diagnosis of peri-implant diseases and conditions: a detailed scanning protocol and case demonstration

OBJECTIVES

Ultrasonography has shown its promising diagnostic value in dental implant imaging research in the three treatment phases, namely, planning, intraoperative, and postoperative phase. With increasing awareness of peri-implant diseases and a lack of an efficient diagnostic method, the aim is to propose ultrasound imaging as a potential solution by providing a detailed scanning protocol and case demonstration.

METHODS

Ultrasound device specification and the setup for optimizing peri-implant tissue imaging was described. Two useful imaging modes, viz. B-mode and color flow, were introduced. Important anatomical structures for accurate diagnosis of peri-implant diseases were illustrated. Finally, a detailed scanning sequence was proposed.

RESULTS

Ultrasound images were acquired on live humans to exemplify the four peri-implant diseases and conditions, endorsed by the 2017 World Workshop organized by the American Academy of Periodontology and the European Federation of Periodontology. Ultrasound can provide not only cross-sectional anatomical images but also functional images (color flow images) that may be useful for evaluating the degree of peri-implant tissue inflammation.

CONCLUSIONS

High-frequency ultrasonography could be another cross-sectional imaging modality in adjunct to radiographs for diagnosing imminent peri-implant diseases and conditions that negatively influence quality of life of millions of patients with implants. This case study provides a framework for future related research work and clinical scanning guidelines.

Ultrasonographic characterization of lingual structures pertinent to oral, periodontal, and implant surgery

OBJECTIVES

Increased applications of ridge augmentation in the lingual posterior mandible call for an urgent need to study its anatomy. Therefore, our first aim was to validate ultrasound in measuring the mandibular lingual structures in human cadavers. Secondarily, to test its feasibility in imaging the lingual nerve in live humans.

MATERIALS AND METHODS

Nine fresh un-embalmed fully/partially edentulous cadaver heads were utilized for aim 1. Three areas in the lingual mandible were imaged (mandibular premolar, molar, and retromolar). Immediately after, biopsies were harvested from each site. The thickness of the mucosa, mylohyoid muscle, and lingual nerve diameter was measured via ultrasound and statistically compared to histology. Similarly, the lingual nerve in live humans was also imaged.

RESULTS

None of the differences between the ultrasound and histology measurements reached statistical significance (p > .05). The mean mucosal thickness via ultrasound and histology was 1.45 ± 0.49 and 1.39 ± 0.50 mm, 5 mm lingual to the mylohyoid muscle attachment. At 10 mm beyond the attachment, the ultrasound and histologic values were 1.54 ± 0.48 and 1.37 ± 0.49, respectively. The mean muscle thickness measured via ultrasound and histology was 2.31 ± 0.56 and 2.25 ± 0.47 mm, at the 5 mm distance. At the 10 mm distance, the measurements were 2.46 ± 0.56 and 2.36 ± 0.5 mm, respectively. The mean ultrasonic lingual nerve diameter was 2.38 ± 0.44 mm, versus 2.43 ± 0.42 mm, with histology. The lingual nerve diameter on 19 live humans averaged to 2.01 ± 0.35 mm (1.4-3.1 mm).

CONCLUSIONS

Within its limitations, ultrasound accurately measured mandibular lingual soft tissue structures on cadavers, and the lingual nerve on live humans.

Ultrasonography for chairside evaluation of periodontal structures: A pilot study

BACKGROUND

The crestal bone level and soft tissue dimension are essential for periodontal diagnosis and phenotype determination; yet, existing measurement methods have limitations. The aim of this clinical study was to evaluate the correlation and accuracy of ultrasound in measuring periodontal dimensions, compared to direct clinical and cone-beam computed tomography (CBCT) methods.

METHODS

A 24-MHz ultrasound probe prototype, specifically designed for intraoral use, was employed. Periodontal soft tissue dimensions and crestal bone levels were measured at 40 teeth and 20 single missing tooth gaps from 20 patients scheduled to receive a dental implant surgery. The ultrasound images were interpreted by two calibrated examiners. Inter-rater agreement was calculated by using inter-rater correlation coefficient (ICC). Ultrasound readings were compared with direct clinical and CBCT readings by using ICC and Bland-Altman analysis.

RESULTS

The following six parameters were measured: 1) interdental papilla height (tooth), 2) mid-facial soft tissue height (tooth), 3) mucosal thickness (tooth), 4) soft tissue height (edentulous ridge), 5) mucosal thickness (edentulous ridge), and 6) crestal bone level (tooth). Intra-examiner calibrations were exercised to achieve an agreement of at least 0.8. ICC between the two readers ranged from 0.482 to 0.881. ICC between ultrasound and direct readings ranged from 0.667 to 0.957. The mean difference in mucosal thickness (tooth) between the ultrasound and direct readings was -0.015 mm (95% CI: -0.655 to 0.624 mm) without statistical significance. ICC between ultrasound and CBCT ranged from 0.654 to 0.849 among the measured parameters. The mean differences between ultrasound and CBCT range from -0.213 to 0.455 mm, without statistical significance.

CONCLUSION

Ultrasonic imaging can be valuable for accurate and real-time periodontal diagnosis without concerns about ionizing radiation.

Classification of Sinus Membrane Perforations Occurring During Transcrestal Sinus Floor Elevation and Related Treatment

The predictability of transcrestal sinus floor elevation (tSFE) in elevating the sinus membrane following posterior maxillary ridge resorption has been widely demonstrated. To minimize complications and increase success, a literature search was conducted to validate procedures used for tSFE. A decision tree based upon timing of perforations was then developed to improve membrane-perforation management during the procedure. At each surgical procedure, the clinician is encouraged to use size of the perforation, time during the procedure in which the perforation occurred, and resulting symptoms to determine the best treatment approach. This article discusses all possible sinus membrane perforations based on timing of that surgical procedure, allowing the clinician to recognize and successfully rectify this clinical complication while successfully completing the surgery. With this aim, a classification of sinus membrane perforations occurring during tSFE is proposed, simultaneously providing guidelines to effectively manage these complications.

Quantitative tooth mobility evaluation based on intraoral scanner measurements

BACKGROUND

Tooth mobility assessment is subjective and current techniques require the translation of a continuous variable to a categorical variable based on the perception of the examiner. The aim of this study was to evaluate the reliability of a novel technique to assess tooth mobility.

METHODS

Three experienced periodontists were asked to push tooth #16 into a buccal position to in a typodont model with different mobility (M1-M2). Tooth position was obtained using an intraoral scanner and files were compared in metrology software. Mobility was calculated at three reference points at the cervical (C), middle (M), and occlusal (O) regions of the buccal surface of the tooth to determine the linear deviation in the three axes (x, y, and z). Reliability was determined by intraclass-correlation coefficient, differences between M1 and M2 determined by t test, and the analysis of variance (ANOVA) was used to compare the data at the C-M-O regions.

RESULTS

Excellent reliability was assessed by Cronbach alpha >0.9 on the x-y-z axes for both mobility tested, except for M1-C X (0.85), M1-M Y (0.89), and M2-M Z (0.89). The correlation between the examiners demonstrated excellent (˃0.90) or good (0.75˃ x ˂0.90) consistency, except for M1-C Y (0.73; examiner 1 to 2) and M1-M X (0.69; examiners 1 to 3). Significant changes were detected in all axes at the three reference points comparing M1 and M2, and a similar proportional change was observed between O-M-C reference points for M1 and M2.

CONCLUSION

A novel technique to assess tooth mobility based on intraoral scanner measurements provided reliable data in an in vitro experiment.