Cancer progression and therapeutic resistance are driven by complex molecular interactions between genomic instability and immune modulation. Defects in the DNA damage response (DDR) not only promote tumor heterogeneity but also shape the tumor immune landscape through the generation of neoantigens, activation of the cGAS–STING pathway, and modulation of immune checkpoints. This review provides an integrative overview of the molecular mechanisms linking DDR dysfunction to immune crosstalk, emphasizing how these processes influence tumor evolution and response to therapy. We discuss emerging therapeutic strategies that exploit DDR–immune interactions, including PARP and ATR inhibitors, synthetic lethality approaches, and combination regimens with immune checkpoint blockade. Understanding the bidirectional connection between DNA repair pathways and immune signaling unveils new translational opportunities for precision oncology and offers a framework for developing combinatorial therapies capable of overcoming resistance and improving long-term cancer control.

Head and neck squamous cell carcinoma (HNSCC) remains one of the most aggressive solid tumors, characterized by marked molecular heterogeneity and a complex tumor microenvironment (TME). Recent evidence highlights the pivotal role of microRNAs (miRNAs) in regulating tumor progression, immune evasion, angiogenesis, and stromal remodeling. This review synthesizes current insights into miRNA-mediated molecular pathways that modulate the TME in HNSCC and discusses emerging therapeutic strategies, including nanocarrier- and exosome-based miRNA delivery systems, targeting these molecules. Key miRNAs, including miR-21, miR-146a, and miR-221, orchestrate bidirectional signaling between cancer cells, fibroblasts, and immune infiltrates, thereby shaping tumor aggressiveness and therapy resistance. Advances in nanotechnology have facilitated the development of miRNA-based therapeutics—such as mimics, antagomiRs, and exosome-mediated systems—capable of restoring physiological expression patterns and reprogramming the TME toward an anti-tumor state. However, clinical translation remains hindered by challenges in targeted delivery, molecular stability, and tumor heterogeneity. By integrating molecular and translational perspectives, this review underscores how miRNA-targeting strategies may evolve into a new generation of precision therapies, bridging the gap between molecular oncology and personalized treatment of head and neck cancer.

Background/Objective: Advanced peri-implantitis presents a significant challenge in contemporary implant dentistry and sometimes necessitates implant removal when regenerative therapies are no longer reliable. Protocols for staged bone reconstruction, re-implantation, and definitive prosthetic rehabilitation following peri-implantitis continue to evolve. This study aims to present a clinical case of advanced peri-implantitis with vertical interproximal bone loss managed with a staged surgical and prosthetic approach and review current concepts in implant removal, bone regeneration, re-implantation, and soft-tissue management. Methods: A patient with peri-implantitis affecting two maxillary implants underwent treatment over one year. The initial surgical stage included removal of the failing implants and reconstruction of the defects using guided bone regeneration with a composite graft of 50% xenogeneic bone substitute and 50% autogenous bone, covered by a barrier membrane. After six months of healing, a second surgical stage was performed, involving placement of two new implants in positions 2.2 and 2.4, additional bone augmentation, and soft tissue grafting to enhance soft tissue volume and the width of keratinized gingiva following mucogingival line rebounce. After an additional six months of osseointegration, full maxillary prosthetic rehabilitation was completed in August 2025. Results: Clinical and radiographic assessments demonstrated successful bone regeneration, stable implant integration, adequate peri-implant soft-tissue conditions, and favorable functional and esthetic outcomes at follow-up. The case is discussed in the context of current evidence regarding indications for implant removal, regenerative strategies after explantation, timing of re-implantation, and the importance of keratinized gingiva and prosthetic design in long-term peri-implant health. Conclusions: Staged explantation, guided bone regeneration, delayed re-implantation, and comprehensive soft-tissue and prosthetic management may represent a viable treatment strategy in selected cases of advanced peri-implantitis.

Background: Maxillary sinus floor augmentation is widely used to enable implant placement in the atrophic posterior maxilla, yet comparative data for porcine-derived xenografts remain limited. Objective: To evaluate long-term bone regeneration and implant outcomes following sinus augmentation using a collagenated porcine xenograft. Methods: This paper reports a retrospective case series of three partially edentulous patients (aged 46–56 years) who underwent lateral sinus augmentation with a small-particle collagenated porcine xenograft (THE Graft™, Purgo Biologics, Gyeonggi-do, Republic of Korea) and staged implant placement. In one case, a controlled perforation of the Schneiderian membrane was performed to access and remove a sinus mucocele, followed by repair using a resorbable collagen membrane. Core biopsies were harvested at implant placement for histology (hematoxylin-eosin, Masson–Goldner) and tartrate-resistant acid phosphatase (TRAP) staining. Clinical outcomes included surgical events, vertical bone gain, marginal bone levels, and implant survival at long-term follow-up. Results: Healing was uneventful in all cases. Mean vertical bone gain was 12.0 mm (baseline 1.33 mm to 13.33 mm final). At a mean 46.8-month follow-up (range 38.3–52.2 months), 100% of implants were functional without failure; marginal bone loss remained < 1 mm during the first year and was stable thereafter. Histology at 3.7, 4.7, and 7.5 months showed vascularized new trabecular bone intimately contacting residual xenograft particles (new bone 20–30%, residual biomaterial 30–40%, connective tissue 30–50%). TRAP-positive multinucleated giant cells at 7.5 months indicated ongoing biomaterial degradation without severe inflammatory reactions. Conclusions: Within the limits of a small case series, collagenated porcine xenograft supported predictable bone regeneration and stable long-term implant function after sinus floor elevation, with favorable histologic integration and gradual resorption.

Background/Objectives: Horizontal alveolar ridge resorption following tooth loss often compromises implant placement and requires augmentation procedures to restore adequate bone volume. This pilot case series descriptively evaluated the clinical, radiographic, and histological outcomes of lateral ridge augmentation (LRA) using a collagenated porcine-derived xenograft combined with autogenous bone. Methods: Three consecutive partially edentulous patients presenting with severe horizontal ridge deficiency (residual bone width ≤ 4 mm) underwent LRA using a mixture of porcine-derived xenograft and autogenous bone covered with a resorbable collagen membrane. After a healing period of 3–5 months, core biopsies were harvested at implant placement and subjected to histological and histomorphometric analysis, including TRAP staining. Results: All sites healed uneventfully without intraoperative or postoperative complications. Radiographic evaluation demonstrated substantial horizontal bone gain, allowing placement of standard-diameter implants. Histological analysis revealed newly formed trabecular bone, residual graft material, and well-vascularized connective tissue, indicating active bone regeneration and biomaterial integration. TRAP-positive multinucleated giant cells (MNGCs) were observed at the biomaterial interface, suggesting ongoing remodeling. Long-term follow-up (mean 54.2 months) showed stable implant function without biological or mechanical complications. Conclusions: Within the limitations of this pilot case series, LRA using a collagenated porcine-derived xenograft combined with autogenous bone demonstrated preliminary favorable clinical, radiographic, and histological outcomes.

Background and Objectives: Superior mesenteric artery syndrome (SMAS) is an uncommon cause of proximal duodenal obstruction that requires clinicoradiological correlation. Materials and Methods: We retrospectively reviewed 13 patients with SMAS identified at the Clinical County Emergency Hospital Bihor, Romania, during 2019–2024. Clinical records and contrast-enhanced computer tomography (CT) examinations were reviewed descriptively. Results: The cohort included 13 adults aged 19–85 years (mean 45.5 ± 17.8; median 43 years). Abdominal pain was reported in 12/13 patients (92.3%), vomiting or emetic symptoms in 6/13 (46.2%), feeding difficulty or appetite disturbance in 5/13 (38.5%), and documented weight loss in 3/13 (23.1%). CT measurements were available for the aortomesenteric angle in 7/13 patients (range, 10–25°) and for the aortomesenteric distance in 8/13 (range, 3–8 mm); direct third-part duodenal compression and proximal dilatation were interpreted together with compatible symptoms. Imaging showed Nutcracker-type left renal vein compression in 3/13 patients (23.1%) and possible May–Thurner anatomy in 1/13 (7.7%); these findings were not adjudicated as clinical syndromes without corresponding manifestations. Based on the management labels, 9/13 patients (69.2%) underwent surgery at some point and 4/13 (30.8%) received medical therapy only. Standardized follow-up and procedure-level outcome data were not available for all patients. Conclusions: This small, retrospective series is descriptive and cannot estimate prevalence, diagnostic delay, or comparative treatment effectiveness. It illustrates heterogeneous adult presentations and supports interpreting aortomesenteric measurements together with compatible symptoms and evidence of duodenal obstruction.