Search Results (1,462)

“Beak larva” is a collective term for four fossil specimens from Kachin amber, which are holometabolan larvae with a forward-projecting beak. This arrangement is very unusual, and so far it has been unclear whether these specimens are larvae of beetles or of lacewings. We present here new details of the mouthparts of one of these larvae based on synchrotron radiation-based X-ray µ-CT (SRµCT) imaging. We can identify that the main part of the beak is formed by the labrum and the labium; the mandibles insert laterally into this beak. The beak has two distinct channels to which the mandibles seem to be connected. The maxillae are tightly connected to the labium and head capsule and have an endite each (unclear if lacinia, galea, or mala), also inserting into the beak. Overall, these details reveal a mouthpart arrangement incompatible with an interpretation as a lacewing. The arrangement is most similar to that in some beetle larvae, namely those of Elateroidea. It most closely resembles that of the larvae of the species-poor sister groups Cerophytidae and Jurasaidae. It seems likely that the beak larvae are closely related to Jurasaidae, possessing an intermediate morphology. The combined data allow us to reconstruct aspects of the entire group, including the beak larvae, Cerophytidae, and Jurasaidae, indicating that they undergo hypermetamorphosis. The latter is most expressed in Jurasaidae. Combined with the paedomorphic female, this group seems to have four rather distinct morphologies and ecologies: (1) early mobile larvae, (2) physogastric, strongly wormlike larvae, (3) “normal”-appearing adult males, and (4) females with another unique morphology. Full article

By using virtual surgical planning (VSP) and 3D printed guides, complex maxillofacial defects can be reconstructed with high accuracy and predictability. A fully digital workflow resulting in a modular all-in-one 3D printed guide system for fibula osteotomies, bone segment positioning, fully guided dental implant placement and dental prosthesis fixation for mandibular reconstruction was developed at Ghent University Hospital. A follicular ameloblastoma of the left mandible was resected in a 28-year-old male. The defect was reconstructed with a two-segment fibular free flap with immediate placement of three dental implants and immediate implant loading with a screw-retained bridge. A split thickness skin graft and Elemental PerioPlast were used as wound dressing. Comparison of the preoperative planning with the postoperative CT-scan showed a deviation immediately after surgery, which was no longer present at the 6-month follow-up. The patient achieved a stable occlusion and 44 mm mouth opening and reported high satisfaction. This case illustrates that fully digital, immediate mandibular reconstruction with simultaneous implant placement and prosthetic rehabilitation is feasible and accurate and enhances early functional recovery. Future improvements in intraoperative validation may further refine accuracy and reproducibility in complex oncologic reconstructions. Full article

Aim: Static guided computer-assisted apicoectomy has been shown to improve the precision of periapical surgery; however, limited data are available regarding its performance and accuracy in hard bone conditions. The primary aim of this study was to collect data on how this technique functions in hard bone and to evaluate the accuracy of different guided approaches under these conditions. Specifically, the accuracy of three surgical instruments—a commercially available bone drill, a bone trephine (partially guided), and an endo-trephine with a stopper (fully guided)—was compared in hard bone. Materials and methods: Sheep mandibles were scanned using cone-beam computed tomography (CBCT) and an intraoral scanner (STL). Digital planning was performed using commercially available dental implant surgical planning software. Guided apicoectomy procedures were carried out with the aid of 3D-printed surgical guides. Following the interventions, matching metal cylinders were inserted into the prepared osteotomies, and post-operative CBCT scans were acquired. Apical deviation from the digitally planned endpoint and angular deviation were analyzed to assess accuracy in hard bone. Results: The drill demonstrated a statistically significantly higher apical deviation compared to the endo-stop trephine (p < 0.001). No statistically significant difference in apical deviation was found between the bone trephine and the endo-stop trephine. Additionally, no significant differences were observed among the three approaches in the mesiodistal (x) and buccolingual (y) directions or in angular deviation; however, a statistically significant difference was detected in the vertical (z) dimension. Conclusions: Within the limitations of this study, static guided apicoectomy proved to be a reliable technique in hard bone conditions. The fully guided trephine approach demonstrated the highest drilling accuracy, while partially guided trephination and drilling showed greater deviations. These findings provide valuable data on the behavior and precision of different endosurgical guided instruments in hard bone and support the use of fully guided systems when high accuracy is required. Full article

Feline pulmonary carcinomas are rare and often carry a poor prognosis, particularly when associated with feline lung–digit syndrome. We report a cat with primary pulmonary carcinoma and extensive metastases—including digits, pleura, mandible, scapula, spleen, skeletal muscle, and distant lymph nodes—supporting the broader “MODAL syndrome” concept. Palliative therapy with toceranib phosphate and meloxicam achieved prolonged survival and excellent quality of life, with no adverse effects despite dose escalation. Rapid progression after discontinuation suggests a role for toceranib in delaying tumour growth. Immunohistochemistry revealed c-kit expression in one metastatic lesion but not in the primary tumour or most metastases, highlighting intratumoral heterogeneity and the complexity of targeted therapy. The observed benefit likely reflects toceranib’s multi-target activity (VEGFR2, PDGFR), impacting angiogenesis and tumour progression. This case represents the first report of toceranib phosphate use in feline pulmonary carcinoma and underscores its potential as a palliative option. Full article

The Late Cretaceous deposits of Morocco have yielded one of the richest and most diverse assemblages of marine reptiles in the world, with the mosasaurids representing the dominant group. Among the most common mosasaurs are members of the subfamily Halisaurinae. Halisaurines ranged in size from the relatively small Halisaurus, which reached 4–5 m in length, to the larger Pluridens serpentis, which may have reached 7.5 m in length. Here we report a new, giant species of Pluridens, Pluridens imelaki. The new Pluridens is characterized by a slender, rectangular snout, a T-shaped premaxilla–maxilla junction, interlocking premaxilla–maxilla joint, a prominent dorsal ridge on the premaxilla, an exceptionally long and slender mandible, a tooth count of ~25 dentary teeth, straight, triangular tooth crowns that are strongly bent back just above the tooth–root junction, a low coronoid process and a tall and slender retroarticular process. The skull is 1.25 m long, suggesting a body length of ~9 m or more, comparable in size to large predators such as Thalassotitan. Differences between P. imaleki and P. serpentis in the jaw and tooth structure, eye size and innervation of the rostrum, as well as overall size, suggest they had different foraging strategies and occupied distinct ecological niches. Pluridens imelaki reveals that Halisaurinae were not only more species-rich than previously recognized, but also exhibited greater diversity in tooth morphology, jaw shape, and body size than previously thought. Rather than simply being outcompeted by Mosasaurinae, the Halisaurinae staged a minor adaptive radiation in the Late Cretaceous and were important members of the ecosystem in low latitudes. Pluridens imelaki appears to have been exceptionally rare in the phosphates, being documented by only a single specimen among the many hundreds of mosasaur remains recovered over many years. This underscores how the species richness of the phosphates and other diverse assemblages is driven by rare taxa that are only revealed through extensive sampling. Full article

Background: The mental foramen is a key anatomical structure of the mandible through which the mental nerve and accompanying vessels emerge. Accurate knowledge of its location and morphology is essential for safe dental and surgical procedures in the anterior mandible. Objective: This study was conducted as a systematic review to summarize current evidence on the morphology, localization, and anatomical variants of the mental foramen and their clinical relevance. Methods: The PubMed and Google Scholar databases were searched for studies published between 2015 and 2025 in accordance with current systematic review guidelines. Cone-beam computed tomography (CBCT) studies and anthropological investigations assessing the position, dimensions, and anatomical variants of the mental foramen were included. Results: Thirty-five studies (30 CBCT-based and 5 anthropological) comprising a total of 6240 mandibles or patients were analyzed qualitatively. Considerable variability was observed in the horizontal and vertical position of the mental foramen in relation to mandibular borders and dental landmarks. Anatomical variations included differences in size and shape, the presence of unilateral or bilateral accessory mental foramina, and rare cases of unilateral or bilateral absence of the foramen. Conclusions: The synthesis of recent CBCT and anthropological data across diverse populations highlights clinically relevant patterns of variability. This study identifies key positional patterns and variants of the mental foramen, which can inform clinical planning and help reduce the risk of mental nerve injury. Full article

Introduction: Stage three osteonecrosis of the jaw (ONJ), whether medication-related (MRONJ) or osteoradionecrosis (ORN), often necessitates aggressive surgical management due to extensive necrosis, infection, and risk of pathologic fracture. While free flap reconstruction remains the gold standard post-segmental mandibulectomy, it may not be feasible for elderly or systemically compromised patients. Objective: The presentation of our own experience with advanced mandibular ONJ on patients managed exclusively with a contemporary titanium reconstruction plate system and to evaluate the clinical outcomes of this approach in the context of the current literature. Methods: From a group of 21 patients treated for ONJ, just four patients with Stage 3 MRONJ or Grade III ORN, unfit for microvascular surgery, underwent segmental mandibulectomy followed by alloplastic reconstruction using standard titanium plating. Outcomes were assessed clinically and radiographically over a follow-up period ranging from 3 to 20 months. A focused literature review was conducted to contextualize results. Results: All patients demonstrated stable reconstruction without plate exposure, fracture, or intraoral bone exposure during follow-up. Esthetic and functional outcomes are reported. No hardware complications were reported. The review of the literature supports plate-only reconstruction as a valid alternative for patients unsuitable for free flap surgery, especially when using rigid, anatomically adaptive systems with robust soft tissue coverage. Conclusions: Titanium plate–only reconstruction following segmental mandibulectomy can provide reliable short- to mid-term outcomes in selected patients with advanced ONJ. Used titanium plating systems appears to be a promising option. Full article

Background and Objectives: With the increasing demand for gender-affirming procedures, facial feminization surgery (FFS) has become an essential component in the management of patients with gender dysphoria. In this study, ‘male’ and ‘female’ refer to biological sex as recorded in the medical record; gender identity was not assessed. The mandible is widely recognized as one of the most sexually dimorphic facial bones and plays a critical role in defining masculine and feminine facial contours. However, quantitative mandibular data directly applicable to surgical planning for FFS, particularly in Asian populations, remain limited. The purpose of this study was to analyze gender differences in mandibular morphology using three-dimensional (3D) computed tomography (CT) images and to provide clinically relevant anatomic data applicable to mandibular contouring in FFS. Materials and Methods: In this single-center retrospective study, 275 Korean patients who underwent facial CT between January 2017 and December 2019 were enrolled. Three-dimensional cephalometric analysis was performed to obtain surgically relevant mandibular measurements, including angular, linear, and transverse parameters, as well as non-metric characteristics such as chin shape and inferior mandibular border contour. Statistical comparisons were conducted to evaluate gender differences. Results: Significant gender differences were observed in mandibular angle (p < 0.001), mandible length (p < 0.001), antegonial notch distance (p < 0.001), intercondylar width (p < 0.001), and intergonial width (p < 0.001). Ramus length and chin width did not demonstrate statistically significant differences. Non-metric analysis revealed significant gender differences in chin morphology and inferior mandibular border contour (p < 0.01). Males predominantly exhibited a round or square chin (79.5%) and a rocker-shaped inferior border, whereas females commonly demonstrated a pointed chin (82.3%) and a straight inferior mandibular border (94.4%). Conclusions: The sexual dimorphism of the mandible in the Korean population is characterized by differences in angularity, transverse width, antegonial morphology, and inferior border contour. These findings provide population-specific morphological reference ranges that may support individualized preoperative assessment for mandibular contouring in facial feminization surgery. Full article

Objective: To evaluate the three-dimensional (3D) angular displacement (Roll, Yaw, and Pitch) of the upper cervical vertebrae (C1, C2, and C3) in patients with severe mandibular deviation (MD) due to condylar hyperplasia (CH), utilizing a computed tomography (CT)-based segmentation approach. Methods: This retrospective cross-sectional study included 50 patients with MD ≥ 6 mm caused by hemimandibular elongation (HE) or a hybrid form (HF) of CH. The skull, mandible, and cervical vertebrae (C1–C3) were segmented using 3D Slicer software. Angular deviations (Pitch, Yaw, Roll) were measured relative to the Frankfurt plane. Patients were categorized by the side of CH (right or left), and intergroup comparisons were performed using Kruskal–Wallis and Mann–Whitney U tests. Spearman’s correlation analyses assessed associations between MD magnitude and cervical angles. Results: CH was significantly more prevalent in females (58%; p = 0.021). C2 and C3 exhibited significantly increased lateral Roll inclination toward the side of deviation (p = 0.006 and p = 0.045, respectively). C2 Pitch negatively correlated with MD severity bilaterally (r ≈ −0.51, p = 0.02 right; r ≈ −0.50, p = 0.02 left). Strong intra-vertebral correlations between Pitch and Yaw were observed in C1 and C2, indicating synchronized vertical and rotational motion. No significant intergroup differences were found in Yaw angles (p > 0.05). Conclusions: Patients with CH and severe MD exhibit consistent patterns of 3D cervical displacement, particularly in lateral inclination and vertical movement, suggesting compensatory postural adaptations in the upper cervical spine. Full article

Background and Clinical Significance: Phosphoglyceride crystal deposition disease (PCDD) is an extremely rare condition characterized by the deposition of phosphoglyceride crystals, occasionally forming tumor like lesions that present significant diagnostic challenges. Here, we report, to our knowledge, the first documented recurrent case of PCDD confined to the mandible, which clinically and radiologically mimicked a malignant bone tumor. Case Presentation: An 80-year-old female patient presented with a progressively enlarging mandibular mass, and imaging studies demonstrated an osteolytic lesion with cortical bone destruction and marked fluorodeoxyglucose uptake on positron emission tomography-computed tomography, raising a strong suspicion of malignancy. Histopathological examination revealed foreign-body granulomatous inflammation with characteristic crystal deposition, and the diagnosis of PCDD was definitively established through the combined use of gold hydroxamic acid staining, Raman spectroscopy, and ultrastructural analysis. Although surgical excision with curettage was initially achieved, local recurrence was observed 6 years later, indicating the potential for long-term disease persistence. In addition, a comprehensive literature review conducted in accordance with the PRISMA guidelines was performed to summarize previously reported cases of PCDD, with particular attention to anatomical distribution, radiological characteristics, recurrence patterns, and proposed pathogenic mechanisms. The review confirmed the extreme rarity of mandibular involvement and demonstrated that recurrence can occur apparently even after surgical treatment. Conclusions: This case underscores the importance of a multimodal diagnostic strategy integrating imaging, histopathology, and spectroscopic analyses for the accurate identification of PCDD and highlights the necessity of histopathological confirmation to prevent unnecessary aggressive treatment. Full article

We report new fossil larval specimens that have characters of the group Megaloptera, i.e., are either megalopteran or megalopteran-like larvae from the Triassic, Cretaceous, or Eocene. Fossils from the latter two times are preserved in amber. One of the new fossils reveals that some earlier reported presumed megalopteran-like fossils, that have been already suspected to be beetles, are indeed more likely beetles of the group Myxophaga. A quantitative morphological comparison supports that most fossil megalopteran (and megalopteran-like) larvae did not differ significantly from extant megalopteran larvae, indicating no major losses of morphology over time. However, two newly reported fossil specimens from Kachin amber indeed separate from the other larvae, representing an extinct morphotype. The morphotype is characterised by a prominent terminal filament, indicating that the specimen is a representative of Sialidae. However, unlike most of the known larvae of this group, it possesses a rather elongate prothorax and strongly curved mandibles. These two characters are more commonly known in larvae of Corydalidae. It seems most likely that the presence of these characters in the new morphotype does not represent a plesisomorphy, but is more likely the product of convergent evolution. Full article

Background/Objectives: Intra-oral aggressive fibromatosis (IOAF) is a rare, locally invasive soft tissue tumor originating from fibroblasts. Despite its benign histological nature, IOAF exhibits a high recurrence rate and presents significant diagnostic and therapeutic challenges. This systematic review aims to synthesize the available literature on IOAF, focusing on clinical presentation, radiological and histological features, treatment modalities, and recurrence rates. Methods: A comprehensive systematic search was conducted, following PRISMA guidelines, across Pubmed, Cochrane, and ScienceDirect for case reports and series detailing IOAF published up to October 2025. This review was registered with PROSPERO (CRD42024586634). Data were extracted on demographics, clinical presentation, radiographic and histological findings, treatment strategies, and follow-up outcomes. Quality of included studies was assessed using the Joanna Briggs Institute (JBI) tools. Results: A total of 27 studies were included, encompassing 33 cases. IOAF predominantly affected males (54.5%) with a mean age of 13.15 years. The mandible was the most common site (69.7%). Painless swelling was the most frequent clinical feature (72.7%). Radiological findings were primarily ill-defined radiolucency in 54.5% of the cases. Histopathologically, spindle-shaped fibroblasts and collagen fibers were present in 90% of cases. En bloc resection was the most common treatment (60.6%), followed by excision (27.3%). Recurrence was observed in 12.1% of cases, primarily following conservative treatments. Conclusions: IOAF remains a challenging condition due to its locally aggressive nature and potential for recurrence. Surgical resection remains the primary treatment modality, with en bloc resection yielding the lowest recurrence rates. Further research into molecular pathogenesis and targeted therapies is needed to optimize treatment outcomes. Full article

Background: The aims of the study were to describe facial morphology and analyze facial growth in adolescents with Robin sequence (RS) or Stickler syndrome. Methods: The facial morphology, mandibular size, and facial growth of 69 adolescents (ages 12–18) with RS were analyzed using existing cephalometric radiographs (n = 37) and photographs (n = 69). All participants were followed in our institution since birth. None underwent growth-modifying treatment for micrognathia during infancy, but all had conservative orthodontic treatment during adolescence. Results: Cross-sectional cephalometric analysis according to Tweed revealed differences in RS adolescents as compared with reference values, such as a proportionate retrusion of both jaws, as indicated by decreased SNA and SNB angles (p < 0.05). This finding was mostly associated with skeletal Class I (62.2%) and a vertical facial pattern as indicated by increased FMA and CoGoMe angles (p < 0.05). In Delaire’s analysis, patients showed decreased maxillary, maxillary alveolar (p < 0.05), and mandibular body territories (p > 0.05) but increased ramus (p > 0.05) and nasopremaxillary territories (p < 0.05). According to Ricketts’ analysis, mandibular width was decreased in half of our patients (p > 0.05). The mandibles were harmoniously downsized before and after the growth spurt (p < 0.05); however, they exhibited greater growth velocities than controls. A long-term study during puberty revealed an increase in SNB angles and a decrease in ANB angles (both p < 0.05), which improved the maxillomandibular relationship. Additionally, the vertical facial pattern attenuated (FMA, SNGoGn, and CoGoMe angles decreased; p > 0.05). On cross-sectional photographic analysis, 33.3% of patients had an orthofrontal (straight), 59.4% a cisfrontal (convex), and 7.3% a transfrontal (concave) profile. Their vertical facial proportions were normal. In the subjective profile analysis, most patients (approximately 84%) had good or acceptable profiles, with no major deficit of chin projection. The initial degree of neonatal retrognathia and type of cleft palate surgery did not affect major skeletal parameters (p > 0.05). However, the degree of neonatal functional impairment affected the vertical parameters (SNGoGn, FMA angle; p < 0.05). Conclusions: Overall, RS patients presented a bi-retrognathic profile, a normal jaw relationship, and a tendency toward a vertical growth pattern. Partial mandibular catch-up growth occurred during the pubertal growth spurt. The degree of neonatal retrognathia does not predict further mandibular growth. Full article

Objectives: This prospective cohort study aimed to evaluate the accuracy and precision of static computer-guided, flapless implant surgery in partially edentulous patients, comparing the virtually planned and clinically achieved implant positions. Materials and Methods: From 2017 to 2022, 40 patients (20 males and 20 females) received a total of 129 implants across 59 partial rehabilitations, with 62 implants placed in the maxilla and 67 in the mandible. All interventions were performed by a single experienced operator using dental-supported stereolithographic guides and a flapless protocol. The discrepancy between planned and actual implant positions was measured using reverse engineering software, assessing linear deviations at the implant Platform (coronal) and apex, as well as angular deviations. Subgroup analyses were conducted based on the jaw (maxilla vs. mandible) and the type of surgical guide support (Kennedy classes I–IV). Results: The mean linear deviation was 1.16 ± 0.58 mm at the apex and 0.80 ± 0.41 mm at the implant Platform (coronal). The mean angular deviation was 3.23° ± 1.86°. Slightly higher deviations were observed in the mandible than in the maxilla. Group-wise analysis showed minor variations depending on the type of guide support. Conclusions: Static computer-guided surgery demonstrated measurable linear and angular deviations between planned and achieved implant positions. These discrepancies should be considered during treatment planning, especially in narrow ridges or Class I configurations. Full article

Objectives: This study evaluated the impact of combining icariin with a bovine xenograft on the enhancement of early socket healing in Wistar rats. Methods: Male Wistar rats underwent incisive extraction and were randomized into three groups (n = 8/group): (1) control, (2) xenograft, and (3) icariin–xenograft. On days 7 and 14, the animals were decapitated and their mandibles were examined. Histological analysis was conducted to assess the collagen matrix and the expression of BMP-2 and HIF-1α. Results: The icariin–xenograft group exhibited superior outcomes compared to the xenograft-alone and control groups. Histological analysis showed an earlier arrangement of connective tissue and an improved collagen matrix outcome in the icariin-treated sockets. Immunohistochemistry revealed elevated BMP-2 and HIF-1α expression in the icariin–xenograft group, indicating enhanced osteogenic and angiogenic signaling. Conclusions: Icariin-enhanced xenografts speed up the repair of early extraction sockets by enhancing the development of the collagen matrix and increasing the activity of pathways that promote osteogenesis and angiogenesis in low-oxygen conditions. This bioactive grafting technology appears to be a cost-effective method for preserving sockets and performing regenerative therapy in dentistry. Full article