Unusual array of neural communications in the infratemporal fossa: Useful for skull base surgery.

Variations in the branching pattern of the mandibular nerve frequently accounts for failure to obtain adequate local anesthesia in routine oral and dental procedures, and also for unexpected injury to the nerves during surgery. The knowledge of the neurovascular relationships of the infratemporal region is relevant in odontostomatology practice. In this article we present a rare case of atypical communication between the inferior alveolar nerve and lingual nerve and the mylohyoid and lingual nerves. Further, the clinical implications of these communications on the development of the supplementary innervation and their possible role in anesthesia is discussed in detail. The communication between mylohyoid and lingual nerve was found in this case near the submandibular ganglion after the lingual nerve passes in close relation to third molar tooth, which makes it more susceptible to injury during third molar extractions. The communicating branch between the mylohyoid nerve and lingual nerve may also innervate the tongue, and surgeons should be aware of this variation to avoid post- operative complcations after oral surgeries. Thus the precise anatomy of structures of infratemporal region and its variations may prove beneficial to clinicians, especially to oral and maxillofacial surgeons.

Bilateral clavicular attachment of omohyoid muscle.

Omohyoid muscle present in cervical region is of particular importance to anatomists as it defines anteriorly the carotid triangle and divides the posterior cervical triangle. It has superior and inferior bellies and an intermediate common tendon. Like sternohyoid, sternothyroid and thyrohyoid muscles, omohyoid is also an infrahyoid muscle, but it differs from them in its course. The infrahyoid muscles are formed from a muscle primordium occurring in the anterior cervical area. Anderson (Anderson, 1881) theorized that the superior belly of the omohyoid muscle is a true infrahyoid muscle, whereas the inferior belly most likely shares a common embryology with the subclavius muscle. In the present study, during routine dissection in the neck region of an adult male cadaver of 50 years age, an anomalous origin of inferior belly of omohyoid with absence of intermediate tendon was observed bilaterally. It was arising from clavicle on both sides. Both the muscle bellies were measured from the lateral end of fascial sling. The inferior belly of omohyoid extending from the lateral margin of sling to clavicular surface was measured 3.3cm in length on left side and 3.6cm on right side. The omohyoid is important in neck dissections because it is considered as an ideal landmark for level III and IV lymph node metastases. Knowledge of variations of this muscle is very important for surgeries in neck region because of its close relation to the internal jugular vein and brachial plexus. Its crucial relationship to vascular structures in the neck makes it an important landmark during neck surgeries.

Pronator teres accessorius: A new variant in flexor antebrachial musculature.

Muscles of flexor compartment of forearm have a common origin from medial epicondyle of humerus. Additional bellies of flexor muscles are commonly reported but presence of supernumerary muscles is an infrequent phenomenon. The present study describes an unusual muscle mass in flexor compartment of forearm simulating pronator teres. During routine dissection the upper limb of a 50 years old male cadaver, a supernumerary muscle was found on left side of the upper limb in the flexor compartment. The origin of the muscle was 2cm wide and aponeurotic in nature and attached to an oblique line extending from the inferior surface of the medial epicondyle and the medial surface of the trochlea. It was inserted on an oblique line 2.5cm wide on the radius in area between supinator superiorly and flexor digitorum profundus inferiorly. Existence of accessory muscles, which connect flexor muscles, could be explained embryologically by incomplete cleavage of flexor mass during development. The flexor muscles of the forearm develop from the flexor mass which subsequently divides into two layers: superficial and deep. The deep layer gives rise to flexor digitorum superficialis, flexor digitorum profundus and flexor pollicis longus. These supernumerary muscles are extremely rare entities and probably represent deranged embryological development or the process of atavism in which the anomalous part persist for a longer time in the tree of evolution.

Adductor accessorius - an unusual supernumerary adductor muscle of thigh.

The knowledge of variant anatomy of medial compartment of thigh is extremely important in surgical procedures requiring obturator nerve block. The nerve block is also recommended for providing additional analgesia following major knee surgeries and for relieving painful adductor muscle spasm. The interfascial injection technique is commonly followed in ultrasound guided obturator nerve block. For this procedure it is imperative to identify the adductor muscles on sonography to inject the anesthetic solution in the intermuscular fascial planes. The presence of an additional muscle can prove useful in myocutaneous flap surgeries for reconstruction especially of perineum. We hereby report a case of such an anomalous supernumerary adductor muscle present between adductor brevis and proximal part of adductor magnus, in an adult Indian male cadaver, recorded during routine dissection in Department of Anatomy, Vardhman Mahavir Medical College and Safdarjung Hospital. The muscle was innervated by the posterior division of obturator nerve. The morphology, embryological basis and clinical aspects are also discussed.

Rare atypical vascular pattern of subscapular artery: Anatomico-clinical insight.

BACKGROUND AND OBJECTIVE: The use of muscles of scapular region in transposition and reparative surgery has made the anatomical knowledge of axillary artery and its branches imperative. The subscapular arterial tree is frequently used as a source of microvascular grafts to replace damaged or diseased portion of arteries especially in upper and lower limbs. This investigation is aimed to study the variation in branching pattern of the third part of axillary artery. MATERIALS AND METHODS: Routine educational cadaveric dissection of a young adult Indian male cadaver. RESULTS: The present article highlights a rare variation of the subscapular artery and its branches. The subscapular artery displayed a unique pattern of trifurcation. Its branches were seen supplying serratus anterior, subscapularis, latissimus dorsi and teres major muscles. CONCLUSIONS: The study focuses on a new variation of the subscapular artery which could prove useful for interventional radiologists and surgeons in reconstructive surgeries.

Unusual branching pattern of brachial artery - Embryological basis and clinicoanatomical insight.

Variations in the arterial pattern of upper limb are of colossal importance to the surgeons as they are liable to iatrogenic injuries. During routine dissection for undergraduate medical students, an anomaly of brachial artery was discovered. The brachial artery terminated at higher level into ulnar and radial artery. The common interosseus artery took origin arising from radial artery. The ulnar artery did not give any branches in the forearm. Both radial and ulnar artery displayed a superficial course in the forearm. The anatomical knowledge of these variations may be of great help for the clinicians in planning and conducting flap harvesting during reconstructive surgeries and in arteriography.

A rare conglomeration of neurovascular variations in the brachium-antebrachium: clinico-embryological elucidation.

During routine dissection in left upper limb in an elderly male cadaver, variations in the arterial and neural pattern were noticed. The undersized brachial artery divided terminally into radial and ulnar artery at a distance of 15.4 cm from the tip of coracoid process, proximal to its usual division in cubital fossa. Additionally, the superior and inferior ulnar collateral artery instead of arising from the brachial artery, emanated from ulnar artery. The course of the median nerve also deserves a brief mention as it crossed the brachial artery from medial to lateral side to position itself laterally in the midbrachium. Coursing further, it shifted from lateral to medial side over the ulnar artery in the distal third of arm, thus placing itself medial to ulnar artery in the cubital fossa. There was also a communication between a medial offshoot of the musculocutaneous nerve and the median nerve 3 cm from the bifurcation of the brachial artery. Although the variations in the origin, termination, course and branching pattern of upper limb vessels and nerves are well documented, but the multitude of disparity in morphology with confusing neurovascular assembly put together in the same limb denotes an outstanding case. An attempt has been made to correlate the present anatomical variations with embryological aspects. Moreover, the clinical inferences of such variations are discussed for planning, performing and analyzing invasive and noninvasive clinical procedures in this region.

Unilateral atypical disposition of femoral vessels: clinico- embryological annotations.

The boundaries and contents of femoral triangle constitute an important lesson in gross anatomy teaching to undergraduate medical students. Apart from this, the normal disposition of the femoral vessels in the femoral triangle is vital for planning certain operating maneuvers in this region. Femoral vessels are very frequently utilized, during various surgical and clinical procedures. Thus, the precise knowledge of the normal anatomy as well as the variations in the femoral vessels is important for surgeons and anatomists. We report a unilateral variation in the disposition of femoral vessels in the femoral triangle, in a 42 yr old male formalin- preserved cadaver. The femoral artery traversed anterior to femoral vein to occupy a medial position in close proximity to the Sapheno-femoral junction. The embryological and clinical implications of the observed variation are discussed.

An unusual array of extensor musculature and tendons of the hand clinico-anatomical insight.

Extensor tendon injury is a frequent finding in clinical practice. During a routine dissection class of undergraduate medical students examining the extensor aspect of the right hand, they found an interesting pattern of extensor tendons. The extensor digitorum (ED) exhibited three tendons for the middle and ring fingers. The intermediate tendon of the ED was found to pass to the junctura connecting the tendons of the ring and middle fingers. Additionally the Extensor carpi ulnaris displayed two tendinus slips. The lateral slip was inserted on the base of fifth metacarpal as usual, whereas the medial slip divided into two strands- proximal and distal. Apart from the above findings in the current case specimen, there was an accessory muscle belly for the index finger and the extensor digiti minimi bifurcated into two tendinus slips which gained attachment to the dorsal digital expansion of the little finger. These accessory muscle bellies and tendons could possibly be utilized for tendon reconstructions such as repairs, tenoplasties or tendon transfers.

Multifaceted profile of an unusual paramedian occipital condyle-anatomical and computerised tomographic evaluation.

During extensive osteological study of 150 dry skulls in the Department of Anatomy, Vardhman Mahavir Medical college, an unusual Paramedian Occipital (POC) condyle was detected in the occipital bone of a cadaveric skull. The anatomical details of this unusual occipital condyle were carefully studied and its morphometric measurements taken. A coronal multiplanner reformatted image and a volume rendered image were taken to study radiological details and establish significant clinical correlation. Precise understanding of anatomy of craniovertebral junction and its anomalies have become immensely important for the present day surgeon during orthopaedic and neurosurgical procedures of this region . Technical advancements in imaging modalities such as CT and MRI scans further signify the importance of these anatomical variations ,which are often missed in routine examination. Osteological study combined with radiological details of the paramedian occipital condyle in the present case aims to emphasize the importance of bony anomalies in the craniovertebral region and their role in diagnosis and appropriate treatment of neurovascular compression syndromes of craniovertebral junction. The present study highlights anatomical details, clinical relevance and embryological basis of such a rare unusual paramedian occipital condyle.

Retroaortic left renal vein associated with unilateral superior renal polar artery: a clinico-embryological perspective.

The aim of the current study is to report an unusual occurrence of a retroaortic left renal vein in an adult male cadaver of Caucasian origin. This unusual variant was discovered during the course of preclinical educational training programme for undergraduate medical students. The vascular anomaly was dissected and the surrounding adnexa carefully studied for associated variations. Subsequently, morphometry was performed on the specimen to measure certain important parameters. The left renal vein was found to emerge from lower part of renal hilum and traversed posterior to abdominal aorta and finally terminated into Inferior vena cava. Additionally, the left renal artery was higher in position and originated from the abdominal aorta at the level of upper border of body of Ist lumbar vertebra. This type of anomaly is very important as it may be associated with varicocoele. Furthermore, in preoperative planning for nephrectomy, partial nephrectomy and living donor nephrectomy, the surgeons should keep in mind the possibility of this vascular anomaly. It is also stated that left renal vein appears to be at the centre of a huge venous network which makes the nephrectomy hazardous and permits the spread of infectious material and neoplasms.

Intrathoracic intrusion of left lobe of thyroid gland co-existent with absent isthmus: clinico-anatomical considerations.

BACKGROUND: Morphological alterations of thyroid gland are common and result because of disturbed embryogenesis. These may vary from hypoplasia, ectopy to hemiagenesis and genesis of the gland. The authors strive to report an unusual morphological alteration of the left lobe of the thyroid gland. The current study presents a case of unusual extension of the thyroid gland discovered incidentally while dissecting the anterior cervical region of an adult Indian male cadaver. The left lobe displayed medial extension from its inferior angle which overlapped the common carotid artery (CCA). The isthmus was absent; instead a fibrous strand was interposed in between the two lobes with ramification into both the lobes. The relevance of diagnosing such extensions of thyroid gland is immense. It may alter the topographical relationship of thyroid gland with other adjacent cervical structures. Further, it may present abnormal signals upon scintillation scans and may be confused with a tumor mass on MRI scans. Lastly, the presence of lobar extension along with absence of isthmus is a gross morphological variant and in our opinion not to be overlooked by anatomists, ultrasonologists as well as thyroid surgeons. Additionally, the study presents possible embryological explanation for these gross anatomical variations.

Unusual architecture of extensor digitorum muscle of hand in conjunction with accessory belly of extensor carpi radialis brevis: a clinico-anatomical insight.

The present article highlights an unusual combination of variations of the extensor digitorum and extensor carpi radialis brevis muscles in the dorsum of forearm and hand. The extensor carpi radialis brevis exhibited an accessory musculotendinous belly which inserted into the dorsal digital expansion of index finger. The extensor digitorum showed trifurcation into three distinct parts. Resultant multiple extensor tendon insertion pattern is reported upon highlighting the embryological basis and clinical importance. Knowledge of such anatomical variations adds upon the already existing information in literature and is also of profound interest to the clinician. Anatomical awareness of accessory multiple extensor tendons in the dorsum of hand is essential for successful management of extensor tendon injuries and graft transfer operations.

Unusual variation of plantaris muscle-clinical and surgical notes.

Plantar muscle is one of the most dis-regarded muscles of the body. However, its injury may be considered in differential diagnosis of painful calf. Variations pertaining to plantaris muscle are rare and therefore infrequently reported in anatomical literature. The present case report endeavors to describe a rare variation of the plantaris muscle. A routine dissection experiment revealed an accessory belly associated with plantaris and a fibrous strand extending from medial belly to the oblique popliteal ligament. Since plantaris is known to be associated with lateral head of gastrocnemius, this accessory belly may be thought of as a supplement for its activity. A clinical insight into the topographical relationship between these accessory bellies and other posterior knee structures will aid diagnosis and alter course of treatment of knee disorders. Moreover, the presence of these muscle variants creates challenges for the radiologists while interpreting MRI/ CT scans. Familiarization with these anatomical anomalies may alert the knee surgeons intraoperatively so that these may be of use for reconstructive purposes.

Clinico-embryological submission of an unilateral anomalous presentation of axillary artery.

OBJECTIVES: Descriptions of the variant arterial pattern of upper limb are not exceptional and are therefore frequently reported in anatomy archives. BACKGROUND: A noteworthy deviation from the usual branching pattern was observed unilaterally in a single cadaver. This unique division of axillary artery (AA) was present on the right side in an adult human cadaver of Indian origin. RESULTS: The first part of axillary artery gave off the superior thoracic and thoraco-acromial arteries. Just proximal to the upper border of pectoralis minor the AA was observed to divide into two trunks a medial and a lateral. The lateral trunk continued into the brachium as the usual axillary artery where as the medial trunk displayed the other branches deep and distal to the pectoralis minor muscle. The remarkable feature was the wide caliber of the axillary artery where it bifurcated into two branches. An attempt has been made to dwell upon the embryological basis of the present anomaly. CONCLUSIONS: The relevance of anomalous arterial pattern of upper limb (U.L.) is realized while performing percutaneous arterial venous catheter insertion into subclavian vein via the infraclavicular route. We advocate a meticulous familiarization of the anatomy of axillary artery and its topographical relationship to other neurovascular structures for the operating plastic surgeon, anesthetist and radiologist (Fig. 1, Ref. 12).

Unilateral anomalous antebrachial vasculature--a clinico-embryological insight.

OBJECTIVES: An important and frequently reported arterial variant of the upper extremity is the superficial ulnar artery (SUA). Although SUA is not an uncommon variation, its presence should be detected timely as any surgical procedure in this region could put this unnaturally present superficial vessel to risk. Therefore, we sought to report this anomaly relating to the brachial arterial branching pattern. MATERIALS AND METHODS: Through the course of a usual instructive gross anatomy class an arterial variant of the brachial artery was noted. A scrupulous dissection was carried out and the specimen photographed. RESULTS: The present study reports the unilateral presence of abnormal branching pattern and disposition of antebrachial blood vessels. The brachial artery is seen to branch off into superficial ulnar artery (SUA) and usual radial artery. Interestingly, common interosseous artery (CIA) springs from the radial artery instead of the ulnar artery which is the usual case. CONCLUSIONS: Simple procedures such as venepuncture and intra arterial injections may become cumbersome and complication prone. The study is a humble attempt to caution the radiologists before interpreting angiographic films and the surgeons before performing reconstructions in this region.

Unusual innervation pattern of pectoralis minor muscle-anatomical description and clinical implications.

The highlight of the current case study is unique branching pattern of the medial pectoral nerve in relation to the pectoralis minor muscle. In addition, the third thoracic spinal nerve also was observed to penetrate the muscle. The lateral pectoral nerve did not innervate the muscle. The pectoralis minor was observed to be pierced extensively by multiple branches from medial pectoral nerve. Therefore, this study was planned to report this unusual presentation. Such an extensive neural arrangement in relation to pectoralis minor is rather unusual and to the best of our knowledge has been not reported earlier. The possible clinical consequence of much an anomaly could be motor and sensory loss associated with accidental injury of these multiple nerves penetrating the substance of pectoralis minor while performing axillary lymphadenectomy. In accordance to the above case description, the surgeon should be cautioned of these possible neural branches while performing axillary dissection in mastectomy. Additionally, iatrogenic sensory or motor losses may be prevented by appropriate knowledge of these variations.

Unilateral anomalous brachial and antebrachial musculature associated with duplication of anterior interosseous nerve: a case report.

The present case aims to provide an accurate anatomical description of coexistent accessory heads of flexor pollicis longus in the arm and forearm, extra muscular slips of the accessory belly of flexor pollicis longus to flexor digitorum profundus, and double anterior interosseous nerves. The morphology of the anomalous accessory muscle bellies is correlated with their clinical significance and embryological basis. Knowledge of such muscular and neuroanatomical variants is imperative prior to traumatic evaluation and reconstructive surgery.

Anomalous disposition of profunda femoris artery: a clinicoanatomical appraisal.

During educational dissection of the left lower limb of an adult Indian male cadaver, an unusual variation of the branches of the femoral artery and profunda femoris artery (PFA), were observed. The profunda femoris artery and medial circumflex femoral artery took origin from a common arterial trunk from the medial side of femoral artery. The PFA coursed lateral to the femoral vein. The lateral circumflex femoral artery (LCFA) took origin, 1.2 cm proximal to the origin of the latter. The lateral circumflex femoral artery (LCFA) took origin directly from the femoral artery. The femoral vein was constantly medial to the PFA and coursed between it and femoral artery. The great saphenous vein was observed to course medial to the PFA and at its termination coursed anterior to the latter to drain into the femoral vein. Changes in caliber of femoral artery were recorded at the site of origin of the variant branches.

An atypical composition of adductor hallucis co-existent with an accessory plantar muscle and duplication of flexor digiti minimi pedis.

Adductor hallucis (AH) is frequently employed in transposition onto the first metatarsal head to alleviate symptoms of hallux valgus. Although tis muscle receives sufficient anatomical description, it is often disregarded in clinical practice. The rare anomalies associated with AH, merit a detailed study owing to its contribution to the treatment of hallux valgus. Additionally, the AH may be employed in plastic and reconstructive surgeries as a graft to cover defects of the foot. Therefore, we sought to report this infrequent anomaly relating to the AH muscle. Through the course of a regular educational gross anatomy class a muscular variant of the plantar musculature was noticed. A meticulous dissection was carried out and the specimen photographed. The oblique head of AH displayed three bellies whereas the transverse head was unremarkable. Another accessory belly was observed taking origin from the fourth metatarsal bone. Additionally, the flexor digiti minimi brevis (FDMB) displayed two bellies medial and lateral. A preoperative radiological assessment of the foot to be operated upon may provide the necessary information and may detect these muscular anomalies. Utilizing these variations to their benefit during operation will shorten the procedure time and may reduce post-operative risks and complications. We report this unique muscular anomaly to alert the foot surgeons and radiologists and plan their procedures accordingly.