Module 5 - SHS310

Identify all components indicated by the letters

A - parotid salivary gland

B - submandibular salivary gland

C - sublingual salivary gland

Looking at the pictures: which of the pictures show no evidence of orofacial myofunctional disorder?

B

Looking at the pictures, Which of the pictures is a direct result of low tongue position in the mouth?

C

Looking at the pictures, Which of the pictures represents an individual who would be at risk for sleep apnea?

A, C, and D

What is the location and function of the parotid salivary glands?

Location - front of each ear, extending toward the cheek area

Function - produce watery saliva and provide lubrication during swallowing

What saliva is produced in the parotid gland?

Serous (watery) saliva

What is the location and function of the submandibular salivary gland?

Location - Beneath the mandible (lower jaw)

Function - Moisten the oral cavity and support bolus formation during the oral preparatory phase

What saliva is produced in the submandibular gland?

Mucoid (viscous) saliva

What is the location and function of the sublingual salivary gland?

Location - under the tongue

Function - assist in bolus cohesion and maintain oral moisture

What saliva is produced in the sublingual gland?

Mucoid (viscous) saliva

There are additional small salivary glands, where are they found and their function?

Found in the lips cheek, tongue, and palate

provide constant moisture within the oral cavity

What role does serous saliva have?

• Lubricates bolus during swallowing

• Helps move the bolus efficiently through the pharynx

• Important for the pharyngeal phase

What role does the mucoid saliva have?

• Helps form and hold the bolus together

• Maintains moisture in the oral cavity

• Important for the oral preparatory phase

Why is saliva important for swallowing?

• Keeps the oral cavity moist

• Reduces tooth decay

• Begins digestion

• Helps create a cohesive bolus

• Provides lubrication for smooth transport through the pharynx and esophagus

What is the duration of oral preparatory phase?

~ 1 to 3 seconds

Is oral preparatory voluntary or involuntary?

Voluntary

What are the key structural positions and movement in the oral preparatory phase?

• Lips seal to keep food inside mouth.

• Tongue is “dished” to form a bowl for liquids.

• Jaw performs mastication for solids.

• Velum is down, allowing breathing while chewing.

• Submandibular and sublingual glands produce mucoid saliva to form bolus.

Is the airway protection or bolus propulsion in the oral preparatory phase?

No airway closure yet. focus is bolus preparation, not propulsion

What are the pressures in the oral preparatory phase?

Oral cavity pressure is neutral; no propulsion yet

What is happening to the UES and LES in the oral preparatory phase?

UES is closed and LES is not involved yet

What is the duration of the oral transport phase?

~0.5 seconds

Is oral transport phase voluntary or involuntary?

Voluntary, but transitions into involuntary reflex triggers

What are the key structural positions and movements in oral transport phase?

• Tongue tip elevates.

• Tongue performs peristaltic-like movement to move bolus posteriorly.

• Contact with velum and faucial pillars triggers the swallow reflex → velum elevates.

• Velopharyngeal closure begins at the end of this phase.

Is the airway protection or bolus propulsion in the oral transport phase?

Airway is still limited in protection and propulsion of bolus to pharynx

What are the pressures in oral transport phase?

Oral cavity pressure becomes slightly positive to push bolus backward

What is the UES and LES doing in the oral transport phase?

UES remains closed until reflexively opened in the next phase

What is the durations of the pharyngeal phase?

~0.5 secs

Is the pharyngeal phase voluntary or involuntary?

Involuntary, controlled by the central pattern generator

What are the key structural positions and movements in the pharyngeal phase?

Airway Protection Events:

• Velopharyngeal closure (velum rises).

• Hyo-laryngeal elevation (hyolaryngeal complex pulled up and forward).

• True vocal fold adduction.

• Epiglottic inversion.

Bolus Propulsion Events:

• Pharyngeal walls contract peristaltically.

• Pressure generated behind the bolus.

• Parotid glands produce serous saliva for lubrication.

Is the pharyngeal phase in the airway protection or bolus propulsion?

Both occur at the same time

What are the pressures of the pharyngeal phase?

High pressure generated behind bolus by pharyngeal constrictors

Low pressure created below bolus by UES relaxation

What is the UES and LES doing pharyngeal phase?

UES relaxes and opens, while LES is not involved yet

What is the duration of the esophageal phase?

8 to 20 seconds

Is the esophageal phase voluntary or involuntary?

involuntary

What are the key structural positions and movements to the esophageal phase?

• UES closes after bolus passes.

• Esophagus uses peristalsis to move bolus downward.

• LES dilates to allow entry into stomach.

Is the airway protection or bolus propulsion during the esophageal phase?

• Airway protection complete (all structures return to breathing configuration).

• Primary action: propulsion via esophageal peristalsis.

What are the pressures in the esophageal phase?

Low pressure in front of bolus; peristaltic high pressure behind bolus

LES maintains high resting pressure to prevent reflux

What does the UES and LES do in the esophageal phase?

• UES: relaxes then closes.

• LES: opens to allow bolus into stomach; prevents gastric reflux.

What variables influence swallowing?

• Bolus characteristics: consistency, volume, taste, temperature

• Swallow mode: single vs sequential

• Environment: mealtime eating vs clinical swallow test

• Cued vs uncued swallow

What are some unique characteristics of infant swallowing

• Rooting and sucking reflexes dominate feeding behavior.

• Infants can breathe while swallowing because:

  • Velum locks into space between tongue and epiglottis

  • This configuration temporarily seals airway

• Different anatomy:

  • Larger velum

  • More horizontal orientation

  • Elevated, anteriorly positioned hyoid

  • Elevated larynx

• Infants perform 3–4 suck pumps → then swallow.

Which phases of swallowing are voluntary?

Oral preparatory phase and oral transport phase (cortically controlled).

Which phases of swallowing are involuntary?

Pharyngeal phase and esophageal phase

What is the function of the Central Pattern Generator (CPG)?

Generates pre-programmed, sequential motor commands for the involuntary phases of swallowing.

Where is the Central Pattern Generator located?

In the medulla

What is the main function of the Nucleus Tractus Solitarius (NTS)?

Acts as the sensory nucleus for swallowing—receives sensory input from CN V, VII, IX, and X.

What kinds of sensory information go to the NTS?

Taste, general sensation from the face, tongue, palate, pharynx, and larynx.

What is the main role of the Nucleus Ambiguus (NA)?

Provides motor output for swallowing—sends motor commands to muscles of the palate, pharynx, larynx, esophagus, lips, jaw, and tongue.

Which nucleus triggers the motor sequence of the swallow?

Nucleus Ambiguus (NA), based on CPG commands.

Which nucleus integrates sensory input to initiate the swallow reflex?

Nucleus Tractus Solitarius (NTS)

Which cranial nerves send sensory input to the NTS?

CN V, VII, IX, and X

Which cranial nerves receive motor output from the NA for swallowing?

CN V, VII, IX, X, and XII

What happens once the swallow is triggered?

The CPG automatically coordinates and completes the pharyngeal and esophageal phases.

What is the definition of dysphagia?

Difficulty in swallowing secondary to paralysis or paresis, typically affecting the pharyngeal phase.

Which phase of swallowing is most affected in dysphagia?

The pharyngeal phase

What are “tethered oral tissues”?

Another term for restricted frenum or tongue tie—a condition where the lingual frenulum is too tight or short.

How do tethered oral tissues affect swallowing?

They prevent the tongue tip from lifting to the alveolar ridge, disrupting the normal peristaltic tongue movement needed for the oral transport phase.

What swallowing problems can tethered oral tissues cause in infants?

Difficulty breastfeeding because the baby cannot extend the tongue properly.

How does a restricted frenum affect bolus movement?

The tongue stays low and forward, leading to anterior tongue carriage and inefficient oral transport.

What is the Modified Barium Swallow (MBS)?

An evaluation conducted by an SLP to assess the pharyngeal phase of swallowing using X-ray imaging.

What is FEES (Fiberoptic Endoscopic Evaluation of Swallowing)?

A swallow evaluation performed by an SLP working with a physician, where a small camera is inserted through the nose to visualize pharyngeal structures during swallowing.

Which provider gives the medical diagnosis during FEES?

The physician (M.D.); the SLP describes the swallowing function.

What is a Barium Swallow (Esophagram)?

An evaluation performed by a gastroenterologist to assess the esophageal phase of swallowing.

Which swallow evaluation is used to examine the esophageal phase?

The barium swallow

Which evaluations are conducted by an SLP?

• Modified Barium Swallow (MBS)

• FEES (in collaboration with a physician)

What is an Orofacial Myofunctional Disorder (OMD)?

A disorder of muscle function of the face and mouth, primarily involving abnormal tongue placement and difficulty in the oral preparatory and oral transport phases of swallowing.

What are other names for OMD?

Tongue thrust, immature swallow, reverse swallow, anterior tongue carriage.

What oral phases of swallowing are affected in OMD?

Oral preparatory and oral transport phases.

What are the main categories of causes of OMD?

• Oral habits

• Restricted frenum (tongue tie)

• Adaptation to restricted airway

How do oral habits cause OMD?

Objects in the mouth (pacifiers, thumbs, sippy cups) prevent oral closure and push the tongue forward.

How does a restricted frenum cause OMD?

Prevents the tongue tip from raising to the alveolar ridge, leading to anterior tongue carriage and disrupted tongue peristalsis.

How does airway obstruction cause OMD?

The tongue moves forward to enlarge the airway, resulting in low, anterior tongue posture and open-mouth breathing.

How is OMD connected to mouth breathing?

Low or forward tongue posture opens the mouth, leading to habitual mouth breathing and altered facial development.

How is OMD connected to posture?

Mouth breathers often adopt a forward head posture to open the airway.

How does OMD influence facial growth?

Low tongue posture removes the tongue’s “retainer” effect, causing:

• High, narrow palate

• Decreased nasal cavity volume

• Elongated lower face

• Receded chin

• Short upper lip

How is OMD related to sleep apnea?

Without proper tongue anchoring, the tongue can fall backward during sleep, contributing to sleep-disordered breathing or obstructive sleep apnea.

How does OMD affect speech?

Causes dentalized or interdental /s, z/ due to anterior tongue carriage; same structures needed for proper swallowing.

What are common characteristics of OMD?

• Forward tongue position

• Tongue thrust during swallowing

• Open-mouth posture

• Difficulty creating lip seal

• High, narrow palate

• Scalloped tongue

• Thumb/pacifier habits

• Restricted frenum

How do these characteristics impact function?

• Tongue thrust: inefficient swallow, orthodontic issues

• Open-mouth posture: mouth breathing, facial changes

• Low tongue posture: altered palate and nasal cavity

• Restricted frenum: impaired breastfeeding, disordered swallow

• Scalloped tongue: chronic pressure against teeth

• Habits: reinforce improper oral posture

What visual signs help identify OMD in photos?

• Open-mouth rest posture

• Visible tongue during /s/ and /z/

• Narrow or V-shaped palate

• Receded chin

• Elongated lower face

• Pursed lips when swallowing

• Scalloped tongue edges

• Anterior tongue resting position

What does OMD therapy (OMT) aim to accomplish?

• Retrain muscle patterns

• Establish proper swallow pattern

• Correct tongue resting posture

• Improve nasal breathing

• Reduce oral habits

• Support orthodontic treatment

• Improve speech affected by tongue placement

• Improve airway stability (related to sleep apnea)

Which professionals treat OMD?

• SLPs trained in OMD

• Certified Orofacial Myologists (COM)

• Orofacial Myofunctional Therapists

• Dentists/Orthodontists

• Oral hygienists (RDH)

• Nutritionists (in some cases)

Can all SLPs treat OMD?

No—ASHA requires additional training to treat OMD.