Rat fracture models are extensively used to characterize normal and pathological bone healing. Despite, systematic research on inter- and intra-individual differences of common rat bones examined is surprisingly not available. Thus, we studied the biomechanical behaviour and radiological characteristics of the humerus, the tibia and the femur of the male Wistar rat—all of which are potentially available in the experimental situation—to identify useful or detrimental biomechanical properties of each bone and to facilitate sample size calculations. 40 paired femura, tibiae and humeri of male Wistar rats (10–38 weeks, weight between 240 and 720 g) were analysed by DXA, pQCT scan and three-point-bending. Bearing and loading bars of the biomechanical setup were adapted percentually to the bone’s length. Subgroups of light (skeletal immature) rats under 400 g (N = 11, 22 specimens of each bone) and heavy (mature) rats over 400 g (N = 9, 18 specimens of each bone) were formed and evaluated separately. Radiologically, neither significant differences between left and right bones, nor a specific side preference was evident. Mean side differences of the BMC were relatively small (1–3% measured by DXA and 2.5–5% by pQCT). Over all, bone mineral content (BMC) assessed by DXA and pQCT (TOT CNT, CORT CNT) showed high correlations between each other (BMC vs. TOT and CORT CNT: R2 = 0.94–0.99). The load–displacement diagram showed a typical, reproducible curve for each type of bone. Tibiae were the longest bones (mean 41.8 ± 4.12 mm) followed by femurs (mean 38.9 ± 4.12 mm) and humeri (mean 29.88 ± 3.33 mm). Failure loads and stiffness ranged from 175.4 ± 45.23 N / 315.6 ± 63.00 N/mm for the femurs, 124.6 ± 41.13 N / 260.5 ± 59.97 N/mm for the humeri to 117.1 ± 33.94 N / 143.8 ± 36.99 N/mm for the tibiae. Smallest interindividual differences were observed in failure loads of the femurs (CV% 8.6) and tibiae (CV% 10.7) of heavy animals, light animals showed good consistency in failure loads of the humeri (CV% 7.7). Most consistent results of both sides (left vs. right) in failure loads were provided by the femurs of light animals (mean difference 4.0 ± 2.8%); concerning stiffness, humeri of heavy animals were most consistent (mean difference of 6.2 ± 5%). In general, the failure loads showed strong correlations to the BMC (R2 = 0.85–0.88) whereas stiffness correlated only moderate, except for the humerus (BMC vs. stiffness: R2 = 0.79). Altogether, the rat’s femur of mature specimens showed the most accurate and consistent radiological and biomechanical results. In synopsis with the common experimental use enabling comparison among different studies, this bone offers ideal biomechanical conditions for three point bending experiments. This can be explained by the combination of a superior aspect ratio and a round and long, straight morphology, which satisfies the beam criteria more than other bones tested.

In our study, the effect of the use of autofluorescence (Visually Enhanced Lesion Scope—VELscope) on increasing the success rate of surgical treatment in oral squamous carcinoma (OSCC) was investigated. Our hypothesis was tested on a group of 122 patients suffering from OSCC, randomized into a study and a control group enrolled in our study after meeting the inclusion criteria. The preoperative checkup via VELscope, accompanied by the marking of the range of a loss of fluorescence in the study group, was performed before the surgery. We developed a unique mucosal tattoo marking technique for this purpose. The histopathological results after surgical treatment, i.e., the margin status, were then compared. In the study group, we achieved pathological free margin (pFM) in 55 patients, pathological close margin (pCM) in 6 cases, and we encountered no cases of pathological positive margin (pPM) in the mucosal layer. In comparison, the control group results revealed pPM in 7 cases, pCM in 14 cases, and pFM in 40 of all cases in the mucosal layer. This study demonstrated that preoperative autofluorescence assessment of the mucosal surroundings of OSCC increased the ability to achieve pFM resection 4.8 times in terms of lateral margins.

The evaluation of surveillance imaging of OSCC patients is a difficult task physicians have to face daily. Multiple patients experience a recurrence of this disease, which underlines the importance of regular patient monitoring programs. Our study analysed the value of surveillance imaging, such as computed tomography (CT) and nuclear magnetic resonance imaging (NMRI), as a patient monitoring programme and its effectiveness in achieving improvement in early recurrence detection. The study comprised 125 patients, out of which 56 (n = 56) showed radiological and 69 (n = 69) showed clinical and radiological conspicuous patterns in domestic follow-ups, respectively. The use of CT and NMRI showed a significant dependence on the histological result (p = 0.03). However, the different groups showed no significant dependence on the histological result (p = 0.96). The distribution of the histological biopsies, which were taken due to radiological changes, were prone to wrong positive diagnoses (false positives) in 71 percent. To conclude, imaging modalities should be chosen for each patient individually to reduce false positives, improve the early detection of recurrence, and increase the cure rate.

The medial approach for minimally invasive harvesting of a deep circumflex iliac artery (DCIA) flap is described for reconstruction of the jaw. The associated preservation of the crest of the ilium prevents the raising of the abdominal internal oblique muscle (IO) in a standard fashion. However, reconstructive surgery of composite mandibular defects includes bone and soft tissue. To achieve this goal, we combined this technique with a new perforator-based raising of the IO for reconstruction of intraoral soft tissue. In this study, we present eight cases of patients with composite mandibular defects who underwent the myo-osseous DCIA flap procedure with an IO perforator. Virtual surgical planning was employed to preplan the size and configuration of the graft. Cutting guides were made using CAD/CAM technology. The surgical procedure followed the described medial approach for minimally invasive harvesting, leaving the iliac crest, spine, and skin intact. In addition, we completely cut and isolated the IO with its sole attachment being the ascending branch of the DCIA. We used either a surgical guide with a slot to lead through both the transverse branch of the bone and the ascending branch of the IO or a surgical guide consisting of 2 parts. In all instances, the flap successfully survived with a 100% success rate. There were no signs of infection, wound opening, or bleeding in either patient. Furthermore, the patients did not exhibit permanent complications related to the donor site. The internal oblique perforator flap exhibited remarkable integration in all patients and underwent rapid transformation. Notably, the flap developed keratinized mucosa (KM) that closely resembled the attached gingiva. Our study demonstrated the effectiveness of a medial approach for harvesting a newly designed more flexible chimeric myo-osseous deep circumflex iliac artery flap. By incorporating virtual surgical planning and custom-made cutting guides for obtaining deep circumflex iliac artery flaps through the medial route along with an internal oblique perforator flap, we have established a highly promising method for the rehabilitation of patients with composite mandibular defects. This approach not only improves functional outcomes, but also enhances aesthetic results to maintain patients’ quality of life.

Background: Saliva sampling is increasingly used for respiratory virus diagnostics in dentistry and oral medicine due to patient comfort and reduced exposure risk. How routine behaviors—mechanical oral hygiene, rinsing, and food intake—affect short-term SARS-CoV-2 detectability remains insufficiently characterized for clinical workflows. Methods: In this international two-center pilot study, twelve RT-PCR-confirmed COVID-19 patients provided paired mouth-rinse saliva samples and pharyngeal swabs at predefined time points. The study assessed (I) an intensified 3 min mechanical oral hygiene protocol (toothbrushing of teeth, gingiva, tongue, and palate, followed by toothpaste–saliva gargling); (II) repeated short mouth rinses; and (III) postprandial sampling. Viral RNA was quantified by RT-PCR; Ct-trajectories were analyzed intra-individually. Results: Cycle threshold (Ct) values from pharyngeal swabs remained relatively stable over time, whereas mouth-rinse samples exhibited notable fluctuations throughout the 24 h period. An average increase of 3 Ct units was observed three minutes after the final mouth rinse (T24+3). Meal ingestion was associated with increased Ct values, rising by 4–5 units for pharyngeal swabs and 3–11 units for mouth rinses immediately after eating. Conclusions: In clinical dental settings, saliva diagnostics are feasible but acutely modulated by common behaviors. Mechanical oral hygiene, brief rinsing, and food intake can transiently reduce detectable oral SARS-CoV-2 RNA, with potential implications for timing of sampling, chairside triage, and infection-control protocols. This pilot study provides initial evidence supporting the development of standardized pre-analytical instructions (e.g., fasting window, pre-rinse policy, and sampling timing relative to oral hygiene and meals) to enhance the reliability of saliva-based testing in dental care.