Imaging of salivary gland cancers derived from a sublingual gland herniated into the submandibular space: a report of three cases

Sublingual gland herniation into the submandibular space through a mylohyoid muscle defect is a common anatomical variation; however, salivary gland cancers that arise from a herniated sublingual gland have not been described yet. Here, we report three patients with salivary gland cancers originating from a herniated sublingual gland. All tumors were detected as palpable submandibular masses, located anterior to the submandibular gland, medial to the mandible, and lateral to the mylohyoid muscle, with contact with the sublingual gland through a mylohyoid muscle defect. Intraoperative findings confirmed that the masses were derived from herniated sublingual glands. Pathological examination showed one case of mucoepidermoid carcinoma and two cases of adenoid cystic carcinoma. Imaging findings of the tumor location, in addition to the continuity with the sublingual gland through the mylohyoid muscle defect, are crucial for accurately diagnosing the tumor origin, which is essential for determining the appropriate clinical management.

Structural analysis of the mylohyoid muscle as a septum dividing the floor of the oral cavity for the purposes of dental implant surgery: variety of muscle attachment positions and ranges of distribution

OBJECTIVES

The objective was to investigate the details of the attachments of the mylohyoid muscle to the mandible anterior to the hyoid and mylohyoid lines to understand the positional relationship between the sublingual space and the mylohyoid, knowledge that is essential for dental implant surgery in the incisal region, as well as the routes of communication between the sublingual space and other spaces.

METHODS

While evaluating the presence or absence of an anterior mylohyoid muscle fiber attachment to the mandible, sublingual gland herniation, spaces between muscle fascicles were also recorded as sites of penetration. The mean muscle thickness in each of these areas was also calculated.

RESULTS

In all specimens, the mylohyoid originated not only from the mylohyoid line but also from the lingual surface of the center of the mandibular body (the mandibular symphysis) below the mental spines. The mylohyoid muscle fascicles were thickest in the posterior region, and further anterior to this, they tended to become thinner. Sublingual gland herniations passing through the mylohyoid were noted in the anterior and central regions, but not in the posterior region. Penetration between the muscle fascicles was most common in the central region, and no such penetration was evident in the posterior region.

CONCLUSIONS

These results suggest that the mylohyoid functions only incompletely as a septum, and that routes of communication from the sublingual space to the submandibular space may be present in both the anterior and central muscle fascicles of the mylohyoid. Therefore, bleeding complications during dental implant placement in the anterior mandible can be serious issues. There is a potential for sublingual hematoma that could compromise the airway by pressing the tongue against the soft palate into the pharynx.

Anatomic Variation of Submental Artery: A Case of Submental Artery Coursing Through a Developmental Defect of Mylohyoid Muscle

Knowledge about variations in mylohyoid muscle and submental artery is essential for maxillofacial surgeons, as these structures are commonly encountered in maxillofacial ablative and reconstructive surgery. While cadaveric and radiologic studies on mylohyoid variations have been documented in the literature, we report an intraoperative variation observed in relation to mylohyoid muscle and submental artery.

An anatomical study of the blood supply to the mylohyoid muscle: the so-called "mylohyoid branch" of the inferior alveolar artery is an arterial anastomosis

BACKGROUND

The aim of this study was to clarify the morphology of the mylohyoid branch of the inferior alveolar artery and the main blood supply to the mylohyoid muscle.

METHODS

The maxillary artery (MA) and inferior alveolar artery (IAA) within the infratemporal fossa, the facial and submental arteries within the submandibular triangle, and the nerve to the mylohyoid muscle and related artery were dissected in twelve sides from embalmed cadaveric heads. The main blood supply to the extraoral (inferior) surface of the mylohyoid muscle was recorded.

RESULTS

The mylohyoid branch of the inferior alveolar artery was an anastomosis of the descending branch of either the inferior alveolar or maxillary artery and the ascending branch of either the submental or facial artery. The anastomosis was classified into four types according to the origins of the arteries. The main blood supply to the extraoral surface of the mylohyoid muscle was the submental artery.

CONCLUSIONS

The results of this study indicate that the mylohyoid branch of the IAA in human adults is an anastomosis of branches of the maxillary and facial arteries.

Dual innervation of the mylohyoid muscle by the trigeminal and hypoglossal nerves: A case report

During the routine dissection of a cadaveric specimen, the left mylohyoid muscle was found to be innervated by both the trigeminal and hypoglossal nerves. This variation was found unilaterally. To our knowledge this dual innervation of the mylohyoid muscle is an extremely rare variation. The possibility of these variants may lead to clinical consequences such as anesthesia failure and iatrogenic injury during surgical procedures in this region. We discuss this anatomical variation and possible developmental etiologies.

Anatomy and variations of digastric muscle

The digastric muscle consists of the anterior belly and the posterior belly connecting the mandible, hyoid bone and temporal bone. Its unique morphology, structure and variations have drawn genuine interests in this muscle from anatomists, scientists and physicians for a long time, and the variations of the digastric muscle have been documented since the 18th century. As the usage of computed tomography and magnetic resonance imaging in the neck has become ever increasing, recognizing the variations of the digastric muscle can be a great value since it helps physicians to make better treatment plans and avoid unnecessary invasive procedures in the neck. Although the variations of the digastric muscle do not necessarily cause clinical symptoms, they still have important clinical applications. This article discusses the anatomy, embryology, descriptions of the morphological variations and clinical significance of the digastric muscle.

Reconstruction with submental flap for aggressive orofacial cancer- an updated series

PURPOSE

Submental flap is gaining popularity for head and neck reconstruction. We have reported in 2007 our early experience of using submental flap for aggressive orofacial malignancy. Novel flap design and application is described in this updated series.

MATERIALS AND METHODS

15 patients who had received submental flap reconstruction after extirpation of newly diagnosed aggressive orofacial lesions were retrieved. The details of the flap harvest was studied for flap size, inclusion of mylohyoid muscle, antegrade versus retrograde blood supply, and compared with our previous series.

RESULTS

The dimension of flap skin paddle was 30cm² (range 20-72). Retrograde pedicle flow was used in 2(13.3%) patients. Mylohyoid muscle was included in the flap in 6(40%) patients. There was no total flap necrosis while partial flap necrosis occurred in 1 patient(6.7%). There was a significant increase of inclusion of mylohyoid muscle to the flap in this series (p = 0.02). Novel techniques including double-paddled flap skin to resurface full-thickness defect and chimeric osteocutaneous mandible submental flap for maxillary defect were successfully performed.

CONCLUSIONS

Submental flap is a viable reconstructive option in selected patients with aggressive orofacial malignancy. The indications are expanding and its technical modification is evolving and resulting in more innovative applications.

Large Plunging Ranula Presenting as Isolated Neck Swelling: Steps in Diagnosis and Surgical Steps in Management

Ranula is a salivary gland cyst which typically present as localized superficial swelling over the floor of mouth. Complex or plunging ranulas develop when the mucus extravasation extends through or around the mylohyoid muscle, deeper into the neck, and present with neck lump along with or without swelling over floor of mouth. We report a case of large plunging ranula presenting as an isolated large neck mass in a 38-year-old female patient. The steps in diagnosis and surgical steps in management of the pathology are systematically described.