The mouth

The mouth is the common aperture to the aerodigestive tract. With the coordinated assistance of the tongue and lips it contributes to the formation of meaningful sound whilst the presence of intact dental arches allow for mastication. The oral cavity proper represents the atrium beyond the lips reaching to the palatoglossal arches posteriorly, where the oropharynx begins beyond the oropharnygeal isthmus. It is restricted by the cheeks laterally, the hard and soft palate superiorly and the mobile tongue resting on the mylohyoid muscle inferiorly. The paired major salivary glands drain into the oral cavity along with numerous minor salivary glands. The tongue is a thick, mucosa covered muscular structure concerned with mastication, taste, talking and swallowing. The palate is the roof of the mouth, separating the oral and nasal cavities and participating in speech and swallowing. It can be divided into two parts: a bony anterior hard palate and soft posterior palate.

The Challenges of Treating Lipoblastoma in the Sublingual Space – A Case Report

The presence of lobulated tumour arising from immature adipose tissue is called lipoblastoma when occurring as localised or discrete lesion, and lipoblastomatosis when spread diffusely. The purpose of this case study is to report a case of an 18 – year old man who presented with lipoblastoma in the left sublingual space which was found to be in close proximity with the left sublingual gland. Magnetic resonance imaging (MRI) was taken and showed the tumour was confined within the sublingual space and no penetration was noted inferiorly through the mylohyoid muscle. Tumour dimension measured clinically was 3 cm x 2 cm x 2 cm and the anterior margin of the tumour crossed the midline and entered into the right sublingual space. Complete excision with sparing of neurovascular bundle was performed under general anaesthesia. Follow-up of 2 months showed complete remission of the lesion without any complications.

Adults Do Not Distinguish Action Intentions Based on Movement Kinematics Presented in Naturalistic Settings

Predicting others’ actions is an essential part of acting in the social world. Action kinematics have been proposed to be a cue about others’ intentions. It is still an open question as to whether adults can use kinematic information in naturalistic settings when presented as a part of a richer visual scene than previously examined. We investigated adults’ intention perceptions from kinematics using naturalistic stimuli in two experiments. In experiment 1, thirty participants watched grasp-to-drink and grasp-to-place movements and identified the movement intention (to drink or to place), whilst their mouth-opening muscle activity was measured with electromyography (EMG) to examine participants’ motor simulation of the observed actions. We found anecdotal evidence that participants could correctly identify the intentions from the action kinematics, although we found no evidence for increased activation of their mylohyoid muscle during the observation of grasp-to-drink compared to grasp-to-place actions. In pre-registered experiment 2, fifty participants completed the same task online. With the increased statistical power, we found strong evidence that participants were not able to discriminate intentions based on movement kinematics. Together, our findings suggest that the role of action kinematics in intention perception is more complex than previously assumed. Although previous research indicates that under certain circumstances observers can perceive and act upon intention-specific kinematic information, perceptual differences in everyday scenes or the observers’ ability to use kinematic information in more naturalistic scenes seems limited.

Removal of Large Wharton’s Duct Salivary Stones Using a CO2 Laser: A Report of Two Cases

Introduction: Salivary stones inside the Wharton’s duct adjacent to the mylohyoid muscle are often removed by a little incision of the mouth floor under local anesthesia. However, in the case of relatively large salivary stones, a large incision is required, which is commonly accompanied by hemorrhage and the need for surgical hemostasis, resulting in prolonged surgery. Furthermore, troublesome sequelae such as ranula and lingual nerve paralysis can occur after surgical procedures. Methods: Two patients who had relatively large salivary stones (>1 cm diameter) in the Wharton’s duct were underwent incision of the mouth floor soft tissues with a CO2 laser. Results: In both patients, the stone was removed in a few minutes without causing abnormal bleeding, nerve injury, or sublingual gland disorders and was completely healed. Conclusion: We report the usefulness and safety of the CO2 laser in two patients with relatively large salivary stones, who underwent successful surgical removal.

Bilateral isolated mylohyoid groove fracture progressing as submandibular abscess: an usual fracture pattern of mandible

The mylohyoid ridges or lines are pairs of anatomical bony structures located on the internal or lingual surface of mandible. They are the origin for the mylohyoid muscle. These bony structures are distinct in the mandibular molar region, well protected and gradually become undiscernible towards anterior mandible. Bilateral, isolated fracture of the mylohyoid ridges without concomitant mandibular fracture is rare and, to the best of the authors knowledge, was never previously described. This case report describes an isolated bilateral mylohyoid groove fracture, where one side of a necrotic bone fragment at the fracture site progress to became a nidus of infection, which later caused submandibular space abscess requiring emergency surgical intervention. Diagnosis, possible theory to explain the occurrence of isolated mylohyoid groove fracture and management of these condition are explained in this report.

Swallowing Dysfunction Following Radiation to the Rat Mylohyoid Muscle is Associated with Sensory Neuron Injury

Radiation based treatments for oropharyngeal and hypopharyngeal cancers result in impairments in swallowing mobility, but the mechanisms behind the dysfunction are not clear. The purpose of this study was to determine if we could establish an animal model of radiation-induced dysphagia in which mechanisms could be examined. We hypothesized that (1) radiation focused at the depth of the mylohyoid muscle would alter normal bolus transport and bolus size; and (2) that radiation to the mylohyoid muscle will induce an injury/stress-like response in trigeminal sensory neurons whose input might modulate swallow. Rats were exposed to 48 or 56 Gy of radiation to the mylohyoid given 8 Gy in 6 or 7 fractions. Swallowing function was evaluated by videofluoroscopy 2- and 4-weeks following treatment. Neuronal injury/stress was analyzed in trigeminal ganglion by assessing ATF3 and GAP-43 mRNA at 2-, 4- and 8-weeks post. Irradiated rats exhibited decreases in bolus movement through the pharynx and alterations in bolus clearance. Additionally, ATF3 and GAP-43 mRNAs were upregulated in trigeminal ganglion in irradiated rats, suggesting that radiation to mylohyoid muscle induced an injury/stress response in neurons with cell bodies that are remote from the irradiated tissue. These results suggest that radiation-induced dysphagia can be assessed in the rat, and that radiation induces injury/stress-like responses in sensory neurons.

Sublingual epidermoid cyst: unusual diagnosis in Otorhinolaringology

Dermoid and epidermoid cysts are rare in the head and neck, specially in the oral cavity, accounting for 1.6 %. It represents an even smaller percentage of all the oral cysts, less than 0.01%. Usually asymptomatic, however, occasionally, obstructive symptoms like dysphagia or speech difficulties are found. We present a case of a 32 years old female patient with a sublingual epidermoid cyst. The patient was referred to our ENT department with complaints of an oral mass, speech difficulties and solid food dysphagia for 1 month. Physical examination revealed a well circumscribed symmetrical mass on the floor of the mouth with no inflammatory signs, tender and fluctuant on palpation. Computed tomography (CT) was requested. CT scan showed a sublingual cystic mass inferiorly limited by the mylohyoid muscle. Aspiration was performed to improve symptoms until surgery. The liquid that resulted from aspiration showed a granulated white cheesy material. Enucleation of the cyst was performed intraorally in the operating room. Histopathologic investigation confirmed the diagnosis of epidermoid cyst. The patient fully recovered and there was no recurrence. Although rare, cases like this exist. There are several differential diagnoses and a high level of suspicion is necessary for a correct workup, diagnosis and follow-up. Surgical excision is usually necessary and curative.