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Parapharyngeal Space
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
The parapharyngeal space is an inverted, pyramidal-shaped neck space filled with fat and areolar tissue (Figure 60.1). Its superior base comprises the sphenoid and temporal bones and includes the jugular and hypoglossal canal and the foramen lacerum. Its inferior apex is at the greater cornu of the hyoid bone. It has three sides, medial, lateral, and posterior, and an anterior leading edge that is the pterygomandibular raphe.
Common head and neck viva topics
Published in Joseph Manjaly, Peter Kullar, Advanced ENT Training, 2019
The parapharyngeal space connects to the retropharyngeal space (abscess formation in this space is common in childhood, due to the involvement of the retropharyngeal lymph nodes). The retropharyngeal space extends to the superior mediastinum at the level of T2 vertebrae, hence when suspected imaging should include the chest. The parapharyngeal space also connects to the submandibular space via the pterygomandibular raphe.
Anatomy and Embryology of the Mouth and Dentition
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, Head & Neck Surgery Plastic Surgery, 2018
The pterygomandibular raphe is a thin band of tendinous fibres passing between the hamulus of the medial pterygoid plate and the posterior end of the mylohyoid line of the mandible. It gives origin anteriorly to the buccinator muscle and posteriorly to the superior constrictor muscle.
Prospective multi-center study on expansion sphincter pharyngoplasty
Published in Acta Oto-Laryngologica, 2019
Guillermo Plaza, Peter Baptista, Carlos O'Connor-Reina, Gabriela Bosco, Nuria Pérez-Martín, Kenny P. Pang
Taking into account the important role of the lateral pharyngeal wall and, more precisely, the increased collapsibility in patients with OSAHS, Cahali [3] first described this important issue with a novel technique, lateral pharyngoplasty. Pang and Woodson [4] in 2007, described the ESP to treat patients with OSAHS. The philosophy of this procedure is to transform a ‘bad’ muscle, the palatopharyngeus muscle, into a ‘good’ one. The aim is to caudally detach it from its insertions in the constrictor muscles and, once released, rotate it upwards and laterally, to suture it again at the height of the pterygoid hamulus, at the pterygomandibular raphe. Although some authors do not accept that changing the direction vector of the muscle might keep it as a functioning muscle [10,11], at least by cutting the caudal edge of the muscle, its closing action is very reduced, as can be seen during the procedure while electrically stimulating it.
Oral mucosa grafting in periorbital reconstruction
Published in Orbit, 2018
Surgery is often but not exclusively performed under general anaesthesia using nasotracheal or orotracheal intubation secured to one side of the mouth to allow exposure of the contralateral buccal mucosa.84,93 Insertion of a Dingman intraoral retractor,84,94 a Steinhauser mucosal stretcher,95 or two atraumatic Babcock clamps76 optimizes accessibility by keeping the mouth maximally open and aids dissection by placing the tissues under tension. Otherwise the assistant simply stretches the inner side of the cheek outwards by applying tension on the corner of the mouth or the lower lip to facilitate surgical access during harvesting.96 The conjunctival defect is measured to estimate the graft size required. The opening of Stensen duct opposite the second upper molar tooth is visually identified which may be augmented by squeezing the parotid gland (Figure 3.).77,78 The shape and extent of the graft is then carefully outlined with a surgical marker pen on dry mucosa, staying 1 cm inferior to the papilla of Stensen duct and 1–1.5 cm margin away from the lip vermillion, posterior to the labial commissure and anterior to the pterygomandibular raphe to prevent distortion from post-operative scarring.74,77,78,85,97,98 The graft outline should take into account an average of 20% graft contracture.99 Submucosal infiltration with adrenaline containing local anaesthetic solution (bupivacaine 0.25% mixed with 1:200000 adrenaline), facilitates haemostasis as well as hydrodissection of the mucosa from the underlying submucosal fatty tissue.96,100 An initial full-thickness mucosal incision is made with a microscalpel along the marked anterior apex and margins of the graft outline. The rest of the dissection is completed from front to back using Jameson’s scissors, staying close to the mucosal layer. A submucosal dissection plane is fashioned above the adipose layer superficial to the buccinator muscle. Dissection is maintained in the correct plane to avoid harvesting the underlying buccinator.74,77,88,101 Injury to the buccal and mental nerves is prevented by avoiding extending the incision too far posteriorly or inferiorly into the lower lip.78,102,103 Salivary flow and patency of the parotid duct are checked at the end of the procedure by milking the duct.77,78 Cautery should be avoided if possible to prevent thermal nerve damage.76,85,104
Mandibular advancement splints for the treatment of obstructive sleep apnea
Published in Expert Review of Respiratory Medicine, 2020
Andrew S. L. Chan, Kate Sutherland, Peter A. Cistulli
OSA is increasingly being recognized as a heterogeneous disorder with multiple pathophysiological causes, both anatomical and non-anatomical. By targeting OSA treatment to specific underlying pathophysiological mechanisms, it may be possible to broaden treatment options and improve clinical outcomes [8]. It has been traditionally thought that the primary mechanism of action of MAS is to cause mechanical advancement of the mandible and thereby increase the antero-posterior dimensions of the oropharynx. However, the specific biomechanical changes that underlie the efficacy of these devices are unknown, although there is some evidence from upper airway imaging studies that mandibular advancement improves the patency of the velopharyngeal segment of the upper airway, the most common site of upper airway collapse and flow limitation in OSA [9,10], with the lateral diameter of the velopharynx increasing to a greater extent than the antero-posterior diameter [7,11,12]. The precise reason for this effect on velopharyngeal patency is unclear. However, soft tissue connections exist between the mandible, tongue, lateral pharyngeal walls and soft palate, within the palatoglossal and palatopharyngeal arches. It has been proposed that such soft tissue connections may be stretched by mandibular advancement [13] and this has been confirmed using dynamic tagged magnetic resonance imaging, with the soft tissue connections appearing to correspond to the region of the pterygomandibular raphe [14]. These structural changes are associated with a dose-dependent reduction in the collapsibility of the upper airway, as measured by a reduction of the upper airway closing pressure during sleep [15] and a reduction in upper airway critical closing pressure (Pcrit) [16], both of which reflect the passive mechanical properties of the upper airway. While some research studies have shown that mandibular advancement stimulates genioglossus muscle activity [17,18], others have found that it reduces genioglossus muscle activity [19,20], and the clinical importance of upper airway neuromuscular reflexes in the mechanism of action of MAS remains uncertain [16]. Research studies have shown that using oral appliances that do not provide mandibular advancement have no significant clinical benefit for the treatment of OSA, suggesting that such a mechanism plays a minor role [21,22]. Thus, mandibular advancement primarily modifies the ‘anatomical imbalance’ as a contributing factor in OSA [8] which can vary in importance depending on ethnicity and gender [23,24]. There is no evidence that MAS have a direct impact on other non-anatomical factors, such as arousal threshold or loop gain [25]. The mechanism of action of MAS is schematically illustrated in Figure 1, with axial magnetic resonance images showing an increase in the caliber of the upper airway.