A novel gelatinized barium sulfate injection method for assessment of bronchoalveolar lavage parameters.

INTRODUCTION: Bronchoalveolar lavage (BAL) is frequently used in pulmonary medicine though it requires further optimization. Practical obstacles such as patient safety and procedural limitation have to date precluded large, controlled trials aimed at standardization of BAL procedure. Indeed, BAL guidelines are based on observational data. Innovative research methods are necessary to advance the clinical practice of BAL. METHODS: In our study, we evaluated the effect of injecting a gelatinized barium solution into different lobes and segments of cadaveric lungs. As the technique requires an irreversible injection into lung airspaces, it is not suitable for in vivo purposes. We measured the volume returned from BAL as well as the distribution of BAL injection via dissection. Segmental anatomic orientation was compared to a radiologist's impression of plain film radiographs taken of injected lungs. RESULTS: Mean injected volume distributions were greatest in the upper lobes and lowest in the lower lobes; mean ratios of injected volume distribution to lung lobe volume also followed this trend. Cannulated bronchi orders favored lower branches in the upper lobe and higher branches in the lower lobes. Segmental anatomy varied by the lung lobe injected and was most varied in the lower lobes. CONCLUSION: This novel gelatinized-barium injection technique provides a minimally complex method to yield clinically meaningful feedback on the performance of BAL. The technique is also adaptable to study of procedural parameters in the context of variable lung anatomies and pathologies.

Optic Canal Size is an Indicator for the Accessory Optic Canal: Applications for Anterior Clinoidectomy.

BACKGROUND: The ophthalmic artery normally travels with the optic nerve through the optic canal. However, sometimes, the ophthalmic artery travels through a foramen within the optic strut named an accessory optic canal, double optic canal, or ophthalmic canal. This variant puts individuals at an increased risk for blindness or death during anterior clinoidectomy due to unforeseen hemorrhage of the ophthalmic artery or internal carotid artery when the optic strut is separated from the body of the sphenoid bone. Several features make the accessory optic canal difficult to recognize on imaging: its variant nature, small size, and ability to masquerade as a caroticoclinoid foramen or a pneumatized sphenoidal structure. Hence, improved methods of presurgical identification are warranted. The aim of this study was to assess the size and shape of the optic canal, with and without a concomitant accessory optic canal, to determine whether measurement of the optic canal may provide useful information regarding the presence of an accessory optic canal. METHODS: In 191 dry crania, optic canals with and without concomitant accessory optic canals were assessed for the following parameters: canal area, canal perimeter, circularity, solidity, the axes and aspect ratio of a best-fit ellipse, and roundness. RESULTS: Normal optic canals were found to have a larger area (P = 0.036), perimeter (P = 0.043), and minor axis of a best-fit ellipse (P = 0.031) than the optic canals that occurred alongside accessory optic canals. CONCLUSIONS: Asymmetry in optic canal size can help indicate the presence of a unilateral accessory optic canal before surgery.

Bilateral Virchow nodes: an unusual finding of pulmonary small-cell neuroendocrine carcinoma metastasis.

An enlarged left-sided supraclavicular node is a signal node for cancer metastasis. In such a case, the enlarged lymph node is often referred to as a Virchow node. The left-sided nature of the node is due to the drainage of the thoracic duct. So, the enlargement of a Virchow node is typically associated with malignancies, including gastrointestinal, pulmonary, and genitourinary carcinomas, in addition to lymphomas. This report documents a particularly unusual finding: bilateral Virchow nodes, representing metastasis of small-cell neuroendocrine carcinoma.

Human body donation and surgical training: a narrative review with global perspectives.

Utilization of human material in surgical simulation training has been well-established as an effective teaching method. Despite the value of donor-based surgical simulation training, its application may be hampered by difficulties regarding access to donated bodies. Therefore, the aim of this review is to assess body donation and body acquisition practices with regard to surgical simulation training programs around the world. The results of this review highlight discrepancies regarding body donation practices and surgical simulation programs among continents and countries. The utilization of donor bodies in surgical simulation appears to mirror body donation practices. In countries that rely mostly or exclusively upon unclaimed bodies or executed criminals, there are scant reports of donor-based surgical simulation programs. In countries where willed-body donation is the principal source of human material, there tend to be many surgical simulation programs that incorporate human material as part of surgical training. This review suggests that, in anatomical and surgical education, the utilization of active willed-body donation programs, as opposed to the utilization of unclaimed human bodies, positively corresponds with the development of beneficial donor-based surgical simulation programs. Likewise, donor-based surgical simulation training programs may have an influence on the perpetualization of willed-body donations.

Bilateral Virchow nodes: an unusual finding of pulmonary small-cell neuroendocrine carcinoma metastasis

ABSTRACT An enlarged left-sided supraclavicular node is a signal node for cancer metastasis. In such a case, the enlarged lymph node is often referred to as a Virchow node. The left-sided nature of the node is due to the drainage of the thoracic duct. So, the enlargement of a Virchow node is typically associated with malignancies, including gastrointestinal, pulmonary, and genitourinary carcinomas, in addition to lymphomas. This report documents a particularly unusual finding: bilateral Virchow nodes, representing metastasis of small-cell neuroendocrine carcinoma.

Cribra orbitalia is a vascular phenomenon unrelated to marrow hyperplasia or anemia: Paradigm shift for cribra orbitalia.

The orbital phenomenon, cribra orbitalia, has long been a source of controversy, especially with regard to its nature, derivation, and relationship to anemia. Therefore, the external surfaces of orbital roofs were systematically examined microscopically in human skulls from historical collections. Superior orbital surfaces of 278 individual crania within the Hamann-Todd collection were assessed at various magnifications using epi-illumination microscopy to identify the presence of cribra orbitalia and characterize its nature. Also, 12 additional individuals with diagnosed anemia in the Hamann-Todd collection were evaluated. Orbital roof alterations, present in one-third of examined crania, had two discrete appearances: Vascular grooves (45%) and application of new bone in a vascular branching pattern on the orbit surface (55%). Porosity of the orbit was not observed. Evaluation of the orbits of 12 individuals with diagnosed anemia revealed one with a single deep defect, suggesting a space-occupying phenomenon, but no evidence of bone accretion, vascular grooves, or porosity. Cribra orbitalia has often been lumped indiscriminately as an indicator of organismal stress, rather than identified as a indicating a specific etiology. Neither that perspective nor porosity are supported by high resolution examination of orbital roof changes. Recognition of the blood vessel imprint pattern falsifies previous speculations and provides a new paradigm. The actual character of cribra orbitalia is documented and new hypotheses generated. While population prevalence of cribra orbitalia seems excessive for explanation on the basis of these hypotheses, the imprints are clearly vascular in origin.

Clinical Implications of the Submental and Sublingual Arteries in Relation to the Mylohyoid Boutonnière.

OBJECTIVE: Mylohyoid musculature may be included in the submental artery flap to protect perforators. However, blood vessels may pass through the mylohyoid muscle and therefore cause bleeding and risk to pedicle or perforator injury when a mylohyoid-containing flap is lifted. The objectives of this study were to identify the prevalence of the submental and sublingual arteries that traverse the mylohyoid and to assess relationships between vasculature transmitted through mylohyoid muscles and mylohyoid boutonnières. STUDY DESIGN: Cross-sectional human cadaveric study. SETTING: The West Virginia University School of Medicine human gross anatomic laboratories. SUBJECTS AND METHODS: A total of 43 intact mylohyoid muscles from 22 cadavers were dissected. The prevalence of submental vasculature perforating the mylohyoid was recorded in addition to the prevalence and contents of mylohyoid boutonnières. RESULTS: Of 43 mylohyoid muscles, 21 (48.8%) transmitted the submental or sublingual arteries, and 30 (69.1%) possessed boutonnières. One muscle had 2 boutonnières. Of 31 mylohyoid boutonnières, 21 transmitted blood vessels (67.7%). Specifically, 9 transmitted an artery and a vein (29.0%), and 12 transmitted an artery (38.7%). Ten boutonnières (32.3%) were exclusively occupied by fascia. CONCLUSION: This report identifies the importance of identifying and carefully ligating branches of the submental artery that pierce the mylohyoid during elevation of the submental island flap. This report also identifies that a boutonnière is often present where a submental or sublingual artery is traversing the mylohyoid to supply sublingual glands, tongue, and anterior mandible.

Duplication of the inferior vena cava: evidence of a novel type IV.

Anatomical variations of the inferior vena cava, including the double inferior vena cava or isolated left inferior vena cava, are uncommon and of great clinical importance. Inferior vena cava variations signify predisposition to deep vein thrombosis and may complicate retroperitoneal surgeries including abdominal aortic surgery. Failure to recognize such variations may predispose a patient to life- threatening complications. This prospective anatomical study assessed 129 cadavers for variations of the inferior vena cava. One of the 129 cadavers (0.78%) possessed a double inferior vena cava and none (0%) possessed an isolated left inferior vena cava. The left-sided inferior vena cava was of a larger diameter than that of the right-sided inferior vena cava - opposite of what would be seen in a Type III duplication. Therefore, this observation expands the three-type classification system to include a Type IV duplication.

Synovial Sarcoma of the Hand.

The incidence of synovial sarcoma is 1.548 per 1,000,000. Synovial sarcoma localized to the palmar surface should, therefore, be considered extremely rare. This report documents a 34-year-old male with a right hand mass that had been present for a few years, continuing to grow in size. The mass was located at the palm and extended from the mid-third metacarpal to involve all digits except the thumb. The mass was determined to be monophasic synovial sarcoma on histopathologic exam. Fluorescence in situ hybridization for SYT gene rearrangement was positive in 72% of cells. Resection of the mass was followed by radiation and chemotherapy. The patient had a long-term follow-up of 3.5 years with no evidence of any local recurrence of the tumor. This report increases awareness of this extremely rare malignancy-an awareness that is crucial for early diagnosis and improved survival rates. It is more common at younger ages but it can occur at any age, so it should be suspected and included in the differential diagnosis, especially when evaluating slow growing, nonresolving hand lesions.

Retinoblastoma in Infancy with Subsequent Bladder Leiomyosarcoma in Adulthood: Genomic Considerations.

Hereditary retinoblastoma is attributed to germline mutation in an RB1 tumor suppressor gene followed by somatic mutation in the other allele. This report details a case of leiomyosarcoma of the bladder in a 24-year-old man with a history of retinoblastoma treated by enucleation and radiotherapy in infancy. Leiomyosarcoma is the most common secondary soft tissue malignancy in retinoblastoma survivors; however, leiomyosarcoma of the bladder in retinoblastoma survivors is very rare. Survivors of hereditary retinoblastoma should be monitored closely for secondary malignancies, and there should be an increased suspicion of malignancy. Furthermore, tumors can occur outside the field of radiation.

Troisier sign and Virchow node: the anatomy and pathology of pulmonary adenocarcinoma metastasis to a supraclavicular lymph node.

Metastatic spread of cancer via the thoracic duct may lead to an enlargement of the left supraclavicular node, known as the Virchow node (VN), leading to an appreciable mass that can be recognized clinically - a Troisier sign. The VN is of profound clinical importance; however, there have been few studies of its regional anatomical relationships. Our report presents a case of a Troisier sign/VN discovered during cadaveric dissection in an individual whose cause of death was, reportedly, chronic obstructive pulmonary disease. The VN was found to arise from an antecedent pulmonary adenocarcinoma. Our report includes a regional study of the anatomy as well as relevant gross pathology and histopathology. Our anatomical findings suggest that the VN may contribute to vascular thoracic outlet syndrome as well as the brachial plexopathy of neurogenic thoracic outlet syndrome. Further, the VN has the potential to cause compression of the phrenic nerve, contributing to unilateral phrenic neuropathy and subsequent dyspnea. Recognition of the Troisier sign/VN is of great clinical importance. Similarly, an appreciation of the anatomy surrounding the VN, and the potential for the enlarged node to encroach on neurovascular structures, is also important in the study of a patient. The presence of a Troisier sign/VN should be assessed when thoracic outlet syndrome and phrenic neuropathy are suspected. Conversely, when a VN is identified, the possibility of concomitant or subsequent thoracic outlet syndrome and phrenic neuropathy should be considered.

Troisier sign and Virchow node: the anatomy and pathology of pulmonary adenocarcinoma metastasis to a supraclavicular lymph node

ABSTRACT: Metastatic spread of cancer via the thoracic duct may lead to an enlargement of the left supraclavicular node, known as the Virchow node (VN), leading to an appreciable mass that can be recognized clinically ­ a Troisier sign. The VN is of profound clinical importance; however, there have been few studies of its regional anatomical relationships. Our report presents a case of a Troisier sign/VN discovered during cadaveric dissection in an individual whose cause of death was, reportedly, chronic obstructive pulmonary disease. The VN was found to arise from an antecedent pulmonary adenocarcinoma. Our report includes a regional study of the anatomy as well as relevant gross pathology and histopathology. Our anatomical findings suggest that the VN may contribute to vascular thoracic outlet syndrome as well as the brachial plexopathy of neurogenic thoracic outlet syndrome. Further, the VN has the potential to cause compression of the phrenic nerve, contributing to unilateral phrenic neuropathy and subsequent dyspnea. Recognition of the Troisier sign/VN is of great clinical importance. Similarly, an appreciation of the anatomy surrounding the VN, and the potential for the enlarged node to encroach on neurovascular structures, is also important in the study of a patient. The presence of a Troisier sign/VN should be assessed when thoracic outlet syndrome and phrenic neuropathy are suspected. Conversely, when a VN is identified, the possibility of concomitant or subsequent thoracic outlet syndrome and phrenic neuropathy should be considered.

Locating the foramen ovale by using molar and inter-eminence planes: a guide for percutaneous trigeminal neuralgia procedures.

OBJECTIVE: The first attempt to cannulate the foramen ovale is oftentimes unsuccessful and requires subsequent reattempts, thereby increasing the risk of an adverse event and radiation exposure to the patient and surgeon. Failure in cannulation may be attributable to variation in soft-tissue-based landmarks used for needle guidance. Also, the incongruity between guiding marks on the face and bony landmarks visible on fluoroscopic images may also complicate cannulation. Therefore, the object of this study was to assess the location of the foramen ovale by way of bony landmarks, exclusive of soft-tissue guidance. METHODS: A total of 817 foramina ovalia (411 left-sided, 406 right-sided) from cranial base images of 424 dry crania were included in the study. The centroid point of each foramen ovale was identified. A sagittal plane through the posterior-most molar (molar plane) and a coronal plane passing through the articular eminences of the temporal bones (inter-eminence plane) were superimposed on images. The distances of the planes from the centroids of the foramina were measured. Also, counts were taken to assess how often the planes and their intersections crossed the boundary of the foramen ovale. RESULTS: The average distance between the molar plane and the centroid of the foramen was 1.53 ± 1.24 mm (mean ± SD). The average distance between the inter-eminence plane and the centroid was 1.69 ± 1.49 mm. The molar and inter-eminence planes crossed through the foramen ovale boundary 83.7% (684/817) and 81.6% (667/817) of the time, respectively. The molar and inter-eminence planes passed through the boundary of the foramen together 73.5% (302/411) of the time. The molar and inter-eminence planes intersected within the boundary of the foramen half of the time (49.4%; 404/817). CONCLUSIONS: The results of this study provide a novel means of identifying the location of the foramen ovale. Unlike the soft-tissue landmarks used in the many variations of the route of Härtel, the bony landmarks identified in this study can be palpated, marked on the face, appreciated fluoroscopically, and do not require any measurement from soft-tissue structures. Utilizing the molar and inter-eminence planes as cannulation guides will improve the approach to the foramen ovale and decrease the amount of radiation exposure to both the patient and surgeon.

The submental arrowhead variation of the mylohyoid and anterior belly of the digastric muscles.

PURPOSE: Submental anatomical variation is of clinical importance with regard to head and neck surgeries. One such anatomical variation is that of additional musculature joining the intermediate tendon of the digastric muscle to the midline of the mylohyoid musculature-a variation which this report refers to, accordingly, as an arrowhead variation. Though the arrowhead variation has been described in several case reports, it has not been subject to cross-sectional study. The purpose of this study is to determine the prevalence of the arrowhead variation. METHODS: Prevalence of the arrowhead variation was assessed in 19 cadavers via gross dissection. RESULTS: Two of the 19 cadavers (10.5%) were found to have arrowhead variations. The arrowhead variation was found in one male (1:11; 9.1%) and one female (1:8; 12.5%), respectively. CONCLUSIONS: This report demonstrates that the submental arrowhead variation of the anterior digastric and mylohyoid musculature has been reported in isolated case reports since the nineteenth century. This report is the first cross-sectional study of the arrowhead variant, identifying it in approximately one in ten individuals and in both sexes. Therefore, the presence of an arrowhead variation should be regularly considered with regard to diagnosis of submental masses. Likewise, the arrowhead variation should be considered in the preoperative planning of the myriad operations performed in the submental region.

A Review of Extensor Hallucis Longus Variants Featuring a Novel Extensor Primi Internodii Hallucis Muscle Merging With Extensor Hallucis Brevis.

The extensor hallucis longus (EHL) muscle/tendon complex has been used in a variety of tendon transfer and tenodesis surgeries to correct iatrogenic hallux varus deformity, equinovarus foot deformity, clawed hallux associated with a cavus foot, and dynamic hyperextension of the hallux and, even, to prevent pedal imbalance after transmetatarsal amputation. Although it is usually considered a unipennate muscle inserting into the dorsum of the base of the distal phalanx of the hallux, a vast majority of EHL muscles possess ≥1 accessory tendinous slips that insert into other neighboring bones, muscles, or tendons, which can complicate these surgeries. The present report reviewed the reported data on EHL variants and describe a new variant, in which the tendons of the extensor primi internodii hallucis muscle of Wood and extensor hallucis brevis muscle merged together proximal to the tarsometatarsal (Lisfranc) joint, a site of rupture for extensor tendons of the foot. The reported variant might have contributed to the development of the clawed hallux seen in our patient and could complicate its operative management by mimicking the normal extensor digitorum longus tendon. Knowledge of the EHL variants and the particular muscular pattern described in the present review could improve the diagnosis and tendon transfer and tenodesis operative planning and outcomes.

Infraorbital foramen location in the pediatric population: A guide for infraorbital nerve block.

BACKGROUND: Infraorbital nerve blocks are often performed for the management of postoperative pain associated with cleft lip correction. Infraorbital nerve block procedures depend on the identification of the infraorbital foramen; however, there is little information regarding the infraorbital foramen location in the pediatric population. AIMS: The aim of this study was to identify the location of the infraorbital foramen in the pediatric population relative to a midpoint between the nasospinale and jugale. METHODS: The study assessed the location of 152 infraorbital foramina relative to a midpoint between the nasospinale and J on dry crania. Crania were from individuals ranging in age-at-death from 6-month fetal to 18 years. The population was subdivided into fetal/infant (≥6 months fetal age-<2 years), child (≥2-<12 years), and adolescent (≥12-≤18 years) groups for comparison. RESULTS: The average distance of the infraorbital foramen from the nasospinale-to-jugale midpoint was 1.55 ± 0.78 mm (Mean ± SD) in the fetal/infant group, 0.80 ± 0.91 mm in the child group, and 1.31 ± 1.68 mm in the adolescent group. Furthermore, infraorbital foramina tended to be located medial to the nasospinale-to-jugale midpoint in the fetal/infant population, directly upon or superomedial to the nasospinale-to-jugale midpoint in the child population, and directly upon or superior/superolateral to the nasospinale-to-jugale midpoint in the adolescent population. CONCLUSIONS: The infraorbital foramen was located within 2 mm, on average, from the nasospinale-to-jugale midpoint regardless of age group. Therefore, the nasospinale-to-jugale midpoint may serve as useful means of identifying the location of the infraorbital foramen in the pediatric population and aid in optimizing infraorbital nerve block procedures. The information in this report is valuable in general, but may be particularly useful in developing countries where there is a lack of ultrasound training and availability for health care providers; or places where infraorbital nerve block may be the sole anesthetic modality for cleft lip surgery, even among adolescent patients.

Oval Window Size and Shape: a Micro-CT Anatomical Study With Considerations for Stapes Surgery.

BACKGROUND: The oval window is an important structure with regard to stapes surgeries, including stapedotomy for the treatment of otosclerosis. Recent study of perioperative imaging of the oval window has revealed that oval window niche height can indicate both operative difficulty and subjective discomfort during otosclerosis surgery. With regard to shape, structures incorporated into the oval window niche, such as cartilage grafts, must be compatible with the shape of the oval window. Despite the clinical importance of the oval window, there is little information regarding its size and shape. METHODS: This study assessed oval window size and shape via micro-computed tomography paired with modern morphometric methodology in the fetal, infant, child, and adult populations. Additionally, the study compared oval window size and shape between sexes and between left- and right-sided ears. RESULTS: No significant differences were found among traditional morphometric parameters among age groups, sides, or sexes. However, geometric morphometric methods revealed shape differences between age groups. Further, geometric morphometric methods provided the average oval window shape and most-likely shape variance. CONCLUSION: Beyond demonstrating oval window size and shape variation, the results of this report will aid in identifying patients among whom anatomical variation may contribute to surgical difficulty and surgeon discomfort, or otherwise warrant preoperative adaptations for the incorporation of materials into and around the oval window.

The Infraorbital Foramen Is Located Midway Between the Nasospinale and Jugale: Considerations for Infraorbital Nerve Block and Maxillofacial Surgery.

Identification of the infraorbital foramen is important in infraorbital nerve block and the prevention of iatrogenic injury of the infraorbital nerve in maxillofacial surgeries. This study assessed the location of 887 infraorbital foramina from 518 adult crania of varied sex and population. The study assessed the midpoint of a line segment spanning from nasospinale to jugale (NS-J) relative to the infraorbital foramen. The mean distance of the NS-J midpoint from the infraorbital foramen was 2.1 ±â€Š1.9 mm (mean ±â€ŠSD) with a mode of 0 mm (266:887; 30%). The NS-J midpoint was located in the same plane or inferior to the infraorbital foramen in 98.4% of sides (873:887). There were no significant differences between sexes, populations, or sides with regard to the NS-J midpoint to infraorbital foramen distance. The NS-J midpoint can be used to locate the infraorbital foramen in both females and males of varied populations regardless of craniofacial diversity. The results of this study will aid in infraorbital nerve block procedures and maxillofacial surgery.

The Use of Ultrasonography to Identify the Intersection of the Dorsomedial Cutaneous Nerve of the Hallux and the Extensor Hallucis Longus Tendon: A Cadaveric Study.

Terminal branches of the superficial fibular nerve are at risk of iatrogenic damage during foot surgery, including hallux valgus rigidus correction, bunionectomy, cheilectomy, and extensor hallucis longus tendon transfer. One terminal branch, the dorsomedial cutaneous nerve of the hallux, is particularly at risk of injury at its intersection with the extensor hallucis longus tendon. Iatrogenic injuries of the dorsomedial cutaneous nerve of the hallux can result in sensory loss, neuroma formation, and/or debilitating causalgia. Therefore, preoperative identification of the nerve is of great clinical importance. The present study used ultrasonography to identify the intersection between the dorsomedial cutaneous nerve of the hallux and the extensor hallucis longus tendon in cadavers. On ultrasound identification of the intersection, dissection was performed to assess the accuracy of the ultrasound screening. The method successfully pinpointed the nerve in 21 of 28 feet (75%). The sensitivity, positive likelihood ratio, and positive and negative predictive values of ultrasound identification of the junction of the dorsomedial cutaneous nerve and the extensor hallucis longus tendon were 75%, 75%, 100%, and 0%, respectively. We have described an ultrasound protocol that allows for the preoperative identification of the dorsomedial cutaneous nerve of the hallux as it crosses the extensor hallucis longus tendon. The technique could potentially be used to prevent the debilitating iatrogenic injuries known to occur in association with many common foot surgeries.

Metopism: a Study of the Persistent Metopic Suture.

Metopism, the persistence of the metopic suture in adulthood, is a clinically significant radiographic finding. In addition to masquerading as a fracture of the frontal bone, a persistent metopic suture may be associated with other clinically significant anatomical variations including frontal sinus abnormalities. Several geographically and craniofacially distinct populations have yet to be assessed for the prevalence of metopism. This study aimed to determine the prevalence of metopic sutures in adult crania of diverse populations among which scant research exists. A total of 505 adult crania were examined for the presence of a metopic suture. A total of 13 (2.57%) demonstrated metopism. Among subpopulations, metopism was present in 8.06% (5:62) of European crania, 15.38% (2:13) of East Asian crania, 2.20% (2:91) of Egyptian crania, and 2.86% (1:35) of Bengali crania. Metopism was also found in 1 Chilean, Roman, and Tchuktchi cranium, respectively. Metopism was not seen in crania from individuals of African (non-Egyptian) descent (0:62), Peruvians (0:144), Malayans (0:23), or Mexicans (0:23). Among sexes, metopism was present in 3.77% (8:212) of females and 1.79% (5:279) of males. The prevalence of metopism differs between populations and sexes. The results of this study provide anthropological, developmental, and clinical insight with regard to metopism.