Oral function 3 - feeding sequence

Question 1

what is the first part of the feeding sequence

Answer 1

ingestion

Question 2

what is ingestion

Answer 2

movement of food from the external environment into the mouth

Question 3

how is ingestion accomplished

Answer 3

by biting with your anterior teeth and/or using ‘tools’ such as cutlery, cups etc.

Question 4

what do lips provide in the feeding sequence

Answer 4

provide an anterior ‘seal’

Question 5

what is the second part of the feeding sequence

Answer 5

transport

Question 6

what is stage 1 transport

Answer 6

Stage I transport is moving material from the front of the mouth to the level of the posterior teeth.

Question 7

what are the steps to stage 1 transport

Answer 7

• Food is gathered on the tongue tip

* The tongue retracts, pulling the material to the posterior teeth. PULL BACK PROCESS

Question 8

what is after transport

Answer 8

mechanical processing

Question 9

what happens in mechanical processing for solid foods

Answer 9

Some solid foods must be broken down and mixed with saliva before they can be swallowed

Question 10

what happens in mechanical processing in moist solid foods

Answer 10

Moist solid foods such as fruit have to have fluid removed before transport and swallowing

Question 11

how is food generally chewed/masticated

Answer 11

Generally food is chewed/masticated by premolar and molar teeth however, some soft foods are ‘squashed’ by the tongue against the hard palate

Question 12

what muscles are involved in food processing

Answer 12

the ‘mandibular muscles’
the supra hyoid muscles
the tongue muscles
the lips and cheeks

Question 13

how does the tongue control bolus

Answer 13

It gathers food and rotates to reposition the bolus on the occlusal table

Question 14

what is the tongues role in chewing

Answer 14

the tongue plays a key role in controlling and transporting the bolus within the mouth.

Question 15

what do the tongue and cheeks work together to do

Answer 15

The tongue and the cheek act in a reciprocal manner to place the food on the occlusal surfaces of the teeth. ‘tongue pushing’ (red) and ‘cheek pushing’ (blue) are observed during chewing.

Question 16

what are the tongue movements during chewing

Answer 16

The forward movement of the tongue during the occlusal and initial opening phases creates a contact between the tongue and the hard palate
The contact zone moves progressively backwards squeezing the processed food through the fauces – the so called ‘squeeze-back’ mechanism.
This material accumulates on the pharyngeal surface of the tongue and remains there until swallowing occurs.
During processing of solid foods, the mouth is continuous with the oropharynx
A posterior seal may be produced during the ingestion of liquids (liquids are swallowed from the mouth without stage II transport

Question 17

what are the 3 phases of the chewing cycle

Answer 17

opening phase
closing phase
occlusal phase

Question 18

what is the opening phase

Answer 18

the jaw depressor muscles are active

Question 19

what is the closing phase

Answer 19

jaw elevator muscles are active

Question 20

what is the occlusal phase

Answer 20

mandible is stationary, teeth are joined. In the ICP

Question 21

how does the chewing cycle differ from person to person

Answer 21

it is a narrower chewing cycle for brittle foods such as carrots and a wider one for tougher foods such as meat.

Question 22

what should be considered when designing prostheses

Answer 22

chewing style

Question 23

if the patient performs ruminator mandibular movements what kind of teeth should be used

Answer 23

use teeth with cusps to achieve balanced occlusion (especially when patients have favourable ridge form).

Question 24

if the dentures have occlusal surfaces which are evenly worn, what is this suggestive of

Answer 24

vertical (chopping) mandibular movement

Question 25

what type of teeth should be used for vertical mandibular movement

Answer 25

In this case, especially in flat, atrophic mandibular ridges, cuspless teeth might be used.

Question 26

why is it important to consider tongue movement when designing prosthesis

Answer 26

inaccurate placement of the mandibular teeth might interfere with tongue’s movements and will compromise the retention/stability of the denture as if the tongue does not have enough room it will hit the denture. You want the teeth to be on the ridge.

Question 27

what is the tongue important for in dentures

Answer 27

The tongue is important in controlling the denture. Some patients can use their tongue to control their denture while they eat incisally, this is called neuromuscular control

Question 28

what does mechanical breakdown of food in the mouth result in

Answer 28

facilitates swallowing

might improve digestive efficiency in GI tract

Question 29

what does masticatory performance correlate with

Answer 29

occlusal contact area

Question 30

when is it not necessary to replace missing teeth

Answer 30

the other components of the masticatory apparatus are functioning properly

Question 31

what is the shortened dental arch

Answer 31

20 teeth is considered the minimum for acceptable masticatory function, aesthetics, maintenance of oral hygiene. However other treatment options may be appropriate here as well.

Question 32

when are absent molar teeth replaced

Answer 32

Absent molar teeth are only replaced if their absence gives rise to problems. SDA provides sufficient occlusal stability

Question 33

what should be paid attention to if a patient has an SDA

Answer 33

If a SDA does exist then particular attention must be given to the possibility of simply maintaining the status quo rather than providing an RPD as there is a intolerance especially to lower dentures.

Question 34

how does dentures effect biting forces

Answer 34

Biting forces are reduced in complete denture wearers

Question 35

what is biting load carried by in complete dentures

Answer 35

Biting load carried by mucosa of the residual ridge and this is not designed to bear masticatory loads.

Question 36

how can biting forces of complete dentures be increased

Answer 36

by supporting dentures on teeth or implants

Question 37

what aerate classifications of prosthesis

Answer 37

mucosa supported
teeth supported
bone supported

Question 38

what are mucosa supported prosthesis

Answer 38

complete or partial

e.g acrylic partial denture

Question 39

what are tooth supported prosthesis

Answer 39

removal PD e.g cobalt chrome

fixed bridges

Question 40

what are bone supported prosthesis

Answer 40

implants

Question 41

what is a cantilever bridge

Answer 41

has a pontic connecter to a retainer on one end only

It is used to replace single teeth and only one retainer is used to support the bridge

Question 42

when are cantilever bridges not recommended

Answer 42

Not recommended when occlusal forces on the pontic are heavy

Question 43

what are adhesive bridge/resin bonded bridge

Answer 43

An immediate, temporary adhesive bridge is appropriate, followed by a permanent bridge once the tissues have settled.
Quick, non-destructive (conservative of tooth tissues), aesthetic and durable (good life span)

Question 44

What happens in stage II transport

Answer 44

forward movement of the tongue during the occlusal and initial opening phase creates a contact between the tongue and the hard palate - this CONTACT ZONE MOVES PROGRESSIVELY BACK IN WHAT IS CALLED THE SQUEEZE BACK MECHANISM

material accumulates on the pharyngeal surface of the tongue