oral functions 4 - aerodigestive tract reflexes and speech Flashcards
what are the 3 stages in swallowing
- buccal phase = voluntary
- pharyngeal phase = involuntary
- oesophageal = involuntary
what is swallowing
- process by which the accumulated food bolus is transported through the lower pharynx and oesophagus to the stomach (feeding function)
- prevents ingested material from entering the lower airway (protective function)
how is bolus formed
- the water in saliva allows the bolus to stick together to be swallowed
why is swallowing potentially dangerous
- because the ‘food-way’ crosses the airway
how are liquids swallowed
- liquids are gathered on the tongue, anterior to the pillars of the fauces
- the mouth is separated from the pharynx by a posterior oral seal = this doesn’t happen with solid bolus
- the liquid bolus is then propelled through the oropharynx and hypo pharynx and then into the oesophagus
how is solid bolus swallowed
- chewed food material accumulates on the pharyngeal part of the tongue and vallecula (oropharynx)
- there is no true posterior oral seal
- the bolus is then propelled from the tongue through the hypo pharynx and then into the oesophagus
what are some key points of swallowing
- liquids are swallowed from the mouth = oral seal
- solids are swallowed from the oropharynx = no oral seal
- both are mixed rapidly through the hypo pharynx past the laryngeal inlet
what do tongue movements do in swallowing
- the forward movement of the tongue during the occlusal and initial opening phases creates a contact between the tongue and hard palate
- the contact zone moves progressively backwards, squeezing the processed food through the fauces
- tongue breaks up the bolus to be swallowed in smaller amounts
what are the swallowing events
- propulsion of food
- prevention of reflux
- protecting the airway
what is the duration of the masticatory sequence
- the duration varies with the different extents of food consistency
how strong are swallowing forces
- these are strong enough to move bolus up hill or down hill
how is reflux prevented
- elevation of the soft palate
- tongue (sides) contacts pillars of fauces
- tongue (dorsal) contacts posterior pharyngeal wall
- upper oesophageal sphincter stops reflux from oesophagus into pharynx
- lower oesophageal sphincter stops reflux from stomach into oesophagus
how can erosion occur
- stomach acid can erode teeth by reflux, vomitting, regurgitation and rumination
- when palatal surface erosion is present, 2/3 of the time stomach acid is responsible = causes cupping on the palatal surface - is intrinsic erosion
how can you prevent fizzy drinks causing erosion
- patients will not stop drinking these even if asked
- instead need to suggest that they drink them with a straw or only at mealtimes to lessen damage
what are other types of tooth surface loss than erosion
- attrition
- abrasion
- abfractions
what is attrition
- is tooth wear occlusally caused by contact between occluding teeth
- the teeth inter-digitate indication that attrition is occurring
- there are equal amounts between upper and lower
what is abrasion
- occurring on its own is unusual = might be caused by biting or chewing objects between the teeth
- the most common presentation of tooth wear it the result of a combined lesion involving erosion and abrasion
- acids weaken the outer 3-5 microns of mineralised tissue and increase the susceptibility of the enamel and dentine to abrasion from tooth brushing with or without toothpaste
what is abfraction
- stress lesion s
- wedge-shaped notch caused by the flexure and ultimate material fatigue of susceptible teeth at locations away from the point of loading
- the breakdown is dependant on the magnitude, duration, frequency and location of occlusal forces
- premolars are specifically at risk due to high occlusal load here
how is the airway protected during swallowing
- upward and forward movement of larynx
- closure of laryngeal inlet = aryepiglottic muscles, epiglottis
- adduction of vocal folds = movement of them towards midline of body, or towards other part
- stop breathing = apnoea
what is dysphasia
- sometime called aphasia
- a specific language disorder
- involving damage to particular parts of the brain = Broca’s area and Wernick’s area
what is dysphagia
- difficulty/inability to swallow
what is odynophobia
- pain on swallowing
- a pathological condition in which the affected person experiences extreme pain when swallowing be it foods, liquids, drugs
what is dysarthria
- difficulty speaking that is caused by problems with the muscle used in speech
- due to neuro-muscular defects = important to notice these in a patient as can affect treatment - e.g. dentures
what are some oral causes of language and speech defects
- malocclusions
- loss of teeth and denture
- cleft lip/palate
- tongue related issues
- dry mouth
what is malocclusions
- e.g. anterior open bite
- caused by digit sucking as a baby
- tongue thrust
- skeletal origin
what can cleft lip/palate do to speech
- oral and nasal cavities are not separated
- speech as a ‘nasal’ quality
- palatal defect has to be repaired or filled with an obturator
what are some tongue related issues with speech
- tongue tie = easy fix
- partial atrophy = tongue not completed
- tongue stud
what does dry mouth do
- xerostomia
- one of the serious repercussions of dry mouth if impeded speech
- wit inadequate saliva production, pronouncing words becomes difficult
- people who have dry mouth and difficulty speaking cannot simply swallow and start talking normally
what is torus mandibularis/tori
- does not affect speech of languor but can affect RPD’s
- have to change design to accommodate if patient doesn’t want them removed
- they are just lumps in the mouth - benign
- also get it on the palate (torus platinus) = need to deist a horseshoe denture to accommodate it
what are some denture related issues for speech
- problems mainly arise from restricted tongue space
- denture base can be too thick
- artificial teeth may not be set properly
how does the tongue need to be situated to make ‘s’ sounds
- the polished surface is correctly shaped so the tongue can form narrow channel in the midline for producing the ‘s’ sound
how is the sound ‘sh’ made
- excessive thickening of the palate laterally prevents close adaptation of the tongue to the palate so that the ‘s’ becomes a ‘sh’
what can happen to prevent sounds ‘f’, ‘v’ and ‘ph’ being made properly
- wrong occlusal planes may mean pronouncing these sounds wrong = labio-dental sounds
- dentures must be fabricated to a morphology that does not cause interference with tongue/lip/cheek movement
what can happen if loss of teeth
- loss of anterior teeth may present the clear reproduction of certain sounds particularly ‘f’ and ‘v’ which are made by the lower lip contacting the edges of the maxillary incisors
- the replacement of missing upper teeth make a significant contribution to quality of speech
how are ‘f’ ‘v’ and ‘ph’ sounds made
- the lips of the maxillary incisor teeth should touch the vermilion border of the lip during fricative sounds
how is speech assessed after replacing missing teeth
- the tone of the lips and cheeks may be assessed by asking fundamental questions such as address, family etc
- this will indicate the functional relationship of the lips and tongue to dentures in speech
why must musical instruments be considered when replacing missing teeth
- the aerodigestbive tract and facial tissues produce vocal sounds and also contribute to the playing of wind instruments
- dentists should be aware of the implications of oral an dental disease, and treatments, in patients who are musicians
what factors influence the final choice of treatment fro missing teeth for musicians
- cost
- effects on adjacent teeth
- aesthetics
- function = embouchure is important as a musician
what is embouchure
- the position and use of lips, tongue and teeth in playing a wind instrument
- vary between player and instrument
what instruments have an intra-oral mouthpiece
- single-reed = clarinet, saxophone
- double reed = oboe, bassoon
what instruments have extra oral mouthpieces
- piccola, flute
- trumpet, horn, trombone, tuba
what changes in the mouth when playing ‘high’ and ‘low’ sounds
- position of mouthpiece relative to teeth
- mouth opening
- relation of jaws
- position of hyoid bone
- position of dorsum of tongue
why must you consider denture design when treating musicians
- for example trumpet mouthpiece is usually entered on the lips
- it tends to move all from teeth backwards
- wind instrument players may have special needs in respect to the retention of the appliance and placement of teeth
what are issues for musician and dentists for treatment
- teeth = restorations, loss and replacement, aesthetic dentistry
- tongue
- facial muscles = lip, cheeks
