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Peer W Kämmerer, Monika Daubländer Department of Oral, Maxillofacial and Facial Plastic Surgery, University Medical Centre Mainz, Mainz, GermanyWe read the article by Al-Shayyab1 with great interest, though we think that there is a methodical bias. Usage of standard dental syringes with 27-gauge needles is not recommended for periodontal ligament (PDL) injections as they are very unlikely to achieve the correct pressure needed for successful single tooth anesthesia. In accordance with this, specialized syringes with short 30-gauge needles are commonly used all over the literature.2 The author addresses this in the “Discussion” section and writes that “a standard conventional dental syringe was used in the present study, not a special PDL syringe, since the former is readily available in the clinic and proves equally successful when a standard 27-gauge short needle was used,” citing Malamed from 1982 (a time during which the modern PDL syringes were not developed yet3) and Madan et al who write that “intraligamentary injection technique is equally effective when a standard 27-gauge needle is used”.4 The second assumption refers to the needle only, not the syringe. In addition, this needle issue is not proven by any reference or study. Therefore, one might come to the conclusion that PDL was not carried out correctly. Also, the authors did not evaluate pulp or tissue anesthesia and started the extraction procedure after a latency period of 5 minutes in all cases. In accordance with this, the success rates of the PDL injection cannot be given, but would be of interest.View the original paper by Al-Shayyab and colleagues.

J Oral Pathol Med (2010) 39: 786-792 Background: Vascular endothelial growth factor (VEGF) plays an important role in promoting angiogenesis and is overexpressed in several malignancies. Polymorphisms of the VEGF gene can alter VEGF protein expression, which may be biologically significant and account for heterogeneity in disease risk and outcome. The aim of this case-control study was to evaluate potential associations between single nucleotide polymorphisms (SNP) of the VEGF gene with susceptibility of oral squamous cell carcinoma (OSCC). Patients and methods: Five VEGF SNP (-1154 G/A, +405 G/C, +936 C/T, -2578 C/A and -460 C/T) were determined in peripheral blood isolated from 80 patients with OSCC and from 40 age- and gender-matched healthy volunteers (RT-PCR). Results: The +936 T allele and the -2578 C/A SNP were expressed significantly more often in the OSCC-group (P = 0.002; P < 0.0001) where three associations between two SNPs (+936 and +405, -2578 and -1154, -460 and -2578) were found. Conclusion: Our findings provide support that +936 T allele and -2578 C/A SNP of the VEGF gene alone or in combination with other SNP are associated with OSCC. The SNPs may be used as biomarker for the development of specialized anti-VEGF drugs. Further studies must confirm the value of preoperative genetic analysis for prognosis. [ABSTRACT FROM AUTHOR]

This study aimed to identify factors influencing the completeness of primary and re-excision of basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (SCC), and cutaneous carcinoma in situ (CIS) of the head and neck. A retrospective single-center analysis was conducted, encompassing 1513 instances of cutaneous tumors recorded between 2015 and 2022. This dataset comprised 1108 primary excisions and 405 re-excisions, all of which were histologically verified cases of BCC, SCC, and CIS located within the head and neck region. Correlation analyses were performed, considering variables such as patients' gender and age, tumor localization, preoperative suspicion or histological confirmation of skin tumor diagnosis, surgeons' levels of training, and the utilization of magnifying glasses. The primary objective was to assess the impact of these factors on the completeness of both primary and re-excisions of skin tumors. The analysis revealed a significant correlation between the localization of BCC and the completeness of primary excision. Specifically, the nose and ear exhibited a significantly higher rate of incomplete excisions (R1), whereas the cheek demonstrated a substantial reduction in the R1 rate. The utilization of magnifying glasses exhibited a positive correlation with the completeness of primary BCC excision. However, no discernible influencing factors were identified for BCC re-excisions and the combined group of primarily and re-excised cutaneous squamous cell carcinoma (SCC) and carcinoma in situ (CIS). Tumor entity and localization emerged as crucial factors influencing the completeness of skin tumor excisions, with specific anatomical sites exhibiting varying rates of incomplete procedures. Notably, the use of magnifying glasses demonstrated a significant positive correlation with reduced rates of incomplete excisions, re-excisions, and subsequent procedures, suggesting its potential as a valuable tool in enhancing surgical precision and optimizing outcomes., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Several methods have been described for treating deep Cairo Class RT1 recessions. Most involve relieving incisions, which cause scar tissue formation or use a tunneled approach. This report introduces a modified technique for treating a single deep recession beyond the mucogingival margin. The approach uses a laterally closed coronally advanced flap (LCAF) without relieving incisions, combined with a subepithelial connective tissue graft and enamel matrix derivative., Methods: A 28-year-old woman was referred to our periodontal practice for the treatment of a progressive deep Cairo Class I recession with hypersensitivity and limited access to hygiene measures. The root coverage procedure was performed using a modified LCAF, combined with a connective tissue graft from the palate and enamel matrix derivative. The case was followed for 6 months., Results: The healing process was uneventful. Six months after surgery, the root surfaces remained completely covered. Hypersensitivity resolved entirely, and there was only a slight formation of visible scar tissue., Conclusions: This modified technique of an LCAF is a feasible and effective method for treating single deep RT1 recessions. By avoiding visible relieving incisions, scar tissue formation is minimized. The preparation of an LCAF allows for adequate coronal advancement., Key Points: As far as our knowledge, this is the first description of a laterally closed coronally advanced flap (LCAF) combining the advantage of a minimalized scarring root coverage with a simplified coronally advancement for recessions exceeding the mucogingival junction. This modified technique combines the advantages of a lateral closing with a CAF for covering deep class RT1 recessions. Meticulous handling of the delicate pedicles combined with a coronal advancement of at least 2 mm beyond the cemento-enamel junction is the key factor for the successful adaption of this technique., Plain Language Summary: Deep gum recessions originating from traumatic hygiene measures can cause hypersensitivity and limit patients´ access to oral hygiene. Especially in deep recessions, the common surgical techniques have shortcomings due to a post-surgical lack of keratinized gingiva or visible scar tissue formation. This case study shows the treatment of a 28-year-old woman´s deep recession on a mandibular front tooth introducing a modified surgical technique for covering deep gum recessions exceeding the area of the keratinized gingiva (so-called deep Cairo RT1 recessions). This new technique uses a "laterally closed coronally advanced flap" (LCAF), which combines a curtain-similar lateral closing of the flap pedicles with a coronal advancement to cover the recession without making cuts that can lead to scars. It is combined with a tissue graft from the patient's palate and a special protein to regenerate the periodontium. Six months after surgery, complete root coverage was achieved without remaining hypersensitivity and with restored access for oral hygiene measures. Minimal visible scar tissue formed. This case study demonstrates that the LCAF is a feasible technique for covering single deep gum recessions exceeding the keratinized area of the gingiva., (© 2024 American Academy of Periodontology.)

Introduction. Ecological concerns and the depletion of petroleum resources have driven the exploration of biodegradable 3D-printing materials derived from bio-renewable sources, such as polylactic acid (PLA) and polyhydroxyalkanoates (PHA). This study aimed to compare the potential cytotoxic effects of a biodegradable PLA/PHA blend filament, a conventional photopolymer (MED610), and a combination of MED610 with a support material (SUP705) before and after steam sterilization in vitro, with a focus on their application in the production of surgical guides. Materials and Methods. PLA/PHA, MED610, and SUP705 (both in their pure and steam-sterilized forms; n = 6 per group) were assessed for their cytotoxic effects on human fibroblasts using the neutral red uptake assay. Positive controls included zinc diethyldithiocarbamate and zinc dibutyldithiocarbamate, while high-density polyethylene served as a negative control. A stock solution of the extraction medium was used as the vehicle control (VC). Results. Significant differences in cell viability were observed between pure PLA/PHA (1.2 ± 0.24) and MED610 (0.94 ± 0.08) ( p = 0.005). However, both materials exhibited non-cytotoxicity, with cell viability exceeding 70% compared to VCs. SUP705 (0.58 ± 0.42) demonstrated significantly reduced cell viability compared to PLA/PHA ( p = 0.001) and MED610 ( p = 0.007). After steam sterilization, no significant difference in cell viability was noted between MED610 (1.0 ± 0.08) and PLA/PHA (1.2 ± 0.25) ( p = 0.111). While both materials remained non-cytotoxic after sterilization, SUP705 (0.60 ± 0.45) exhibited cytotoxic effects compared to MED610 ( p = 0.006) and PLA/PHA ( p < 0.001). Steam sterilization did not induce significant cytotoxic effects in the investigated materials ( p = 0.123). Conclusion. Pure and steam-sterilized PLA/PHA and MED610 were not cytotoxic, supporting their potential use in the production of surgical guides. However, the observed cytotoxicity of SUP705 suggests caution in scenarios requiring sterile conditions, as the removal of support material from complex printed parts may be challenging. The consideration of PLA/PHA is recommended in such settings to ensure biocompatibility., (Creative Commons Attribution license.)

Purpose/objectives: This prospective crossover preclinical trial aimed to evaluate the learning curve of dental students in successfully administering intraligamentary anesthesia (ILA) using three different syringe systems., Methods: Dental students performed ILA using three devices in two separate sessions, each targeting mandibular and/or maxillary premolars. The devices included two manual systems (pistol-type and lever-based) and one computer-controlled local anesthetic delivery system (CCLAD). The primary research parameter was the success rate of anesthesia, defined as the percentage of successful ILA administrations confirmed by a negative response to a cold test. Secondary parameters included pain experienced during needle penetration and injection, students' self-reported levels of mental tension and handling of the syringes, and any potential side effects., Results: A total of 110 students performed ILA on 599 teeth during the study period. When comparing the CCLAD system to the manual syringes, the CCLAD system exhibited a significantly higher overall success rate in the first session (92.5% vs. 77.4%; p < 0.001), potentially due to its precise control of anesthetic flow and pressure, which likely facilitated more effective anesthetic delivery. However, when examining the individual manual techniques, no significant difference was found between the pistol-type manual and the CCLAD system (p = 0.66). All techniques' success rate increased from the first to the second session (80.4% vs. 86.9%; p = 0.0357). Additionally, penetration pain demonstrated a significant decrease across all techniques (p < 0.01). Notably, students' anxiety levels decreased, and self-assurance increased significantly over the sessions. Undesired reversible side effects were documented in 10.9% of cases., Conclusion: These findings suggest that repeated practice of ILA, particularly with different syringe systems, enhances anesthetic success and psychological readiness for patient interaction. Additional training sessions may further improve proficiency., (© 2024 The Author(s). Journal of Dental Education published by Wiley Periodicals LLC on behalf of American Dental Education Association.)

Objectives: Venous thromboembolism (VTE) is still considered to be a significant medical issue. Physical measures to prevent perioperative venous thrombosis include early mobilization and intermittent pneumatic compression (IPC). The aim of this study was to evaluate whether IPC can reduce the incidence of postoperative thromboembolic events in patients with oral squamous cell carcinoma (OSCC) undergoing maxillofacial surgery., Materials and Methods: Between March 2020 and May 2021, 75 patients with OSCC who did not receive perioperative prophylaxis using IPC were retrospectively examined to determine the occurrence of postoperative thromboembolism. Accordingly, 79 patients who received perioperative thrombosis prophylaxis using an IPC system as part of surgical tumor therapy from May 2021 to September 2023 were included in the study. The primary outcome measure was the occurrence of postoperative thromboembolism., Results: In the control group without IPC, thromboembolic events were observed in five out of 75 patients during postoperative hospitalization. In the intervention group, no thromboembolic occurrences were identified among the 79 patients studied (p = 0.02). The mean Caprini score in the control group was 7.72, whereas in the intervention group it averaged 8.30 (p = 0.027)., Conclusions: The implementation of IPC-devices as supplementary perioperative thrombosis prophylaxis resulted in a notable decrease in postoperative venous thromboembolism (Number Needed to Treat = 15), which is why implementation of the system as a regular part of the clinical routine for perioperative management of OSCC patients can be considered a sensible approach., Clinical Relevance: The use of IPC enhances patient outcomes and may lead to improved postoperative care protocols in this high-risk patient population., (© 2024. The Author(s).)

Purpose: Ridge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition., Methods: In this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation., Results: Vertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as "Success" according to the ICOI scheme, with no differences in implant quality between the two study groups., Conclusions: Improved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation., (© 2024. The Author(s).)

Free flap failure represents a substantial clinical burden. The role of intraoperative volume management remains controversial, with valid studies lacking. Here, using a large animal model, we investigated the influence of volume management on free flap perfusion and metabolism. Autotransfer of a musculocutaneous gracilis flap was performed on 31 German domestic pigs, with arterial anastomosis and catheterization of the pedicle vein for sequential blood sampling. Flap reperfusion was followed by induction of a hemorrhagic shock with maintenance for 30 min and subsequent circulation stabilization with crystalloid solution, crystalloid solution and catecholamine, autotransfusion or colloidal solution. Flap perfusion and oxygenation were periodically assessed using hyperspectral imaging. Flap metabolism was assessed via periodic blood gas analyses. Hyperspectral imaging revealed no difference in either superficial or deep tissue oxygen saturation, tissue hemoglobin or tissue water content between the test groups at any time point. Blood gas analyses showed that lactate levels were significantly increased in the group that received crystalloid solution and catecholamine, after circulatory stabilization and up to 2 h after. We conclude that, in hemorrhagic shock, volume management impacts acid-base balance in free flaps. Crystalloid solutions with norepinephrine increase lactate levels, yet short-term effects on flap perfusion seem minimal, suggesting that vasopressors are not detrimental., (© 2024. The Author(s).)

Background: This systematic review assesses the current literature (2020-2024) evaluating the impact of smoking on dental implant failure rates. Methods: A non-funded Pubmed database review was conducted according to PRISMA guidelines, and the results were tabulated to extract the study design, patient characteristics, follow-up time, comparison, outcome, and strengths and weaknesses, including risk of bias. This review included 33 studies with 29,519 implants placed in over 18,301 patients. We included prospective and retrospective clinical studies, randomized and non-randomized controlled trials, cohort studies, and observational studies that examined smoking's effects on implant failure rates. Studies had to classify individuals into two groups, smokers and non-smokers, with at least ten implants. Exclusions included reviews, case reports, experimental studies, guidelines, non-English publications, studies lacking comparative data on failure rates, those excluding smokers, and studies focusing on head and neck cancer patients or specialized implants. Results: Our findings indicate a significant correlation in 25 out of 33 studies between smoking and increased implant failure rates, affecting both early and late stages of implant integration and survival as well as revealing a dose-response relationship, with higher daily cigarette consumption significantly increasing the risk of implant failure. Conclusions: This review highlights the importance of smoking cessation efforts, patient education, and tailored patient care in dental implantology. Future research should explore the effects of smoking frequency and alternative tobacco products, such as e-cigarettes, aiming to improve success rates among smokers.

Introduction: This study aimed to evaluate the use of botulinum toxin (BTX) for the treatment of bruxism in oral and maxillofacial surgery in Germany., Material and Methods: A dynamic online questionnaire comprising 7 to 25 questions was formulated to gather general and specific information regarding using BTX to treat bruxism. The questionnaire underwent internal and external assessments for validation. Subsequently, it was distributed to 906 oral and maxillofacial surgeons (OMFS) affiliated with the German Association for Oral and Maxillofacial Surgery (DGMKG). Weekly reminders were dispatched over four weeks to enhance response rates. Participation in the study was voluntary and anonymized. Descriptive methods were employed for data analysis., Results: 107 OMFS participated in the study, yielding a response rate of 11.81%. On average, 17 patients with bruxism were per month, with 4 of these patients receiving BTX therapy. BTX administration was frequently accompanied by splints and physiotherapy (35.51% of participants). Botox® (Allergan) was the preferred BTX preparation, utilized by 40.79% and reconstituted with saline by 92.11% of participants. The masseter muscles were primarily targeted for BTX treatment (67.57% of participants), averaging 29 BTX (Allergan-) units per side. Injection points for each masseter muscle typically amounted to six per side, preferred by 30.67% of participants. Follow-up assessments post-BTX treatment were conducted regularly, predominantly after four weeks, by 36% of participants. In 8% of cases, additional BTX injections were necessary due to inadequate outcomes. Side effects were reported in 4% of cases, commonly manifesting as a non-disturbing reduction in bite force. Most participating OMFS (61.84%) using BTX for bruxism therapy regarded bruxism treatment with BTX as evidence-based. Notably, 97.37% of respondents expressed their willingness to recommend BTX-based bruxism treatment to their colleagues. Overall, the efficacy of BTX therapy for bruxism was rated as good (53.95%) and very good (40.79%)., Conclusion: The use of BTX for the management of bruxism among OMFS in Germany has demonstrated efficacy. Substantial variances in certain facets of bruxism treatment employing BTX have been observed., Clinical Relevance: Additional research endeavors are warranted to comprehensively investigate distinct elements of BTX therapy for bruxism, including the optimal dosage of BTX units and the precise localization of injection sites across various muscles., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: The primary objective of this in vitro experiment was an assessment of proliferative capacity, metabolic activity, and potential cellular detriment of human periodontal ligament cells (hPDL) exposed to cigarette smoke (CS), electronic cigarette vapor (eCV), and heated tobacco product aerosol (HTP), or air (control)., Materials and Methods: Using a CAD/CAM-designed exposition chamber, hPDL were exposed to CS, eCV, HTP, or air (control) based on the Health Canada Intense Smoking Regime. Cell proliferation, metabolic activity, and cellular detriment were assessed at various time points., Results: Compared to the control, hPDL exposed to CS exhibited significantly decreased cell numbers at all time points. HTP exposure led to reduced cell numbers 48 h and 72 h post-exposure, while eCV-exposed cells showed no significant decrease. The metabolic activity of eCV-treated hPDL was slightly reduced at 7 h but recovered at 24 h and 48 h. In contrast, CS-treated cells exhibited significantly decreased metabolic activity at 24 h and 48 h, and HTP-exposed cells showed a significant decrease after 48 h. Flow cytometry indicated both apoptotic and necrotic cell death following CS exposure, with necrotic cell death being more pronounced., Conclusions: eCV and HTP demonstrated comparatively reduced detrimental effects on hPDL compared to CS., Clinical Relevance: The findings suggest that conventional cigarette smoke poses a substantial risk to periodontal health by significantly impairing cell proliferation and metabolic activity. However, alternatives such as eCV and HTP may offer a comparatively reduced risk., (© 2024. The Author(s).)

Purpose: Particulate bovine bone substitutes (BS) are commonly used in oral regeneration. However, more literature is needed focusing on comparative analyses among various particulate bovine BS. This study evaluates pre-clinical and clinical data of different particulate bovine BS in oral regeneration., Methods: A narrative review was conducted by screening the PubMed database Included in the review were pre-clinical and clinical studies until 2024 comparing a minimum of two distinct particulate bovine BS. In addition to examining general data concerning manufacturing and treatment processes, biological safety, physical and chemical characteristics, and graft resorption, particular emphasis was placed on assessing pre-clinical and clinical data related to ridge preservation, sinus floor elevation, peri-implant defects, and various forms of alveolar ridge augmentation utilizing particulate bovine BS., Results: Various treatment temperatures ranging from 300 to 1,250 °C and the employment of chemical cleaning steps were identified for the manufacturing process of particulate bovine BS deemed to possess biosecurity. A notable heterogeneity was observed in the physical and chemical characteristics of particulate bovine BS, with minimal or negligible graft resorption. Variations were evident in particle and pore sizes and the porosity of particulate bovine BS. Pre-clinical assessments noted a marginal inclination towards favorable outcomes for particulate bovine BS subjected to higher treatment temperatures. However, clinical data are insufficient. No distinctions were observed regarding ridge preservation, while slight advantages were noted for high-temperature treated particulate bovine BS in sinus floor elevation., Conclusions: Subtle variances in both pre-clinical and clinical outcomes were observed in across various particulate bovine BS. Due to inadequate data, numerous considerations related to diverse particulate bovine BS, including peri-implant defects, must be more conclusive. Additional clinical studies are imperative to address these knowledge gaps effectively., (© 2024. The Author(s).)

The structure and handling properties of a P407 hydrogel-based bone substitute material (BSM) might be affected by different poloxamer P407 and silicon dioxide (SiO 2 ) concentrations. The study aimed to compare the mechanical properties and biological parameters (bone remodeling, BSM degradation) of a hydroxyapatite: silica (HA)-based BSM with various P407 hydrogels in vitro and in an in vivo rat model. Rheological analyses for mechanical properties were performed on one BSM with an SiO 2 -enriched hydrogel (SPH25) as well on two BSMs with unaltered hydrogels in different gel concentrations (PH25 and PH30). Furthermore, the solubility of all BSMs were tested. In addition, 30 male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. Defects were filled randomly with PH30 (n = 15) or SPH25 (n = 15). Animals were sacrificed after 12 (n = 5 each), 21 (n = 5 each), and 63 days (n = 5 each). Histological evaluation and histomorphometrical quantification of new bone formation (NB;%), residual BSM (rBSM;%), and soft tissue (ST;%) was conducted. Rheological tests showed an increased viscosity and lower solubility of SPH when compared with the other hydrogels. Histomorphometric analyses in cancellous bone showed a decrease of ST in PH30 (p = .003) and an increase of NB (PH30: p = .001; SPH: p = .014) over time. A comparison of both BSMs revealed no significant differences. The addition of SiO 2 to a P407 hydrogel-based hydroxyapatite BSM improves its mechanical stability (viscosity, solubility) while showing similar in vivo healing properties compared to PH30. Additionally, the SiO 2 -enrichment allows a reduction of poloxamer ratio in the hydrogel without impairing the material properties., (© 2024 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals LLC.)

Introduction: Autologous platelet concentrate (APC) are pro-angiogenic and can promote wound healing and tissue repair, also in combination with other biomaterials. However, challenging defect situations remain demanding. 3D bioprinting of an APC based bioink encapsulated in a hydrogel could overcome this limitation with enhanced physio-mechanical interface, growth factor retention/secretion and defect-personalized shape to ultimately enhance regeneration., Methods: This study used extrusion-based bioprinting to create a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate. Chemico-physical testing exhibited an amorphous structure characterized by high shape fidelity. Cytotoxicity assay and incubation of human osteogenic sarcoma cells (SaOs2) exposed excellent biocompatibility. enzyme-linked immunosorbent assay analysis confirmed pro-angiogenic growth factor release of the printed constructs, and co-incubation with HUVECS displayed proper cell viability and proliferation. Chorioallantoic membrane (CAM) assay explored the pro-angiogenic potential of the prints in vivo . Detailed proteome and secretome analysis revealed a substantial amount and homologous presence of pro-angiogenic proteins in the 3D construct., Results: This study demonstrated a 3D bioprinting approach to fabricate a novel bioink of alginate/cellulose hydrogel loaded with thrombocyte concentrate with high shape fidelity, biocompatibility, and substantial pro-angiogenic properties., Conclusion: This approach may be suitable for challenging physiological and anatomical defect situations when translated into clinical use., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Grandjean, Perumal, Manicam, Matthey, Wu, Thiem, Stein, Henrich, Kämmerer, Al-Nawas, Ritz and Blatt.)

Objectives: This scoping review explores the risk and management of traumatic injuries to the inferior alveolar and lingual nerves during mandibular dental procedures. Emphasizing the significance of diagnostic tools, the review amalgamates existing knowledge to offer a comprehensive overview., Materials and Methods: A literature search across PubMed, Embase, and Cochrane Library informed the analysis., Results: Traumatic injuries often lead to hypo-/anesthesia and neuropathic pain, impacting individuals psychologically and socially. Diagnosis involves thorough anamnesis, clinical-neurological evaluations, and radiographic imaging. Severity varies, allowing for conservative or surgical interventions. Immediate action is recommended for reversible causes, while surgical therapies like decompression, readaptation, or reconstruction yield favorable outcomes. Conservative management, utilizing topical anesthesia, capsaicin, and systemic medications (tricyclic antidepressants, antipsychotics, and serotonin-norepinephrine-reuptake-inhibitors), proves effective for neuropathic pain., Conclusions: Traumatic nerve injuries, though common in dental surgery, often go unrecorded. Despite lacking a definitive diagnostic gold standard, a meticulous examination of the injury and subsequent impairments is crucial., Clinical Relevance: Tailoring treatment to each case's characteristics is essential, recognizing the absence of a universal solution. This approach aims to optimize outcomes, restore functionality, and improve the quality of life for affected individuals., (© 2024. The Author(s).)

Purpose: Digitalization is assuming increasing significance in dental education, as dental students are increasingly exposed to digital implant planning and contemporary technologies such as 3D printing. In this study, we present a cohort analysis aimed at assessing the potential benefits derived from the utilization of 3D prints to seamlessly translate planned procedures into real-life applications., Methods: 21 dental students participated in a virtual planning and hands-on course across two cohorts (C1: n = 10, C2: n = 11). The virtual implant planning phase involved the placement of four implants on an atrophic lower jaw model. Subsequently, Cohort 1 (C1) executed the implantation procedure on a prefabricated hands-on model, while Cohort 2 (C2) engaged with 3D prints representing their individual implant planning during the hands-on session. Subjective assessments of knowledge, skills, and the perceived utility of 3D prints were conducted through pre- and post-course questionnaires, utilizing a 5-point scale., Results: In the subjective evaluation, 17 out of 21 participants expressed a positive appraisal of the use of personalized models. Notably, there was no statistically significant improvement in overall knowledge scores; however, there was a discernible increase of 0.5 points in the ratings related to perceived expertise and procedural abilities., Conclusion: While there was a notable increase in the subjective ratings of knowledge and abilities, no statistically significant difference was observed between the two groups. The consensus among dental students is that individually planned and printed implant models serve as a valuable and effective tool in hands-on courses., (© 2024. The Author(s).)

In this retrospective study, the clinical and economic implications of microvascular reconstruction of the mandible were assessed, comparing immediate versus delayed surgical approaches. Utilizing data from two German university departments for oral and maxillofacial surgery, the study included patients who underwent mandibular reconstruction following continuity resection. The data assessed included demographic information, reconstruction details, medical history, dental rehabilitation status, and flap survival rates. In total, 177 cases (131 male and 46 females; mean age: 59 years) of bony free flap reconstruction (72 immediate and 105 delayed) were included. Most patients received adjuvant treatment (81% with radiotherapy and 51% combined radiochemotherapy), primarily for tumor resection. Flap survival was not significantly influenced by the timing of reconstruction, radiotherapy status, or the mean interval (14.5 months) between resection and reconstruction. However, immediate reconstruction had consumed significantly fewer resources. The rate of implant-supported masticatory rehabilitation was only 18% overall. This study suggests that immediate jaw reconstruction is economically advantageous without impacting flap survival rates. It emphasizes patient welfare as paramount over financial aspects in clinical decisions. Furthermore, this study highlights the need for improved pathways for masticatory rehabilitation, as evidenced by only 18% of patients with implant-supported dentures, to enhance quality of life and social integration.

Objectives: This in vivo study aimed to assess the impact of needle bevel design on puncture pain, anesthetic success, and mechanical deformations in intraligamentary injection (ILA) cases, comparing a short triple facet cut (STF) to a triple lancet cut (TL) after single or repetitive use., Materials and Methods: In a prospective single-blind trial, 200 ILA needles (STF, n = 100; TL, n = 100) were randomly assigned for dental procedures. Patients received ILA either with STF or TL needles, used once (group A; n = 50 each) or repeatedly (group B; n = 50). Puncture pain was assessed using a numerical rating scale (NRS). Anesthetic success was determined via cold spray (yes/no), and scanning electron microscopy (SEM) analyzed needle tip deformations., Results: Puncture pain did not significantly differ between STF and TL, regardless of needle use or injection area. Success rates were comparable in single use (82% STF vs. 79% TL; p > 0.05). For repetitive use, STF exhibited a significantly higher success rate (80% vs. 69%; p = 0.012). Mechanical deformations were prevalent in 97.5% of needles, with TL showing greater deformations than STF after single and repeated uses. Barbs were more common in TL (90/100) than STF (84/100), with a higher relative risk for barbed-like deformation in TL (RR single use: 1.26; p < 0.001; multiple use: 7.87, p < 0.001)., Conclusions: The short triple facet-designed bevel demonstrated significantly less mechanical deformation, suggesting potential advantages in maintaining needle lumen patency., Clinical Relevance: The intraligamentary needle bevel design is linked to mechanical deformation and anesthetic success after repetitive use, but not to puncture pain., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Alveolar ridge augmentation is often required before dental implant placement. In this context, autologous bone grafts are considered the biological gold standard. Still, bone block harvesting is accompanied by some serious potential disadvantages and possible complications, such as pain, bleeding, and nerve irritation. Several studies aimed to compare autologous to allogeneic bone grafts concerning bone quality and implant survival rates; this is the first prospective study analyzing and comparing morbidity-related parameters after alveolar ridge augmentation using autogenous and allogeneic bone blocks from patients' perspective., Methods: Using a questionnaire, 36 patients were asked to evaluate the surgery as well as the post-operative period concerning pain, stress, sensibility deficits, satisfaction with, and consequences from the surgery as well as the preferred procedure for future alveolar ridge augmentations., Results: No significant differences were shown regarding stress and pain during and after surgery, whereas the rate of nerve irritations was twice as high in the autologous group. The swelling was significantly higher in patients with autologous bone blocks (p = 0.001). Nevertheless, the overall satisfaction of patients of both groups was very high, with over 8/10 points., Conclusions: The swelling was the main reason for patients' discomfort in both groups and was significantly higher after autologous bone augmentation. Since this side effect seems to be a highly relevant factor for patients' comfort and satisfaction, it needs to be discussed during preoperative consultation to allow shared decision-making considering the anticipated morbidity., (© 2023 The Authors. Clinical Implant Dentistry and Related Research published by Wiley Periodicals LLC.)

Objectives: Pre-vascularization of the collagen membranes with autologous platelet concentrates is a standard procedure in oral and maxillofacial surgery. This study analyzed the possible interaction of an acellular collagen membrane of porcine origin (NM) with platelet-rich fibrin (PRF) regarding its rehydration protocol with differences in pH values and effect on angiogenesis., Materials and Methods: NM was analyzed alone and combined with solid PRF by plotting or co-culturing with injectable PRF. Different media (venous blood, buffer solution with a fixed pH value of 7, saline solution, and injectable PRF) were used to analyze the influence on pH value during rehydration. Chorion allantois membrane assay (CAM) was applied to check pro-angiogenic effects after 24, 48, and 72 h, followed by immunohistochemical analysis., Results: Rehydration in injectable PRF showed acidity over time (p < 0.05). A definite pro-angiogenic effect of NM alone was found regarding neo-vessel formation supported by the respective light microscopically analysis without significant differences to PRF alone (p > 0.005). This pro-angiogenic effect could not be exaggerated when NM was combined with liquid/solid PRF (each p > 0.005)., Conclusions: Rehydration with liquid PRF of the collagen membrane results in acidity compared to a saline solution or patient's blood. The significant pro-angiogenic potential of the membrane alone resulted in enhanced neo-vessel formation that could not be optimized with the addition of PRF., Clinical Relevance Statement: Using injectable PRF for rehydration protocol of the collagen membrane leads to acidosis that can ultimately optimize wound healing. Differences in the physio-mechanical interplay of collagen matrices and autologous platelet concentrates must result in clinical algorithms if pre-vascularization can maximize outcomes., (© 2024. The Author(s).)

(1) Background: Considering that the specialty literature supplies only general data about the variability of the cervical branch of the facial nerve, this study aimed to determine this branch's variation and individual peculiarities depending on the nerve branching pattern and anthropometric type of the head. (2) Methods: The study was conducted on 75 hemifaces of adult formalized cadavers. Ahead of anatomical dissection, each head was measured to establish the anthropometric type, according to Franco and colleagues. The branching patterns were then distributed according to the Davis classification. (3) Results: The number of cervical branches (CB) of the facial nerve varied from one to five branches, with the following rate: 1 CB (61.3%), 2 CB (28%), 3 CB (6.7%), 4 CB (2.7%), and 5 CB (1.3%). Seven branching patterns of the facial nerve were revealed: Type I in 18.7%, Type II in 14.7%, Type III in 20%, Type IV in 14.6%, Type V in 5.3%, Type VI in 18.7%, and Type NI in 8% (bizarre types). According to the branching pattern, the mean numbers of the cervical branches were as follows: Type I-1.6 ± 1.02; Type II-1.4 ± 0.50; Type III-1.4 ± 0.50; Type IV-1.4 ± 0.67; Type V-2.0 ± 1.41; Type VI-1.8 ± 1.12; and Type-NI-1.8 ± 0.75; p = 0.599. According to the anthropometric type of the head, the mean number of CB in the mesocephalic type (MCT) was 1.5 ± 0.82, in the dolichocephalic type (DCT), 1.7 ± 0.87, and in the brachycephalic type, (BCT) 1.8 ± 1.04; p = 0.668. (4) Conclusions: The cervical branch of the facial nerve varies depending on the facial nerve branching pattern and the anthropometric type of the head. The highest degree of variation was characteristic of BCT and Type V and the lowest, of MCT and Types II, III, and IV.

Over the past 50 years, digitization has gradually taken root in dentistry, starting with computer tomography in the 1970s. The most disruptive events in digital dentistry were the introduction of digital workflow and computer-aided manufacturing, which made new procedures and materials available for dental use. While the conventional lab-based workflow requires light or chemical curing under inconsistent and suboptimal conditions, computer-aided manufacturing allows for industrial-grade material, ensuring consistently high material quality. In addition, many other innovative, less disruptive, but relevant approaches have been developed in digital dentistry. These will have or already impact prevention, diagnosis, and therapy, thus impacting patients' oral health and, consequently, their oral health-related quality of life. Both software and hardware approaches attempt to maintain, restore, or optimize a patient's perceived oral health. This article outlines innovations in dentistry and their potential impact on patients' oral health-related quality of life in prevention and therapy. Furthermore, possible future developments and their potential implications are characterized., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objectives: Autogenous and allogeneic blocks for shell augmentation of the jaw have shown comparable results. This observational clinical study aimed to compare both materials for shell augmentation concerning surgery time and intra- and postoperative complications., Material and Methods: Bone augmentation with the shell technique using autogenous or allogenous bone was performed in 117 patients with segmental jaw atrophy. The primary study parameter was the surgical time, comparing both materials. Subsequently, intra- and postoperative complications were recorded., Results: Allogeneic (n = 60), autogenous (n = 52), or both materials (n = 5) were used. The use of allogeneic material led to a significantly shorter operation time (p < 0.001). A more experienced surgeon needed significantly less time than a less experienced surgeon (p < 0.001). An increasing number of bone shells (p < 0.001), an additional sinus floor elevation, and intraoperative complications also significantly increased the operation time (p = 0.001). Combining allogeneic and autogenous shells (p = 0.02) and simultaneous sinus floor elevation (p = 0.043) significantly impacted intraoperative complications. No correlations were found between the included variables for postoperative complications (all p > 0.05). In total, 229 implants were inserted after a healing time of 4-6 months, with a survival of 99.6% after a mean follow-up duration of 9 months., Conclusions: Compared to the autogenous technique, allogeneic shell augmentation has a shorter surgical time and a similar rate of intra- and postoperative complications as autogenous bone. Together with its promising clinical results, this technique can be recommended., (© 2023. The Author(s).)

Objectives: In this prospective, double-blinded, randomized split-mouth study, the local hemostatic effect of platelet-rich fibrin (PRF) inserted into the extraction socket in patients taking factor Xa (FXa) inhibitors (apixaban, rivaroxaban, edoxaban) was compared to a hemostatic gelatine sponge (GS) as the "therapeutic gold standard" without withdrawal of oral anticoagulant therapy., Materials and Methods: Single-tooth extraction was conducted under local anesthesia in n = 21 patients using a split-mouth design (42 teeth). Using a double-blind approach, the extraction socket on one side of the jaw was filled with PRF and on the other with a GS. Bleeding was assessed immediately after surgery, in 30 min, 1 h, 1.5 h, and on follow-up appointments in 24 h and on the 7th day., Results: In 67% of cases, mild postoperative oozing could be stopped 30-90 min after tooth extraction via gauze pressure without any delayed bleeding. Concerning bleeding events, there was no difference among the PRF and GS groups and no significant difference among rivaroxaban, apixaban, and edoxaban (all p > 0.15)., Conclusion: PRF and GS are reliable hemostatic methods in postextraction sockets of patients taking FXa inhibitors., Clinical Relevance: Consequently, there is no need to discontinue FXa inhibitors because of a single-tooth removal, eliminating the risk of thrombus formation., (© 2023. The Author(s).)

(1) Background: The current landscape of midface reconstruction is marked by ongoing evolution, with notable advancements in surgical techniques, microvascular procedures, and the implementation of multidisciplinary approaches, all of which have significantly enhanced both functional and aesthetic outcomes. Conventionally, microvascular anastomoses for free flaps in midfacial reconstruction have been executed using cervical vessels. However, this approach necessitates neck access, resulting in extraoral scars and a substantial pedicle length. In light of these considerations, using intraoral anastomoses via the facial vessels emerges as a promising alternative. This retrospective multicentric study aims to provide a comprehensive account of immediate midface reconstruction through intraoral anastomoses. (2) Methods: Between 2020 and 2023, patients were included who underwent intraoral resection of midface/orbit segments (Brown Classes I-VI) as a result of malignant diseases. In all cases, immediate reconstruction was accomplished by utilizing the facial vessels through an intraoral approach. Outcome criteria were identification of vessels, parotid duct or facial nerve damage, success of vascular anastomoses, and flap survival. (3) Results: A total of 117 patients with 132 flaps (91 osseous and 41 cutaneous) were included. The intraoral preparation of facial vessels was successfully completed in less than 1 h, and no complications related to the dissection or anastomoses were observed. In two cases, the vessel diameter was insufficient to facilitate anastomoses, necessitating adopting an extraoral approach. During a follow-up period of 48 months, two osseous flaps were lost, accounting for a 1.5% loss rate out of 132 flaps used. Additionally, 3 flaps experienced partial loss, including a skin island of a scapula, the border zone of a femur, and a rectus flap, resulting in a 2.3% partial loss rate out of 130 flaps utilized. (4) Conclusions: This case series underscores the feasibility of employing intraoral anastomoses for immediate complex midface reconstruction following oncological resection. This approach is particularly advantageous for flaps with shorter pedicles, as it helps mitigate external scarring and minimizes the risk of facial nerve injury.

Free flap tissue transfer represents the gold standard for extensive defect reconstruction, although malperfusion due to thrombosis remains the leading risk factor for flap failure. Recent studies indicate an increased immune response and platelet activation in connection with pathologic coagulation. The underlying cellular and molecular mechanisms remain poorly understood, however. The presented study, therefore, aims to investigate if transfer-related ischemia alters intra-flap metabolism and electrolyte concentrations compared to central venous blood after free flap transfer in pigs to establish a novel experimental model. Free transfer of a myocutaneous gracilis flap to the axillary region was conducted in five juvenile male pigs. The flap artery was anastomosed to the axillary artery, and intra-flap venous blood was drained and transfused using a rubber-elastic fixed intravenous catheter. Blood gas analysis was performed to assess the effect of transfer time-induced ischemia on intra-flap electrolyte levels, acid-base balance, and hemoglobin concentrations compared to central venous blood. Time to flap reperfusion was 52 ± 10 min on average, resulting in a continuous pH drop (acidosis) in the flaps' venous blood compared to the central venous system ( p = 0.037). Potassium ( p = 0.016), sodium ( p = 0.003), and chloride ( p = 0.007) concentrations were significantly increased, whereas bicarbonate ( p = 0.016) and calcium ( p = 0.008) significantly decreased within the flap. These observations demonstrate the induction of anaerobic glycolysis and electrolyte displacement resulting in acidosis and hence significant tissue damage already after a short ischemic period, thereby validating the novel animal model for investigating intra-flap metabolism and offering opportunities for exploring various (immuno-) thrombo-hemostatic issues in transplantation surgery.

Reconstruction of significant maxillomandibular defects is a challenge that has been much discussed over the last few decades. Fundamental principles were developed decades ago (bone bed viability, graft immobilization). Clinical decision-making criteria are highly relevant, including local/systemic factors and incision designs, the choice of material, grafting technique, and donor site morbidity. Stabilizing particulated grafts for defined defects-that is, via meshes or shells-might allow significant horizontal and vertical augmentation; the alternatives are onlay and inlay techniques. More significant defects might require extra orally harvested autologous bone blocks. The anterior iliac crest is often used for nonvascularized augmentation, whereas more extensive defects often require microvascular reconstruction. In those cases, the free fibula flap has become the standard of care. The development of alternatives is still ongoing (i.e., alloplastic reconstruction, zygomatic implants, obturators, distraction osteogenesis). Especially for these complex procedures, three-dimensional planning tools enable facilitated planning and a surgical workflow., (© 2023 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.)

Objectives: The aim of the ITI Consensus Workshop on zygomatic implants was to provide Consensus Statements and Clinical Recommendations for the use of zygomatic implants., Materials and Methods: Three systematic reviews and one narrative review were written to address focused questions on (1) the indications for the use of zygomatic implants; (2) the survival rates and complications associated with surgery in zygomatic implant placement; (3) long-term survival rates of zygomatic implants and (4) the biomechanical principles involved when zygoma implants are placed under functional loads. Based on the reviews, three working groups then developed Consensus Statements and Clinical Recommendations. These were discussed in a plenary and finalized in Delphi rounds., Results: A total of 21 Consensus Statements were developed from the systematic reviews. Additionally, the group developed 17 Clinical Recommendations based on the Consensus Statements and the combined expertise of the participants., Conclusions: Zygomatic implants are mainly indicated in cases with maxillary bone atrophy or deficiency. Long-term mean zygomatic implant survival was 96.2% [95% CI 93.8; 97.7] over a mean follow-up of 75.4 months (6.3 years) with a follow-up range of 36-141.6 months (3-11.8 years). Immediate loading showed a statistically significant increase in survival over delayed loading. Sinusitis presented with a total prevalence of 14.2% [95% CI 8.8; 22.0] over a mean 65.4 months follow-up, representing the most common complication which may lead to zygomatic implant loss. The international experts suggested clinical recommendations regarding planning, surgery, restoration, outcomes, and the patient's perspective., (© 2023. Deutsche Gesellschaft für Implantologie im Zahn‐, Mund‐ und Kieferbereich e.V., Japanese Society of Oral Implantology.)

Objectives: This systematic review and meta-analysis examined the effects of electronic cigarettes on periodontal health compared to conventional cigarette smoke and a non-smoking population., Materials and Methods: MEDLINE, Embase, Web of Science, CENTRAL, and ClinicalTrials.gov were screened for literature. Eligibility criteria included clinical studies published between 2006 and 2022 that compare e-cigarettes and conventional cigarettes on periodontal health (bleeding on probing (BoP), plaque index (PI), probing depth (PD), attachment loss (AL), marginal bone loss (MBL), tooth loss, molecular inflammation markers, salivary flow rate). Meta-regression analysis was used to examine the influence of moderator variables., Results: Sixteen studies were found to be eligible for qualitative synthesis. Individual analyses showed that cigarette smokers had significantly higher PI, PD, AL, and MBL and increased concentrations of proinflammatory mediators than e-cigarette users and non-smokers. Meta-analysis revealed a 0.33-fold lower chance for BoP in e-cigarette users compared to smokers (p = 0.03), whereby meta-regression failed to detect any effects regarding the age of users and frequency of smoking. A 0.01-fold decreased chance for positive BoP in e-cigarette users compared with non-smokers was seen (p < 0.01)., Conclusions: The current findings suggest that that e-cigarette use might be considered a healthier alternative to cigarette smoking concerning periodontal health. Even so, harmful effects of electronic nicotine delivery system (ENDS) usage on periodontal health were seen as well. However, a definitive decision on this research question remains elusive due to the absence of randomized controlled trials., Clinical Relevance: Electronic cigarettes, marketed as a safer alternative to traditional cigarettes, are becoming increasingly popular. Evidence on the use of electronic cigarettes as a cessation aid and its beneficial impact compared to cigarette smoke remains inconclusive, so the analysis conducted in this review addresses a recent question of high clinical relevance., (© 2023. The Author(s).)

Purpose: The present systematic review aimed to investigate the accuracy of zygomatic implant (ZI) placement using dynamic computer-aided surgery (d-CAIS), static computer-aided surgery (s-CAIS), and a free-hand approach in patients with severe atrophic edentulous maxilla and/or deficient maxilla., Methods: Electronic and manual literature searches until May 2023 were performed in the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases. Clinical trials and cadaver studies were selected. The primary outcome was planned/placed deviation. Secondary outcomes were to evaluate the survival of ZI and surgical complications. Random-effects meta-analyses were conducted and meta-regression was utilized to compare fiducial registration amounts for d-CAIS and the different designs of s-CAIS., Results: A total of 14 studies with 511 ZIs were included (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179). The pooled mean ZI deviations from the d-CAIS group were 1.81 mm (95% CI: 1.34-2.29) at the entry point and 2.95 mm (95% CI: 1.66-4.24) at the apex point, and angular deviations were 3.49 degrees (95% CI: 2.04-4.93). The pooled mean ZI deviations from the s-CAIS group were 1.19 mm (95% CI: 0.83-1.54) at the entry point and 1.80 mm (95% CI: 1.10-2.50) at the apex point, and angular deviations were 2.15 degrees (95% CI: 1.43-2.88). The pooled mean ZI deviations from the free-hand group were 2.04 mm (95% CI: 1.69-2.39) at the entry point and 3.23 mm (95% CI: 2.34-4.12) at the apex point, and angular deviations were 4.92 degrees (95% CI: 3.86-5.98). There was strong evidence of differences in the average entry, apex, and angular deviation between the navigation, surgical guide, and free-hand groups ( p < 0.01). A significant inverse correlation was observed between the number of fiducial screws and the planned/placed deviation regarding entry, apex, and angular measurements., Conclusion: Using d-CAIS and modified s-CAIS for ZI surgery has shown clinically acceptable outcomes regarding average entry, apex, and angular deviations. The maximal deviation values were predominantly observed in the conventional s-CAIS. Surgeons should be mindful of potential deviations and complications regardless of the decision making in different guide approaches.

Purpose: The macrogeometry of a dental implant plays a decisive role in its primary stability. A larger diameter, a conical shape, and a roughened surface increase the contact area of the implant with the surrounding bone and thus improve primary stability. This is considered the basis for successful implant osseointegration that different factors, such as implant design, can influence. This narrative review aims to critically review macro-geometric features affecting the primary stability of dental implants., Methods: For this review, a comprehensive literature search and review of relevant studies was conducted based on formulating a research question, searching the literature using keywords and electronic databases such as PubMed, Embase, and Cochrane Library to search for relevant studies. These studies were screened and selected, the study quality was assessed, data were extracted, the results were summarized, and conclusions were drawn., Results: The macrogeometry of a dental implant includes its surface characteristics, size, and shape, all of which play a critical role in its primary stability. At the time of placement, the initial stability of an implant is determined by its contact area with the surrounding bone. Larger diameter and a conical shape of an implant result in a larger contact area and better primary stability. But the linear relationship between implant length and primary stability ends at 12 mm., Conclusions: Several factors must be considered when choosing the ideal implant geometry, including local factors such as the condition of the bone and soft tissues at the implant site and systemic and patient-specific factors such as osteoporosis, diabetes, or autoimmune diseases. These factors can affect the success of the implant procedure and the long-term stability of an implant. By considering these factors, the surgeon can ensure the greatest possible therapeutic success and minimize the risk of implant failure., (© 2023. The Author(s).)

Purpose: This study aimed to investigate the effect of three different osteosynthesis plate systems on failure rates and complications after continuity-interrupting mandibular resections with alloplastic reconstructions., Materials and Methods: Records of respective patients from 2010 to 2020 were analyzed retrospectively. The analyses included the osteosynthesis plate type (2.4 MANDIBULAR (RP1: MANDIBULAR [Medicon®, Tuttlingen, Germany]; RP2: Modus® Reco 2.5 [Medartis®, Basel, Switzerland]; and RP3: Modus 2 Mandible [Medartis®, Basel, Switzerland]), extent & location of the defect, age, sex, radiotherapy, and nicotine abuse. In case of failure, timepoint, and the problem, namely oral/extraoral dehiscence, screw loosening, and plate fractures that led to removal, were analyzed. Complications were classified according to Clavien-Dindo system., Results: A total of 136 patients were included. The mean follow-up time was 18 ± 26 months. Survival rates after 1, 2, and 5 years were 69.9%, 66.9%, and 64.7%, respectively. Although survival was not significantly associated with the reconstruction system, the most frequent complications were seen in cases of RP1 & RP2 when compared to RP3 (p = 0.033). In brief, dehiscences were seen significantly less often in cases of RP3 (12.5%) when compared to RP1 (44.7%) and RP2 (26.9%; p = 0.024). Fractures of the osteosynthesis systems occurred in 3 of 4 cases (75%) with RP1, in 1 of 4 cases (25%) using RP2, and in no single case using the RP3 system (p = 0.03). Most of the observed complications occurred up to 12 months postoperatively. A total plate survival rate of 64.7% and a total plate complication rate of 47.8% were seen., Conclusion: In conclusion, it seems that RP3 should be preferred over RP1 and RP2 regarding failure rates and complications., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2023 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Purpose: The purpose of this document is to clarify the biomechanical principles involved when zygoma implants are placed under functional loads., Methods: Two independent reviewers conducted electronic search of the literature from January 2000 to February 2023 describing the biomechanical principles involved using the zygoma implant for maxillary reconstruction. Articles describing the stresses within the zygoma implant, the maxillary bone and the zygoma bone under functional loads were included., Results: The lack of maxillary boney support at the implant platform resulted in significant higher stress measured within the zygoma implant as well as the zygoma bone., Conclusion: The maxilla is the primary support when zygoma implants are placed under functional loads. Quad-cortical stabilization of the zygoma implants and their cross-arch stabilization are recommended to reduce the degree of stress whenever possible., (© 2023. The Author(s).)

Purpose: To assess the outcome [zygomatic implant (ZI) survival] and complications of the original surgical technique (OST) and an Anatomy-Guided approach (AGA) in the placement of ZI in patients with severely atrophic maxillae., Methods: Two independent reviewers conducted an electronic literature search from January 2000 to August 2022. The inclusion criteria were articles reporting at least five patients with severely atrophic edentulous maxilla undergoing placement OST and/or AGA, with a minimum of 6 months of follow-up. Number of patients, defect characteristics, number of ZI, implant details, surgical technique, survival rate, loading protocol, prosthetic rehabilitation, complications, and follow-up period were compared., Results: Twenty-four studies comprised 2194 ZI in 918 patients with 41 failures. The ZI survival rate was 90.3-100% in OST and 90.4-100% in AGA. Probability of complications with ZI with OST was as follows: sinusitis, 9.53%; soft tissue infection, 7.50%; paresthesia, 10.78%; oroantral fistulas, 4.58%; and direct surgical complication, 6.91%. With AGA, the presenting complications were as follows: sinusitis, 4.39%; soft tissue infection, 4.35%; paresthesia, 0.55%; oroantral fistulas, 1.71%; and direct surgical complication, 1.60%. The prevalence of immediate loading protocol was 22.3% in OST and 89.6% in the AGA. Due to the heterogeneity of studies, statistical comparison was only possible after the descriptive analysis., Conclusions: Based on the current systematic review, placing ZI in severely atrophic edentulous maxillae rehabilitation with the OST and AGA is associated with a high implant survival rate and surgical complications within a minimum of 6 months follow-up. Complications, including sinusitis and soft tissue infection around the implant, are the most common. The utilization of immediate loading protocol is more observed in AGA than in OST., (© 2023. The Author(s).)

Improved serological biomarkers are needed for the early detection, risk stratification and treatment surveillance of patients with oral squamous cell carcinoma (OSCC). We performed an exploratory study using advanced, highly specific, DNA-aptamer-based serum proteomics (SOMAscan, 1305-plex) to identify distinct proteomic changes in patients with OSCC pre- vs. post-resection and compared to healthy controls. A total of 63 significantly differentially expressed serum proteins (each p < 0.05) were found that could discriminate between OSCC and healthy controls with 100% accuracy. Furthermore, 121 proteins were detected that were significantly altered between pre- and post-resection sera, and 12 OSCC-associated proteins reversed to levels equivalent to healthy controls after resection. Of these, 6 were increased and 6 were decreased relative to healthy controls, highlighting the potential relevance of these proteins as OSCC tumor markers. Pathway analyses revealed potential pathophysiological mechanisms associated with OSCC. Hence, quantitative proteome analysis using SOMAscan technology is promising and may aid in the development of defined serum marker assays to predict tumor occurrence, progression and recurrence in OSCC, and to guide personalized therapies.

Periodontitis is a chronic biofilm-associated inflammatory disease of the tooth-supporting tissues that causes tooth loss. It is strongly associated with anaerobic bacterial colonization and represents a substantial global health burden. Due to a local hypoxic environment, tissue regeneration is impaired. Oxygen therapy has shown promising results as a potential treatment of periodontitis, but so far, local oxygen delivery remains a key technical challenge. An oxygen (O 2 )-releasing hyaluronic acid (HA)-based dispersion with a controlled oxygen delivery was developed. Cell viability of primary human fibroblasts, osteoblasts, and HUVECs was demonstrated, and biocompatibility was tested using a chorioallantoic membrane assay (CAM assay). Suppression of anaerobic growth of Porphyromonas gingivalis was shown using the broth microdilution assay. In vitro assays showed that the O 2 -releasing HA was not cytotoxic towards human primary fibroblasts, osteoblasts, and HUVECs. In vivo, angiogenesis was enhanced in a CAM assay, although not to a statistically significant degree. Growth of P. gingivalis was inhibited by CaO 2 concentrations higher than 256 mg/L. Taken together, the results of this study demonstrate the biocompatibility and selective antimicrobial activity against P. gingivalis for the developed O 2 -releasing HA-based dispersion and the potential of O 2 -releasing biomaterials for periodontal tissue regeneration.

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55-1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15-0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19-0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years ( p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

Purpose: Zygomatic implants (ZIs) have been considered a reliable alternative treatment for patients with maxillary atrophy and/or maxillary defects. The use of a navigation system for assisting ZI placement could be a reliable approach for enhancing accuracy and safety. The purpose of this in vitro study was to evaluate the accuracy of a new dynamic surgical navigation system with its minimally invasive registration guide for quad zygomatic implant placement in comparison with a gold standard navigation approach. Materials and Methods: A total of 40 zygomatic implants were placed in 10 3D-printed models based on the CBCT scans of edentulous patients. For registration, a surgical registration guide with a quick response plate was used for the test group, and five hemispheric cavities as registered miniscrews in the intraoral area were used for the control group. In each model, a split-mouth approach was employed (two ZIs in bilateral zygomata) to test both systems. After ZI placement, a CBCT scan was performed and merged with pre-interventional planning. The deviations between planned and placed implants were calculated as offset basis, offset apical, and angular deviation and compared between the systems. Results: The offset basis, offset apical, and angular deviation were 1.43 ± 0.55 mm, 1.81 ± 0.68 mm, and 2.32 ± 1.59 degrees in the test group, respectively. For the control group, values of 1.48 ± 0.57 mm, 1.76 ± 0.62 mm, and 2.57 ± 1.51 degrees were measured without significant differences between groups (all P < .05). The accuracy of ZI positions (anterior and posterior) were measured without significant differences between groups. Conclusion: Two navigation systems with different registration techniques seem to achieve comparable acceptable accuracy for dynamic navigation of zygomatic implant placement. With the test group system, additional pre-interventional radiologic imaging and invasive fiducial marker insertion could be avoided.

(1) Background: Electrical stimulation is a promising alternative to promote bone fracture healing but with the limitation of tracking the osteogenesis progress in vivo. To overcome this issue, we present an opportunity to combine the electrical stimulation of a commercial titanium implant, which promotes osteogenesis within the fracture, with a real-time readout of the osteogenic progress by impedance sensing. This makes it possible to adjust the electrical stimulation modalities to the individual patient's fracture healing process. (2) Methods: In detail, osteogenic differentiation of several cell types was monitored under continuous or pulsatile electrical stimulation at 0.7 V AC/20 Hz for at least seven days on a titanium implant by electric cell-substrate impedance sensing (ECIS). For control, chemical induction of osteogenic differentiation was induced. (3) Results: The most significant challenge was to discriminate impedance changes caused by proliferation events from those initiated by osteogenic differentiation. This discrimination was achieved by remodeling the impedance parameter Alpha (α), which increases over time for pulsatile electrically stimulated stem cells. Boosted α-values were accompanied by an increased formation of actin stress fibers and a reduced expression of the focal adhesion kinase in the cell periphery; morphological alterations known to occur during osteogenesis. (4) Conclusions: This work provided the basis for developing an effective fracture therapy device, which can induce osteogenesis on the one hand, and would allow us to monitor the induction process on the other hand.

Bone fracture healing is a multistep process, including early immunological reactions, osteogenesis, and as a key factor, angiogenesis. Molecules inducing osteogenesis as well as angiogenesis are rare, but hold promise to be employed in bone tissue engineering. It has been demonstrated that the bone sialoprotein (BSP) can induce bone formation when immobilized in collagen type I, but its effect on angiogenesis still has to be characterized in detail. Therefore, the aim of this study was to analyse the effects of BSP immobilized in a collagen type I gel on angiogenesis. First, in vitro analyses with endothelial cells (HUVECs) were performed detecting enhancing effects of BSP on proliferation and gene expression of endothelial markers. A spheroid model was employed confirming these results. Finally, the inducing impact of BSP-collagen on vascular density was proved in a yolk sac membrane assay. Our results demonstrate that BSP is capable of inducing angiogenesis and confirm that collagen type I is the optimal carrier for this protein. Taking into account former results, and literature showing that BSP also induces osteogenesis, one can hypothesize that BSP couples angiogenesis and osteogenesis, making it a promising molecule to be used in bone tissue regeneration.

Background : The role of medication-related osteonecrosis of the jaw (MRONJ) as a dento-maxillo-facial pathology is becoming increasingly important due to its growing prevalence. The success of preventive and therapeutic measures relies mainly on the dentist's ability to correctly diagnose the disease. Methods : The aim of this study was to evaluate the skills of dental students of different educational levels in choosing the correct stage, diagnostics, and treatment option for MRONJ based on clinical and radiographic imaging (panoramic radiograph, CBCT). The study was designed as a cross-sectional cohort study. Twenty dental students were asked to complete a questionnaire in their third and fifth year of studies in which they had to correctly stage the disease, choose the radiological diagnostics and recommend the treatment. The control group contained experienced oral and maxillofacial surgeons. Results : With an overall performance of 59% (third year: 145.2/248 points; fifth year: 145.3/248 points), no statistically significant difference between the educational levels could be observed. The classification based on CBCT imaging was significantly more often correct compared to panoramic radiographs ( p < 0.001). Conclusions : This study highlights students' lack of knowledge in staging, diagnostics, and treatment of MRONJ, even though the CBCT positively affected decision-making. No significant increase in knowledge could be confirmed through clinical education. This study highlights the need for students to catch up on MRONJ diagnostics and treatment planning. Further expansion of teaching in this disease's context and X-ray diagnostics is needed.

Three-dimensional (3D) printing is a rapidly evolving field and has gained increasing importance in the medical sector. However, the increasing usage of printing materials is accompanied by more wastages. With a rising awareness of the environmental impact of the medical sector, the development of highly accurate and biodegradable materials is of great interest. This study aims to compare the accuracy of polylactide/polyhydroxyalkanoate (PLA/PHA) surgical guides printed by fused filament fabrication and material jetted guides of MED610 in fully guided dental implant placement before and after steam sterilization. Five guides were tested in this study and each was either printed with PLA/PHA or MED610 and either steam-sterilized or not. After implant insertion in a 3D-printed upper jaw model, the divergence between planned and achieved implant position was calculated by digital superimposition. Angular deviation and 3D deviation at the base and the apex were determined. Non-sterilized PLA/PHA guides showed an angle deviation of 0.38 ± 0.53° compared to 2.88 ± 0.75° in sterile guides ( P > 0.001), an offset of 0.49 ± 0.21 mm and 0.94 ± 0.23 mm ( P < 0.05), and an offset at the apex of 0.50 ± 0.23 mm before and 1.04 ± 0.19 mm after steam sterilization ( P < 0.025). No statistically significant difference could be shown for angle deviation or 3D offset at both locations for guides printed with MED610. PLA/PHA printing material showed significant deviations in angle and 3D accuracy after sterilization. However, the reached accuracy level is comparable to levels reached with materials already used in clinical routine and therefore, PLA/PHA surgical guide is a convenient and green alternative., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2022 Author(s).)

Purpose: the aim of this study was to identify potential risk factors favoring complications by assessing the number and types of complications associated with allogeneic or autogenous bone blocks applied as onlay grafts for alveolar ridge augmentation prior to implantation. Methods: A retrospective chart review on the success of 151 allogeneic and 70 autogenous bone blocks in a cohort of 164 consecutive patients, who were treated over a period of 6 years by the same surgeon, was conducted. Statistical conclusions were based on ROC curves and multiple logistic regression models. Results: Complications were observed more frequently with autogenous bone blocks (14 out of 70 cases; 20%) compared to allogeneic bone blocks (12 out of 151 cases; 7.9%; p = 0.013). However, these complications were minor and did not impact the successful dental rehabilitation. In a multiple logistic regression model, the risk of a complication was increased by the use of an autogenous bone block (OR = 3.2; p = 0.027), smoking (OR = 4.8; p = 0.007), vertical augmentation above a threshold of 2.55 mm (OR = 5.0; p = 0.002), and over-contouring (OR = 15.3; p < 0.001). Conclusions: Overall, the complication rate of ridge augmentations carried out with autogenous or allogeneic bone blocks was low. Despite previous recommendations, over-contouring and a vertical augmentation above a threshold of 2.55 mm should be avoided.

Autologous platelet concentrates, like liquid platelet rich fibrin (iPRF), optimize wound healing; however, the underlying immunological mechanisms are poorly understood. Platelets, the main cellular component of iPRF, highly express the protein, Glycoprotein A repetitions predominant (GARP), on their surfaces. GARP plays a crucial role in maintaining peripheral tolerance, but its influence on the immune capacity of iPRF remains unclear. This study analyzed the interaction of iPRF with immune cells implicated in the wound healing process (human monocyte derived macrophages and CD4 + T cells) and evaluated the distinct influence of GARP on these mechanisms in vitro. GARP was determined to be expressed on the surface of platelets and to exist as a soluble factor in iPRF. Platelets derived from iPRF and iPRF itself induced a regulatory phenotype in CD4 + T cells, shown by increased expression of Foxp3 and GARP as well as decreased production of IL-2 and IFN-γ. Application of an anti-GARP antibody reversed these effects. Additionally, iPRF polarized macrophages to a "M0/M2-like" phenotype in a GARP independent manner. Altogether, this study demonstrated for the first time that the immune capacity of iPRF is mediated in part by GARP and its ability to induce regulatory CD4 + T cells.

Tumor recurrence in oral squamous cell carcinoma (OSCC) is frequent. However, no consensus about follow-up interval is available. The aim of this study was to analyze the recurrence pattern, detection method and associated parameters for possible risk stratification. Histopathological and epidemiological features were obtained retrospectively and correlated with tumor recurrence and overall survival, distant and lymph node metastases. A total of 760 patients were included, of which 216 patients showed tumor recurrence (mean after 24 ± 26 months). Within the first 12 months, 24% of the recurrences were detected. The primary detection method was clinical examination (n = 123, 57%). Tumor recurrence significantly correlated with advanced histopathological grading (G2/3 vs. G1, p < 0.000) and lymph node metastasis (p = 0.004). Tumor recurrence was frequent. Clinical examination was the primary detection method and manifestation within the first 6−12 months was high. The degree of histopathological grading may be useful for risk stratification.