Displacement of oropharyngeal structures during suction-swallowing cycles

Abstract

Suction ability plays an important role in supporting oral nutrition and needs special care following neurological disorders and tumor-associated defects. However, the details of suction are still poorly understood. The present study evaluates displacement of orofacial structures during suction and deglutition based on manometric controlled MRI. Nine healthy subjects were scanned wearing an intraoral mouthpiece for water intake by suction and subsequent swallowing. Suction-swallowing cycles were identified by intraoral negative pressure. Midsagittal MRI slices (3 T; temporal resolution 0.53 s) were analyzed at rest, suction and pharyngeal swallowing. The mandibular displacement was measured as the distance between the anterior nasal spine and the inferior point of the mandible. Following areas were defined: subpalatal compartment (SCA), retrolingual (RLA), epipharyngeal (EPA) and mouth floor area (MFA). During rest, an average distance of 7 cm was observed between the mandibular measurement points. The measured SCA was 3.67 cm(2), the RLA 6.98 cm(2), the EPA 9.00 cm(2) and the MFA 15.21 cm(2) (average values). At the end of suction, the mandibular distance reduces (to 6.88 cm), the SCA increases significantly (to 5.96 cm(2); p = 0.0002), the RLA decreases (to 6.45 cm(2)), the EPA increases (to 10.59 cm(2)) and the MFA decreases (to 15.02 cm(2)). During deglutition, the mandible lifted significantly (to 6.81 cm; p = 0.0276), the SCA reduced to zero, the RLA was not measurable, the EPA reduces significantly (to 3.01 cm(2); p < 0.0001) and the MFA increases (to 16.36 cm(2)). According to these observations, a combined displacement of the tongue in an anteroposterior direction with active tongue dorsum-velum contact appears to be the predominant activity during suction and responsible for the expansion of the subpalatal area.

Interaction between deglutition, tongue posture, and malocclusion: A comparison of intraoral compartment formation in subjects with neutral occlusion or different types of malocclusion

“…4 Approaches involving the use of magnetic resonance imaging, or even radiographic methods, involve ethical issues. 8 A noninvasive method of assessing tongue posture during function is the use of the intraoral manometry technique. [9][10][11][12] This technique is based on the concept of the biofunctional model of the oral cavity, combining aspects from anatomy, dentistry, and otorhinolaryngology.…”

Dysphagia in amyotrophic lateral sclerosis: Quantification of bulbar motor dysfunction

“…Regarding the oral phase of swallowing, other studies have focused on maximal isometric tongue pressure 3–9 . Apart from this, sub‐palatal pressure gradients were described supporting oropharyngeal swallowing 9–12 . As seen in a magnetic resonance imaging (MRI) study negative sub‐palatal pressures seem to ensure an anchorage of the tongue to the hard palate that supports the essential elevation of the larynx during swallowing 13 …”

“…gradients were described supporting oropharyngeal swallowing. [9][10][11][12] As seen in a magnetic resonance imaging (MRI) study negative subpalatal pressures seem to ensure an anchorage of the tongue to the hard palate that supports the essential elevation of the larynx during swallowing. 13 To reveal the impact of sub-palatal pressures on dysphagia, measures of patients who were suffering from ALS were compared to healthy volunteers.…”

Real‐time MRI of swallowing: intraoral pressure reduction supports larynx elevation

“…For example, to date, intraoral manometry of the isometric tongue pressure or atmospheric pressure in the oral cavity has been discussed exclusively within the context of oral bolus transport. Pushing the bolus is seen as the tongue's main task and a gradient of negative atmospheric intraoral pressure has been suggested to support bolus transport . However, a pressure gradient has never been proven experimentally and the functional context of a negative intraoral pressure during swallowing still remains an open question.…”

“…Pushing the bolus is seen as the tongue's main task and a gradient of negative atmospheric intraoral pressure has been suggested to support bolus transport. 3,4 However, a pressure gradient has never been proven experimentally and the functional context of a negative intraoral pressure during swallowing still remains an open question.…”