Oral Functions: Feeding

Question 1

What is ingestion and what is carried out by?

Answer 1

Movement of food from the external environment into the mouth

• Accomplished by biting (anterior teeth) and/or using ‘tools’ (cutlery, cups, etc)
• Lips provide anterior oral ‘seal’.

Question 2

What facial muscles are used in ingestion and what do they do?

Answer 2

• Help to control food bolus and prevent spillage:

–Orbicularis oris
– Buccinator

Question 3

What is transport and how is it carried out?

Answer 3

Moving material from the front of the mouth to the level of the posterior teeth

Food is gathered on tongue tip

• Tongue retracts, pulling the material to the posterior teeth (pull back process; takes about one second)

Question 4

What anatomy is transport associated with

Answer 4

retraction of the hyoid bone and narrowing of the oropharynx

Question 5

What is mechanical processing?

Answer 5

• Some solid foods must be broken down and mixed with saliva before they can be swallowed
• Moist solid foods (e.g. fruit) have to have fluid removed before transport and swallowing

Question 6

How is mechanical processing carried out?

Answer 6

• Foods chewed (or masticated) by premolar and molar teeth
• Some soft foods are ‘squashed’ by tongue against hard palate

Question 7

What muscles are involved in food processing? (general groups)

Answer 7

– the “mandibular (former mastication) muscles”
– the supra-hyoid muscles
– the tongue muscles
– the lips and cheeks

Question 8

What neck muscle is involved in chewing?

Answer 8

sternocleidomastiod

Question 9

What are the actions of the tongue in chewing?

Answer 9

The tongue ‘controls’ the bolus
Tongue gathers food for transport and rotates to reposition the bolus on the occlusal table (from side to side)
Along with the cheeks, it keeps the bolus on the chewing surfaces

Question 10

What are the intrinsic tongue muscles and what do they do?

Answer 10

alter shape
longitudinal
vertical
transverse

Question 11

What are the extrinsic muscles and what do they do?

Answer 11

alter shape and position
genioglossus
hypglossus
palatoglossus
styloglossus

Question 12

What is the reciprocal action of the tongue and cheeks?

Answer 12

The tongue and cheeks act in a reciprocal manner to place the food on the occlusal surfaces of the teeth. “Tongue-pushing” and “cheek- pushing” cycles are observed during chewing.

Question 13

What is the squeeze back mechanism?

Answer 13

During swallowing, the tongue presses food backward against the palate in a wave-like motion. This “squeeze-back” action helps push the food down your throat through the fauces.

Question 14

What is the difference between swallowing solids and liquids?

Answer 14

Solid foods, the mouth is continuous with the oropharynx

Liquid foods, posterior oral seal is produced during the ingestion of liquids (liquids are swallowed from the mouth)

Question 15

What are the 3 phases of the chewing cycle?

Answer 15

opening phase - jaw depressor muscles are active

occlusal phase - mandible is stationary, teeth are joined

closing phase - jaw elevator muscles are active

Question 16

What strokes does a good occlusion create?

Answer 16

narrow and less broad

Question 17

What strokes does chewing on hard food create?

Answer 17

broader and wider

Question 18

What should be considered when designing prostheses?

Answer 18

chewing style

Question 19

If dentures have occlusal surfaces that are worn (flat), what might be the cause?

Answer 19

vertical (chopping) mandibular movement

Question 20

When designing the denture, what type of teeth might be used for flat atrophic mandibular ridges?

Answer 20

cuspless teeth

Question 21

What does mechanical breakdown of the food in the mouth acheive?

Answer 21

–Facilitates swallowing
–Might improve digestive efficiency in G.I. Tract

Minimum chewing with a ‘good’ dentition is sufficient to ensure adequate digestion of most foods

Question 22

What does deteriorated masticatory performance cause?

Answer 22

– avoiding foods that are “difficult”
– such as green vegetables, some meats

there is no clear evidence that poor mastication causes malnutrition in people with G.I. tract disorders especially with modern foods and methods of preparation.

Question 23

What is the minimum amount of teeth required for a SDA (shortened dental arch)?

Answer 23

20 teeth is considered the minimum for acceptable:
– masticatory function
– aesthetics
– maintenance of oral hygiene

Question 24

What does a SDA provide?

Answer 24

• Absent molar teeth are only replaced if their absence gives rise to problems.
• SDA provides sufficient occlusal stability.
• SDA provides satisfactory comfort and appearance.
• chewing and comfort were not significantly enhanced by the provision of RPDs.

Question 25

What should be done if a SDA is present?

Answer 25

particular attention must be given to the possibility of simply maintaining the status quo rather than providing an RPD.

Question 26

What is the biting load carried by in complete denture wearers?

Answer 26

mucosa of residual ridge (not designed to bear masticatory loads therefore support area is reduced)

Question 27

Where is the biting load carried to in dentate patients?

Answer 27

PDL

Question 28

How can biting forces be increased in patients with dentures?

Answer 28

by supporting dentures on teeth or implants

Question 29

What are the types of supports in replacing missing teeth?

Answer 29

• ‘Mucosa-supported’ prosthesis
  – complete – Partial
• ‘Tooth-supported’ prosthesis
  – removable
  – fixed (‘bridges’)
• ‘Bone supported’ prosthesis (Implants)

Question 30

What is an example of mucosa-supported prothesis?

Answer 30

acrylic partial dentures

Question 31

What is an example of tooth-supported prothesis?

Answer 31

CoCr partial dentures
Bridges

Question 32

What is a cantilever bridge and what is it used for?

Answer 32

• A pontic connected to a retainer at one end only
• Is used to replace single teeth and only one retainer is used to support the bridge.
• Not recommended when occlusal forces on the pontic will be heavy

Question 33

What is an adhesive bridge/resin bonded/maryland?

Answer 33

dental prosthesis that replaces a missing tooth by bonding a pontic (artificial tooth) to the adjacent natural teeth using resin cement, without the need for extensive tooth preparation.

Question 34

What are the advantages of an adhesive bridge?

Answer 34

Quick, non-destructive (conservative of tooth tissues), aesthetic, and durable (good life span)

Question 35

What are the two designs of adhesive bridges?

Answer 35

cantilever
fixed-fixed

Question 36

What is mucosa borne?

Answer 36

Craddock class 2
Occlusal load transmitted to bone via the oral mucosa NOT RECOMMENDED!

Question 37

What is tooth borne?

Answer 37

Occlusal load transmitted to bone via the rests and PDL RECOMENDED