Accessory tympanic plate ossicle: a new osteological entity.

The auricular cartilage, which is typically soft and flexible, can calcify or ossify because of diseases such as diabetes mellitus, trauma, radiation therapy for cancer, and more commonly from frostbite. Calcified, ossified, or hardened auricular cartilage is a rare finding in the clinical literature and appears to be absent in the physical and forensic anthropological literature. This study examines the ossified auricular cartilage and tests whether the hypothesis can be identified in postmortem skeletonized tissue and be part of the external auditory meatus. A total of 290 crania were examined for accessory ossicles. A descriptive and interpretative analysis was performed grossly, histologically, and morphometrically to document the morphology and location of the ossicles, investigate their structure, and perform hypothesis testing. Results revealed that seven females and one male crania from a total of 290 crania (2.76%) exhibit semi-ossified auricular cartilage attached to the tympanic plate of the temporal bone. The morphology and location of the ossicles at the junction of the auricle and external auditory meatus indicate they are hardened auricular cartilage that was verified with histological observations. Regression analysis indicates that addition of the ossicle to the depth of the auditory tube significantly changes coefficient of determination (R2) with respect to cranial breadth. In conclusion, results indicate that small cartilaginous structures of the external ear may ossify forming accessory tympanic plate ossicles that potentially could be identified in skeletal remains as a new osteological entity. This report highlights the types of information that can be gained using an approach that integrates forensic anthropology, gross anatomy, and histology.

Regression analysis of nasal shape from juvenile to adult ages for forensic facial reconstruction.

The nose is a prominent feature for facial recognition and reconstruction. To investigate the relationship of the nasal shape with the piriform aperture in Korean adults and juveniles, we performed regression analysis. By regression analysis, prediction equations for nasal shape were obtained in relation to the shape of the piriform aperture considering sex and age groups. Three-dimensional skull and face models, rendered from computed tomography images, were assessed (331 males and 334 females). Juveniles (<20 years) were divided into three age groups according to the development of the dentition. Adults were divided into three age groups of two decades each, according to their age. To measure the nasal area, nine landmarks and nine measurements were chosen, while seven landmarks and five measurements were selected to measure the piriform aperture area. Four measurements were defined to explain the direct relationship between the nasal aperture and nasal shape. First, descriptive statistical analyses were performed according to sex and age groups. Subsequently, the correlation of nasal soft tissue measurements with piriform measurements was analyzed. Last, we performed a linear regression analysis of the measurements with higher correlations, considering sex and age groups as variables. Prediction equations were used to estimate the nasal bridge length, height, protrusion, and width. Equations considering sex and age groups showed better explanation ability. Measurements related to the height of the nasal bridge presented improvement. This study may assist in the more accurate approximation of nasal shape in facial reconstruction.

A comparison of pre- and post-clinical education learning preferences among medical students who elected to dissect compared to those who did not during the COVID-19 pandemic.

Anatomy instructional methods varied widely during the COVID-19 pandemic and programs are assessing innovations for retention. Learning preferences were assessed among medical students dichotomized as elective dissectors (ED) or non-dissectors (ND) during the COVID-19 partial re-opening in 2020 (preclinical) and again in 2022 after clinical exposure (post-clinical) to assess the viability of elective dissection post-pandemic. A mixed-method approach was used for the assessment of test scores, learning preference surveys, learning activities rankings, and thematic analyses. No significant differences occurred in anatomy examination scores. Dissection was considered useful by both preclinical groups but significantly more so by ED, while the presence of an instructor was significantly preferred by ED although a majority of ND agreed. Elective dissection was significantly preferred by ND but also by a large minority of ED students. Pre- and post-clinical ND believed that elective dissection offered more academic flexibility, did not hinder clinical learning, and did not negatively impact medical education. The corresponding ED stated that confidence improved, clinical experiences were enhanced, and dissection was irreplaceable. Preclinical ND preferred self-learning, while ED students preferred online learning, but these differences largely disappeared post-clinically. Learning activity rankings were not significantly different among all groups (ND, ED, preclinical, and post-clinical). A hybrid laboratory with a virtual learning environment ranked highest across groups and preferences increased over time suggesting that students benefited from this instructional method during clinical exposure. The absence of laboratory experience ranked lowest, and preference decreased over time suggesting that anatomy dissection is valued.

Cholesterol Granuloma in the Maxillary Sinus: A Rare Presentation Associated With an Odontogenic Cyst.

Cholesterol granuloma is a histopathological finding characterized by a mass of connective tissue and granulation tissue. It is primarily observed in the middle ear, mastoid process, or paranasal sinuses, with rare occurrences in the dental odontogenic region. A dentigerous cyst encloses the crown of an unerupted tooth by expanding its follicle and attaches to the neck of the tooth. Here, we report a 63-year-old female who presented to the dental clinic complaining of an ill-fitted denture. A panoramic radiograph showed a well-defined radiolucent lesion in the upper left maxillary sinus with an impacted third molar. Computed tomography revealed loss of the anterior and lateral sinus walls. The cyst was enucleated surgically. The final diagnosis was confirmed by histopathological examination, which revealed focal areas of cholesterol clefts in the cystic wall of the dentigerous cyst.

Themes in neuronavigation research: A machine learning topic analysis.

Objective: To understand trends in neuronavigation we employed machine learning methods to perform a broad literature review which would be impractical by manual inspection. Methods: PubMed was queried for articles with "Neuronavigation" in any field from inception-2020. Articles were designated neuronavigation-focused (NF) if "Neuronavigation" was a major MeSH. The latent dirichlet allocation topic modeling technique was used to identify themes of NF research. Results: There were 3896 articles of which 1727 (44%) were designated as NF. Between 1999-2009 and 2010-2020, the number of NF publications experienced 80% growth. Between 2009-2014 and 2015-2020, there was a 0.3% decline. Eleven themes covered 1367 (86%) NF articles. "Resection of Eloquent Lesions" comprised the highest number of articles (243), followed by "Accuracy and Registration" (242), "Patient Outcomes" (156), "Stimulation and Mapping" (126), "Planning and Visualization" (123), "Intraoperative Tools" (104), "Placement of Ventricular Catheters" (86), "Spine Surgery" (85), "New Systems" (80), "Guided Biopsies" (61), and "Surgical Approach" (61). All topics except for "Planning and Visualization", "Intraoperative Tools", and "New Systems" exhibited a monotonic positive trend. When analyzing subcategories, there were a greater number of clinical assessments or usage of existing neuronavigation systems (77%) rather than modification or development of new apparatuses (18%). Conclusion: NF research appears to focus on the clinical assessment of neuronavigation and to a lesser extent on the development of new systems. Although neuronavigation has made significant strides, NF research output appears to have plateaued in the last decade.

Predicting the eyebrow from the orbit using three-dimensional CT imaging in the application of forensic facial reconstruction and identification.

Eyebrows are the most important facial feature in facial recognition with its shape rated to be more helpful than color or density for facial reconstruction or approximation. However, little extant research has estimated the position and morphological territory of the eyebrow from the orbit. Three-dimensional craniofacial models, produced from CT scans of 180 Koreans autopsied at the National Forensic Service Seoul Institute, were used to conduct metric analyses of subjects (125 males and 55 females) between 19 and 49 (mean 35.1) years. We employed 18 craniofacial landmarks to examine the morphometry of the eyebrow and orbit with 35 pairs of distances per subject measured between landmark and reference planes. Additionally, we used linear regression analyses to predict eyebrow shape from the orbit for every possible combination of variables. The morphology of the orbit has more influence on the position of the superior margin of the eyebrow. In addition, the middle part of the eyebrow was more predictable. The highest point of the eyebrow in female was located more medially than the male. Based on our findings, the equations for estimating the position of the eyebrow from the shape of the orbit is useful information for face reconstruction or approximation.

Extended reality veterinary medicine case studies for diagnostic veterinary imaging instruction: Assessing student perceptions and examination performance.

Educational technologies in veterinary medicine aim to train veterinarians faster and improve clinical outcomes. COVID-19 pandemic, shifted face-to-face teaching to online, thus, the need to provide effective education remotely was exacerbated. Among recent technology advances for veterinary medical education, extended reality (XR) is a promising teaching tool. This study aimed to develop a case resolution approach for radiographic anatomy studies using XR technology and assess students' achievement of differential diagnostic skills. Learning objectives based on Bloom's taxonomy keywords were used to develop four clinical cases (3 dogs/1 cat) of spinal injuries utilizing CT scans and XR models and presented to 22 third-year veterinary medicine students. Quantitative assessment (ASMT) of 7 questions probing 'memorization', 'understanding and application', 'analysis' and 'evaluation' was given before and after contact with XR technology as well as qualitative feedback via a survey. Mean ASMT scores increased during case resolution (pre 51.6% (±37%)/post 60.1% (± 34%); p < 0.01), but without significant difference between cases (Kruskal-Wallis H = 2.18, NS). Learning objectives were examined for six questions (Q1-Q6) across cases (C1-4): Memorization improved sequentially (Q1, 2 8/8), while Understanding and Application (Q3,4) showed the greatest improvement (26.7%-76.9%). Evaluation and Analysis (Q5,6) was somewhat mixed, improving (5/8), no change (3/8) and declining (1/8).Positive student perceptions suggest that case studies' online delivery was well received stimulating learning in diagnostic imaging and anatomy while developing visual-spatial skills that aid understanding cross-sectional images. Therefore, XR technology could be a useful approach to complement radiological instruction in veterinary medicine.

Extended reality visualization of medical museum specimens: Online presentation of conjoined twins curated by Dr. Jacob Henle between 1844-1852.

Background: The purpose of this study is to characterize a full-term conjoined twins' cadaver curated by Dr. Jacob Henle sometime between 1844 and 1852 and demonstrate digital distribution of an old and rare medical museum specimen using an extended reality (XR) model workflow. Methods: The cadaver (Preparation 296) is in the Department of Anatomy and Cell Biology at the University of Heidelberg. An XR display workflow comprises image capture, segmentation, and visualization using CT/MR scans derived from the cadaver. Online radiology presentation to medical students focuses on diagnostic characteristics of anatomical systems depicted with XR models. Results: Developmental defects in Preparation 296 include duplicated supradiaphragmatic structures and abnormal osteological features. Subdiaphragmatically, the gut is continuous on the right, but terminates at the distal esophagus on the left. One large liver occupies the abdomen with one spleen located on the left side. Observations suggest duplication of the primitive streak and separate notochords rostrally. Duplication occurs near the yolk sac and involves midgut formation while secondary midline fusion of the upper extremities and ribs likely results from the proximity of the embryos during development. Medical students access the model with device agnostic software during the curricular topic "Human Body Plan" that includes embryology concepts covering mechanisms of twinning. Conclusions: The workflow enables ease-of-access XR visualizations of an old and rare museum specimen. This study also demonstrates digital distribution and utilization of XR models applicable to embryology education.

Case-based radiological anatomy instruction using cadaveric MRI imaging and delivered with extended reality web technology.

PURPOSE: Extended reality (XR) technology enhances learning in medical education. The purpose of this study was to develop and apply a case-based approach for teaching radiological anatomy utilizing XR technology for improved student exploration and engagement. METHODS: The workflow consisted of MRI scanning cadavers followed by radiological, pathological, and anatomical assessment, and finally case presentation based on XR visualizations and student interaction. Case information (Subject, History, and Physical Exam) was presented to student groups who generated and recorded hypotheses using Google Forms. RESULTS: Use of all components of the system was voluntary and a total of 74 students responded to the survey request (response rate = 95%). Assessment of the experience was conducted through a qualitative survey comprising four Likert scale questions (1-5, 1 lowest), three binary questions, and open-ended comments. Mean, standard deviation, and overall agreement (mean ± SD, OA) showed that students found MRI scans of cadavers to be helpful for dissections (4.14 ± 1.1, 74.3%) and provided an understanding of relevant anatomy (4.32 ± 0.9, 79.7%), while 78.4% of students used the DICOM viewer to visualize scans of cadavers. The difficulty of use was found to be average (2.90 ± 1.0, 23%). zSpace visualizations were used by 40.5% of students, generally agreeing that an understanding of spatial relationships improved as a result (3.60 ± 1.0, 43.2%). More case-based sessions were favored by 97.3% of students. CONCLUSIONS: Results suggest that cadaveric MRI radiological visualization and XR technology enhance understanding of case-based anatomical dissections and encourage student exploration and engagement.

Extraoral anatomy in CBCT ­ a literature review. Part 4: Pharyngocervical region

This review about extraoral anatomy depicted in cone beam computed tomography describes the pharyngocervical region. Large (≥ 8 × 8 cm) field of views of the maxilla and/or mandible will inevita-bly depict the pharyngocervical region that com-prises the posterior upper airway, the pharyngeal part of the digestive tract, as well as the cervical segment of the spine. The latter consists of seven cervical vertebrae (C1-C7) with corresponding distinctive features, i.e., the atlas (C1) and the axis (C2). In addition, cervical vertebrae serve as ref-erences for the vertical position of anatomical structures. For instance, C4 is a typical landmark since it generally denotes the level of the chin, of the body of the hyoid bone, of the base of the epiglottis, and of the bifurcation of the common carotid artery, respectively. The pharynx, which is functionally involved in respiration, deglutition, and vocalization, extends from the lower aspect of the skull base to the esophagus. Anatomically, the pharynx is divided into three segments, i.e. the nasopharynx, the oropharynx, and the laryn-gopharynx. All communicate anteriorly with cor-responding cavities, i.e. the nasal cavities, the oral cavity, and the larynx. Although not directly located within the pharyngocervical region, the hyoid bone and the styloid process are also dis-cussed in this review, since both structures are commonly visible on CBCT images of this region.

Medical School Hotline: A New Osteological Resource at the John A. Burns School of Medicine.

The Mann-Labrash Osteological Collection of the University of Hawai'i is the newest collection of contemporary known-identity human skeletal remains in the United States. The collection, consisting of the partial or complete remains of individuals of European, African, Asian, and Pacific Islander ancestry, is an invaluable educational and research resource for medical students and visiting researchers. The collection reflects the population diversity of Hawai'i. The Mann-Labrash Osteological Collection provides a unique and irreplaceable resource for medical students and scientists interested in anatomy, disease, trauma, developmental defects, and biological diversity, particularly as they pertain to Hawai'i and the people of Polynesia.

Extraoral anatomy in CBCT ­ a literature review. Part 3: Retromaxillary region

In this review about extraoral anatomy as depicted by cone beam computed tomography, the retromaxillary region is discussed. A medium-sized (6 x 6 cm) or large (≥ 8 x 8 cm) field of view of the maxilla will inevitably depict the retromaxillary region that can be considered a «transition¼ zone between the viscerocranium and the neurocranium. Major structures of the region include the sphenoid bone and the pterygopalatine fossae. The sphenoid bone is a single but complex bone located between the maxilla and the brain. It is composed of a central body, bilateral greater and lesser wings, and pterygoid processes. Important neurovascular structures pass through the sphenoid bone: the optic nerve and the ophthalmic artery via the optic canal, the maxillary nerve via the foramen rotundum, and the pterygoid nerve via the Vidian canal. The central body of the sphenoid bone also contains the highly variable sphenoid sinus that is the most posteriorly located paranasal sinus. The bilateral pterygopalatine fossae behind the maxillary sinuses contain several important neurovascular structures that supply the maxilla and the midface.

Extraoral anatomy in CBCT ­ a literature review. Part 2: Zygomatico-orbital region

This second article about extraoral anatomy as seen in cone beam computed tomography (CBCT) images presents a literature review of the zygomatico-orbital region. The latter bounds the maxillary sinus superiorly and laterally. Since pathologic changes of the maxillary sinus are a frequent indication for three-dimensional radiography, the contiguous orbital cavity and the zygomatic bone may become visible on CBCT scans. The zygomatic bone forms the cheek prominence and has large contact areas with the maxilla through the zygomaticomaxillary suture in the infraorbital region as well as with the sphenoid bone along the lateral orbital wall. Each of the three surfaces of the zygomatic bone displays foramina that transmit neurovascular structures. The orbital cavity is located immediately above the maxillary sinus from which it is separated only by a thin bony plate simultaneously serving as the orbital floor and the roof of the maxillary sinus. Several openings, such as the superior and inferior orbital fissures, the ethmoidal and cranio-orbital foramina, and the optic and infraorbital canals, connect the orbit to the anterior and middle cranial fossae as well as to the infratemporal and pterygopalatine fossae.

Early-Onset Dementia in War Veterans: Brain Polypathology and Clinicopathologic Complexity.

The neuropathology associated with cognitive decline in military personnel exposed to traumatic brain injury (TBI) and chronic stress is incompletely understood. Few studies have examined clinicopathologic correlations between phosphorylated-tau neurofibrillary tangles, ß-amyloid neuritic plaques, neuroinflammation, or white matter (WM) lesions, and neuropsychiatric disorders in veterans. We describe clinicopathologic findings in 4 military veterans with early-onset dementia (EOD) who had varying histories of blunt- and blast-TBI, cognitive decline, behavioral abnormalities, post-traumatic stress disorder, suicidal ideation, and suicide. We found that pathologic lesions in these military-EOD cases could not be categorized as classic Alzheimer's disease (AD), chronic traumatic encephalopathy, traumatic axonal injury, or other well-characterized clinicopathologic entities. Rather, we observed a mixture of polypathology with unusual patterns compared with pathologies found in AD or other dementias. Also, ultrahigh resolution ex vivo MRI in 2 of these 4 brains revealed unusual patterns of periventricular WM injury. These findings suggest that military-EOD cases are associated with atypical combinations of brain lesions and distribution rarely seen in nonmilitary populations. Future prospective studies that acquire neuropsychiatric data before and after deployments, as well as genetic and environmental exposure data, are needed to further elucidate clinicopathologic correlations in military-EOD.

Extraoral anatomy in CBCT ­ a literature review. Part 1: Nasoethmoidal region

Cone beam computed tomography has become a widely used imaging technique for dental indications. Depending on the selected size of the field of view, anatomical structures outside the dentomaxillary complex become visible. As a consequence, the clinician must be able to interpret also those anatomical regions. In this article, the anatomy of the nasoethmoidal region is presented based on a literature review. The nose is characterized by the nasal septum and the superior, middle, and inferior conchae. The turbinates may be pneumatized (concha bullosa), mainly the middle concha. The ethmoid bone has a complex morphology (ethmoid labyrinths) and contributes with its perpendicular plate to the nasal septum. Other structures of the septum include the vomer and the septal cartilage. The nasal meatuses stabilize the airflow and direct the inhaled air to the nasopharynx via the choanae. The middle nasal meatus, which is also a part of the so called ostiomeatal complex, serves as the major drainage area (semilunar hiatus) of the paranasal sinuses, i.e., maxillary sinus, anterior ethmoid cells, and frontal sinus. Posterior ethmoid cells empty into the superior meatus and the sphenoid sinus drains into the sphenoethmoidal recess, located above the superior concha. The nasolacrimal duct that is running along the middle portion of the lateral nasal wall opens into the inferior nasal meatus.

Delayed diagnosis of a primary intraosseous squamous cell carcinoma: A case report.

Primary intraosseous squamous cell carcinoma is a rare malignant central jaw tumor derived from odontogenic epithelial remnants. Predominantly, it affects mandible, although both jaw bones may be involved. This report describes a 60-year-old man who was initially misdiagnosed with a periapical infection related to the right lower wisdom tooth. After four months, the patient presented to a private dental clinic with a massive swelling at the right side of the mandible. Panoramic radiographs and advanced imaging revealed a lesion with complete erosion of the right ramus, which extended to the orbital floor. A biopsy from the mandibular angle revealed large pleomorphic atypical squamous cells, which is the primary microscopic feature of a poorly differentiated squamous cell carcinoma.

The Morphology of the Infraorbital Nerve and Foramen in the Presence of an Accessory Infraorbital Foramen.

BACKGROUND: The accessory infraorbital foramen (AIOF) is an anatomical variation associated with the infraorbital foramen (IOF) and nerve (ION). Its occurrence and neural contents have clinical implications regarding failure of loco-regional anesthesia and risk of neural damage during surgical interventions involving the maxillary region. Thus, morphologic characterization of the AIOF and neural contents as well as the spatial relationships to the IOF are potentially useful for optimizing surgical procedures. Additionally, predictive features of the AIOF based on its relationship to IOF morphology could enable the surgeon to anticipate its presence and proceed accordingly. The purpose of this study was to determine whether the presence of an AIOF and its neural contents affected the size, shape, and composition of the IOF and ION. The specific hypothesis tested was that the topography and fascicular composition of the ION and IOF differs between individuals possessing an AIOF and those lacking this anatomical variant. METHODS: Gross topographic features of the IOF (42 crania) were compared between specimens possessing (test) or lacking (control) an AIOF. Nerve fascicles of ION (60 cadaveric sides) were examined histologically and compared morphometrically between specimens presenting or lacking an AIOF. An additional sample of 30 crania was subjected to cone-beam computed tomography (CBCT) analysis to determine the course of the canal leading to the AIOF. RESULTS: The AIOF incidence was 47.6% (20 crania) and 32.1% of the sides (27 sides). A single AIOF was observed in 24 sides and double AIOF in three sides. The AIOF occurred bilaterally in 7 specimens (16.7%). The majority of AIOF (86.7%) were located superomedial to IOF. A slightly higher frequency of the AIOF was found in left side compared to the right. Using CBCT, a patient sample showed an AIOF incidence in 21 sides of 16 patients (65.6%). A single AIOF was observed in 19 sides. Only 1 double AIOF was found in the scans, whereas 3 were found in the dry skull group. The AIOF occurred bilaterally in 3 scans (10%). The majority of AIOF (90.4%) were located superomedial to the IOF based on the CBCT scans. The AIOF was consistently seen connected to the infraorbital canal and progressed superiorly and medially from the infraorbital canal to the maxillary surface. The size of the ION without an AIOF was not significantly different than the ION in the presence of an AIOF (1.45 × 10/1.32 × 10 µm, P < 0.35) based on fascicular area. However, the number of ION fascicles was greater in specimens without an AIOF compared to those showing this feature (15.15/12.71, P < 0.04) CONCLUSION:: Results indicate that the area of the ION is not affected by an AIOF, suggesting that the field of innervation of this area is not modified by its occurrence. However, the ION appears to divide more proximally into its component branches when the AIOF is present.

Radiographic Diagnosis of Fibrous Dysplasia in Maxilla.

Fibrous dysplasia is a rare bone disorder characterized by the replacement of normal bone by abnormal fibrous tissue. Here we present a 16-year-old female with a fibrous dysplasia in the maxilla and obliteration of the sinus in the same side. Cone beam computed tomography scan revealed a mixed radiopacity that extended from the alveolar crest of the right posterior teeth to the right orbital floor in the superior-inferior direction. The radiopaque areas had homogenous ground glass appearance. There is a loss of bone trabeculation, thinning of the cortical boundaries but still intact, and a loss of the lamina dura around the right posterior permanent teeth. The radiographical features of the lesion were indicative of fibrous dysplasia in the maxilla.

Osteoma Cutis and Tonsillolith: A Cone Beam Computed Tomography Study.

In this study, we report a rare case of osteoma cutis (OC) and tonsillolith, diagnosed using cone beam computed tomography. The dystrophic calcifications in the face and tonsils were incidentally found during examination of the patient's scan with no relation to the main chief complaint. The diagnosis was OC, combined with dystrophic calcification of the tonsils. It is important to mention that OC is a rare soft-tissue ossification of cutaneous tissue, typically on the face and clinically asymptomatic. It may be primary but the majority of cases are secondary. Incidental finding of OC and tonsilloliths on a two-dimensional dental radiograph does not provide sufficient information concerning the location of these calcifications. Thus, cone beam computed tomography (CBCT) provides critical information for the diagnosis of asymptomatic OC lesions not available through any other means of clinical detection.

The Face ­ A Musculoskeletal Perspective. A literature review

The individual appearance and facial expression are based on the musculoskeletal system of the face. The bones of the face contribute to the anterior portion of the skull. This region is also referred to as the facial skeleton or viscerocranium. The muscles of the face include all mimetic muscles innervated by the cranial nerve VII (facial nerve). Two masticatory muscles (masseter, temporalis) that are supplied by the motoric portion of the cranial nerve V3 (mandibular nerve) also contribute to the contour of the face. The mimetic muscles (also known as facial muscles or skin muscles) generally originate from underlying bone surfaces and insert to the skin of the face or intermingle with other facial muscles. This complex musculature contributes to the functioning of the orofacial sense organs and the mediation of emotional and affective states (facial expression). Other soft tissue components of the face include the fasciae and fat compartments. The face commonly exhibits a superficial and a deep fascia, and various facial fat compartments are present.