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Pediatric odontogenic tumors are rare but are frequently overlooked because they often mimic simple cysts on routine radiographic examinations. The radiographic appearance on panoramic imaging and cone-beam computed tomography (CBCT) frequently does not correlate with the true biological nature of these lesions. On CBCT, classic odontogenic tumors often demonstrate mixed radiolucent–radiopaque patterns with ill-defined borders, internal calcifications, septations, or other structural features. The diagnostic challenge arises when an odontogenic tumor mimics a unilateral, well-defined radiolucent area or a cystic lesion with clear borders and no associated tooth displacement, erosion, root resorption, or cortical bone dehiscence. Panoramic radiography has inherent diagnostic limitations but remains widely used for routine dental screening. CBCT provides enhanced three-dimensional assessment and improves diagnostic accuracy in the evaluation of jaw lesions. A marked increase in dental follicle diameter necessitates differentiation between cystic transformation, inflammatory processes, and other odontogenic pathologies. Cortical swelling and bone asymmetry warrant careful evaluation. In this context, an atypical cyst-like lesion detected on routine panoramic radiography prompted a needle aspiration biopsy, which revealed a dry tap and suggested a solid lesion. This prompted CBCT evaluation. Two juvenile cases are presented in which clinical findings, panoramic radiography, and CBCT provided discordant diagnostic impressions of cystic-appearing lesions with well-defined borders and bone expansion. These cases illustrate a diagnostic pathway in which imaging demonstrates a cyst-like appearance with benign radiological features, fine-needle aspiration biopsy reveals the absence of cystic fluid, and histopathology confirms that radiology alone cannot reliably distinguish true cysts from solid odontogenic tumors in pediatric patients.

The temporomandibular joint (TMJ), which differs anatomically and biochemically from hyaline cartilage-covered joints, is an under-recognized joint in arthritic disease, even though TMJ damage can have deleterious effects on physical appearance, pain and function. Here, we analyzed the effect of IL-1β, a cytokine highly expressed in arthritic joints, on TMJ fibrocartilage-derived cells, and we investigated the modulatory effect of mechanical loading on IL-1β-induced expression of catabolic enzymes. TMJ cartilage degradation was analyzed in 8–11-week-old mice deficient for IL-1 receptor antagonist (IL-1RA−/−) and wild-type controls. Cells were isolated from the juvenile porcine condyle, fossa, and disc, grown in agarose gels, and subjected to IL-1β (0.1–10 ng/mL) for 6 or 24 h. Expression of catabolic enzymes (ADAMTS and MMPs) was quantified by RT-qPCR and immunohistochemistry. Porcine condylar cells were stimulated with IL-1β for 12 h with IL-1β, followed by 8 h of 6% dynamic mechanical (tensile) strain, and gene expression of MMPs was quantified. Early signs of condylar cartilage damage were apparent in IL-1RA−/− mice. In porcine cells, IL-1β strongly increased expression of the aggrecanases ADAMTS4 and ADAMTS5 by fibrochondrocytes from the fossa (13-fold and 7-fold) and enhanced the number of MMP-13 protein-expressing condylar cells (8-fold). Mechanical loading significantly lowered (3-fold) IL-1β-induced MMP-13 gene expression by condylar fibrochondrocytes. IL-1β induces TMJ condylar cartilage damage, possibly by enhancing MMP-13 production. Mechanical loading reduces IL-1β-induced MMP-13 gene expression, suggesting that mechanical stimuli may prevent cartilage damage of the TMJ in arthritic patients.

Sauropod dinosaurs include the largest terrestrial vertebrates that have ever lived. Virtually every part of the sauropod body is heavily modified in association with gigantic size and associated physiological alterations. Sauropod skulls are no exception: they feature elongated, telescoped facial regions connected to tilted neurocrania and reoriented jaw adductor muscles. Several of these cranial features have been suggested to be adaptations for feeding on the one hand and the result of paedomorphic transformation near the base of Sauropoda on the other. However, the scarcity of sauropodomorph ontogenetic series has impeded further investigation of these hypotheses. We re-evaluated the cranial material attributed to the early sauropodomorph Anchisaurus, which our phylogenetic analyses confirm to be closely related to sauropods. Digital assembly of µ CT-scanned skulls of the two known specimens, a juvenile and an adult, permitted us to examine the detailed ontogeny of cranial elements. The skull anatomy of Anchisaurus is distinguished by a mosaic of ancestral saurischian and sauropod-like characters. Sauropod-like characters of the braincase and adductor chamber appear late in ontogeny, suggesting that these features first evolved by the developmental mechanism of terminal addition. Shape analyses and investigation of allometric evolution demonstrate that cranial characters that appear late in the ontogeny of sauropodomorphs closely related to sauropods are already present in the embryos and juveniles of sauropods, suggesting a predisplacement-type shift in developmental timing from the ancestral anchisaurian condition. We propose that this developmental shift relaxed prior constraints on skull morphology, allowing sauropods to explore a novel range of phenotypes and enabling specializations of the feeding apparatus. The shift in timing occurred in concert with the evolution of gigantism and physiological and locomotory innovations.

Parrotfishes (Labridae: Scarini) have jaws formed by teeth fused into a beak-like structure in most species, and are classified into 3 functional groups (browsers, scrapers and excavators) based on jaw morphology, foraging behavior and feeding impact on the benthos. We compared the feeding morphology of 3 parrotfish species in the Abrolhos Bank, SW Atlantic. We also estimated rates of bioerosion caused by the largest and most abundant parrotfish in the region, Scarus trispinosus, and compared them to literature estimates from 12 species. The 3 studied species differed in dentary, suspensorium and mouth/head height. Large (>40 cm) Sc. trispinosus individuals were functionally classified as excavators because of their body size, robust premaxilla and jaws with simple joints, in addition to the large proportion of their bites leaving pronounced marks on the substratum. Large (>40 cm) adult Sparisoma amplum were also classified as excavators because of their mouth/head height, dentary and suspensorium size and robust jaws (dentary) with simple joints. Sc. zelindae had the most mobile jaw among the 3 species and was functionally classified as a scraper, as were juveniles or initial phases of the other 2 species. Body size and feeding rates of Sc. trispinosus were positively correlated with the volume of substratum removed, with large adults removing 207 cm³ d−1 and eroding ~75 500 cm³ yr−1. Our results reinforce the importance of studies on jaw morphology and osteology for the assessment of parrotfish feeding modes, and indicate that large adult Sc. trispinosus and Sp. amplum play unique roles as excavating fishes in the Abrolhos Bank.

Background Children and adolescents with juvenile idiopathic arthritis (JIA) may suffer pain from temporomandibular disorder (TMD). Still, routines for the assessment of temporomandibular joint (TMJ) pain in health and dental care are lacking. The aims of this study were to examine the prevalence of TMD in children and adolescents with JIA compared to their healthy peers and to investigate potential associations between JIA and TMD. Methods This comparative cross-sectional study is part of a longitudinal multicentre study performed during 2015–2020, including 228 children and adolescents aged 4–16 years with a diagnosis of JIA according to the ILAR criteria. This particular substudy draws on a subset of data from the first study visit, including assessments of TMD as part of a broader oral health examination. Children and adolescents with JIA were matched with healthy controls according to gender, age, and centre site. Five calibrated examiners performed the clinical oral examinations according to a standardised protocol, including shortened versions of the diagnostic criteria for TMD (DC/TMD) and the TMJaw Recommendations for Clinical TMJ Assessment in Patients Diagnosed with JIA. Symptoms were recorded and followed by a clinical examination assessing the masticatory muscles and TMJs. Results In our cohort of 221 participants with JIA and 221 healthy controls, 88 (39.8%) participants with JIA and 25 (11.3%) healthy controls presented with TMD based on symptoms and clinical signs. Painful TMD during the last 30 days was reported in 59 (26.7%) participants with JIA vs. 10 (5.0%) of the healthy controls ( p  <  0.001). Vertical unassisted jaw movement was lower in participants with JIA than in controls, with means of 46.2 mm vs. 49.0 mm, respectively (p <  0.001). Among participants with JIA, a higher proportion of those using synthetic disease-modifying antirheumatic-drugs and biologic disease-modifying antirheumatic-drugs presented with painful masticatory muscles and TMJs at palpation. Conclusion Symptoms and clinical signs of TMD were seen in approximately half of the JIA patients compared to about one fourth of their healthy peers. Painful palpation to masticatory muscles and decreased vertical unassisted jaw movement were more frequent in participants with JIA than among healthy controls and should be part of both medical and dental routine examinations in patients with JIA.

Background MRI manifestation of temporomandibular joint arthritis is frequently reported in children with juvenile idiopathic arthritis. However, little attention has been paid to temporomandibular joint disk abnormalities. Objective To assess combinations of MRI findings in the symptomatic temporomandibular joint in children with juvenile idiopathic arthritis with focus on disk abnormalities. Materials and methods This was a retrospective study of 46 patients with juvenile idiopathic arthritis, mean age 12 years (range: 5-17 years). Mean disease duration was 70 months (standard deviation: 61 months). MR images of 92 temporomandibular joints were scored for thickness of abnormally enhancing synovium (synovitis), joint effusion, bone marrow oedema, abnormal bone shape, bone erosion and disk abnormalities. Results The 92 temporomandibular joints were categorized as A: No synovitis and normal bone shape (30/92; 33%), B: Synovitis and normal bone shape (14/92: 15%), C: Synovitis and abnormal bone shape (38/92; 41%) and D: No synovitis but abnormal bone shape (10/92; 11%). Thirty-six of the 46 patients (78%) had synovitis and 33/46 (72%) had abnormal bone shape, most frequently in combination (30/46; 65%). Disk abnormalities (flat disk, fragmented disk, adherent disk and displaced disk) were found in 29/46 patients (63%). Disk abnormalities were found in all categories of juvenile idiopathic arthritis involved temporomandibular joints (B: 8/14 [57%]; C: 25/38 [66%] and D: 7/10 [70%]). Disk displacement was found in half of the joints (7/14) in category B. Synovitis was most pronounced in this category. Conclusion Disk abnormalities were frequent. Disk displacement also occurred in joints with early temporomandibular joint arthritis, i.e., with normal bone shape. Other disk abnormalities were found in joints with bone abnormalities. Attention should be paid to disk abnormalities both in early and long-standing temporomandibular joint arthritis in children with juvenile idiopathic arthritis.

We described chanid material from the Paleocene (Danian) localities of División del Norte and Belisario Domínguez near the archeological site of Palenque, Chiapas State, southeastern Mexico. The parsimony-based morphological phylogeny indicates that the specimens are closely related to the extant milkfish, Chanos chanos (Teleostei, Ostariophysi), and the comparative anatomy reveals a remarkable qualitative similarity of almost every visible bone. Among the synapomorphies for the genus Chanos , is a pleurostyle or caudal complex, which is missing in all other chanid fossils. Extant milkfish are highly variable in meristic and morphometric traits, and we found a signal for quantitative variation with geometric morphometrics tools in the fossil sample. We first dealt with post-mortem body torsion and missing landmarks. The main analysis shows a pattern of two forms present in both localities. A group of specimens shows a bigger head and deeper body than the slender and smaller head of the rest, implying that two types of milkfish coexisted in time and space. We tested for allometry and explored scenarios that can explain the patterns, such as sexual dimorphism or two sympatric and closely related species for the morphotypes, and differential resource utilization for the jaw, head, and depth variations. Furthermore, we argue that, alongside the morphological stasis, Chanos has conserved the life history trait of fry migration towards near-shore nurseries through protracted time (~63mybp). We infer the fish were juvenile, and the paleontological assemblage and taphonomy suggest that the localities exhibit the influence of both marine and transitional environments.

The occurrence of cysts and tumors in pediatric patients varies across different age groups. Follicular and dentigerous cysts are among the most common lesions. However, typical odontogenic tumors in juvenile patients are not frequently observed. Early stages of cyst and odontogenic tumor development might exhibit some similar characteristics due to the presence of unerupted teeth or their relationship with various stages of tooth formation and eruption. Many small lesions are discovered accidentally on routine orthopantomography (OPG), while the bigger ones manifest themselves as bone swelling, cortical perforation, or displacement and mobility of teeth. Each odontogenic tumor has characteristic clinical and radiological features. Biopsy of larger lesions, or incisional biopsy of smaller lesions, allows detailed histopathological evaluation to determine tumor type and growth behavior and guide appropriate treatment planning. In some cases, atypical signs on OPGs, like asymmetry in dental follicles, occurrence of round or oval bone lesions near impacted or retained teeth, and visibility of irregular radiolucent, radiopaque, or mixed jawbone lesions, might suggest the occurrence of some possible odontogenic tumor in juvenile patients. Each case should be handled individually. In this case, we demonstrate how atypical appearances of dental follicles on panoramic radiographs may not correspond with cone-beam computed tomography findings and may indicate the early stages of odontogenic myxoma in a juvenile patient.

ObjectiveWe performed a systematic review to investigate the appearance of imaging signs on magnetic resonance imaging (MRI), cone-beam computed tomography (CBCT), and conventional computed tomography (CT) scans of the temporomandibular joints (TMJs) of patients with juvenile idiopathic arthritis (JIA).Materials and methodsWe performed electronic searches of the PubMed, Embase, Web of Science, Scopus, Lilacs, and the Cochrane Library databases to identify studies investigating JIA and its related imaging findings. Inclusion criteria were as follows: original article studies based on humans and systematic reviews, studies enrolling patients under 18 years of age with a diagnostic of JIA, the use of International League of Associations for Rheumatology (ILAR) criteria and one type of medical imaging (MRI, CBCT, or CT), and papers published in the English language.ResultsA total of six studies met the inclusion criteria, four involving MRI and two involving CBCT. Additionally, all six studies analyzed the imaging findings of pathological TMJ affected by JIA. The results showed that synovial membrane enhancement, condylar erosions, and condylar flattening were the most prevalent imaging findings in JIA.ConclusionMRI examinations are more specific for detecting anomalies in the TMJ than CBCT and CT. Additionally, these results must be correlated with clinical signs to verify the correct diagnosis.Clinical relevanceThis study identified the most prevalent imaging signs of JIA to provide an early and correct diagnosis of the disease.

Large whales face a range of threats, including vessel strikes and entanglement in fishing gear. Elevated humpback whale mortality, predominantly in juveniles, has occurred in the Northeast US since 2016. The New York Bight, a region with dense shipping and fishing vessel traffic, has become a hotspot for these strandings. Scarring patterns can provide information on anthropogenic threats, as well as predation and behavior. We used drone imagery to examine scarring reflective of entanglements, vessel strikes, killer whale interactions and bottom feeding in both juvenile and adult humpback whales in the New York Bight. The vast majority of both adult (87.1%) and juvenile (86.8%) humpbacks showed entanglement scars, indicating that humpbacks frequently interact with fishing gear across age classes. Vessel strike scars were observed more frequently in juvenile whales (14.2%) than in adults (2.2%), in contrast to prior observations north of our study area in the Gulf of Maine, though the difference was of borderline significance (mean p -value 0.051, Fisher’s Exact tests on 1000 bootstrapped populations incorporating uncertainty in length measurements). These results support previous suggestions that juvenile humpbacks in the New York Bight may be particularly vulnerable to vessel strike due to inshore and surface feeding, and suggest that vessel strike scars may be obtained locally. Killer whales are thought to primarily target young animals, and killer whale scars were observed more often in juveniles (11.6%) than adults (4.4%), though this difference was not significant (mean p -value 0.26). Jaw scuffing indicative of bottom feeding was observed more frequently in adults (68.9%) than in juveniles (27.4%; mean p -value 3.47 x 10 −5 ), suggesting that this behavior is acquired as whales mature. Our findings underscore differences in behavior between adult and juvenile humpback whales and highlight the exposure of humpback whales to anthropogenic threats in heavily urbanized coastal regions.