Orbital Margin Research Articles

Zygomaticofacial foramen in dry adult human skulls: a morphological study.

A wide range of medical procedures in the zygomatic region in maxillofacial surgery, implantology, and aesthetic medicine requires a detailed study of the zygomaticofacial foramen (ZFF) due to the high risk of damage to its contents during manipulation.This study aimed to estimate the shape, diameter, and location of ZFF and their relationships with anatomical landmarks. A studywas conductedon 53 dry adult human skulls. Standard morphometric measurementswere takenusing sliding calipers.The number, diameter, shape, and location of ZFF were notedon both sides, andthe distances between the ZFF and surrounding anatomical landmarks were measured.Conventional statistical methods were usedto evaluate the data. Out of 106 sides, no ZFFwas noticedin 2.8%, one foramen was found in 40.6%, two foramina were found in 39.6%, threein 10.4%, four in 4.7%, andfive in 1.9%. The vertical diameter was 0.98 ± 0.35 mm, while the transverse diameter was 0.87 ± 0.31 mm. The shape of the ZFF was oval in 67%, round in 26.2%, semilunar in 4.9%, and irregular in 1.9%. The distance from the ZFF to the infraorbital margin was 6.63 ± 2.09 mm, tothe frontozygomatic suture was 26.24 ± 3.49 mm, tothe zygomaticomaxillarysuture,was 19.75 ± 3.55 mm, tothe zygomaticotemporal suture was 22.31 ± 3.98 mm and, to the most prominent point of the zygomatic bone was 8.03 ± 2.64 mm. The variations in the number and location of ZFF mustbe consideredwhile performing regional blockanesthesia,and surgical or aesthetic procedures in the zygomatic region.

Osteology and relationships of the Late Triassic giant dicynodont Lisowicia

Abstract Unexpectedly abundant remains of herbivorous therapsids in the Late Triassic strata of southern Poland have significantly supplemented knowledge of their evolution. The skeletal morphology of the Late Norian (or Rhaetian) dicynodont Lisowicia bojani supports its close relationship to the Carnian Woznikella, both known from the Polish part of the Germanic Basin. Three evolutionary lineages of dicynodonts—Laurasian–Gondwanan Rhadiodromus klimovi → Jachaleria candelariensis lineage, Laurasian lineage Shaanbeikannemeyeria xilougouensis → Lisowicia bojani, and the Gondwanan lineage Kannemeyeria simocephalus → Dinodontosaurus brevirostris—are distinguished based on characters of cranial and postcranial elements. In the lineages characterized by the parietal oval in cross-section and the two distinct articulations on the sternum, there is a tendency to exclude the frontal from the orbital margin and to reduce the number of sacral vertebrae. In the lineage with the parietal narrow and triangular in cross-section, the frontal forms part of the orbit margin, there is a single joint on the sternum, and there is a tendency towards flattening the skull roof. In both lineages the shoulder girdle is convergently modified, the acromion process decreased, and joints on the sternum moved posteriorly.

Wrong site but intact sight

Orbital foreign bodies are common. A large metallic foreign body involving ipsilateral orbit into the maxillary sinus is potentially vision-threatening. This case report describes a potentially serious incident involving a 49-year-old man who presented with an injury to his right eye with an iron nail while working in a factory. An iron nail penetrating the infraorbital margin of the right eye extended into the maxillary sinus associated with periorbital edema. X-ray showed a metallic foreign body extending from the right eye infraorbital margin into the maxillary sinus. Under local anesthesia, under all aseptic precautions, a linear iron nail measuring 4.5 cm in length was removed from the right orbit without any evidence of damage to vital structures. This case represents one of the largest reported infraorbital metallic (iron nail) foreign bodies, highlighting its rarity and potential danger to vision and overall health.

Comprehensive Mapping and Dynamic Monitoring of the Temporal Branch of the Facial Nerve in Complex Cranial Reconstruction Surgery and Revision Cranioplasty.

Facial nerve (FN) injury is a significant risk during complex cranial reconstruction surgeries, especially in revision cases where normal anatomy is distorted. The authors introduce a technique to mitigate FN injury, including preoperative FN mapping, intraoperative FN mapping, and continuous FN monitoring. Preoperative mapping uses a handheld ball-tip stimulator to elicit compound muscle action potentials (CMAP) in the frontalis muscle. Needle electrodes are placed above the orbital margin to record responses, starting at the stylomastoid foramen and extending until the entire temporal branch is mapped. Intraoperatively, continuous mapping is achieved using an electrified insulated suction device, allowing dynamic mapping during soft tissue dissection. Continuous monitoring involves placing stimulation electrodes near the stylomastoid foramen and recording CMAP responses from the frontalis and orbicularis oculi/orbicularis oris muscles. The authors tested this technique in 5 patients. The authors successfully mapped the temporal branch of the FN with isolated frontalis CMAP recordings in all patients. Intraoperative FN mapping and continuous monitoring were successfully performed in all cases. Two patients experienced complete cessation of FN CMAPs, which resumed upon loosening the tension on the myocutaneous flap held by fishhooks. One patient showed a 39% decrement in frontalis CMAP that did not recover. Despite these issues, all patients had intact FN function postoperatively and at follow-up. Our technique shows promise in mitigating FN injury during complex cranial reconstruction and cranioplasty revision surgery. Further research with a larger cohort is needed to confirm efficacy and statistical significance.

A novel theory for rapid localization of the transverse-sigmoid sinus junction and “keyhole” in the retrosigmoid keyhole approach: micro-anatomical study, technique nuances, and clinical application

To determine a rapid and accurate method for locating the keypoint and “keyhole” in the suboccipital retrosigmoid keyhole approach. (1) Twelve adult skull specimens were selected to locate the anatomical landmarks on the external surface of the skull.The line between the infraorbital margin and superior margin of the external acoustic meatus was named the baseline. A coordinate system was established using the baseline and its perpendicular line through the top point of diagastric groove.The perpendicular distance (x), and the horizontal distance (y) between the central point of the “keyhole” and the top point of the digastric groove in that coordinate system were measured. The method was applied to fresh cadaveric specimens and 53 clinical cases to evaluate its application value. (1) x and y were 14.20 ± 2.63 mm and 6.54 ± 1.83 mm, respectively (left) and 14.95 ± 2.53 mm and 6.65 ± 1.61 mm, respectively (right). There was no significant difference between the left and right sides of the skull (P > 0.05). (2) The operative area was satisfactorily exposed in the fresh cadaveric specimens, and no venous sinus injury was observed. (3) In clinical practice, drilling did not cause injury to venous sinuses, the mean diameter of the bone windows was 2.0–2.5 cm, the mean craniotomy time was 26.01 ± 3.46 min, and the transverse and sigmoid sinuses of 47 patients were well-exposed. We propose a “one point, two lines, and two distances” for “keyhole” localization theory, that is we use the baseline between the infraorbital margin and superior margin of the external acoustic meatus and the perpendicular line to the baseline through the top point of the digastric groove to establish a coordinate system. And the drilling point was 14.0 mm above and 6.5 mm behind the top point of the digastric groove in the coordinate system.

Surgical Correction of Orbital Hypertelorism With Absorbable Plate Instead of Frontal and Orbital Bar and Inverted U-Shaped Osteotomy.

The aim of the study is to investigate the effect and feasibility of using absorbable plate instead of frontal and orbital bar and inverted U-shaped osteotomy to correct the widening of orbital distance. The surgical effect and feasibility of using absorbable plate instead of frontal and orbital bridge plus inverted U-osteotomy for orbital widening syndrome in seven cases between January 2019 and February 2022 were retrospectively analyzed. First, the surgical procedure for orbital hypertelorism was inverted U-shaped orbital osteotomy, and a frontal bone flap was removed, exposing the superior orbital margin and the orbital circumference, and the orbital bone was directly cut off by inverted U-shaped osteotomy. The widened bone in the middle of the orbit was removed, and a long absorbable plate was used to replace the orbitofrontal bridge. The two sides of the orbit were fixed on the absorbable plate, and the absorbable plate was fixed on the rear skull. The clinical effect of treatment, complications (such as cerebrospinal fluid leakage and infection), safety, and feasibility of surgery were evaluated. Using absorbable plate instead of fronto-orbital bridge achieved the effect of orbitofrontal bridge, without orbital distance widening, cerebrospinal fluid leakage, and intracranial infection. Operating time was reduced. There was no metal fixation, and there was no risk of a second operation. The effect of replacing the frontal-orbital bridge with an absorbable plate and inverted U-shaped osteotomy is positive, the operation time is short, and the orbital distance is clearly improved. This approach can replace the traditional orbital-distance operation, and the incidence of postoperative cerebrospinal fluid leakage and infection is low. Long-term follow-up results are stable.

Dimension, Location and Clinical Importance of Supraorbital Foramen and Notch: A Combined Cadaveric and Dry Skull Study.

The exit points of the supraorbital nerve and its branches hold significant importance in various medical procedures, including supraorbital endoscopic surgeries, forehead-facial aesthetic plastic surgeries, medical aesthetic applications and maxillofacial surgeries. Therefore, the primary objective of the present study was to precisely define the dimension, location and clinical significance of the supraorbital foramen/notch. By doing so, we aimed to enhance our understanding of this anatomical structure and its implications for surgical and aesthetic interventions in the supraorbital region. For our study, we conducted anatomical dissections and bone measurements to assess the significance of anatomical variations of the supraorbital foramen/notch. We utilized a sample consisting of 28 cadavers and 38 skulls. The supraorbital foramen/notch was bilaterally analyzed in all 28 cadavers and 38 dry bones. We morphometrically analyzed the distance between the supraorbital foramen/notch and various anatomical landmarks, including the nasion, supraorbital margin, infraorbital margin, temporal crest, glabella, frontal cavity and midline of the face. Additionally, we measuredthe distance between the supraorbital foramen/notches and the frontal foramen/notches, and the width of the supraorbital foramen/notch and the distance between both supraorbital foramina/notches. There are 32 (57.14%) supraorbital foramina, and the remaining are 24 (42.86%) supraorbital notches in cadavers and there are 36 (47.37%) supraorbital foramina, and the remaining are 40 (52.63%) supraorbital notches in skulls. We observed consistency in the dimension and location values of anatomical measurement parameters between cadavers and dry skulls on both right and left sides, with the exception of the parameter "distance from temporal crest" (p=0.042). Furthermore, our correlation analysis revealed a significant positive relationship between the right and left sides across all parameters, except for the following instances: in dry skulls, "distance from supraorbital margin" and in cadaver parameters, "distance from temporal crest, " "distance from frontal cavity" and "width." In our study, we observed that the distributions of supraorbital foramina and notches were nearly similar. Furthermore, our findings indicated comparable measurements between the right and left sides in both cadavers and skulls. These results suggest a degree of consistency in supraorbital anatomy within our study sample, regardless of the specimen type (cadavers or skulls) or laterality (right or left side). This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Traumatic superior oblique tendon rupture with ptosis: A case report

The traumatic rupture of the superior oblique tendon with ptosis is extremely rare, and the surgical treatment is very challenging. We reported a case of a 41-year-old man with superior oblique tendon rupture and ptosis due to an iron hook injury. The ocular movement disorders were not obvious except for mild superior oblique underaction but were accompanied by severe extorsion. The distal stump of the superior oblique tendon was shortened and anchored to the periosteum of the supra-nasal orbital margin near the trochlea. Post-operative follow-up revealed the surgical outcome was better than expected, which resulted in significant improvement in binocularity and cosmetic outcomes without complication in the present case. The exploration of the levator palpebral superioris (LPS) in the early post-traumatic stage might not be necessary in circumstances without eyelid laceration. Shortening and anchoring of the ruptured superior tendon could restore almost normal binocularity, decrease the extorsion, and avoid acquired Brown syndrome.

Location of infraorbital and accessory infraorbital foramina in Iranian population: a retrospective radiological study with crucial clinical implications.

The location of infraorbital foramen (IOF) and the prevalence of accessory IOF vary among different populations. It may lead to infraorbital nerve (ION) blockage during surgery. This study aimed to assess the IOF location and AIOF frequency in Iranian people. In this retrospective cross-sectional study, 500 paranasal sinus computed tomography scans of adults were examined using the INFINITT PACS system. The distance from IOF to infraorbital margin (IOM), mid-pupillary line (MPL), midsagittal line (MSL), canine eminence (CE), and skin thickness (ST) was 8.97 ± 1.79, 5.73 ± 1.84, 24.86 ± 2.23, 20.39 ± 3.47, and 10.90 ± 2.59mm, respectively. The vertical and transverse diameters of the foramen were 3.03 ± 0.65 and 3.71 ± 0.76mm, respectively. In addition, the shape of 63.5% of the foramina was oval. The prevalence of AIOF was 9%, and its most common location was superomedial to IOF. We believe that in this study, landmarks like IOM, MPL, MSL, CE and ST could help the clinicians localize IOF and improve the ION anesthesia success rate. Furthermore, the occurrence of AIOF should be considered by physicians to reduce the chance of injuries to the infraorbital neurovascular complex.

The Use of E-Learning in Peyton's 4-Step Approach: Evaluation of Facial Computed Tomography Scans.

Imparting procedural skills is challenging. Peyton's approach is an effective face-to-face teaching technique increasingly used in complex skills training. Institutions are beginning to incorporate online training as part of their procedural curriculum. We developed E-Peyton's to employ Peyton's approach through an electronic learning platform. The efficacy of E-Peyton's approach in teaching the interpretation of facial computed tomography (CT) scans is evaluated in this study. Naïve learners (n=41) were randomized into 2 groups based on teaching techniques employed: E-Peyton's (n=20) and Peyton's (n=21) approaches. The distance between the infraorbital margin and the posterior ledge was measured using a 3-part standardized measuring protocol on OsiriX. Twenty measurements were assessed for accuracy against the benchmark (±2mm) at week 0 and week 1. Training durations were compared. Questionnaires were administered before and after the study to identify learners' acceptance of teaching techniques and their confidence in interpreting facial CT scans. Learners in both teaching techniques had comparable skills retention. Gap scores indicate significant improvement in learner's confidence levels regardless of teaching technique (P<0.05). Both teaching techniques were well-accepted by learners. E-Peyton's and Peyton's approaches required a similar training duration. The COVID-19 pandemic highlights the importance of effective remote learning platforms. E-Peyton's approach is comparable to that of Peyton's in all areas of assessment. E-Peyton's approach effectively automates Peyton's approach, allowing for standardized, high-quality procedural skills training while reducing manpower burden.

A new recumbirostran ‘microsaur’ from the lower Permian Bromacker locality, Thuringia, Germany, and its fossorial adaptations

Several recumbirostran ‘microsaurs’ are known from early Permian sites across Germany, including the Tambach Formation in Thuringia, central Germany. The only ‘microsaur’ thus far described from the Tambach Formation was the ostodolepid recumbirostran Tambaroter carrolli. However, there is also the documented presence of an undescribed recumbirostran ‘microsaur’ at the well-known Bromacker locality. The Bromacker locality is highly recognized and best known for its very diverse and extremely well-preserved terrestrial tetrapod assemblage combined with the co-occurrence of an exceptional vertebrate ichnofossil record. Here we describe a second new recumbirostran taxon from the Tambach Formation, which is also the first from the Bromacker locality itself. Phylogenetic analysis indicates that the new taxon, Bromerpeton subcolossus gen. et sp. nov., is a brachystelechid recumbirostran, a group also known elsewhere in Germany. The following features differentiate Bromerpeton from the other members of the clade: the presence of 13 maxillary teeth, narrow postorbitals that do not substantially contribute to the postorbital region of the skull, the frontal does not contribute to the orbital margin, and the presence of five manual digits. This new recumbirostran ‘microsaur’ further adds to the unique ecosystem that is preserved at the Bromacker locality, granting us a better understanding of what was living underfoot the larger more well-known animals at the locality. Likewise, it expands our understanding of the evolution of recumbirostran ‘microsaurs’, especially with regards to digit and limb reduction within the clade.

Management of Post Tumor Resection in Inferolateral Eyelid using Periosteal Flap and Canthoplasty Technique – A Case Report

Introduction : Eyelid defect repair goals are providing supportive connecting tissue and functional mucosal epithelium. Posterior lamellar reconstruction for tumor resection defect is still challenging. In this case, lower eyelid reconstruction can be accomplished by elevation and rotation of periosteal flap as posterior lamella.&#x0D; Case Illustration : A 68-years-old male came with inferolateral eyelid mass of Left Eye (LE) that was increasing in last 3 months. On LE examination found solitary cystic cutaneous lesion in inferior palpebra near lateral canthal, sized7x5mm, fixated, regular, and chewy consistency. Anterior of mass has same color as adjacent skin with hyperpigmentation lesion and posterior side was translucent with telangiectasia. He was suspected with LE ductal dd epidermoid cyst.&#x0D; Discussion : Periosteal flap and canthoplasty is procedure to repair inferolateral eyelid defect that are large to be closed primarily, however it requires adequate lateral canthal skin and tarsal plate. Posterior lamellais restored to create connective tissue framework, proper contour, and vertical canthal height. Tumor was removed and preperiosteal plan inferior to inferior orbital rim was dissected. The anterior lamella then transposed superiorly to make sure it will cover posterior lamellar reconstruction. Periosteal flap from lateral canthal tendon of infraorbital margin was harvested, flap was crossed to form sharp canthal angle and sutured to tarsal edges of lower eyelids as posterior lamella. A week later, LE showed natural contour and good function without eyelid malposition.&#x0D; Conclusion : Periosteal flap as posterior lamella reconstruction of eyelid defects is effective and efficient to repair eyelid defect due to its simplicity, reliability, and low risk complication.

Morphometry of the infraorbital foramen in dentate and edentulous adult humans and its clinical relevance

The infraorbital foramen (IOF) serves as an important anatomical reference for infraorbital nerve block during different procedures. Its clinical and surgical relevance, associated with conflicting results in its anatomy description justifies the present study. Thus, this work aims to describe the IOF, qualitatively and quantitatively, and propose an accurate measurement to define its location. One hundred and seventy-four IOFs of dry skulls were analyzed and divided in dentate (DE) and edentulous (ED) groups. Distances were measured between the IOF and the margin of the alveolar arch of the maxilla (MAAM), the inferior orbital margin (IOM), the intermaxillary suture (IMS), the vertical plane of IOF. A new methodology was proposed to optimize the identification of IOF based on the IMS distance. Oval-shaped IOFs (n=81/174) with inferomedial orientation (n=104/174) and with a crest-shaped upper margin (n=163/174) constituted the norm for this sample. Distance between IOF and MAAM was 29.97 ± 4.09 mm, to IOM 7.27 ± 1.8 mm, and to IMS 35.09 ± 3.77 mm. ED individuals had IOF closer to MAAM (p=0.0124). The highest point of this methodology was the lack of statistical differences in the IMS distance in ED and DE specimens, making this method applicable for both. Therefore, to minimize iatrogenic injuries, clinicians and surgeons must consider the total or partial presence of teeth, the methodology established to find the IOF, its inferomedial orientation, and the prevalent crest on its superior margin.

Correlation between Tomography Scan Findings and Clinical Presentation and Treatment Outcomes in Patients with Orbital Floor Fractures

Background: Orbital floor fractures involve damage to the orbital floor but not the infraorbital margin. Despite intensive research, they remain a controversial topic. The aim of this study was to investigate the relationship between parameters gathered by means of computed tomography (CT), the clinical presentation, and treatment outcomes, in patients suffering from orbital floor fractures. Methods: Forty patients with orbital floor fractures were included in this study. Information regarding diplopia, impaired ocular mobility, asymmetric eyeball placement, and infraorbital paresis was gathered from the medical records. Nine CT-based parameters were assessed. Two parameters were calculated, based on them. The follow-up data of 30 patients were analyzed. The results were statistically evaluated. The significance level was p &lt; 0.05. Results: Statistical evaluation revealed multiple correlations between CT-based findings, symptoms, and treatment results. Among others, the hernia into the maxillary sinus was significantly larger in patients without improvement in infraorbital paresis (p = 0.0031) and without improvement in assymetric eyeball placement (p = 0.0037). There was no correlation between the entrapment of the rectus inferior muscle and impaired ocular mobility (p = 0.664431; p = 0.420289) and between the direct fracture of the infraorbital canal and infraorbital paresis (p = 0.371102). Conclusions: The widely assumed thesis that impaired ocular mobility in orbital fractures is caused by entrapment of the rectus inferior muscle is disproved by CT-based data. CT-based findings, symptoms, and treatment results in patients with orbital floor fractures were significantly correlated. A large hernia may be a negative prognostic factor.

A case of impacted canine located on the infraorbital margin

A case of impacted canine located on the infraorbital margin

Cranial anatomy of Libognathus sheddi Small, 1997 (Parareptilia, Procolophonidae) from the Upper Triassic Dockum Group of West Texas, USA.

Libognathus sheddi, a leptopleuronine procolophonid from the Upper Triassic Cooper Canyon Formation, Dockum Group, West Texas, was based on an isolated left dentary and partial coronoid. New material referable to Libognathus sheddi, from the Cooper Canyon Formation, provides new information on the cranial anatomy. This new cranial material includes the antorbital portion of a skull, a left maxilla and premaxilla, quadratojugals, and dentaries, including intact tooth rows in the upper and lower jaws. Libognathus shows autapomorphies including; dentary deep with ventral margin oblique to tooth row immediately from the symphysis at ≥23°; anterior projecting coronoid contacting the lingual surface of the dentary underlying the last two dentary teeth; reduced contact between the lacrimal and the nasal; suborbital foramen formed by the maxilla and ectopterygoid, excluding the palatine; a posterior supralabial foramen shared by the maxilla and jugal; a Y-shaped antorbital pillar formed by the palatine, and massive orbitonasale and facial foramina (shared with unnamed southwest USA leptopleuronines). Phylogenetic analysis indicates that Libognathus is a highly derived leptopleuronine procolophonid, closely related to Hypsognathus fenneri and other southwest USA Revueltian leptopleuronines, which fall out as sister taxa to Hypsognathus, a relationship supported by a maxillary dentition restricted anterior to the orbital margin, a possibly synapomorphic orbitonasale septum in the form of an "antorbital pillar" created by the palatine, an anteroventral process of the jugal, and the presence of a small diastema between the first dentary tooth and the more posterior dentition. Libognathus exhibits a possible ankylosed protothecodont tooth implantation with frequent replacement, differing from some other proposed procolophonid implantation and replacement models. Chinle Formation and Dockum Group leptopleuronines are restricted to the Revueltian teilzone/holochronozone, making them possible Revueltian index taxa.

Clinical manifestations of nasoethmoid-central midface and lateral mid midface trauma: an analytical study

Background: Patients with facial trauma were analyzed to determine the clinical presentation of fractures of the naso-ethmoid, mid and lateral face. Methods: 61 patients in the trauma unit of Dayanand Medical College were prospectively analyzed during a period of two years (August 2013 to August 2015). Results: Road traffic accidents were the major cause of fractures (72.13%) followed by assaults (14.75%) and falls (8.19%). The age group commonly affected was 21-30 years (54.09%) followed by 31-40 years (13.11%). Facial fractures were more in males, the females being 5 times less at risk. Epistaxis, swelling, tenderness, nasal obstruction, external nasal deformity and crepitus were noted in almost all patients. Ecchymosis, telecanthus and CSF rhinorrhea were noted in 90.9%, 72.7%, and 18.18% respectively. 90% presented with circumorbital ecchymosis, facial edema and anterior open bite. Other symptoms were epistaxis (81%), infraorbital nerve anesthesia and surgical emphysema (47.6%) and lengthening of face (42.8%). The commonest presentation was circumorbital ecchymosis (95.5%), subconjuctival hemorrhage (85.7%), flattening of cheek and step deformity at the infraorbital margin (81%). Facial edema was seen in 76% and trismus in 42.9%. Conclusions: Common symptoms and signs of nasoethmoid fractures included epistaxis, swelling and tenderness, nasal obstruction, external nasal deformity and crepitus in all patients, circumorbital ecchymosis in 90% and telecanthus in 73%.

Use of Simple Skull Radiographs in Orbital Correlations in Nigeria

Introduction: Anthropometric measurements have been carried out in many studies to segregate people into races, ethnicity and various biological traits in the past. Such studies include cephalometry being deployed because of its significance in forensic and clinical evaluations of individuals. The objective of this study is to determine the correlation between the shape types of the orbit with different age groups and their prevalence using simple skull X-rays.&#x0D; Materials and Methods: Plain X-rays of the skull with posteroanterior exposures were obtained for a retrospective period of 5-year period from 2004 to 2009. The selected radiographs were those based on clear recognition of their orbital margins assessed by 2 experienced Radiologist who determined the shapes of the orbits as being oval, circular or quadrangular. Out of total of five hundred (500) plain X-rays of the skull obtained, only 255 satisfied the inclusion criteria.&#x0D; The data was analyzed statistically using INSTAT software to compare the mean values in relation to age distribution of the subjects with the Student’s T-Test. Chi-Square (with Yates correction) was used for the comparison of proportions.&#x0D; Results: In the first 30 years of postnatal life, the oval shape orbit had been found to be more predominant with values of 22(64.7%), 17(30.9%), and 27(38.0%) respectively. As from the age of 30 to 70 years, the circular type had values of 16(34.0%), 8(33.3%), and 8(61.5%) respectively in each of the decades. Between the age of 60 to 70 years, the oval and circular types had equal prevalences.&#x0D; Conclusions: In addition to the known oval and quadrangular (triangular) types of orbital shape, this study revealed a 3rd type of orbit which we described as circular in shaped. The oval type of orbit is found to be more common from birth to age of 30 years but from but from 40 to 70 years the circular type predominates.

Craniomandibular anatomy of a juvenile specimen of Edmontosaurus regalis Lambe, 1917 clarifies issues in ontogeny and biogeography

ABSTRACT Edmontosaurus regalis is a hadrosaurid represented by abundant fossil material from the late Campanian–early Maastrichtian of what is now Alberta, Canada. Despite its prevalence, juvenile craniomandibular elements of E. regalis are poorly known. A newly collected partial skeleton from the Horseshoe Canyon Formation, UALVP 60425, represents a small saurolophine with a partial skull (skull length ∼500 mm). It can be referred to Edmontosaurini based on the presence of a postorbital fossa and anteroposteriorly long frontals that lack a dorsally oriented nasal contact and contribute significantly to the orbital margin. Despite its small size and presumed immaturity, UALVP 60425 is assigned to E. regalis based on a horizontal shelf on the postorbital process of the jugal. The deep postorbital fossa that, in part, diagnoses E. regalis is acquired during growth. UALVP 60425 shares many features with the Alaskan Prince Creek saurolophine (Ugrunaaluk kuukpikensis); both show consistent anatomical differences in the lacrimal, jugal, and postorbitals from E. annectens throughout their growth series. New data from UALVP 6025 supports referring the Alaskan saurolophine material to Edmontosaurus cf. regalis in the absence of large-sized cranial material from the Prince Creek Formation.

New information on the Eocene frog Thaumastosaurus (Anura, Pyxicephalidae) from the Phosphorites du Quercy, France

Abstract We present new disarticulated cranial elements of the Eocene frog Thaumastosaurus from several localities in the Phosphorites du Quercy, France, providing novel information about the variation of its anatomical characteristics. With the use of micro-computed tomography (μCT) scanning technology, we examine and discuss various types of dermal cranial ornamentation in extant Pyxicephalus, the closest extant relative of Thaumastosaurus, in which these features are useful in species diagnoses, paying particular attention to the individual and ontogenetic variation, and sexual dimorphism, as well as interspecific variation among extant species. We suggest that various types of dermal cranial ornamentation in Thaumastosaurus could be potentially used in diagnoses at species level, although ontogenetic variation should be taken into consideration. Apart from ornamentation, the size and general morphology of the maxillae and squamosa in Thaumastosaurus reveal an unexpected disparity of morphotypes, which suggests the potential presence of cryptic taxa. Some squamosa reveal that their processus zygomaticus extended up to the postnasal wall, so their associated maxillae were excluded from the orbital margin, whereas others were short and their respective maxillae participated in the formation of the orbital margin. Thaumastosaurus is envisaged as the product of an Early Palaeogene direct, potentially overseas, dispersal from isolated Afro-Arabia to Europe.