Mastication and swallowing

Question 1

Describe function of mastication

Answer 1

• Break down food
• Stimulate saliva
• Taste and smell
• Aid digestion

Question 2

List teeth type:

Answer 2

• Incisors -> Biting and stripping
• Canines -> Piercing and seizing
• Premolars/molars -> Grinding

Question 3

List the two movements of TMJ

Answer 3

• Hinge

- Translation/sliding

Question 4

List the actions of TMJ movement

Answer 4

• Depression -> lateral pterygoid, mylohyoid and digastric muscles
• Elevation -> Temporalis, masseter and medial pterygoid muscles.
• Retrusion -> Posterior fibres of temporalis muscle
• Protrusion -> Medial and lateral pterygoid muscles
• Lateral excursion -> unilateral movement of pterygoid or temporalis muscles.

Question 5

List the 3 steps of chewing cycle

Answer 5

1. opening stroke
2. closing stroke
3. power stroke

Question 6

Describe opening stroke

Answer 6

• Depression of mandible -> lateral pterygoid muscle
• Swing to working side
• Tongue positions food

Question 7

Describe closing stroke

Answer 7

• Elevation of mandible -> Medial pterygoid muscle
• Swing to working side
• Food between teeth

Question 8

Describe power stroke

Answer 8

• Clench teeth -> Masseter and medial pterygoid; posterior temporalis on balancing side
• Swing medially to balancing side
• Grind food between occlusal surface
• Most variable step between individuals

Question 9

List the three steps of swallowing phase

Answer 9

1. Oral phase
2. Oropharynx phase
3. Oesophagus phase

Question 10

Describe oral phase of swallowing

Answer 10

• Only voluntary phase
• Bolus squeezed against hard palate
• Styloglossus and palatoglossus

Question 11

Describe oropharynx phase of swallowing

Answer 11

• Automatic

- Nasopharynx and larynx close

Question 12

Describe oesophagus phase of swallowing

Answer 12

• Automatic

- Peristalsis