1. Dental Anatomy
Skull + Muscles of Mastication/Facial Expression + Tongue
© April 2015 Rachel Krystina Marfell

2. The Skull
The skull or cranium forms housing round the brain and the lower part forms the skeleton of the face .
It is a very complex structure
The top half the skull that forms the brain housing is made up 8 bones frontal x1, parietal x2, temporal x2 , occipital x1, sphenoid x1 ethmoid x1.
The facial skeleton consists of 14 bones
Sphenoid sweeps upwards behind the eyes
Ethmoid bone separates the brain and nasal cavity-postioned behind the orbits
© April 2015 Rachel Krystina Marfell

3. The Skull These are: Zygomatic arch Nasal bones
Vomer –thin flat bone of the nasal septum
Maxilla – top jaw
Mandible – lower jaw and only movable joint on the skull
© April 2015 Rachel Krystina Marfell

4. The Skull

5. Nerves
The nerve supply leaves the brain through holes at the base of the skull . These holes are called foreman.
The foreman holes also allow for blood supply to the skull.
The nerve supply to the rest of the body comes from the spinal cord.
© April 2015 Rachel Krystina Marfell

6. Maxilla This fixed to the skull so it cannot be move .
Its is two half –right and left maxillae
The outer layer of the maxilla’s compact bone is much thinner than the mandible
It has a hard palate which is the roof of the month- this separates the oral cavity from the nose cavity
On both sides of the nasal cavity the bone is hollow .
Each hollow part is the maxillary sinus or antrum
© April 2015 Rachel Krystina Marfell

7. Maxilla The maxilla consists of four processes:
Zygomatic Process-This extends to the side to join the zygomatic bone and forms the cheekbone
Alveolar Process- Projects downwards contains the upper teeth. This process ends at the posterior part of the maxilla where is a rounded bulge called the TUBEROSITY.
Palatine Process- Extends medially and forms the hard palate.
Frontal Process- Extends superiorly and forms the wall of the orbit.
© April 2015 Rachel Krystina Marfell

9. Mandible This is lower half of jaw that can move.
Shaped like a horseshoe or U shape
The main body of the mandible is the horizontal part of the alveolar process and where the lower teeth sit.
Each vertical end is called the ramus .
The angle of the mandible is the junction of the body and the ramus.
On the inner surface there is a ridge called the Mylohyoid line and this marks the floor of the month.
© April 2015 Rachel Krystina Marfell

10. Mandible
Right at the top of the ramus coronoid process which is in front ,with the condyle behind .
The curve part in the middle is the sigmoid notch

11. Tempro-mandibular joint
This the joint involving the condyle of the mandible and the temporal bone at the base of the skull .
When the month is closed the condyle rests in a hollow in the temporal bone called the glenoid fossa

12. Muscles of Mastication
Consists of 4 major muscles
Masseter – Closes the Mandible
Temporal- -Closes the mandible and pulls it backwards
Medial pterygoid – Closes the mandible
Lateral pterygoid –Swings the jaw side to side when acting alone – if both medial and lateral pterygoid acting together pull the jaw forwards.
Masseter extends from zygomatic arch to the outside of the ramus of the mandible
Temporal muscle extends from the side of the head to the coronoid process
M.Pterygoid extends from behind the maxilla to inside the ramus
L.Pterygoid extends from behind the maxilla to the condyle of the mandible

13. Muscles of Mastication

14. Muscles of Facial Expression
Orbicularis Oculi – is the ring of muscle surrounding the eye
Orbicularis Oris – is the ring of muscle surrounding the mouth
Buccinator –is the muscle inside the cheek
Zygomaticus major-extends from the cheek bone to the corners of the mouth.
Orbicularis oculi- opens + closes eyes
Orbicularis oris – opens + closes month – plunker lips
Buccinator-chewing – assist the mastication by pressing the teeth
© April 2015 Rachel Krystina Marfell

15. Muscles of facial expression

16. Tongue

17. Tongue It’s a mobile muscle which covered papillae and taste buds
A mucus membrane covers the tongue.
Blood supply
Lingual artery
Lingual vein
Nerve supply
Lingual nerve
Glosspharyngeal nerve
© April 2015 Rachel Krystina Marfell

18. Tongue Papillae- Filiform Fungi Form Circumvallate Muscles Intrinsic
Extrinsic
© April 2015 Rachel Krystina Marfell

19. Tongue -Functions Assit in swallowing and mastication Speech Taste
Cleansing
Position of the teeth is influenced by pressure from the tongue
© April 2015 Rachel Krystina Marfell

20. Tongue- Taste Taste buds are receptors
Microscopic in size around 9000 of them in the mouth.
Found over the whole surface of the dorsum of the tongue.
© April 2015 Rachel Krystina Marfell

21. Any Questions
Homework – please revise as Quiz next week