Bilateral supernumerary sternocleidomastoid heads with clinical and surgical implications (original) (raw)
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BILATERAL FOUR AND SIX HEADS OF THE STERNOCLEIDOMASTOID MUSCLE. A CADAVERIC FINDING
International Journal of Pharmaceutical Research, 2019
Background: The sternocleidomastoid muscle present a wide patterns of variations which including supernumerary muscular heads. Aim: The aim of the present study is report bilateral four and six heads of the sternocleidomastoid muscle. Materials and Methods: The anatomical variation was found during routine dissection performed in the laboratory of Morphology of the University of Pamplona. Findings: On the right side, two sternal head were a continuous sheet with a small gap of 1 mm; the third head originating from sternoclavicular joint until the clavicular head. The fourth, clavicular head that arose from the medial and middle third of the clavicle. On the left side of the neck, two sternal heads were lying side by side. Of the four clavicular heads, two were superficial and another two lying in a deep plane. Conclusions: Knowledge of these anatomical variations is important for any therapeutics and diagnostic intervention in the region neck.
Anatomical description and clinical significance of unilateral triheaded sternocleidomastoid muscle
International Journal of Research in Medical Sciences, 2014
Objective of this report is to observe and report unusual pattern of origin of sternal and clavicular heads of Sternocleidomastoid (SCM). An embryological insight into the possible causes for present anomaly is elucidated. The neck region of an adult male cadaver during gross anatomy teaching program. An abnormal Sternocleidomastoid (SCM) was observed while dissecting the neck region of an adult. Additional clavicular head of SCM muscle were found on the right side. The accessory clavicular head coursed deep to the sternal head whereas the some fibres of main clavicular head joined the accessory belly and together they fused with the main sternal head of SCM. There was another slip arising from sternal head and merge with deep cervical fascia near base of mandible. The topographical anatomy of SCM is extremely important, particularly because it serves as a useful surgical landmark and its relation to crucial neuro-vascular structures of the neck. The usage of SCM in reconstruction operations for covering defects is discussed. A detailed knowledge of the anatomy of SCM proves vital for radiological studies of the neck.
A RARE CASE OF BILATERAL STERNOCLEIDOMASTOID MUSCLE VARIATION
International Journal of Pharmaceutical Research, 2019
Background: The abnormal origin, presence of additional head and layered arrangement of fibers are the reported variations of sternocleidomastoid muscle. Aims: The aim of the present study is report a rare bilateral anatomical variation of the sternocleidomastoid muscle. Materials and Methods: The anatomical variations were found during a routine dissection performed in the laboratory of Morphology of the University of Pamplona. Findings: In accordance with their origin, insertion, in the right side, in the superficial layer were dissected muscular bundle considered as sternocleidooccipital and sternomastoid muscle. In the deep layer, muscular bundles considered as cleidomastoid and sternocleidomastoid muscle was observed. In the left side, additional head originated from the investing deep layer of cervical fascia in the roof of the lesser supraclavicular fossa, traversed obliquely downward, backward, fused with clavicular head. Conclusion: The presence of this anatomical variation it might cause difficulty in assessing the vital neurovascular structures of the neck.
International Journal of Morphology, 2012
Anatomical variations of the sternocleidomastoid muscle are rare and concern its origin, insertion, and the number of heads. We report on a rare bilateral variant of the sternocleidomastoid muscle with aberrant and supernumerary muscular heads, observed in a cadaveric subject. On the right side of the neck, a typical sternomastoid head of the sternocleidomastoid muscle, and three aberrant clavicular heads of variable thickness, origin, and termination were noticed. On the left side, two sternomastoid heads were present; the medial one was of typical pattern, while the lateral was supernumerary. The cleidomastoid portion of the left sternocleidomastoid muscle was fused with the double sternomastoid segment. A strap-like muscle originating from the middle third of the clavicle and inserting onto the transverse process of the C3 vertebra was noticed. This is known as the cleidocervical muscle. On the right side of the neck, the posterior cervical triangle was diminished, the minor supraclavicular fossa was considerably narrow, whereas on the left, it was diminished in addition to a bilateral shortening of the major supraclavicular fossa minimizing space needed for potential surgical access. These findings are of prominent significance for anesthetists in ultrasound guided needle positioning in brachial plexus block, as well as in subclavian or external jugular vein catheterization, and in surgical interventions involving structures lying under the sternocleidomastoid muscle.
Bilateral sternocleidomastoid variant with six distinct insertions along the superior nuchal line
Anatomy & Cell Biology, 2018
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 and occiput, and should thus be appreciated by the clinician. Herein we discuss the case report, possible embryological origins, and the clinical significance of the observed variant SCM.
International Journal of Morphology, 2023
This study aimed to classify and investigate anatomical variations of the sternocleidomastoid (SCM) muscle, which is commonly used as an anatomical landmark to indicate the correct position for central venous catheterization, in a Thai population. Thirtyfive embalmed cadavers from the Northeast Thailand (19 females and 16 males) were systemically dissected to reveal the SCM muscles in both sides for gross human anatomy teaching. Variations in the SCM origin and insertion were observed and recorded. The prevalence of anatomical variations was approximately 11.4 % (4 of 35 cadavers) and was not different by sex. Such variations were classified into 5 types based on origin, insertion, and presence of additional heads, as follows: type I (n=31; 88.6 %), type II (n=1; 2.85 %), type III (n=1; 2.85 %), type IV (n=1; 2.85 %), and type V (n=1; 2.85 %). Clinical considerations and prevalence of variant SCM muscle have also been discussed. Since the incidence of this anatomical variations was more than 10 %, the cervical surgeons should seriously consider this issue before insertion of a central venous catheter to avoid complications.
A Rare Case of Unilateral Third Head of Sternocleidomastoid Muscle
International Journal of Morphology, 2008
A rare case of unilateral third head of sternocleidomastoid muscle was noted during routine dissections for undergraduate medical students. The additional third head originated from the middle third of the clavicle and joined the normal two heads (sternal and clavicular) of the muscle in the middle of the neck. The insertion and nerve supply of the muscle was normal. This case may be important for head and neck surgeons and for plastic surgeons doing muscle graft surgeries.
We classified sternocleidomastoid muscle abnormality and calculated its incidence in a Thai population. Such abnormality should be considered to prevent complications from central venous catheterization.This study aimed to classify and investigate abnormalities of the sternocleidomastoid (SCM) muscle, which is commonly used as an anatomical landmark to indicate the correct position for central venous catheterization, in a Thai population. Thirty-five embalmed cadavers from northeast Thailand (19 females and 16 males) were systemically dissected to reveal the SCM muscle anatomy. Variations in SCM origin and insertion were recorded. The prevalence of abnormality was approximately 11.4% (4 of 35 cadavers) and did not differ by sex. Abnormalities were classified into 5 types based on origin, insertion, and presence of additional heads, as follows: type I (n=31; 88.6%), type II (n=1; 2.85%), type III (n=1; 2.85%), type IV (n=1; 2.85%), and type V (n=1; 2.85%). As the incidence of abnorma...
Int. J. …, 2010
FAZLIOGULLARI, Z.; CICEKCIBASI, A, E.; UNVER DOGAN, N.; YILMAZ, M. T.; BUYUKMUMCU, M. & ZIYLAN, T. The levator claviculae muscle and unilateral third head of the sternocleidomastoıd muscle: case report. Int. J. Morphol., 28(3):929-932, 2010.