Consequences of the COVID-19 Pandemic and Governmental Containment Policies on the Detection and Therapy of Oral Malignant Lesions-A Retrospective, Multicenter Cohort Study from Germany

(1) Background: In response to the global COVID-19 pandemic, governmental measures have been undertaken. The impact of the crisis on the healthcare of patients with cancer is largely unexplored. This multicenter cohort study aimed to investigate a potential screening delay and its consequences in patients with oral cancer (OC) during the pandemic. (2) Material and Methods: Data of patients who were first diagnosed with OC during different periods were collected, especially in terms of OC incidence, tumor stage/entity and time to intervention. The periods lockdown (LD) (13 March-16 June 2020), post-lockdown (PLD) (17 June-1 November 2020), and the corresponding equivalents in 2018/19 were differentiated and compared. (3) Results: There was no obvious trend towards a higher incidence of OC or higher tumor stages, whereas a trend towards a shorter time to intervention during the LD2020 could be observed. Subgroup analyses revealed an increased incidence in OC within the PLD2020 in Mainz, which might be explained by the partial closure of dental practices in this federal state during LD. (4) Conclusions: While there was no overall higher incidence of OC, we found closure of practices during LD to possibly delay cancer diagnosis. Therefore, measures must be taken to identify patients at risk and to ensure basic healthcare, especially in the context of dental screening measures

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 dentomaxillo- 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

The Effect of Optical Conditioning of Preparations with Scan Spray on Preparation Form

Svrha rada: Za primjenu sustava CAD/CAM u ordinacijama dentalne medicine potrebno je odabrati sprej za skeniranje. Njegovom primjenom mijenja se prekrivena preparacija, što može nepovoljno utjecati na rubno zatvaranje i interno prianjanje restauracije. Zadaća ovog istraživanja bila je odrediti utjecaj spreja na preparacijsku formu procjenom morfologije i debljine triju različitih sprejeva za skeniranje. Materijali i metode: Određivala se površinska morfologija prekrivanja triju (A, B, C) različitih sprejeva za skeniranje uz pomoć konfokalnoga laserskog mikroskopa. Debljina sprejem nanesenog premaza mjerila se na staklenoj pločici i u simuliranim kliničkim uvjetima profilometrom i uređajem za digitalizaciju površine. Podaci su analizirani jednosmjernim testom ANOVA (α = .05). Rezultati: Konfokalni laserski mikroskop prikazao je grubu i nepravilnu sprejem pokrivenu površinu nakon uporabe svih sprejeva, te se od spreja A preko spreja B do spreja C broj malih zrnaca povećavao. Srednja debljina prekrivanja na staklenoj pločici iznosila je za sprej A 25,3 Μm, za B 18,9 Μm i za C 19,2 Μm. Statistički značajne razlike bile su između sprejeva A i B (p=0,017). U simuliranim kliničkim uvjetima srednja debljina prekrivanja iznosila je za sprej A 15,5 Μm, za B 15,0 Μm i za C 13,3 Μm. Razlika je bila statistički značajna samo između sprejeva A i C (p=0,033). Zaključak: Premazi nakon korištenja različitih sprejeva imali su drugačije površinske morfologije i različite debljine. Posljedično tome primjena spreja za skeniranje utječe i na konačnu CAD/CAM restauraciju, premda se kliničkim korištenjem postigla prihvatljiva debljina prekrivanja.Objective: CAD/CAM systems require scan spray for chairside sampling of tooth surfaces. However, this leads to alterations of the sprayed preparation and may affect marginal and internal adaption of the restoration. The aim of this study was to define the effect of scan spray on preparation form by evaluating the morphologies and the thicknesses of three different scan sprays. Materials and Methods: The surface morphology of the coatings of different scan sprays (A, B, C) was evaluated by use of a confocal laser scanning microscope. The thicknesses of spray coatings were measured on a glass plate as well as under simulated clinical conditions using a profilometer and a surface digitalisation device. The data were analysed by a 1-way ANOVA (α = .05). Results: The confocal laser scanning microscopy showed rough and irregular formed coating surfaces of all sprays, whereas an increasing numbers of small spray particles were seen from spray A over spray B to spray C. Mean coating thicknesses on the glass plate were: spray A 25.3 Μm, spray B 18.9 Μm and spray C 19.2 Μm. Significant differences were detected between spray A and B (P = .017). Under simulated clinical conditions median coating thicknesses were: spray A 15.5 Μm, spray B 15.0 Μm and spray C 13.3 Μm. A statistically significant difference could be detected only between spray A and C (P = .033). Conclusions: The coatings of the used scan spray systems showed different surface morphologies and exhibited different thicknesses. Consequently, the application of scan sprays affects the precision of the final CAD/CAM restorations. However, the scan sprays under investigation showed acceptable coating thicknesses for clinical use

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1) : A Prospective Multicentric Cohort Study

(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

Risk Factors for Complications Following Staged Alveolar Ridge Augmentation and Dental Implantation: A Retrospective Evaluation of 151 Cases with Allogeneic and 70 Cases with Autogenous Bone Blocks

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

Intraoral Microvascular Anastomosis in Immediate Free Flap Reconstruction for Midfacial Tumor Defects: A Retrospective Multicenter Study

(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

Establishment of a Numerical Model to Design an Electro-Stimulating System for a Porcine Mandibular Critical Size Defect

Electrical stimulation is a promising therapeutic approach for the regeneration of large bone defects. Innovative electrically stimulating implants for critical size defects in the lower jaw are under development and need to be optimized in silico and tested in vivo prior to application. In this context, numerical modelling and simulation are useful tools in the design process. In this study, a numerical model of an electrically stimulated minipig mandible was established to find optimal stimulation parameters that allow for a maximum area of beneficially stimulated tissue. Finite-element simulations were performed to determine the stimulation impact of the proposed implant design and to optimize the electric field distribution resulting from sinusoidal low-frequency ( f = 20 Hz ) electric stimulation. Optimal stimulation parameters of the electrode length h el = 25 m m and the stimulation potential &#966; stim = 0.5 V were determined. These parameter sets shall be applied in future in vivo validation studies. Furthermore, our results suggest that changing tissue properties during the course of the healing process might make a feedback-controlled stimulation system necessary

Zygoma implant under function: biomechanical principles clarified

Abstract 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

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