Unusual anatomical variants of infrahyoid muscles - case report.

Anatomical anomalies of neck muscles are rarely observed and usually comprise variations of digastric and omohyoid muscles. Neck muscles' abnormalities might be correlated with embryological development and are observed in individuals with aneuploidies such as Edward's syndrome (18-trisomy) or Down syndrome (21-trisomy). Some infrahyoid muscles are important landmarks during surgery, therefore their anatomical variations of these muscles are related to higher risk of surgical complications. Herein, we present a rare case of infrahyoid muscles anomalies found during routine dissection of male cadaver. Redundant muscle bellies of sternohyoid muscle (sternohyoid azygos muscle), presence of levator glandulae thyroideae and also one hypoplastic superior belly of the omohyoid muscle were observed. Presence of muscle fibers within found structures was confirmed using Masson's trichrome staining method.

The previously undescribed variant of the thyrohyoid muscle and its potential impact on surgical procedures.

The thyrohyoid muscle belongs to the infrahyoid group located in the carotid triangle. It normally originates from thyroid cartilage and inserts into hyoid bone. Quite often, it is continuous with the sternohyoid muscle. Furthermore, there are variants that have their origin in the cricoid cartilage only, however, this occurs very rarely. During anatomical dissection, a two-headed variant of this muscle was found. One head had its origin in the cricoid cartilage and the other in the thyroid cartilage. This variant of thyrohyoid had not been previously described in the available literature. Therefore, we believe that it may be referred to as the cricothyrohyoid muscle. As the thyrohyoideus is often used as a landmark during surgical procedures in the prelaryngeal area and as a muscle graft, a thorough knowledge of its anatomy and variation is extremely important. We speculate that the two-headed version of this muscle may be problematic during surgical procedures in this region, however, it may also provide more options as a muscular graft.

Infrahyoid muscle flap as augmentation of pharyngeal repair after total laryngectomy.

INTRODUCTION: To assess the usage of contralateral infrahyoid muscles as onlay flap in prevention of pharyngo-cutaneous fistula (PCF) in total laryngectomy (TL) patients with high risk factors of PCF development. METHODS: This study included 10 patients who suffered from advanced laryngeal carcinoma with presence of risk factors for development of PCF. We added an enforcement muscular layer during neo-pharynx wall repair, the infrahyoid muscle flap of the contralateral side of the tumour origin as an onlay muscular flap to cover the anastomotic site for healing augmentation. Patients were followed up for PCF development where the PCF incidence was calculated. RESULTS: One patient died from congestive heart failure in the 21th post-operative day so, the actual PCF rate in TL patients with high risk factors of PCF development in our study was 11.11% (1 out of 9 cases). CONCLUSIONS: Infrahyoid muscle flap may have a role in preventing PCF after TL in patients with high risk factors of PCF development in this case series study to be further assessed in other studies to justify its role.

Transoral Laser-Assisted Infrahyoid Supraglottic Laryngectomy for Selected Patients With Supraglottic Cancer.

Supraglottic laryngectomy has evolved from open to transoral endoscopic approaches with advancements in surgical techniques and instruments such as lasers, endoscopes, ultrasonic devices, and robotics. Transoral laser-assisted microsurgery has emerged as an effective treatment option, offering faster functional recovery and serving as an alternative to partial laryngectomy or non-surgical therapies. Traditional endoscopic supraglottic laryngectomy involves resection of both suprahyoid and infrahyoid supraglottic structures. However, in cases where the tumor is limited to the infrahyoid epiglottis, a new technique known as transoral laser-assisted infrahyoid supraglottic laryngectomy allows for tumor removal while preserving the suprahyoid epiglottis, aryepiglottic folds, and vallecula, ensuring optimal preservation of laryngopharyngeal function. This procedure enables patients to swiftly return to their daily routines with minimal complications. This article discusses the surgical technique, potential indications, and advantages and disadvantages of the new approach for infrahyoid epiglottic cancer.

Evaluation of treatment outcome amongst two different treatment modalities for reconstruction of carcinoma of tongue patients: The infrahyoid myocutaneous flap versus radial forearm flap.

Introduction: Oral cancer is one of the most common cancers not only in India but also in South Asia. Treatment of oral cancer is not only limited to cure but also requires good reconstruction of the surgical defects for a better quality of the life. There are many well-proven options for reconstruction purposes for the defects of the oral cavity including local regional flaps to microvascular-free flaps. After resections of mobile parts of the tongue (up to 50%) speech and swallowing are impaired significantly, however, even after sophisticated plastic reconstruction, serious swallowing and speech problems persist. Material and Methods: The pilot study was carried out after the allocation of fourteen patients with carcinoma of the tongue into two treatment test groups; the Radial forearm flap (RFF) and Infrahyoid neuromuscular flap (IHF) group to evaluate and compare the treatment outcome for reconstruction using two different treatment modalities. The pilot study was carried out after the allocation of fourteen patients with carcinoma of the tongue into two treatment test groups. the clinical parameters likewise swallowing reflex, speech analysis, donor site complication, time taken for the surgery, and cost-effectiveness of the flap was evaluated using IBM SPSS Statistics for Windows software, 20.0 (IBM Corp., Armonk, USA). The data were numerically coded and entered into the program. Both the descriptive statistics and the inferential statistics involving one-way ANOVA and Tukey's Post Hoc test were analyzed to compare both intergroup and intragroup comparisons at different time intervals. Results: The swallowing and aspiration analysis showed a highly statistically significant difference at 3 months and 6 months by Post Hoc test between the groups. The speech analysis scores at all intervals were not statistically significant while for tongue movements the results were significant. The time taken and expenditure for surgery by IHF were less in comparison to RFF. Conclusion: The infrahyoid flap is a quick, easy, and reliable reconstructive method, which is cost-effective when used with knowledge of its clinical utility and limitations, the functional results are excellent with great patient satisfaction.

The Outcome of Treatment for Thyroglossal Tract Anomalies.

Background Thyroglossal tract anomalies are the most common cause of midline neck swelling. Thyroglossal cysts present between the base of the tongue and cricoid cartilage as painless, midline swelling that moves on deglutition and protrusion of the tongue. If the thyroglossal cyst gets infected or is violated surgically, it can result in a thyroglossal sinus or fistula. Investigations in patients with suspected thyroglossal cysts include a thyroid function test, ultrasonography of the neck, and fine needle aspiration cytology (FNAC). Computed tomography (CT) or magnetic resonance imaging (MRI) can be done for larger cysts or suspected malignancies. The gold standard treatment is Sistrunk surgery. Recurrence rates with Sistrunk surgery are lower when the surgery is performed accurately. This study was conducted to document the clinical presentation and treatment outcome in patients treated for thyroglossal tract anomalies. Methods This is a retrospective analysis of 46 medical case records of patients operated on for thyroglossal tract anomalies at a rural tertiary care hospital from April 1995 to April 2021. Patients fulfilling the inclusion and exclusion criteria were evaluated with a detailed history, various clinical presentations, location, extent of anomalies, and thyroid function test results documented. Ultrasound images were reviewed, and the findings were documented. All patients have consent, and they underwent Sistrunk surgery. Patients in whom the normal thyroid gland was found to be absent were started on replacement thyroxine after surgery. The specimen was subjected to histopathological examination by a senior pathologist. The outcome regarding complications, recurrence, and further treatment were reviewed. The outcome of the thyroglossal fistula was compared with that of thyroglossal cysts, and the outcome of infrahyoid thyroglossal tract anomalies was compared with that of suprahyoid thyroglossal tract anomalies. Results In this study, among the 46 patients, 24 (52.2%) were female and 22 (47.8%) were male. The minimum age was three years, the maximum was 58, and the mean was 20.6 years. In this study, 71.7% of the patients were diagnosed with thyroglossal cysts, 10.9% had thyroglossal fistulas, and two had lingual thyroids. The most common location of the cyst was infrahyoid (73.9%). 44 patients underwent Sistrunk surgery, and two patients diagnosed with lingual thyroid underwent excision. Three patients had complications (two pharyngo-cutaneous fistulas, one wound dehiscence), and all were managed conservatively. There were no recurrences in our study. Conclusion Thyroglossal tract anomalies are the most common congenital cervical anomalies. A complete Sistrunk procedure includes the removal of the entire thyroglossal tract, inclusive of the body of the hyoid bone along with the cuff of base tongue tissue, and gives the best result for thyroglossal tract anomalies.

Ultrasonographic measurements of the omohyoid muscle during shoulder muscles contraction.

BACKGROUND: The main function of the omohyoid muscle is to depress and withdraw the hyoid bone. This is an integral part of the swallowing process facilitating hyoid stabilization for tongue movement. Although the muscle is inferiorly attached to the scapula bone, its function during shoulder or scapula muscles contraction has yet not been studied. AIM: To investigate whether changes occur in omohyoid muscle morphology during shoulder muscles contraction. METHODS: The study included 40 healthy subjects (20 males and 20 females, Mean age: 25.68 (± 2.90) years) examined via diagnostic ultrasound. Omohyoid muscle morphology measurements (thickness and cross-sectional area) during different shoulder position (0°, 90° abduction and elevation) in rest and during isomteric contraction were evaluated. RESULTS: The omohyoid muscle was activated when the shoulder was isometrically abducted at 90° abduction. Thickness and the cross-sectional area of the lower belly increased during contractions at 90° abduction compared with a resting position at 90° (p value < 0.01). No changes occurred at 0° isometric abduction. The CSA of the muscle was found to be significantly larger (p < 0.001) during contraction at 90° abduction compared with contraction at 0° abduction. CONCLUSION: Omohyoid muscle was most contracted during abduction position with abduction shoulder muscles isometric contraction. Changes of the scapula position might influence omohyoid muscle function.

Anatomical diversity of inferior belly of the omohyoid muscle - Anatomical, physiological and surgical paradigm.

Omohyoid muscle is one of the infrahyoid muscles of the neck which consists of two bellies combined at an angle by an intermediate tendon. The inferior belly is a flat, narrow band, which inclines forwards and upwards in the lower part of the neck. It generally originates from the upper border of the scapula, medial to scapular notch. The present case showed unilateral anomalous attachment of the inferior belly of the omohyoid on the medial part of clavicle on left side. Inferior belly was 2.2cm lateral to left sternoclavicular joint with 3.2 and 1.5cm in length and breadth, innervated by ansa cervicalis. Only 3% of this type of variation has been observed until now according to previous literature. Anterior and posterior triangles of neck on both sides of the cadaver were dissected during routine dissection for undergraduate teaching. There was no scapular attachment of inferior belly of the omohyoid on the left side. It was directly originating from the upper surface of the medial side of the left clavicle. Variation in the attachment of inferior belly can have a direct impact on the internal jugular vein and brachial plexus during neck surgeries or trauma due to its close relation to the mentioned structures. This variation should also be taken care during infrahyoid myocutaneus flap extraction for reconstruction surgery of tongue in cases of lingual carcinoma.

Onset Timing of Hyoid Muscles Activation during Cervical Flexion Is Position-Dependent: An EMG Study.

Due to the high prevalence of neck pain, considerable attention is paid to the function of cervical flexor muscles. Although the deep and superficial cervical flexor muscles have been evaluated, the impact of hyoid muscles on cervical flexion is still not well known. We, therefore, aimed to investigate the activation of hyoid muscles during physiological cervical flexion, and to determine the impact of different starting positions on cervical flexion muscle activation. The activities of bilateral sternocleidomastoid, scalene, suprahyoid, and infrahyoid muscles were evaluated by surface electromyography (EMG) in twenty young healthy volunteers. They performed a repetitive cervical flexion-extension movement, from neutral position of the head to the maximum flexion with the same speed set at eight seconds in a cycle, in three various positions (sitting, standing, and supine). In sitting and standing positions, the group of suprahyoid muscles was activated in advance of other cervical flexor muscles despite only significant differences were found in scalene muscles, and the activation of the group of infrahyoid muscles was time-synchronous with sternocleidomastoid muscles. On the other hand, in supine position, the activation of all measured cervical flexor muscles was significantly earlier and longer than in the other two positions. This study confirmed the empirical suggestion that hyoid muscles contributed to cervical flexion, and it confirmed that muscle activation was position dependent, even if the given movement is nearly identical.

An anomalous muscle clinging around the inferior belly of omohyoid muscle.

Sternohyoid, sternothyroid, omohyoid and thyrohyoid muscles belong to a group of muscles called infrahyoid muscles. A few variations of these muscles and additional muscles in this area have been reported. We report an anomalous muscle in this area. The anomalous muscle took its origin from the posterior surface of the manubrium sterni and was inserted to the posterior surface of the clavicle. This muscle was 6 cm long and interestingly, it made a loop, which was clinging on to the inferior belly of omohyoid posteriorly, superiorly and anteriorly. The muscle was situated between the lower end of sternocleidomastoid and the carotid sheath. It was supplied by ansa cervicalis. Knowledge of this muscle could be useful in surgeries like removal of cervical rib, and cervical lymph node clearance. Hypertrophy of this muscle might compress the internal jugular vein.

Novel modification of infrahyoid myocutaneous flap for the reconstruction of oral cavity defects.

This study was intended to describe the technique used and the results obtained with the modification of the infrahyoid flap (IHF) for the reconstruction of oral tongue defects following resection for advanced squamous cell carcinoma (SCC). Patients with oral tongue defects following ablation for T2 to T4a SCC had reconstructions using a modified infrahyoid flap. Demographic data, tumour characteristics, and the complications were evaluated for each patient. We observed no complications regarding the healing process of the donor site or success of the flap in 49 (of 55) patients. None of the flaps had massive oedema or venous congestion in the postoperative period. Six patients experienced flap-related complications of which five had partial skin paddle necrosis, but eventually their flaps recovered and re-epithelialised without any further intervention. However, total flap necrosis was seen in one patient in whom a pectoralis major flap was used for the defect reconstruction following revision surgery. History of previous radiotherapy to the neck (p = 0.003), tumour stage (p = 0.017), and metastasis to cervical lymph nodes (p = 0.004) were associated with higher prevalence of partial or total flap necrosis. The modified infrahyoid flap is a reliable, quick, and simple procedure with a reasonable cost that makes it a valuable option for the reconstruction of the oropharynx and oral cavity with minimal donor site morbidity and good outcomes. It seems the modified IHF is a valid surgical procedure that may be considered in selected patients undergoing reconstruction of oncological oral tongue defects with fewer complications.

Infrahyoid myofascial flap transfer for the prevention of concave deformity and gustatory sweating after parotidectomy.

OBJECTIVE: Concave deformities and gustatory sweating are the most common complications that cause substantial patient dissatisfaction after parotidectomy. Various surgical methods to prevent these complications have been described. However, effective techniques have not been established, especially in patients with medium- to large-sized parotidectomy defects. We evaluated the utility of infrahyoid myofascial flap reconstruction of parotidectomy defects for the prevention of these complications. METHODS: We conducted a retrospective case series study in patients with a benign or malignant parotid tumor measuring over 4 cm who underwent immediate pedicle infrahyoid myofascial flap reconstruction after total or subtotal parotidectomy or total resection of either the superficial or deep parotid gland at our hospital. Subjective analyses of facial symmetry, postoperative concave deformities of the anterior neck, gustatory sweating, voice disorders, odynophagia, neck scarring in the parotid and anterior neck areas, sensory disorders, pain, and neck stiffness were performed using patient interview data. Objective evaluations of facial symmetry were made by the first or second author. Both analyses were performed after a follow-up of more than six months. Additionally, patient demographic data, clinicopathological factors, parotidectomy and skin incision types, flap survival, and postoperative complications were evaluated. RESULTS: We included eight patients (male, n=5; mean age, 69.3 years [range, 37-93 years]). Procedures included total or subtotal parotidectomy (n=4), superficial lobe parotidectomy (n=2), and deep lobe parotidectomy with partial superficial lobe parotidectomy (n=2). Infrahyoid myofascial flaps reached the cranial tip of the parotid defect without tension, and their volume sufficiently filled the parotidectomy defect in all patients. There were no local signs of insufficient blood flow within the transferred flaps. Objective and subjective assessments were made after a mean duration of 1.2 years (range, 0.6-1.8). Postoperatively, no patient subjectively reported facial asymmetry. Objectively, facial symmetry was "good" in four patients and "fair" in four patients. No distinctly visible concave deformity in the parotid or anterior neck area occurred in any patient. Gustatory sweating occurred in one patient; this individual had the largest parotidectomy defect. Only one patient experienced donor site morbidity (mild anterior neck stiffness) related to infrahyoid myofascial flap elevation. CONCLUSION: Although complete prevention of gustatory sweating was unsuccessful, infrahyoid myofascial flap reconstruction of medium- to large-sized parotidectomy defects led to postoperative facial symmetry with minimal donor site morbidity.

The Role of Infrahyoid Flap in Tongue Defect Reconstruction Following Tumour Excision.

Carcinoma tongue is one of the commonest cancer of head and neck in India. Various pedicled and free flaps have been used to reconstruct the tongue defect following glossectomies. In this era of free flaps various loco- regional pedicled flaps have been overlooked and infrahyoid flap is one of them. This flap meets the functional and cosmetic acceptance of the tongue defect reconstruction with minimal morbidity to the donor site. This paper presents author's experience of using infrahyoid flap in 10 patients of carcinoma tongue. In all the patient's tongue defect was closed with the infrahyoid flap, in 1 case flap necrosed fully and in 1 partially. Functional outcome and quality of life in all the patients were acceptable.

Vein preservation strategies to improve the survival rate of the infrahyoid musculocutaneous flap.

The infrahyoid musculocutaneous flap (IHMCF) is a good alternative in the reconstruction of moderate-sized oral cavity surgical defects. Insufficient venous drainage can significantly affect the survival rate of this flap. OBJECTIVES: Identify the survival rates of the IHMCF and evaluate the functional capacity of reconstructed patients. DESIGN: We report a case series. SETTING: This study took place at the Department of Head and Neck Surgery of Oncology Hospital Ho Chi Minh City, the largest oncology center in South Vietnam. PARTICIPANTS: One hundred and twelve patients with surgical defects after oral cavity resection for cancer underwent IHMCF reconstruction from November 2013 to November 2018. During the harvest of the flap, our modification of the surgical technique specifically attempted to preserve more secondary veins for IHMCF. MAIN OUTCOME MEASURES: Postoperative viability of the flap was checked by clinical observation. The last examination was performed at 3-months after reconstructive operation or after the completion of adjuvant radiotherapy. The functional capacity of our patients was evaluated by three physicians (Head and Neck Surgeon, Radiation Oncologist, and Physiatrist) with understandability of speech scale and the functional oral intake score items assessed. RESULTS: Two cases of partial skin necrosis (1.8%) were experienced. The majority of patients demonstrated favorable functional rehabilitation at long-term follow up. CONCLUSIONS: The IHMCF is a reliable flap suitable for moderate-sized defects of the oral cavity. Altering the surgical approach to specifically preserve more venous outflow can improve the survival rate of the flap. LEVEL OF EVIDENCE: 4.

Infrahyoid myocutaneous flap: A systematic review.

INTRODUCTION: The infrahyoid myocutaneous flap (IHMCF) is an often-overlooked flap of the anterior neck used for reconstruction of oral cavity and laryngopharyngeal defects. The primary goal of this systematic review is to evaluate the postoperative outcomes and efficacy of this flap. METHODS: A comprehensive search of PubMed, Biological Abstracts, CINAHL Plus, and Web of Science was conducted. Two researchers independently scrutinized the studies to determine inclusions based on relevance, sample size, and English language publications. RESULTS: Twenty-eight studies containing 1027 IHMCF cases met the inclusion criteria. Primary outcomes included flap necrosis and postoperative functional outcomes. The rate of flap survival was 99%. Total skin necrosis and partial skin necrosis were minor complications that occurred in 2.5% and 5.8% of cases respectively. Poor speech and swallowing outcomes were reported in 6.4% and 6.5% of cases respectively. The included studies were predominantly retrospective. An average MINORS score of 9.6 suggests moderate bias among the studies. CONCLUSIONS: The IHMCF is both safe and effective for repairing medium sized mucosal lesions of the head and neck region in carefully selected patients. IHMCF use in oral cavity reconstruction is particularly appealing although functional outcomes remain difficult to statistically assess. Complications of IHMCFs are rare and often minor. To ensure the best outcome, pre-surgical planning needs to be conducted and all contraindications should be respected. Further large prospective multi-centered trials are needed for more accurate analysis.

Submandibular Push Exercise Using Visual Feedback from a Pressure Sensor in Patients with Swallowing Difficulties: A Pilot Study.

Objectives: We aimed to determine the usefulness and effectiveness of a submandibular push exercise with visual feedback from a pressure sensor in patients with dysphagia through continuous exercise sessions. Methods: Twelve patients with dysphagia of various etiologies were included. A total of five exercise sessions (every 3 or 4 days) over three weeks were conducted. During the submandibular push exercise, patients were instructed to maintain a maximum force for 3 s, repeated for 1 min to measure the number of exercises, the maximum pressure, and the area of the pressure-time graph. We statistically compared the values of each exercise trial. Results: Among the 12 patients, eight completed the exercise sessions. As the number of exercise trials increased, the maximum pressure and the area in the pressure-time graph showed a significant increase compared to the previous attempt (p < 0.05). The maximum pressure and the area of the pressure-time graph improved from the first to the fourth session (p < 0.05). The values were maintained after the fourth session, and there was no significant difference between the fourth and the fifth exercise (p > 0.05). There was no significant difference between successful and non-successful groups, except for the Modified Barthel Index (p < 0.05). Conclusion: Through repetitive exercise training, the submandibular push exercise using visual feedback from a pressure sensor can be applied as an exercise method to strengthen swallowing related muscles, such as the suprahyoid and infrahyoid muscles. However, additional studies including more patients and a long-term study period are warranted to evaluate the effects of the exercise for improvement of dysphagia.

PEQULIARITIES OF MORPHOGENESYS AND TOPOGRAPHY OF INFRAHYOID TRIANGLES IN HUMAN PREFETUSES AND FETUSES.

OBJECTIVE: The aim: To investigate morphology and developmental features of anatomical structures in the infrahyoid triangles of human neck during prefetal and fetal periods of human ontogenesis. PATIENTS AND METHODS: Materials and methods: We have studied 30 specimens of human prefetuses from 7th till 12th week (16,0-82,0 mm of parieto-coccygeal length (PCL)) and 30 human fetuses aged from 4th till 10th month (84,0-360,0 mm PCL) of intrauterine development by the means of macro-, microscopy, morphometry, three-dimensional remodeling and statistical analyses. RESULTS: Results: We can observe anterior triangle in human fetuses after the time when common precursor muscular mass splits into two: the anterior and posterior portions which will give rise to the sternocleidomastoid and trapezoid muscles accordingly. The area index of the central triangle in human fetuses 4th - 10th month of intrauterine development shows the increasing tendency with the highest rates at 8th-10th months period - 1100-1200 mm2. The angulated course of omohyoid muscle is visible at late prefetal and early fetal periods (3-4th month; 80,0-130,0 PCL) as well as the presence of intermediate tendon. Peaks of the area of sternocleidomastoid region area evaluation was observed in 190,0-210,0 mm PCL and 260,0-270,0 mm PCL human fetuses; 6th and 7,5th months accordingly. CONCLUSION: Conclusions: The critical periods for the AT and SCM regions should be considered 6th and 8th months of the IUD. Prefetal period shows the presence of AT and border structure for the IH neck - precursor of HB. Fetal period of IUD (4th - 10th months of IUD) should be considered as such that represents an adult-alike morphology of IH neck: presence of IH triangles with fully developed vascular, muscular and fascial content.

Voice rehabilitation after total laryngectomy with the infrahyoid musculocutaneous flap.

BACKGROUND: It is important for the patients to reconstruct the voice phonic function by surgery after total laryngectomy in the developing countries. AIMS/OBJECTIVES: To investigate the clinical outcomes of voice reconstruction using an infrahyoid musculocutaneous flap for patients after total laryngectomies. MATERIALS AND METHODS: Eighteen male patients recruited were laryngectomized. The infrahyoid musculocutaneous flap was designed. After total laryngectomy, the lower edge of the flap was sewed with the upper edge of the tracheostomy opening. Next, the lateral and medial edges of the flap were anastomosed to create a pronunciation tube. Finally, the remaining opening of the tube was sutured with the anterolateral wall of the hypopharynx to establish a communication with the pharyngeal cavity. RESULTS: A total of 17 cases of flaps were survived and only 1 necrosed. There were 17 patients without serious complications, except that 6 cases had mild irritable cough when gulping water. However, it could be relieved through blocking tracheostoma. One year after operation, all patients could more remarkably articulate clear, powerful, and consistent words. The articulatory configuration was existed under rigid laryngoscope and CT. CONCLUSIONS AND SIGNIFICANCE: The use of an infrahyoid myocutaneous flap is feasible for the voice restoration in the patients undergoing total laryngectomy.

Sternocleidohyoid muscle: an unreported variant of cleidohyoid muscle.

Sternohyoid, sternothyroid, omohyoid, and thyrohyoid muscles are collectively known as infrahyoid muscles. These muscles frequently show variations in their attachments. Here, an extremely rare variant muscle belonging to this group has been presented. During cadaveric dissection for undergraduate medical students, an additional muscle was found between sternohyoid and superior belly of omohyoid muscles bilaterally in a male cadaver aged approximately 70 years. This muscle took its origin from posterior surface of the manubrium sterni, capsule of the sternoclavicular joint and the posterior surface of the medial part of the clavicle. It was inserted to the hyoid bone between the attachments of sternohyoid and superior belly of omohyoid muscles and was supplied by a branch of ansa cervicalis profunda. There is no report on such a muscle in the literature and it could be named as "sternocleidohyoid muscle". Knowledge of this muscle could be useful in neck surgeries.

New approach to an overlooked flap: Technique to augment venous drainage of the infrahyoid myocutaneous flap.

BACKGROUND: To describe a technique in which the anterior jugular vein is preserved in the infrahyoid myocutaneous flap (IHMCF) to augment skin paddle venous drainage. METHODS: From April 2018 to December 2019, 14 patients with primary oral cancer underwent radical resection and IHMCF reconstruction. Three-dimensional reconstruction of the anterior jugular vein was used to assess the venous drainage of the skin paddle preoperatively. The anterior jugular vein was preserved during dissection of the flap. Healing of the recipient and donor sites was observed. RESULTS: Total flap necrosis occurred in one patient and marginal skin paddle necrosis occurred in one patient. No flap complications occurred in the other 12 patients. CONCLUSION: This new approach to augment venous drainage of the IHMCF appears to be effective for decreasing risk of flap necrosis.