Alloplastic reconstruction is often required following segmental mandibular resection (SMR). Hardware-associated complications, especially hardware fractures, almost invariably necessitate explantation. Recent advances in manufacturing techniques promise potential advantages over traditional methods, including increased fracture resistance. However, to date, there is no scientific evidence confirming whether these benefits translate to real-life clinical conditions. A total of 210 patients underwent SMR followed by alloplastic reconstruction between 2007 and 2019 at Hannover Medical School. The indications for SMR were tumor (n = 208; n = 196 squamous cell carcinoma) and osteoradionecrosis (n = 2). The mean patient age was 60.61 years, with a range of 14 to 89 years. The cohort comprised 146 male patients (69.52

ABSTRACT Objectives Keratocystoma is a rare benign neoplasm of the parotid gland, histologically characterized by multicystic keratinizing stratified squamous epithelium. Due to its resemblance to squamous malignancies, it represents a diagnostic challenge. This systematic review aims to summarize all published cases of parotid gland keratocystoma and to integrate one newly identified case in order to define its clinicopathologic features and clinical outcomes. Methods A systematic literature search of PubMed and Google Scholar was conducted without date restrictions in accordance with PRISMA 2020 guidelines. The protocol was registered in PROSPERO (CRD420251024191). Peer‐reviewed case reports and case series of histopathologically confirmed keratocystoma limited to the parotid gland were included. Demographic, clinical, radiologic, histopathologic, immunohistochemical, therapeutic, and follow‐up data were extracted and descriptively analyzed. Methodological quality was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklists. One additional institutional case treated at Hannover Medical School in March 2025 was included. Results Fifteen patients (14 from the literature and one new case) were identified. The mean age was 36.9 years (range: 1–77 years) with a slight male predominance. All tumors presented as painless parotid swellings and were treated surgically, most commonly by partial or lateral parotidectomy. No recurrences were reported during a mean follow‐up of 22.8 months. Histologically, all cases demonstrated consistent squamous epithelial features with immunohistochemical positivity for AE1/AE3, CK5/14, and p63. The newly reported case represents the oldest patient described to date. Conclusion Keratocystoma of the parotid gland exhibits reproducible benign clinical behavior and characteristic histopathologic features. Surgical excision appears curative, supporting its classification as a distinct benign salivary gland neoplasm that should be considered in the differential diagnosis of cystic parotid lesions.

Background: Reliable assessment of cervical lymph node metastases remains a key challenge in the management of oral squamous cell carcinoma (OSCC). While elective ipsilateral neck dissection (ND) is widely accepted, the benefit of contralateral ND and the influence of tumor site on metastatic risk remain incompletely defined. This study aimed to evaluate patterns of lymphatic metastases, the diagnostic accuracy of preoperative staging, and the therapeutic relevance of ipsilateral and contralateral ND. Methods: A retrospective single-center cohort study was conducted including 287 patients with histologically confirmed OSCC treated between 2013 and 2019. Patterns of lymph node metastases were analyzed with respect to tumor localization and clinicopathological factors. Multivariate binary logistic regression was performed to identify predictors of cervical lymph node metastases. The diagnostic accuracy of preoperative staging was evaluated using histopathological findings as the reference standard. Results: Tumor localization and histopathological grading significantly influenced the occurrence of lymph node metastases. OSCC of the maxilla demonstrated a significantly lower observed rate of cervical and occult metastases compared with other tumor sites. Occult metastases were detected in 16.9% of primary tumor cases, with only two contralateral occult metastases observed. The calculated number needed to treat (NNT) was 6 for ipsilateral elective ND and 74 for contralateral elective ND. Preoperative staging showed limited diagnostic accuracy, with a negative predictive value of 0.83 and a positive predictive value of 0.65. Conclusions: Elective ipsilateral ND remains an essential component in the surgical management of OSCC due to the considerable rate of occult metastases and the limited reliability of preoperative staging. In contrast, the benefit of contralateral elective ND appears limited in patients without midline-crossing tumors. Maxillary OSCC and well-differentiated tumors demonstrated a significantly lower metastatic risk, supporting a more individualized risk-adapted approach to neck dissection in selected cases.

OBJECTIVE:This study aimed to evaluate treatment-related weight changes in oral cancer and examine their association with functional impairments, public visits, and future life perspectives. MATERIALS AND METHODS:Data from 1359 surgically treated patients were retrospectively analyzed in a multicenter rehabilitation study conducted by the German-Austrian-Swiss Cooperative Group on Tumors of the Maxillofacial Region (DÖSAK). Weight changes were self-reported after treatment using a standardized questionnaire. Associations with tumor stage, surgical treatment, functional impairments, public visits, and future life perspectives were analyzed. RESULTS:Weight loss was significantly associated with advanced tumor stage (p = 0.001), nodal metastasis (p < 0.001), and radical neck dissection (p = 0.038). Weight differences alone did not change patients' public visits compared with the past (p < 0.001). However, weight loss combined with functional impairments in eating (p < 0.001), speaking (p < 0.001), and physical appearance (p < 0.001) was associated with avoidance of public visits. Stable weight was associated with favorable future life perspectives, whereas weight loss was associated with negative future perspectives (p < 0.001). CONCLUSION:Early identification of treatment-related weight changes may help identify patients at risk of functional impairments and adverse psychosocial outcomes, supporting timely nutritional interventions in oral cancer care.

Children and young adults with severe pre-existing conditions frequently require dental treatment under general anesthesia (GA) and are commonly scheduled for postoperative inpatient surveillance due to presumed elevated anesthetic or surgical risks. Although this approach prioritizes safety, it may contribute to prolonged or unnecessary hospitalization, increased healthcare costs, and potential psychological burden, particularly in patients with neurodevelopmental or congenital disorders. In light of the reportedly low incidence of severe complications following dental treatment under GA, this study aims to evaluate the necessity of routine inpatient admission in pediatric patients (< 18 years of age) with comorbidities and to assess the frequency and severity of perioperative complications. All pediatric patients with pre-existing conditions who underwent planned inpatient surgical dental treatment under GA at the Department of Oral and Maxillofacial Surgery at Hannover Medical School between 2014 and 2025 were included. The indications for inpatient treatment, anesthesiological parameters such as the American Society of Anesthesiologists (ASA) classification, and severe perioperative complications (corresponding to grade ≥ 2 of the Clavien-Dindo classification) were analyzed. It was assessed whether the ASA classification or the type of pre-existing condition significantly influenced the occurrence of perioperative complications. A total of 199 patients were analyzed. Patients who underwent surgery were mainly categorized as ASA II (n = 80, 40.2

Purpose This study aimed to evaluate weight changes, the physical and psychological aspects impacting quality of life (QoL) related to the diagnosis and treatment of oral squamous cell carcinoma. Methods Data from 1359 patients with oral cancer were analysed retrospectively during the multicentre rehabilitation study of the German-Austrian-Swiss Cooperative Group on Tumours of the Maxillofacial Region (DÖSAK). Using questionnaires, patients and physicians documented weight changes related to tumour stage and surgical treatment, but also on patients´ public life behaviour, future perspectives and QoL. Results Weight loss was significantly associated with higher tumour stage (p = 0.001) and regional lymph node metastasis (p = 0.000), while patients with negative nodal status managed to maintain weight. To the majority, neck dissection was associated with stable weight (p = 0.016). However, radical neck dissection significantly revealed weight loss compared to other types of neck dissection (p = 0.000). No surgical defect reconstruction technique was associated with weight changes. Furthermore, weight changes during treatment did not lead to changes in patients´ public visiting behaviours (p = 0.000). However, patients with physical impairments related to tumour treatment and attendant weight changes, conversely, avoided public visiting (p = 0.000 and p = 0.029, respectively). Most patients with general weight changes were hopeful towards future, while others with weight loss were more hopeless (p = 0.000). Conclusion Identifying weight changes during oncological therapy is essential to addressing the therapeutic needs of oral cancer patients and improving their QoL.

Subperiosteal implants have experienced fluctuating popularity since their inception. Initially introduced in the mid-20th century, they were overshadowed by the development and success of endosteal implants, which are now the standard in dental implantology. Modern subperiosteal implants are typically custom-made using computer-aided design and computer-aided manufacturing technologies, which ensure a precise fit to the patient's bone anatomy. A meta-analysis was conducted to evaluate the success rates, complications, and patient satisfaction associated with subperiosteal implants. Studies were selected based on predefined inclusion criteria, focusing on clinical trials and observational studies that reported on the long-term outcomes of subperiosteal implants.

This controlled in vivo experimental study examines the impact of 2 periosteum preparation techniques on microcirculation during bone augmentation with isogenic bone grafts in rats. Twenty female Lewis rats were divided into 2 groups (n 1/4 10 each). In one group, the periosteum was prepared with a conventional periosteal elevator; in the other, a piezoelectric device was used. After graft implantation at calvarial sites, intravital microscopy was performed postoperation (day 0) and on days 3, 8, and 28 immediately to assess microvascular parameters: functional capillary density, blood flow velocity, and vessel diameter. Statistical analysis was conducted using analysis of variance on ranks with P < .05. The piezoelectric device group showed higher mean values for functional capillary density, blood flow velocity, and vessel diameter than the conventional instrument group, though differences were not statistically significant. This study suggests that periosteum preparation with a piezoelectric device does not significantly differ from conventional methods regarding microcirculatory outcomes. Either method appears viable for preserving microcirculatory integrity during bone augmentation. Further research in larger models and clinical contexts is recommended to confirm these findings.

Animal models are essential for studying tumor pathophysiology; however, most lack the capacity for repeated in vivo observation of tumor growth and vascularization over extended periods. This study aimed to establish a novel in vivo model using the mouse dorsal skinfold chamber. Tumor induction was performed using different membrane types (two polytetrafluoroethylene meshes and a polydioxanone plate), followed by monitoring of tumor vascularization via intravital fluorescence microscopy (IVM). Tumors developed successfully over six weeks, demonstrating sustained vascular supply and enabling, for the first time, the investigation of vascular networks in advanced tumors. Among the membranes tested, the polydioxanone membrane facilitated easier chamber preparation but may negatively affect angiogenesis and promote inflammation. IVM revealed persistent microcirculation in manifested tumors over six consecutive days, allowing detailed assessment of microvascular parameters, leukocyte–endothelial interactions, and functional capillary density. This model enables repetitive, high-resolution visualization of tumor microcirculation dynamics in vivo. In conclusion, this improved mouse dorsal skinfold chamber combined with IVM provides a powerful tool for investigating tumor angiogenesis and evaluating therapeutic interventions in advanced tumors.

This study demonstrates and investigates the feasibility of a novel approach for dental rehabilitation in complex maxillary and midfacial defects, often resulting in severe pseudo-class III relationships. It explores the use of patient-specific subperiosteal implants (IPS Implants® Preprosthetic) with innovative design variations that anchor to the skull base from below and laterally, extending beyond traditional implants to provide enhanced stability in cases of significant bone loss. Patients with significant maxillary and midfacial bone loss due to postablative defects were included in our case series, with or without irradiation. From 100 patients, 13 required design modifications based on FEM analysis, involving implant anchorage to the lateral skull base and/or pterygoid process. Eight patients received single-sided lateral skull base extensions; one posttraumatic case required bilateral extensions. In five of 13 cases, additional extensions to the pterygoid process were implemented. One case needed both bilateral skull base and pterygoid extensions, while two had bilateral pterygoid and a single-sided skull base extension. Outcomes assessed included primary stability, prosthodontic restoration, complications, and soft tissue management. No implant failures occurred during follow-up, with functional stability established immediately post-insertion. Prosthodontic restoration succeeded in all cases, with no stability loss or periimplantitis. Mucositis was noted around posterior posts in some instances, and one bar required trimming due to soft tissue changes, without affecting implant function. One implant had to be removed, due to chronic pain. Patient-specific IPS Implants® Preprosthetic with design extensions provide a biologically suitable solution for stable dental rehabilitation in severe maxillary and midfacial structure loss, without biomechanical limitations. Achieving rigid fixation distant from the soft tissue transition is crucial for success.

Squamous cell carcinoma (SCC) is the most common malignancy of the oral cavity. Despite cN0 staging, elective neck dissection (END) is often performed to detect occult cervical lymph node metastases (cLNM). Maxillary SCC (MSCC) generally exhibits similar metastases rates to intraoral SCC in other locations. However, due to the rarity of T1 MSCC, the current guidelines of the German Society for Oral and Maxillofacial Surgery do not provide a clear recommendation for neck dissection (ND) in these cases, as existing data are limited. A retrospective analysis was conducted on all cases with SCC of the superior level of the oral cavity diagnosed at Hannover Medical School over the past 20 years (n = 225). cLNM in pT1 cases (n = 36) were specifically examined. In pT1 MSCC cases confined to the alveolar process and hard palate, cLNM was detected in only one patient (1/25, 4.00

Purpose: This study aimed to determine the suitability and optimal concentration of an ultrasonic contrast agent (SonoVue) for intralesional application during contrast-enhanced ultrasonography (CEUS).Methods: An in vitro model simulating an existing lesion in the anatomical environment of the mandibular ascending ramus was developed. After intralesional application, different SonoVue dilutions were compared with dilutions of an iodine-containing radiographic contrast agent (Imeron300) during cone-beam computed tomography.Conclusions: SonoVue provided a significant contrast effect for distinguishing the lesion from the surrounding soft tissue at dilutions of 1/10 and 1/20. Imeron300 showed a slightly superior contrast effect, even at dilutions of 1/50 and 1/100. However, CEUS using SonoVue in low dilutions seemed suitable for intralesional application in vitro. Further in vivo studies are required to validate the current results and determine the optimal contrast-agent concentration.

Mittelgesichtsfrakturen stellen die häufigsten Frakturen im Gesichtsbereich dar und werden zumeist durch tätliche Auseinandersetzungen oder Verkehrsunfälle verursacht. Die Symptomatik variiert je nach Ausmaß der Frakturen sowie deren Dislokationsgrad. Eine hochauflösende dreidimensionale Bildgebung (CT oder DVT) sollte bei klinischem Verdacht standardmäßig durchgeführt werden. Eine sofortige chirurgische Intervention ist oftmals nicht notwendig; im Bereich der Orbita ist sie dann unabdingbar, wenn Inkarzerationszeichen der intraorbitalen Muskulatur vorliegen sowie bei raumfordernden Blutungen, um dauerhafte Schäden des visuellen Apparats zu verhindern. Bei Mittelgesichtsfrakturen ist eine primäre chirurgische Versorgung im Sinne einer offenen Reposition und internen Fixierung zumeist Therapie der Wahl. Die Anzahl und Positionierung der Osteosyntheseplatten müssen, gemäß dem durch o. g. Algorithmus zu erhebenden Verletzungsmuster, individuell festgelegt werden. Bei Frakturen der Orbita ist oftmals die Defektlokalisation für die klinische Symptomatik entscheidend. Hiernach muss zwischen konservativer und (verzögerter) primärer operativer Versorgung entschieden werden. State of the Art ist hierbei die Therapie mit patientenspezifischen Implantaten, wenn die „key areas“ radiologisch involviert sind, bestenfalls in Kombination mit intraoperativer Navigation und Bildgebung.