Medicine and Health Sciences Commons^™

Variant Anatomy Of The Buccal Nerve., Mayank Patel, Joe Iwanaga, Shogo Kikuta, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Knowledge of the anatomy and variations of the nerves of the oral cavity is important to surgeons who operate this region. Herein, we report a rare case of a buccal nerve with two distinct roots. The anatomy of this case and its clinical applications is discussed.

Bilateral Sternocleidomastoid Variant With Six Distinct Insertions Along The Superior Nuchal Line., Graham Dupont, Joe Iwanaga, Juan J Altafulla, Stefan Lachkar, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Anatomical variations of the sternocleidomastoid muscle (SCM) have been observed to occupy multiple origins and insertion points and have supernumerary heads, sometimes varying in thickness. During routine dissection, a SCM was observed to have six distinct insertions that interface with the course of the superior nuchal line, ending at the midline, bilaterally. This variation was also seen to receive innervation from the accessory nerve as well as the great auricular nerve. To our knowledge, this variant of supernumerary insertions and nerve innervations has not yet been reported. These variants may pose as problematic during surgical approaches to the upper neck …

Henle's Ligament: A Comprehensive Review Of Its Anatomy And Terminology Over Almost One And A Half Centuries., Raja Gnanadev, Joe Iwanaga, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

Henle's ligament was first described by German physician and anatomist, Friedrich Henle, in 1871. This review article will cover Henle's original description of the ligament, historical changes in terminology, embryological studies of the ligament, and the clinical significance of Henle's ligament. This article has a particular focus on the variation in the terminology of this structure and the implications of this.

Bilateral Displacement Of The Common Carotid Arteries By A Large Goiter., Lexian J Mcbain, Joe Iwanaga, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

Large goiters are less common in the developing world due to the use of iodized salt. However, these are seen occasionally. Herein, we report a case of very large goiter identified in a cadaver. This case is also of interest due to the significant lateral displacement of the common carotid arteries (CCA) and the midline shift of the trachea. This case and the salient literature addressing this topic have been discussed.

Variations Of The Transverse Sinus: Review With An Unusual Case Report., Chrissie Massrey, Juan J Altafulla, Joe Iwanaga, Zachary Litvack, Basem Ishak, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

The dural venous sinuses are venous channels in the cranium that drain blood and cerebrospinal fluid circulating from the brain into the vascular system via the internal jugular veins. The transverse sinus is a dural venous sinus present in the posterior aspect of the cranium. We report an unusual variant of this sinus with the presence of a fenestration at its proximal segment. We will review and discuss the background and the potential clinical relevance of this anatomical variation.

Bifid Xiphoid Process: Case Report And Review., Seif Eid, Joe Iwanaga, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

The xiphoid process is a bony process that comprises part of the sternum. This anatomical structure exhibits several morphological variations, which may complicate diagnostic examinations and invasive thoracic procedures. Variations include bifurcated or trifurcated, deflected, and curved processes. This report discusses a case of a bifid xiphoid process during cadaveric dissection and compares similar findings in the literature. The aim is to improve our knowledge of anatomical variations in an effort to reduce complications and improve patient care.

Anatomical Study Of The Lingual Nerve And Inferior Alveolar Nerve In The Pterygomandibular Space: Complications Of The Inferior Alveolar Nerve Block., Joe Iwanaga, Paul J Choi, Marc Vetter, Mayank Patel, Shogo Kikuta, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The inferior alveolar nerve block (IANB) procedure delivers anesthetics to the pterygomandibular space through which the lingual nerve (LN) and inferior alveolar nerve (IAN) travel. Injury to the LN has been reported more often than injury to the IAN. However, the number of anatomical studies of LN injury is limited. We aimed to establish evidence by investigating LN and IAN anatomy at the level of the mandibular foramen (MF). Forty-four sides from 22 Caucasian cadaveric heads (16 fresh-frozen and six formalin-fixed cadavers) were used in this study. The LN and IAN were laterally dissected, and the diameter and the distance …

Tendinous Inscriptions Of The Rectus Abdominis: A Comprehensive Review., Rabjot Rai, Lilian C Azih, Joe Iwanaga, Marios Loukas, Martin Mortazavi, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The rectus abdominis muscles are interrupted by tendinous inscriptions, which typically appear as fibrous bands crossing the muscle. The current literature on tendinous inscriptions is scarce; hence, this review will provide a detailed overview of their anatomical description, including their variation, embryology, comparative anatomy, and clinical application. Understanding the anatomy and function of the tendinous inscription assists in providing clinical relevance and in guiding reconstructive surgeons in their surgical planning and design.

Radial Artery Injury With Attempted Intravenous Catheterization On The Dorsal Hand: A Case Report., Yusuf Alimi, Joe Iwanaga, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

Intravenous (IV) access on the dorsum of the hand is of high clinical significance. As it is possible for an arterial injury during IV access on the dorsum of the hand to occur, clinicians and healthcare providers should be cognizant of regional anatomy and anatomical variations during IV placement so as to prevent injuries to the radial artery. We report a case of an injury to the radial artery with an attempted hand IV placement in a cadaver and suggest possible ways to prevent this complication.

Superior Cerebellar Arteries Originating From The Posterior Cerebral Arteries But Normal Course Of The Oculomotor Nerves., Dominic Dalip, Joe Iwanaga, Marios Loukas, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The posterior cerebral artery (PCA) is a branch of the terminal part of the basilar artery and perfuses the temporal lobes, midbrain, thalamus, and the posterior inferior portion of the parietal lobes. It is divided into P1-P4 segments. Variations in the P1 segment of the PCA are important to neurosurgeons when performing surgery, for example, on basilar tip aneurysms. We report bilateral superior cerebellar artery (SCA) arising from the P1 segment of the PCA. Such a configuration appears to be uncommon but should be kept in mind by neurosurgeons, neurointerventionalists, and neuroradiologists.

Duplication Of The Alar Ligaments: A Case Report., Asad Rizvi, Joe Iwanaga, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

The alar ligament is one of the two strongest ligaments stabilizing the craniocervical junction. The literature describes many variations of the attachment, insertion, shape, and orientation of the alar ligament and an understanding of these variations is vital as they can lead to altered biomechanics or misinterpretation on imaging. Herein, we report, to our knowledge, the first case of duplication of the alar ligaments and discuss the anatomical variations present in the literature.

A Variant Of The Sciatic Nerve And Its Clinical Implications., Graham Dupont, Florence Unno, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Variants of gluteal neural anatomy are important to consider, especially during surgical approaches to the hip. During the routine dissection of the gluteal region, a variant of the sciatic nerve was found where the nerve left the pelvis fully split into its tibial and common fibular components. Intrapelvically and extrapelvically, there was no splitting of the two components by the piriformis muscle. Distally, the two parts of the nerve were draped over the medial and lateral edges of the ischial tuberosity. To avoid iatrogenic injury to the sciatic nerve during invasive or surgical approaches to this region, all possible anatomical …

Pelvic Kidney: A Review Of The Literature., Seif Eid, Joe Iwanaga, Marios Loukas, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Kidney development is a complex process that begins during the sixth to eighth weeks of life. Failure of ascent of the kidney will cause the kidney to remain in the pelvis i.e., pelvic kidney. Here, we review this entity in detail and illustrate such embryological derailment. In most cases, a pelvic kidney is an incidental finding and is usually asymptomatic. Anatomic variations of the renal vasculature have been reported in cases of pelvic kidneys and these are highlighted in this review. Clinicians who treat patients for renal or pelvic disease or interpret images of the pelvis should be well informed …

A Comprehensive Review Of The Fabella Bone., Dominic Dalip, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The fabella is a sesamoid bone that is embedded in the lateral head of the gastrocnemius muscle and often articulates directly with the lateral femoral condyle. It is present in 10-30% of the general population with a higher incidence in Asians. The fabella can lead to various pathologies such as fabella pain syndrome and common fibular nerve palsy. Conservative treatment involves physical therapy or injecting local anesthetics or steroids around this bone. However, if symptoms persist, then a fabellectomy can be performed. Physicians should be aware of the fabella bone and the multiple pathologies associated with it in order to …

Variant Distal Ulnar Nerve Loop: A Previously Undescribed Anatomical Finding., Mayank Patel, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

A previously undescribed variant ulnar nerve loop was discovered during the routine anatomic forearm and hand dissection of an adult female. The major finding was that of a large loop traveling around the distal tendon of the flexor carpi ulnaris. The variation presented here appears to be unique. The exact function of such derailed anatomy is not clear but, if found during surgery, might confound normal dissection methods or, when present, could result in varied clinical presentations regarding the sensory or motor examination of the hand.

Fenestration Of The Proximal Left Ovarian Vein., Mayank Patel, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

A fenestration in the left ovarian vein was found in a fresh-frozen female cadaver. The opening did not have any vessels or additional anatomical structures passing through it. The ovarian vein is also referred to as the female gonadal vein. This type of anatomical variation is clinically relevant in procedures that deal with the manipulation of the gonadal veins, specifically conditions such as ovarian vein thrombosis, ovarian vein stenosis, and pelvic congestion syndrome.

Injury Of The Radial Nerve In The Arm: A Review., Taroob J Latef, Muhammad Bilal, Marc Vetter, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Compression of the radial nerve is most commonly described at the supinator muscle (i.e., arcade of Frohse). However, radial nerve compression can occur in the arm. Therefore, the purpose of this article is to review both etiologies of radial nerve entrapment and the sites at which this can occur in the arm. The clinical presentation of radial nerve entrapment in the arm and how it differs from that of entrapment at other sites is reviewed and the conditions potentially predisposing to nerve entrapment are described. Particular attention is paid to the nerve's course and potential variants of the anatomical structures …

Anatomical Study Of The Extreme Lateral Transpsoas Lumbar Interbody Fusion With Application To Minimizing Injury To The Kidney., Joe Iwanaga, Emre Yilmaz, Tamir Tawfik, Amir Abdul-Jabbar, Marc Vetter, Marc Moisi, Koichi Watanabe, Koh-Ichi Yamaki, R Shane Tubbs, Rod J Oskouian

Articles, Abstracts, and Reports

Objective Since the extreme lateral lumbar interbody fusion procedure was first reported by Ozgur in 2006, a large number of clinical studies have been published. Anatomical studies which explore methods to avoid visceral structures, such as the kidney, with this approach have not been examined in detail. We dissected the retroperitoneal space to analyze how the extreme lateral transpsoas approach to the lumbar spine could damage the kidney and related structures. Methods Eight sides from four fresh Caucasian cadavers were used for this study. The latissimus dorsi muscle and the thoracolumbar fascia were dissected to open the retroperitoneum. The fat …

A Comprehensive Review Of Medical Imaging Equipment Used In Cadaveric Studies., Emily Simonds, Charlotte Wilson, Joe Iwanaga, Tyler Laws, Gary Holley, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Medical imaging techniques have led to great advances in clinical anatomy and forensic pathology. New and emerging technologies allow healthcare professionals to view and understand the human body from different perspectives. This gives way to new and improved interventions, treatment plans, and an overall understanding of the human body. Herein, we present a comprehensive review of the various medical imaging equipment used in cadaveric studies along with their individual strengths and limitations.

Piercing Of The Lumbocostal Ligament By The Subcostal Nerve: A Previously Unreported Case., Marc Vetter, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

As lateral approaches gain popularity in lumbar spine surgery, detailed discussions regarding anatomical variations in the innervation of the thoracolumbar region are of increasing importance. Damage to intercostal or subcostal nerves can lead to post-operative complications including regional loss of sensitivity, motor function, or abdominal wall hernias. More specifically, the subcostal nerve has been identified in the literature as one of the more vulnerable structures during such procedures. A clear understanding of the position of the subcostal nerve relative to nearby anatomical structures is therefore important for medical professionals. We herein report a rare anatomical variation in which the subcostal …

Hematoma In The Bucco-Mandibular Space: First Case Report., Joe Iwanaga, Charlotte Wilson, Emre Yilmaz, Cameron K Schmidt, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Our previous studies based on intraoral dissection of fresh cadavers revealed that the fissure and loose connective tissues deep to the mucosa between the incisivus labii inferioris muscle and buccinator muscle form the entrance of the newly discovered bucco-mandibular space. To support the clinical significance of this space, we report the finding of a hematoma within this space in an adult fresh cadaver. Such a finding lends credence to studying the bucco-mandibular space and might help better understand the spread of some infections in the oral region.

Cadaveric Study For Intraoral Needle Access To The Infratemporal Fossa: Application To Posterior Superior Alveolar Nerve Block Technique., Joe Iwanaga, Emily Simonds, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The posterior superior alveolar (PSA) nerve block is, from an anatomical perspective, challenging because the mandibular ramus and the zygomatic process of the maxilla can interfere with the course of the needle. Dentists empirically know that shifting the patient's mandible to the ipsilateral side can improve visibility and accessibility for such blocks. This cadaveric study aimed to establish anatomical evidence for the ipsilateral mandible shifting used in the PSA. The distance between the lateral most bulging point of the alveolar part of the maxilla and ipsilateral anterior border of the ramus of the mandible ranged from 1.4 to 6.9 mm …

Variant Prevertebral Muscle: Unique Cadaveric Findings., Jocelyn R Gonzales, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The levator scapulae muscle typically runs from the transverse process of the atlas to the superior angle of the scapula. In this paper, we describe a rare finding identified during a dissection of a male cadaver, wherein a continuation of the right levator scapulae ran past its normal attachment to the C1 transverse process, fusing with the inferior attachment of the rectus capitis lateralis muscle. No variants were found on the opposite side, and the innervation of the levator scapulae muscle variant was typical of that of a normal levator scapulae. We also describe other related variants of the cranial …

Clinical Anatomy Of The Frenulum Of The Oral Vestibule., Joe Iwanaga, Naoshi Takeuchi, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Introduction The frenula of the oral vestibule include the labial and buccal frenula. Abnormal labial and buccal frenula can affect facial esthetics and oral cavity function by retracting the gingival margin, creating a median diastema, and limiting lip movement. Because of the lack of information on these structures, we aimed to clarify their anatomy. Methods A total of 34 sides from 17 fresh frozen cadaveric Caucasian heads were used in the present study. The specimens were derived from 11 male and 6 female adult cadavers. The relationships between the frenulum of the mucosa and the tissue underneath the mucosa was …

Hiding Within The Cracks: Case Report Of Rare Sutural Bone Found At The Nasion., Bryan Edwards, Joy Mh Wang, Joe Iwanaga, Jennifer Luviano, Marios Loukas, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Pathology such as skull fractures can be misdiagnosed in the presence of anatomical variations. One variant that has had little description in the literature are the sutural bones associated with the nasal bones. Herein, we describe a case of a rare sutural bone at the nasion, between the bones of the right nasal, frontal, and maxillary frontal process. To our knowledge, this is the first report of such a variant bone in this location, and such it should be considered by clinicians when evaluating patients for pathology in this region.

The First Histological Analysis Of The Tissues Lining The Fossa Navicularis: Insights To Its Etiology., Sarvenaz Sheikh, Joe Iwanaga, Steven Rostad, Tarush Rustagi, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

The fossa navicularis (FN) is an anatomical variant on the ventral surface of the basilar part of the occipital bone that, to date, has only been investigated in bone specimens. We aim to clarify the structure of the fossa navicularis by gross anatomical, radiological, and histological methods. The FN was found in the occipital bone of the Caucasian male cadaver. There was no bony or histological continuity between the FN and posterior cranial fossa. The histological analysis found that the overlying tissue was composed of loose connective tissue with a mixture of collagen and elastic fibers and a vascular matrix …

Internal Hernia Of The Greater Omentum: Cadaveric Findings Of A Previously Unreported Variant., Andrea Andrea, Vy Tran, Cameron K Schmidt, Christian Fisahn, Joe Iwanaga, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

Transomental hernias (TOHs) are a rare finding, constituting a fraction of all intestinal hernias. Here, we report the cadaveric discovery of a spontaneous TOH involving the sigmoid colon in an 82-year-old female and discuss the relevant literature. To our knowledge, a TOH involving the sigmoid colon has not been previously reported.

Undetected Small Accessory Mental Foramina Using Cone-Beam Computed Tomography., Joe Iwanaga, Koichi Watanabe, Tsuyoshi Saga, Shogo Kikuta, Yoko Tabira, Sadaharu Kitashima, Christian Fisahn, Fernando Alonso, R Shane Tubbs, Jingo Kusukawa, Koh-Ichi Yamaki

Articles, Abstracts, and Reports

INTRODUCTION: The accessory foramina could not be identified on some imaging modalities such as surface-rendered images. The purpose of this study was to investigate the ability of surface-rendered images in detecting these foramina.

MATERIALS AND METHODS: We analyzed 20 accessory mental foramina (AMF) in nine mandibles removed from cadavers with cone-beam computed tomography (CBCT) and assessed in surface-rendered images. All AMF were divided into three groups depending on their visibility.

RESULTS: Group 1 included AMF that were clearly visible as foramina, Group 2 were not clearly visible but could be recognized with concave parts, and Group 3 were not visible …

Relationship Of The Median And Radial Nerves At The Elbow: Application To Avoiding Injury During Venipuncture Or Other Invasive Procedures Of The Cubital Fossa., Vlad Voin, Joe Iwanaga, Juan P Sardi, Christian Fisahn, Marios Loukas, Rod J Oskouian, R Shane Tubbs

Articles, Abstracts, and Reports

INTRODUCTION: The median and radial nerves are two important neural structures found in the cubital fossa. The trajectory and landmarks used to identify their location are important when procedures are done in this area.

METHODS AND MATERIALS: Ten fresh-frozen cadavers were dissected (20 upper limbs) and measurements were taken from the medial epicondyle to the median and radial nerves as well as to the lateral epicondyle of each limb.

RESULTS: The distance between the medial epicondyle and the median nerve was found to be three centimeters with a range of 2.1 to four centimeters and the distance from the medial …

Giant Arachnoid Granulation Associated With Anomalous Draining Vein: A Case Report., Randle Umeh, Rod J Oskouian, Marios Loukas, R Shane Tubbs

Articles, Abstracts, and Reports

Giant arachnoid granulations (AG) can mimic intracranial lesions. Knowledge of these structures can help avoid misdiagnosis when interpreting imaging. Here, we report a child who presented with a mass within the superior sagittal sinus and an anomalous draining vein. Herein, the diagnosis of a giant AG was made. Clinicians who view or interpret imaging of the head should be aware of these anatomical variants and though when very large, apparently, do not necessarily result in pathology. Based on our case report, giant AG might also demonstrate anomalous draining veins.