Examination Of Occlusion

Question 1

What components make up the articulatory system?

Answer 1

1. TMJ
2. Muscles of mastication
3. Occlusion (tooth surfaces contact during jaw movement)

Question 2

What are the basic movements of the TMJ?

Answer 2

1. Hinge - initial rotation
2. Gliding - sliding from Mandibular fossa onto articulate tubercle (translation)

Question 3

What happens in a hinge movement?

Answer 3

Head of mandible rotates around transverse axis

Question 4

What happens in a gliding movement

Answer 4

Mandible head leaves Mandibular fossa and slides forwards onto articular tubercle
- Translation

Question 5

What are muscles of mastication innervated by?

Answer 5

CNV3 - Trigeminal Mandibular division

Question 6

What are functional movements of the TMJ?

Answer 6

1. Protrusion
2. Retrusion
3. Elevation
4. Depression
5. Lateral excursion

Question 7

How is the TMJ examined in E/O?

Answer 7

1. Palpitation of pre-Auricular area (outside)
2. Palpation of intra-Auricular area (inside)

Question 8

What is looked for in TMJ examination?

Answer 8

1. Sounds e.g. clicking
2. Abnormal movement of joint

Question 9

How are the muscles of mastication innervated?

Answer 9

Mandibular division of trigeminal merve (CNV3)

Question 10

What muscles of mastication can’t be examined?

Answer 10

1. Lateral pterygoid
2. Medial Pterygoid

Question 11

What is felt for when examining muscles of mastication?

Answer 11

1. Tenderness - this can be caused by overworking (Hypotrophy) e.g from clenching jaw
2. Muscle spasms

Question 12

What movement does the temporalis do?

Answer 12

1. Closes jaw
2. Retracts jaw

Question 13

What movement does the masster do?

Answer 13

Closes jaw
Retracts jaw

Question 14

What is occlusion?

Answer 14

This is where the tooth surface come into contact when the jaw is closed or moving

Question 15

What is ICP?

Answer 15

Intercuspal position
- this is position of maximum intercuspation of teeth

Question 16

What is occlusal contacts?

Answer 16

Where cusps meet each other in stable forces e.g. cusp lies in lossa so there is no excess force on the tooth, when jaw is out of line excess force can be applied to sides of tooth causing them to break

Question 17

What is protrusive excursion?

Answer 17

This is when the incisal teeth are touching, the mandible is moved anteriorly and posterior teeth generally aren’t in contact

Question 18

How does lateral excursion work?

Answer 18

This is when the jaw moves to the side
e.g. when the jaw moves right the right side is called the “working” side and then left is the non working side

Question 19

What teeth occlude for lateral excursion?

Answer 19

Most commonly canines touch and also lateral incisors (on working side)

Question 20

What is articulating paper held in?

Answer 20

Millers forceps

Question 21

What is the ideal occlusion?

Answer 21

• Even contacts for ICP
• Anterior guidance for anterior teeth
• No contact on non working side for lateral excursion
• Disoclusion of posterior teeth when there is excursion

Question 22

What is the conformative approach to dentistry?

Answer 22

This is the idea of not changing the natural occlusion pattern too much so it Belen harmoniously with existing pattern

Question 23

What are the reference point when it comes to classifying incisors?

Answer 23

Upper incisor - Singulum
Lower incisor - Incisal edge

Question 24

What is a class 1 incisor?

Answer 24

• This is when the upper incisal edge occludes or lies slightly below cingulum

Question 25

What is a class 2 div 1 incisor?

Answer 25

This is called an overjet
- The lower incisor is most posterior and incisal edge lies posterior to the upper incisal cingulum

Question 26

What is a class 2 div 2 incisor?

Answer 26

This is called an overbite
The lower incisor edge lies posterior to the cingulum of upper incisor
- The upper incisors over the lower incisors

Question 27

What is a class 3 incisor?

Answer 27

This is when the lower incisor edge is anterior, or occludes anterior to the cingulum of the upper incisors
- can have an overjet but this is called negative as the lower incisor is further in front

Question 28

What is are centrelines?

Answer 28

This is a line drawn to see the symmetry of the jaw and see if mandible and maxilla are lined up

Question 29

What is the reference point for molar classification?

Answer 29

Upper 6 - mesio-buccal cusp
Lower 6 - mesio-buccal groove

Question 30

What is a class 1 molar?

Answer 30

This is when the mesio-buccal cusp lies/ occludes with the mesio-buccal groove

Question 31

What are class 2 molars?

Answer 31

This is when the mesio-buccal cusp is more anterior to the mesiobuccal groove
- Upper jaw is anterior

Question 32

What is a class 3 molar?

Answer 32

This is when the messio-buccal cusps is more posterior to the mesiobuccal groove
- lower jaw in more anterior

Question 33

What is the RCP?

Answer 33

This is retruded contact position, is the position when thr condyle are in their most retruded position and teeth and in contact

Question 34

What do pateint have to do to get into the RCP position?

Answer 34

1. Open mouth wide
2. Curl tongue to the roof of the mouth
3. Close teeth together till first tooth contact

Question 35

What is the freeway space?

Answer 35

This is the natural gap between teeth when the jaw is resting around 2-4mm

Question 36

When should upper and lower teeth be in contact?

Answer 36

1. Chewing
2. Swallowing