Approaching 3D printing in oral and maxillofacial surgery - suggestions for structured clinical standards.

PURPOSE: With respect to the European Union 2017 amendment of the Medical Device Regulations (MDR), this overview article presents recommendations concerning medical 3D printing in oral and maxillofacial surgery (OMFS). METHODS: The MDR were screened for applicability of the rules to medical in-house 3D printing. Applicable regulations were summarized and compared to the status of medical use of 3D printing in OMFS in Germany. Recommendations were made for MDR concerning medical 3D printing. RESULTS: In-house printed models, surgical guides, and implants fall under the category of Class I-III, depending on their invasive and active properties. In-house medical 3D printing for custom-made medical devices is possible under certain prerogatives: (1) the product is not being used in another facility, (2) appropriate quality systems are applied, (3) the reason for omitting commercial products is documented, (4) information about its use is supplied to the responsible authority, (5) there is a publicly accessible declaration of origin, identification, and conformity to the MDR, (6) there are records of manufacturing site, process and performance data, (7) all products are produced according to the requirements proclaimed before, and (8) there is an evaluation of clinical use and correction of possible issues. CONCLUSION: Several aspects must be addressed for in house medical 3D printing, according to the MDR. Devising MDR related to medical 3D printing is a growing challenge. The implementation of recommendations in OMFS could help practitioners to overcome the challenges and become aware of the in-house production and application of 3D printed devices.

Comparison of morbidity-related parameters between autologous and allogeneic bone grafts for alveolar ridge augmentation from patients' perspective-A questionnaire-based cohort study.

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.

A comparative study of cyanoacrylate-based tissue adhesive and surgical sutures on marginal flap stability following coronally advanced flap.

INTRODUCTION: The present study evaluated the biomechanical characteristics of cyanoacrylate-based tissue adhesive (TA) compared to surgical sutures in coronally advanced flap (CAF) procedures using an ex-vivo model. MATERIAL AND METHODS: Thirty-six half-pig mandibles were divided into three groups, n=12 each: (I) CAF fixed with sutures (sling and tag suture technique), (II) CAF fixed with TA, and (III) CAF fixed with sutures and TA. At mandibular premolars, gingival recession defects extending 3 mm apical to the cemento-enamel junction (CEJ) were created. CAF procedures were performed using a split-full-split approach, with coronal advancement of the flap to 1 mm above the marked CEJ and stabilization according to the respective groups I-III. Marginal flap stability against pull-of forces (maximum tensile force) was measured with a universal material testing machine until the CEJ became visible. RESULTS: The comparison between groups I-III demonstrated a significantly increased maximum tensile force for the TA (II) compared to the suture group (I) (p<0.001). A significantly increased maximum tensile force was found for the suture and TA (III) compared to the suture group (I) (p<0.001). There was also a significantly increased maximum tensile force in the suture and TA (III) compared to the TA group (II) (p<0.001). CONCLUSION: The results suggest that cyanoacrylate-based TA can increase marginal flap stability compared to sutures in CAF procedures. CLINICAL RELEVANCE: Cyanoacrylate-based TA can be considered a useful and valuable adjunct to conventional suturing techniques in periodontal plastic surgery, especially in cases where high flap stability is required. The results of this ex-vivo study can only be transferred to the clinical situation with limitations. Clinical long-term follow-up data must be generated.

How does dental implant macrogeometry affect primary implant stability? A narrative review.

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.

#OMFSurgery: analyzing the use of social media applications in oral and maxillofacial surgery resident training.

BACKGROUND: Despite its increasing popularity, to our knowledge the use of social media applications (SM) for residents' training in Oral and Maxillofacial Surgery (OMFS) has not been investigated yet. The aim of this study was to evaluate the use of SM applications by OMFS residents for post-graduate training in Germany. METHODS: For explorative assessment, an online questionnaire containing 27 questions about the current use of SM for resident training was sent to OMFS residents in Germany. RESULTS: Sixty-four colleagues participated to the study. Thirty-four participants (54%) responded to regularly use those platforms mainly for OMFS-related content. YouTube (65%, n = 37), Instagram (48%, n = 27), ResearchGate (25%, n = 14) and WhatsApp (16%, n = 9) were the most popular platforms. (Surgical) videos (97%, n = 59), pictures and graphics (82%, n = 50) were the mainly accessed contents. Forty-four participants (69%) stated that SM substantially contributed to their OMFS training. Dentoalveolar surgery and implantology (66%, n = 35) and aesthetic facial surgery (55%, n = 29) content contributed most to OMFS resident training. Fifty-one participants (80%) recommended an official SM account of the DGMKG. CONCLUSIONS: SM is frequently used by OMFS residents for the consumption of training-related content. There is an imbalance toward dentoalveolar and facial aesthetic surgery regarding the presented content. Academic institutions and societies should complement their educational activities to not miss this emerging educational innovation. Official SM content by academic institutions and societies could contribute to the existing educational activities.

Microvascular reconstructions in oral and maxillofacial surgery - Results of a survey among oral and maxillofacial surgeons in Germany, Austria, and Switzerland.

This study aimed to evaluate the use of microvascular free flaps (MFF) in oral and maxillofacial surgery (OMFS) in Germany, Austria, and Switzerland. A dynamic online questionnaire, using 42-46 questions, was sent to OMF surgeons based in hospitals in Germany, Austria, and Switzerland. The questionnaire was evaluated internally and externally. Aside from general information, data were collected on organizational aspects, approaches, MFF types and frequency, presurgical planning, intraoperative procedures, perioperative medications, flap monitoring, and patient management. Participants mostly performed 30-40 MFF each year (11/53). Most stated that the COVID-19 pandemic did influence MFF frequency (25/53) to varying extents. Radial forearm flap was most frequently used (37/53), followed by ALT (5/53), and fibula flap (5/53). Primary reconstruction was performed by most participants (35/48). Irradiated bony transplants were mostly used for implant placement after 12 months (23/48). Most participants (38/48) used reconstruction plates, followed by miniplates (36/48), PSI reconstruction (31/48), and PSI miniplates (10/48). Regarding the postoperative use of anticoagulants, low-molecular-weight (37/48) and unfractioned heparins (15/48) were widely used, most often for 3-7 days (26/48). Clinical evaluation was mostly preferred for flap monitoring (47/48), usually every 2 h (34/48), for at least 48 h (19/48). Strong heterogeneity in MFF reconstructions in OMFS was found, especially regarding the timepoints of reconstruction, types of osteosynthesis, and postoperative MFF management. These findings provide the chance to further compare the different treatment algorithms regarding relevant MFF aspects, such as postoperative management. This could create evidence-based treatment algorithms that will further improve the clinical outcomes in MFF reconstructions.

Evaluation of Medication-Related Osteonecrosis of the Jaw (MRONJ) in Terms of Staging and Treatment Strategies by Dental Students at Different Educational Levels.

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.

A survey regarding the organizational aspects and quality systems of in-house 3D printing in oral and maxillofacial surgery in Germany.

PURPOSE: The aim of the study was to get a cross-sectional overview of the current status of specific organizational procedures, quality control systems, and standard operating procedures for the use of three-dimensional (3D) printing to assist in-house workflow using additive manufacturing in oral and maxillofacial surgery (OMFS) in Germany. METHODS: An online questionnaire including dynamic components containing 16-29 questions regarding specific organizational aspects, process workflows, quality controls, documentation, and the respective backgrounds in 3D printing was sent to OMF surgeons in university and non-university hospitals as well as private practices with and without inpatient treatment facilities. Participants were recruited from a former study population regarding 3D printing; all participants owned a 3D printer and were registered with the German Association of Oral and Maxillofacial Surgery. RESULTS: Sixty-seven participants answered the questionnaires. Of those, 20 participants ran a 3D printer in-unit. Quality assurance measures were performed by 13 participants and underlying processes by 8 participants, respectively. Standard operating procedures regarding computer-aided design and manufacturing, post-processing, use, or storage of printed goods were non-existent in most printing units. Data segmentation as well as computer-aided design and manufacturing were conducted by a medical doctor in most cases (n = 19, n = 18, n = 8, respectively). Most participants (n = 8) stated that "medical device regulations did not have any influence yet, but an adaptation of the processes is planned for the future." CONCLUSION: The findings demonstrated significant differences in 3D printing management in OMFS, especially concerning process workflows, quality control, and documentation. Considering the ever-increasing regulations for medical devices, there might be a necessity for standardized 3D printing recommendations and regulations in OMFS.

The allogeneic shell technique for alveolar ridge augmentation: a multicenter case series and experiences of more than 300 cases.

PURPOSE: Allogeneic cortical bone plates (CP) might be used for alveolar ridge augmentation as an alternative to autogenous grafts (AG) and bone substitutes (BS). We report about a multicenter case series and our experiences of more than 300 cases using CP and the shell technique for reconstruction of the alveolar process to illustrate surgical key steps, variations, and complication management. METHODS: Different types of alveolar ridge defects were augmented using the shell technique via CP. The space between the CP and the alveolar bone was filled with either autogenous or allogeneic granules (AUG, ALG) or a mixture of both. Implants were placed after 4-6 months. Microscopic and histological assessments were performed. In addition, space filling using AUG, ALG and bovine BS was discussed. RESULTS: Scanning electron microscopy demonstrated the compact cortical structure of CP and the porous structure of ALG allowing micro-vessel ingrowth and bone remodeling. Histological assessment demonstrated sufficient bone remodeling and graft resorption after 4-6 months. In total, 372 CP cases and 656 implants were included to data analysis. The mean follow-up period was about 3.5 years. Four implants failed, while all implant failures were caused by peri-implantitis. Next, 30 CP complications were seen, while in 26 CP complications implant placement was possible. CP rehydration, stable positioning by adjusting screws, smoothing of sharp edges, and a tension-free wound closure were identified as relevant success factors. Space filling using ALG and a mixture of AUG/ALG resulted in sufficient bone remodeling, graft resorption and stability of the augmented bone. CONCLUSIONS: CP and the shell technique is appropriate for alveolar ridge augmentation with adequate bone remodeling and low complication rates. Allografts can prevent donor site morbidity and therefore may decrease discomfort for the patient.

Comparison of Hyperspectral Imaging and Microvascular Doppler for Perfusion Monitoring of Free Flaps in an In Vivo Rodent Model.

To reduce microvascular free flap failure (MFF), monitoring is crucial for the early detection of malperfusion and allows timely salvage. Therefore, the aim of this study was to evaluate hyperspectral imaging (HSI) in comparison to micro-Doppler sonography (MDS) to monitor MFF perfusion in an in vivo rodent model. Bilateral groin flaps were raised on 20 Sprague−Dawley rats. The femoral artery was transected on the trial side and re-anastomosed. Flaps and anastomoses were assessed before, during, and after the period of ischemia every ten minutes for overall 60 min using HSI and MDS. The contralateral sides' flaps served as controls. Tissue-oxygenation saturation (StO2), near-infrared perfusion index (NPI), hemoglobin (THI), and water distribution (TWI) were assessed by HSI, while blood flow was assessed by MDS. HSI correlates with the MDS signal in the case of sufficient and completely interrupted perfusion. HSI was able to validly and reproducibly detect tissue perfusion status using StO2 and NPI. After 40 min, flap perfusion decreased due to the general aggravation of hemodynamic circulatory situation, which resulted in a significant drop of StO2 (p < 0.005) and NPI (p < 0.005), whereas the Doppler signal remained unchanged. In accordance, HSI might be suitable to detect MFF general complications in an early stage and further decrease MFF failure rates, whereas MDS may only be used for direct complications at the anastomose site.

Effects of throat packs in upper airway surgery under intubation anesthesia: a randomized controlled trial.

INTRODUCTION: Throat packs (TP) are used in upper airway surgery to avoid accumulation and aspiration of blood, foreign bodies, and fluids. But side effects such as sore throat and TP retention have been reported and challenge the standardized use of TP. The aim of this study is to compare benefits and side effects of TP versus no TP for upper airway procedures in intubation anesthesia. MATERIAL AND METHODS: One hundred forty-eight patients with surgical interventions at the upper airway under intubation anesthesia were included. Of those, n = 74 each were treated without (A, control) and with (B) TP. Study group B was subdivided whether TP was placed by the surgeon (B1; n = 37) or by the anesthesiologist (B2; n = 37). TP-related side effects such as sore throat, foreign body sensation, hoarseness, dyspnea, difficulty of swallowing, nausea, retching, nausea, aspiration, and pneumonia as well as the influence of TP design and the applicant (surgeon or anesthetist) were analyzed. RESULTS: A significantly increased rate of difficulty of swallowing (p = 0.045), intensity of sore throat (p = 0.04), and foreign body sensation (p = 0.024) was found in group B when compared to group A. There was no correlation between hoarseness, dyspnea, nausea, retching, and TP. No case of aspiration or pneumonia was seen but one TP was accidentally forgotten in the patient. B2 showed an increased frequency of difficulty swallowing, followed by A and B1. B1 led to the highest incidence of nausea followed by the A and B2. CONCLUSION: The use of TP led to a high rate of side effects without showing the propagated advantages. CLINICAL RELEVANCE: The use of TP must be considered critically and cannot generally be recommended without specific reasons, such as high aspiration risk.

Long-Term Donor Site Morbidity and Flap Perfusion Following Radial versus Ulnar Forearm Free Flap-A Randomized Controlled Prospective Clinical Trial.

This clinical prospective randomized controlled study aimed to investigate the differences between Radial (RFFF) and Ulnar (UFFF) Forearm Free Flap in terms of success, performance, and donor site morbidity. Thirty patients with reconstruction of the head and neck region were included. For the first time, this study assessed flap-perfusion characteristics, donor-site-wound-healing dynamics and hand perfusion using hyperspectral imaging. Further, subjective (Likert-scale, DASH-score) and objective (grip/pinch-strength) parameters of donor site morbidity were analysed. Postoperative follow-up was performed until 6 months after index surgery. With 100% of patients, RFFF and UFFF were equally successful. Compared to surrounding reference, UFFF revealed significant lower tissue oxygenation saturation (StO2) than RFFF. Compared with UFFF, blood flow in both the thenar and hypothenar region were significantly reduced 6 months following RFFF transfer. After four weeks, 27% more patients demonstrated impaired wound healing following RFFF transfer. After 6 months, epithelial-surface continuity was restored in all patients of both groups. After 6 months, overall rates of both subjective and objective donor site morbidity were comparable between RFFF and UFFF. RFFF and UFFF both demonstrate similar success rates and HSI-perfusion dynamics following transfer. After 4 weeks, wound-healing disorder appeared significantly more often in RFFF than in UFFF; however, they became equal after 6 months. RFFF and UFFF can be considered as mutual alternatives.

Osseointegration of a New, Ultrahydrophilic and Nanostructured Dental Implant Surface: A Comparative In Vivo Study.

This study compared the osseointegration of acid-etched, ultrahydrophilic, micro- and nanostructured implant surfaces (ANU) with non-ultra-hydrophilic, microstructured (SA) and non-ultrahydrophilic, micro- and nanostructured implant surfaces (AN) in vivo. Fifty-four implants (n = 18 per group) were bilaterally inserted into the proximal tibia of New Zealand rabbits (n = 27). After 1, 2, and 4 weeks, bone-implant contact (BIC, %) in the cortical (cBIC) and spongious bone (sBIC), bone chamber ingrowth (BChI, %), and the supra-crestal, subperiosteal amount of newly formed bone, called percentage of linear bone fill (PLF, %), were analyzed. After one week, cBIC was significantly higher for AN and ANU when compared to SA (p = 0.01 and p = 0.005). PLF was significantly increased for ANU when compared to AN and SA (p = 0.022 and p = 0.025). After 2 weeks, cBIC was significantly higher in SA when compared to AN (p = 0.039) and after 4 weeks, no significant differences in any of the measured parameters were found anymore. Ultrahydrophilic implants initially improved osseointegration when compared to their non-ultrahydrophilic counterparts. In accordance, ultrahydrophilic implants might be appropriate in cases with a necessity for an accelerated and improved osseointegration, such as in critical size alveolar defects or an affected bone turnover.

Bleeding disorders in implant dentistry: a narrative review and a treatment guide.

PURPOSE: Considering a high prevalence of congenital and especially acquired bleeding disorders, their heterogeneity and the multitude of possible treatments strategies, a review of the scientific data on this topic is needed to implement a treatment guide for healthcare professionals. METHODS: A selective literature review was performed via PubMed for articles describing oral surgery / dental implant procedures in patients with congenital and acquired bleeding disorders. Out of the existing literature, potential treatment algorithms were extrapolated. RESULTS: In order to assess the susceptibility to bleeding, risk stratification can be used for both congenital and acquired coagulation disorders. This risk stratification, together with an appropriate therapeutic pathway, allows for an adequate and individualized therapy for each patient. A central point is the close interdisciplinary cooperation with specialists. In addition to the discontinuation or replacement of existing treatment modalities, local hemostyptic measures are of primary importance. If local measures are not sufficient, systemically administered substances such as desmopressin and blood products have to be used. CONCLUSIONS: Despite the limited evidence, a treatment guide could be developed by means of this narrative review to improve safety for patients and practitioners. Prospective randomized controlled trials are needed to allow the implementation of official evidence-based guidelines.

Biofunctionalization of Xenogeneic Collagen Membranes with Autologous Platelet Concentrate-Influence on Rehydration Protocol and Angiogenesis.

Background: The aim of this study was to analyze possible interactions of different xenogeneic collagen membranes (CM) and platelet-rich fibrin (PRF). PH values were evaluated in the CM rehydration process with PRF, and their influence on angiogenesis was analyzed in vivo. Materials and Methods: Porcine (Bio-Gide®, Geistlich)- and bovine-derived collagen membranes (Symbios®, Dentsply Sirona) were biofunctionalized with PRF by plotting process. PRF in comparison to blood, saline and a puffer pH7 solution was analysed for pH-value changes in CM rehydration process in vitro. The yolk sac membrane (YSM) model was used to investigate pro-angiogenic effects of the combination of PRF and the respective CM in comparison to native pendant by vessel in-growth and branching points after 24, 48 and 72 h evaluated light-microscopically and by immunohistochemical staining (CD105, αSMA) in vivo. Results: Significantly higher pH values were found at all points in time in PRF alone and its combined variants with Bio-Gide® and Symbios® compared with pure native saline solution and pH 7 solution, as well as saline with Symbios® and Bio-Gide® (each p < 0.01). In the YSM, vessel number and branching points showed no significant differences at 24 and 48 h between all groups (each p > 0.05). For PRF alone, a significantly increased vessel number and branching points between 24 and 48 h (each p < 0.05) and between 24 and 72 h (each p < 0.05) was shown. After 72 h, CM in combination with PRF induced a statistically significant addition to vessels and branching points in comparison with native YSM (p < 0.01) but not vs. its native pendants (p > 0.05). Summary: PRF represents a promising alternative for CM rehydration to enhance CM vascularization.

Biomechanical Characterization of a New Acellular Dermal Matrix for Oral Soft Tissue Regeneration.

OBJECTIVES: Acellular dermal matrices (ADM) are a suitable alternative to autogenous soft tissue grafts (ASG). The aim of this study was to analyze the biomechanical properties and architectural features of ASG and ADM. MATERIALS AND METHODS: ASG were harvested from the hard palate of fresh frozen body donors as connective tissue grafts and compared to ADM of porcine origin (NovoMatrix, NM; mucoderm, MD). Maximum load (ML, Newton [N]) and expansion (E, [mm]) were measured after rehydration in saline solution by tensile strength measurement. Light microscopy (LM) and scanning electron microscopy (SEM) were performed to analyze the architectural features of ASG and ADM in high resolution. RESULTS: ASG demonstrated a significantly decreased ML compared to NM and MD (p < 0.0001 and p = 0.019). NM showed a significantly increased ML compared to MD (p = 0.001). ASG demonstrated a non-significantly reduced E compared to NM (p = 0.13) and a significantly increased E compared to MD (p = 0.025). NM showed an increased E compared to MD (p < 0.0001). LM and SEM highlighted the surface characteristics and internal structures of ASG and ADM, such as the surface compact layer of MD and the densely packed, parallel running and ordered collagen fibers of NM and MD. CONCLUSIONS: Significant differences concerning the biomechanical properties and architectural features of ASG, and ADM were found. CLINICAL RELEVANCE: Information about the biomechanical properties and architectural features of ASG and ADM can contribute to a better understanding of the clinical performance and extend the application area.

An update on the current training situation of German interns in oral and maxillofacial surgery at special times in 2021.

The aim of this study was to evaluate the current state of training of German interns in oral and maxillofacial surgery (OMFS) under the influence of the COVID-19 pandemic in 2021. A previously tested questionnaire consisting of 53 questions was sent to interns in German OMFS (non-) university hospitals and private practices as an online survey. The questionnaire was adapted to current topics, such as the ongoing COVID-19 pandemic, aspects concerning nighttime and weekend services, overtime hours, surgical logbooks, benefits of academic degrees and support for scientific activities, part-time employment, parental leave and childcare. Next, results of questions from before the COVID-19 pandemic were re-evaluated. The COVID-19 pandemic influenced the clinical work (71.83%) and the current state of training (68.64%) in OMFS of most participants. Nighttime and weekend services are possible for employees in possession of only one degree (87.93% with a medical degree) in most hospitals. Not having one or both doctorate degrees was considered to be a disadvantage by 54.95%. In all, 42.11% of the participants attested to a positive influence of research on their training situation, and 50% reported financial or non-financial research support from the employer. Part-time employment was possible for 78.81% of the participants. The course of training was interrupted more often for women due to parental or maternity leave (10.53% of men and 30.95% of women). A total of 40.71% of the participants reported that childcare was available at the hospital, theoretically. The state of OMFS training in Germany can be referred to as positive. Current and future challenges are diverse, including aspects originating from the ongoing COVID-19 pandemic, gender aspects, reconciliation of family and work, and flexible working hours. Addressing these topics will ensure OMFS training at the highest surgical level and further increase interns' satisfaction, preserving the specialty's popularity and reception.

Biomechanical evaluation of cyanoacrylate-based tissue adhesive for intraoral wound closure.

OBJECTIVES: The aim of this study was to analyze the biomechanical characteristics of a novel cyanoacrylate-based tissue adhesive (CTA) for soft-tissue closure of the (non-) tooth-bearing alveolar process and around dental implants. MATERIALS AND METHODS: Halves of porcine mandibles (n = 21) were randomly divided into three experimental intraoral wound closure groups (A-C) with three different mucoperiosteal flap types (F1-3, n = 7 each): F1, crestal incision between the last incisor and the canine with a mesial and distal vestibular relief; F2, crestal double-T-shaped incision and dental implant placement between the canine and the first premolar; and F3, trapezoidal incision on the second premolar. F1-3 were respectively closed using (A) monofil non-resorbable sutures, (B) CTA, and (C) a combination of both. Tensile strength (TS) and elasticity (E) measurements were performed for biomechanical analysis. RESULTS: In F1, CTA showed a significantly reduced TS compared to A (p < 0.001) and C (p < 0.01). In F2, an increased TS of C compared to A (p < 0.01) and B (p < 0.001) was found. Here, E was significantly increased in C compared to B (p < 0.02). In F3, TS was significantly decreased in B compared to A (p < 0.01) and C (p < 0.001). The E in group C was significantly increased compared to B (p < 0.01). CONCLUSIONS: Different biomechanical characteristics between CTA and sutures were found. CTA could be a possible alternative to sutures for intraoral wound closure in special conditions. CLINICAL RELEVANCE: A combination of both, suturing and CTA, could be a promising option in critical soft-tissue wounds requiring high functional stability and elasticity.

3D printing in oral and maxillofacial surgery: a nationwide survey among university and non-university hospitals and private practices in Germany.

OBJECTIVES: Oral and maxillofacial surgery (OMFS) has undergone pioneering progress through the development of three-dimensional (3D) printing technologies. The aim of this study was to evaluate the use of 3D printing at OMFS university and non-university hospitals and private practices in Germany. MATERIALS AND METHODS: For explorative assessment, a dynamic online questionnaire containing 10-22 questions about the current use of 3D printing and the reasons behind it was sent to OMFS university and non-university hospitals and private practices in Germany by the study group from the German Association of Oral and Maxillofacial Surgery (DGMKG). RESULTS: In total, 156 participants responded from university (23 [14.7%]) and non-university hospitals (19 [12.2%]) and private practices without (85 [50.5%]) and with 29 (18.6%) inpatient treatment facility. Highest applications of 3D printing were in implantology (57%), microvascular bone reconstructions (25.6%), and orthognathics (21.1%). Among the participants, 37.8% reportedly were not using 3D printing. Among the hospitals and private practices, 21.1% had their own 3D printer, and 2.5% shared it with other departments. The major reason for not having a 3D printer was poor cost efficiency (37.6%). Possessing a 3D printer was motivated by independence from external providers (91.3%) and rapid template production (82.6%). The preferred printing methods were stereolithography (69.4 %) and filament printing (44.4%). CONCLUSIONS: OMFS 3D printing is established in Germany with a wide range of applications. CLINICAL RELEVANCE: The prevalence of 3D printing in hospitals and private practices is moderate. This may be enhanced by future innovations including improved cost efficiency.

Treatment Modalities of Recurrent Oral Mucosal Melanoma In Situ.

Oral mucosal melanoma (OMM) represents an extremely rare entity that is associated with a poor prognosis due to late diagnosis and early metastasis. Here, extensive surgical therapy is the therapy of choice. In contrary, for OMM in situ, the respective therapeutical recommendations are lacking. In this case report, treatment modalities of an OMM in situ of the palate, including the maxillary alveolar process, are reported. The tumor relapsed twice despite adequate surgical therapy and reconstruction. Therefore, irradiation was performed as an adjuvant therapy. At a follow-up of two years, the patient was free from recurrences.