This study aimed to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) in detecting bone invasion in oral squamous cell carcinoma (OSCC) patients and to explore clinicopathological factors associated with its reliability. 417 patients underwent preoperative contrast-enhanced CT followed by radical surgery. The presence or absence of bone invasion served as the outcome variable, with histopathologic examination of the resection specimen considered the gold standard. Statistical analyses, comprising correlation analyses and the determination of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were conducted. CT exhibited 76.85

Objectives Effective management of neck in oral squamous cell carcinoma (OSCC) is pivotal for oncological outcomes. Although consensus exists for ipsilateral neck dissection (ND), the necessity for contralateral ND remains controversial. This study aimed to assess the prevalence and implications of bilateral/solely contralateral (B/SC) lymph node metastases (LNMs) to determine the need for contralateral elective ND. Additionally, it examined the prevalence and implications of occult B/SC metastases. Materials and methods In a retrospective cohort study, 420 OSCC patients underwent primary surgical treatment following German guidelines at a tertiary center. Preoperative contrast-enhanced computed tomography was conducted, and ND adhered to a standardized approach. Results Solely contralateral metastases occurred in 0.95% of patients, with bilateral metastases observed in 7.13%. Occult B/SC metastases occurred in 3.81% of the cases. Correlation analysis revealed a statistically significant association between B/SC metastases and higher tumor stages, tumor localization at the upper jaw or floor of the mouth, proximity to the midline, ipsilateral LNMs, and lymphatic invasion (all p < 0.05). Patients with B/SC metastases showed poorer disease-free survival, with statistical significance reached in the bilateral LNMs group (p = 0.010). Similarly, a significant difference was noted in overall survival between patients with bilateral and solely ipsilateral metastases (p = 0.044). Conclusions B/SC LNMs are rare in patients with OSCC, especially in those who present with clinico-radiologically negative ipsilateral necks. Higher rates of B/SC metastases occur in case of advanced tumors and those localized at the upper jaw or floor of the mouth. Ipsilateral LNMs significantly elevate the risk of contralateral LNMs, tripling the associated risk. Clinical relevance These findings provide valuable insights for surgeons considering contralateral ND or extended adjuvant treatment for OSCC patients. However, the absence of high-level evidence from randomized controlled trials impedes the establishment of a definitive standard of care.

BACKGROUND:The aim of this study was to assess the prognostic significance of lymph node yield (LNY), lymph node ratio (LNR), and the number of lymph node metastases (LNMs) in patients affected by oral squamous cell carcinoma (OSCC).METHODS:The study included patients who underwent surgical treatment for primary OSCC. Receiver operating characteristic curves were generated to determine the optimal threshold values. Kaplan-Meier curves were employed, along with the log-rank test, for the analysis of survival. To compare the performance in terms of model fit, we computed Akaike's information criterion (AIC).RESULTS:This study enrolled 429 patients. Prognostic thresholds were determined at 22 for LNY, 6.6% for LNR, and 3 for the number of LNMs. The log-rank test revealed a significant improvement in both overall survival and progression-free survival for patients with a LNR of ≤6.6% or a number of LNMs of ≤3 (p < 0.05). Interestingly, LNY did not demonstrate prognostic significance. The AIC analyses indicated that the number of LNMs is a superior prognostic indicator compared to LNY and LNR.CONCLUSIONS:Incorporating LNR or the number of LNMs into the TNM classification has the potential to improve the prognostic value, as in other types of cancers. Particularly, the inclusion of the number of LNMs should be contemplated for future N staging.

Background: Postoperative resorption of hard and soft tissues occurs as a consequence of tooth extraction. The Benex®-Control extractor allows minimally invasive extraction of the tooth without causing pronounced iatrogenic trauma. The aim of this study was to verify whether the resorption of the tissues after extraction can be reduced by using the Benex® system compared to the conventional extraction method. Methods: Postoperative intraoral scans were superimposed after surgery (t0), after 7 days (t1), after 14 days (t2), after 30 days (t3), after 60 days (t4), and after 90 days (t5) within the two groups (study n = 14, control n = 16), and defined regions of interest (ROIs) (1–8) and volume changes were analyzed. In addition, the influence of gingival thickness and the thickness of the labial cortical plate was investigated. Results: The greatest decrease in volume was observed in both groups in ROI3, although there was no significant difference observed between the groups. In the presence of an adjacent tooth, there was less volume loss in the affected ROIs (1, 2 and 7, 8). The thickness of the gingiva and the bony lamella did not significantly influence the change in volume. Conclusions: Due to the small cohort, the results are limited, and the hypothesis is rejected.

Objectives Management of the neck in patients with oral squamous cell carcinoma (OSCC) is pivotal to oncologic control and survival. However, there is controversy regarding necessity of neck dissection (ND) in patients with clinically node-negative neck. We aimed to assess risk factors for occult metastasis and to explore whether the presence of occult lymph node metastases (LNMs) has an impact on recurrence and survival. Material and methods A retrospective cohort study was performed including patients with primary OSCC who underwent radical tumor resection and ND in a high-volume center adhering to the prevailing German guideline. The ND was performed according to a standardized approach. Results Four hundred twenty-one patients with primary surgically treated OSCC were included. The incidence of occult metastasis was 14.49%. A pathological T stage > 1 (multivariate analysis, odds ratio (OR) 3.958, p = 0.042) and the presence of extranodal extension in LNMs (multivariate analysis, OR 0.287, p = 0.020) were identified as independent risk factors for occult metastasis. When comparing patients with and without occult metastasis, there were no significant differences in terms of progression-free survival (log-rank, p = 0.297) and overall survival (log-rank, p = 0.320). There were no cases of ipsilateral neck recurrence. One patient developed contralateral neck metastasis; however, he initially presented with a unilateral pT1 pN0 tumor. Conclusions Overall, our findings suggest that conducting a standardized approach in ND should be applied in terms of management of the neck in order to maintain survival rates and to prevent neck recurrence in OSCC patients. Clinical relevance. None of the risk factors for occult metastasis can be reliably assessed preoperatively. Although elective ND does not guarantee the complete prevention of neck recurrence, it increases the likelihood of either timely removal of micrometastases or strengthens the justification for adjuvant therapy. Consequently, this approach leads to improvements in clinical outcomes.

Since its introduction in 1968, the TNM (tumor, node, metastasis) classification established by the International Union Against Cancer has provided a consistent framework for staging of oral squamous cell carcinoma (OSCC). The introduction of the 8th edition in 2017 brought about significant modifications, encompassing the integration of depth of invasion (DOI) and extranodal extension (ENE) into the T and N classifications. Further, the UICC the criteria for the T3 and T4a categories were amended in 2020. This study aimed to evaluate the impact of reclassification on staging and, subsequently, the survival of patients with OSCC. Primary OSCCs from 391 patients were classified according to the 7th and revised 8th UICC editions (2020). Stage migration was assessed, and stage-specific progression-free survival (PFS) and overall survival (OS) were evaluated using the Kaplan–Meier method. The log-rank test was used to compare the different stages. Cox-proportional hazard modeling was used to compare the two editions. Incorporating the DOI into the T classification resulted in an upstaging of 77 patients, constituting 19.69% of the cohort. In addition, 49 (12.53%) patients experienced an upstaging when considering ENE in the N classification. Consequently, 103 patients underwent upstaging in UICC staging, accounting for 21.74% of cases. Upstaging mainly occurred from stage III to IVA (26.92%) and from stage IVA to IVB (31.78%). Upon comparing the categories in survival analysis, significant differences in OS and PFS were especially observed between stage IVB and lower stages. When examining the hazard ratios, it became evident that UICC 8 stage IVB is burdened by a 5.59-fold greater risk of disease progression than stage I. Furthermore, UICC 8 stage IVB exhibits a 3.83 times higher likelihood of death than stage I disease. We demonstrated significant stage migration from the 7th to the revised 8th UICC edition. Overall, incorporating DOI and ENE into the T and N classifications represents a substantial clinical advancement, leading to a more accurate staging of OSCC patients. Both staging systems exhibited statistically significant discrimination between stages; however, the 8th UICC edition allowed for a more precise categorization of patients based on their prognosis and led to enhanced hazard discrimination, particularly within higher stages.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of unknown etiology that affects the central nervous system and can lead to neurological impairment. Our aim was to determine whether MS patients also show inflammatory changes in the oral cavity more frequently than healthy individuals. For this purpose, we examined plaque samples for various mediators and their correlation with clinical findings. A study group (MS) and a control group were examined and compared. The plaque samples were analyzed for the expression of interleukins (IL-2, -6, -10), matrix metalloproteinases (MMP-7, MMP-9), and a surface antigen CD90 by quantitative real-time PCR. The clinical parameters examined were the Mombelli plaque index; bleeding on probing (BOP) index; periodontal pocket depth; and decayed, missing, and filled tooth (DMFT) index. The expression of MMP9 was significantly (p = 0.035) higher in the control group. The expression of IL-2 was increased four-fold in the MS group; however, this difference was not statistically significant. The mean PD (p < 0.001) and BOP index (p = 0.029) values were increased in the study group. The clinical parameters of the BOP index and PD were significantly amplified in the MS patients. However, no causal relationship between the investigated inflammatory mediators and the clinical findings could be established in this case series.

Abstract Background This in vitro study investigated whether full-guided (FG) or half-guided (HG) implant placement is more suitable for beginners and to what extent the use of the coDiagnostiX (CDX) (10.5, Straumann Group, Basel, Switzerland) implant planning software proves useful in teaching. Methods Twenty students planned implant positions with CDX which were then placed in a model using printed drill templates in the sense of FG implantation (group 1) and HG implantation (group 2). The implant positions could be compared with those of the reference model, and deviations could be determined. The results were tested for significance using the t-test for independent samples for groups 1 and 2. A total of 32 students subsequently completed a questionnaire about the software. Cronbach's α was also calculated to check the reliability of the questions for the individual subject areas. Results In both groups the greatest deviation occurred along the y-axis in the vestibular direction. It measured 1.390 mm in group 1 and 1.570 mm in group 2. Comparing both groups, there were significant deviations along the y-axis (p = .013), along the z-axis (p = .049), and in the total deviation (p = .031). The questionnaire was evaluated in design, with 95% positive answers. In contrast, the evaluation of the area of time and effort resulted in only 55% positive responses. Overall, experience with the software was rated as positive by 74%. Conclusions Group 1 achieved more accurate results, especially along the y-axis in the vestibular direction. In both groups, the implants were placed too deep. The questionnaire indicated a software with high usability and is therefore very suitable for teaching. If clinically feasible, beginners should prefer full-guided implant placement.

This study aimed to explore survival and recurrence patterns in patients undergoing primarily surgical treatment for oral squamous cell carcinoma (OSCC) at a high-volume tertiary medical center in Germany. The study included 421 patients with primary OSCC who underwent radical tumor resection, neck dissection, and reconstruction with a free flap. Prognostic relevance of clinicopathological characteristics was assessed using Cox proportional-hazards models. Kaplan-Meier method estimated local recurrence-free survival, progression-free survival (PFS), and overall survival (OS), while the log-rank test compared survival outcomes between groups. Recurrence manifested in 16.63

OBJECTIVES:Temporomandibular disorders (TMDs) are common and may cause persistent functional limitations and pain. Magnetic resonance imaging (MRI) at 1.5 and 3 T is commonly applied for the evaluation of the temporomandibular joint (TMJ). No evidence is available regarding the feasibility of modern low-field MRI for the assessment of TMDs. The objective of this prospective study was to evaluate the image quality (IQ) of 0.55 T MRI in direct comparison with 1.5 T MRI. MATERIALS AND METHODS:Seventeen patients (34 TMJs) with suspected intraarticular TMDs were enrolled, and both 0.55 and 1.5 T MRI were performed on the same day. Two senior readers independently evaluated the IQ focusing on the conspicuity of disc morphology (DM), disc position (DP), and osseous joint morphology (OJM) for each joint. We analyzed the IQ and degree of artifacts using a 4-point Likert scale (LS) at both field strengths. A fully sufficient IQ was defined as an LS score of ≥3. Nonparametric Wilcoxon test for related samples was used for statistical comparison. RESULTS:The median IQ for the DM and OJM at 0.55 T was inferior to that at 1.5 T (DM: 3 [interquartile range {IQR}, 3-4] vs 4 [IQR, 4-4]; OJM: 3 [IQR, 3-4] vs 4 [IQR 4-4]; each P < 0.001). For DP, the IQ was comparable (4 [IQR 3-4] vs 4 [IQR 4-4]; P > 0.05). A sufficient diagnostic IQ was maintained for the DM, DP, and OJM in 92% of the cases at 0.55 T and 100% at 1.5 T. Minor image artifacts (LS score of ≥3) were more prevalent at 0.55 T (29%) than at 1.5 T (12%). CONCLUSIONS:Magnetic resonance imaging of the TMJ at 0.55 T yields a lower IQ than does MRI at 1.5 T but maintains sufficient diagnostic confidence in the majority of patients. Further improvements are needed for reliable clinical application.

ABSTRACT Objective Temporomandibular dysfunction (TMD) reduces patients’ quality of life (QoL). The aim was to assess the effects of initial Aqualizer™ therapy. Methods Group 1 (initial Aqualizer™ therapy) before definitive splint therapy or Group 2 (no initial therapy). Patients with arthrosis, partial/total prosthesis, or were undergoing splint therapy were excluded. Subjective parameters were evaluated: duration and intensity of pain, influence on wellbeing, changes in the head/neck area, handling and improvement of the Aqualizer™, improvement in QoL. The statistical significance level was 5% (p < 0.05). Results In 53 patients (Group 1 n = 25; Group 2 n = 28), the improvement in patients’ well-being and intensity of pain in both groups was significant (p < 0.001). An improvement in QoL was found in 84% of patients in Group 1 and 75% in Group 2. Conclusion Initial Aqualizer™ therapy can decrease the intensity of pain and increase patients’

Background: Maxillofacial osteosarcoma (MOS) is a rare disease, mostly located to the mandible or maxilla. Surgical resection with wide free margins represents the key intervention to achieve favorable prognosis. MOS are particularly demanding to resect and surgically reconstruct because of the numerous tissue types and functions included in this location. Case reports: We introduce two patients with a highly malignant maxillary OS treated by primary tumor resection and immediate reconstruction with a microvascular soft tissue flap. After confirmation of relapse-free tissue healing and sufficiently free resection margins, osseous reconstruction was performed in a second operation by use of a virtually planned microvascular Fibula Flap. Both patients received implant-supported dental rehabilitation and show relapse-free for seven and three years, respectively. Conclusions: Combination of radical tumor resection, primary soft tissue reconstruction and secondary bone reconstruction allows high oncologic safety and optimal conditions for a thoroughly planned osseous as well as dental rehabilitation.

We aimed to validate the metric accuracy of a 3-dimensional (3D) facial scanner (FS) and an intraoral scanner (IOS) in capturing the nasolabial region in ex vivo unilateral cleft lip and palate (UCLP) models. The nasolabial region of 10 UCLP models was scanned using a 3D FS as well as an IOS and a previously validated stationary 3D scanner as a reference. Intraoral scan was performed directly on the UCLP models. In order to apply the FS on the models, they were embedded in a 3D printed sample face. Both test groups were aligned to the reference by applying a section-based best-fit algorithm. Subsequent analysis of the metric deviation from the reference was performed with a 3D analysis tool. Mean distance and integrated distance served as main parameters for surface and volume comparison. Point comparison served as an additional parameter. Statistical analysis was carried out using t-test for unconnected samples. Considering mean distance and integrated distance as main parameters for 3D evaluation of the scanner's accuracy, FS and IOS differ significantly in their metric precision in scanning the cleft model compared to the reference. The IOS proved to be significantly more accurate than the FS compared to the previously described stationary 3D scanner as reference and validated baseline. Further validation of the tested IOS and FS for 3D assessment of the nasolabial region is presented by adding the previously validated ATOS III Triple Scan blue light scanner as a reference. The IOS shows, compared to a validated baseline scan, significantly higher metric precision in experimental cleft model scanning. The collected data provides a basis for clinical application of the IOS for 3D assessment of the nasolabial region.

Objective Accurate preoperative prediction of lymph node (LN) status plays a pivotal role in determining the extension of neck dissection (ND) required for patients with oral squamous cell carcinoma (OSCC). This study aims to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) in detecting LN metastases (LNMs) and to explore clinicopathological factors associated with its reliability. Methods Data from 239 patients with primary OSCC who underwent preoperative CT and subsequent radical surgery involving ND were retrospectively reviewed. Suspicious LNs were categorized into three groups: accentuated (< 10 mm), enlarged (≥ 10 mm), and melted. Statistical analysis encompassing correlation and comparative analysis, and determination of sensitivity, specificity, PPV, and NPV were performed. Results Overall, sensitivity was significantly higher in the accentuated LNs group (83.54%) compared to the melted LNs group (39.24%, p < 0.05, t test). Conversely, specificity was significantly higher in the melted LNs group (98.19%) compared to the accentuated LNs group (55.15%, p < 0.05, t test). Accentuated LNs exhibited a false negative rate of 13.00%. False positive rates were 51.80%, 30.26% and 8.82%, respectively. Diagnostic accuracy for detecting LNMs in level IIa and IIb exceeded that of level III. Patients with solely accentuated LNs were more likely to have a small, well-differentiated tumor. However, no distinctions emerged in terms of the occurrence of T4 tumors among the three groups. Conclusion CT proves sufficient to predict LNMs in patients with OSCC. Looking ahead, the potential integration of artificial intelligence and deep learning holds promise to further enhance the reliability of CT in LNMs detection. However, this prospect necessitates further investigation.

INTRODUCTION This study aimed to determine whether implant surgery procedures can be implemented in the dental curriculum by designing novel courses for students. Additionally, this study assesses the perception of these courses and how they can be established in the future. MATERIALS AND METHODS Students from the third to fifth years participated in a programme consisting of 4 modules according to their academic year. The modules taught theoretical and practical content as well as clinical references. After participating, the students completed two questionnaires with research questions (RQ1 = evaluation of the relevance and effects; RQ2 = impact of modules 3 and 4) to evaluate the programme. The questionnaires consisted of 52 statements, each rated on a 6-point scale (1 'totally disagree' to 6 'totally agree'). Cronbach's alpha analysis was used, and median values, interquartile ranges and Pearson correlations (p-value) were statistically calculated. RESULTS In total, 94 students completed the questionnaires. Cronbach's alpha exceeded 0.7 for all constructs except for one (skills training). The highest evaluated median was 6, and the lowest was 4.75. Pearson correlations were significant (<0.05) for perceived importance/lectures, perceived importance/tutor performance, lectures/skills training, skills training/tutor performance and tutor performance/lectures. Seventeen analysed free comments expressed strong interest in implantology courses for the curriculum. 88% of the students wished for more practical exercises in dental implantology during the curriculum or suggested expanding the programme in the future. CONCLUSION The programme was highly accepted among dental students. The students wished for more practice in the future to perform supervised procedures on patients.

Abstract Objectives Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of unknown etiology that affects the central nervous system and can lead to neurological impairment. Our aim was to determine whether MS patients also show inflammatory changes in the oral cavity more frequently than healthy individuals. Material and Methods We examined plaque samples for various mediators and their correlation with clinical findings. A study group (MS) and a control group were examined and compared. The plaque samples were analyzed for the expression of interleukins (IL-2, -6, -10), matrix metalloproteinases (MMP-7, MMP-9) and a surface antigen CD90 by quantitative real-time PCR. Clinical parameters examined were the Mombelli plaque index (MPI), bleeding on probing (BOP) index, gingival pocket depth (PD) and Decayed, missing and filled tooth (DMFT) index. Results The expression of MMP9 was significantly (p = 0.035) higher in the control group. The expression of IL-2 was increased 4-fold in the MS group, but this difference was not statistically significant. The mean PD (p < 0.001) and BOP index (p = 0.029) were increased in the study group. Conclusion The clinical parameters of the BOP index and PD were significantly amplified in the MS patients. However, no causal relationship could be established in this case series, thus for the oral and maxillofacial surgical treatment no evidence for restrictions could be derived. Clinical Relevance With the worldwide increasing incidence of MS, it’s important to obtain insights into the effects of the disease on the oral cavity. The study was registered in the German clinical trial registry (DRKS00022956, registered 28/08/2020).

Background Due to the SARS-CoV-2 pandemic and the accompanying contact restrictions, a new challenge arose for dental education. Despite the limited overall situation, it must be ensured that, in addition to theoretical content, practical skills in particular continue to be taught. Therefore, the aim of this study was to develop and implement an online hands-on course for dental students that ensures practical training, even during the pandemic. Methods The newly developed course was held from April 2020 to March 2021. A total of six groups (each consisting of approximately 40–50 students) took part in the course. The participating students were in their 3rd, 4th or 5th year of study. The course taught theoretical basics (via an online platform) and promoted the learning of practical/surgical techniques on models such as bananas, pork bellies, or chicken thighs with live demonstrations (via ZOOM) and interactive post-preparation by students at home (and in a rotating small group of 3–7 students on site). Student self-evaluation (at the beginning and end of the course) and course evaluation were performed using questionnaires. The learning success was analyzed (through self-evaluations) using Wilcoxon signed-rank tests (significance level alpha = 0.05). Results Concerning students´ self-evaluations, the theoretical knowledge, general surgical skills (such as surgical instrument handling), and specific surgical skills (such as performing a kite flap) improved during the course, with significant results ( p < 0.001 for each). About 60% of the students rated the course overall as excellent (grades 9 or 10 on a Likert scale of 1 to 10). The technical implementation of the course was rated with a median of 9 (= very good, on a Likert scale of 1 to 10). 38.5% described the applicability of the skills learned for their later professional life as extremely good. Conclusions The results of this work suggest that, within the limitations of this study, the introduced concept of an online hands-on course could be an appropriate form of teaching practical dental skills, even during a pandemic. Further research is needed in the field of digital education for dental students.

Structured examination and treatment are essential in medicine. For dental students, a structured approach to the assessment of oral mucosal lesions is missing thus far. To validate an approach, a structured questionnaire was compared with the habitually used free description of oral lesions (white lesions, ulcers, hyperplasia). Thirty-three dental students were divided into two groups (Group 1 (n = 17) used the free description; Group 2 (n = 16) used a guided questionnaire) to characterize mucosal lesions in patients and make a tentative diagnosis. Although no difference was found between the groups regarding the suspected diagnosis or the histopathological findings, there was a significant advantage of the structured questionnaire in all aspects of the description compared to the free description (p = 0.000018). Thus, a structured description is an important aspect in the evaluation of oral mucosal changes, and a guided questionnaire should be implemented in the study of dentistry.

AIM:As a common procedure in oral surgery, the removal of wisdom teeth (3M) is associated with a variety of postoperative complications. This study reports of deep tissue abscesses after the removal of 3M in correlation to several factors.MATERIALS AND METHODS:Patients between 2012 and 2017 with removed 3M were retrospectively evaluated in terms of clinical condition and localization and thus assigned tog A (removal of asymptomatic 3M) or group B (removal of symptomatic 3M). Moreover, they were analyzed in terms of abscesses after the removal and correlation with various parameters: localization of the abscess, general diseases, perioperative antibiotic treatment, number of days from removal of the tooth to abscess formation, and postoperative complications after primary abscess incision.RESULTS:About 82 patients (male n = 44, female n = 38) were included, with 88 wisdom teeth removed and postoperative abscesses. Postoperative abscesses occurred more frequently in group B (n = 53) with n = 29 in IIB localization, without a significant correlation. Patients in this group were older, and there were more surgical abscess incisions needed, despite a longer treatment with oral and intravenous antibiosis that correlated with neurologic diseases and age. Younger patients reported significantly more pain.CONCLUSIONS:Detection of potential 3M pathologies at an early and asymptomatic stage is essential to avoid postoperative complications following 3M removal. Additional prospective studies are necessary to develop corresponding guidelines.CLINICAL SIGNIFICANCE:Wisdom tooth extraction is the most common operation in oral surgery, and therefore, adequate risk evaluation is still required.