OCCLUSION AND MALOCCLUSION

Question 1

what do we mean by the ‘ideal occlusion’

Answer 1

• this is the anatomically perfect arrangement of the teeth which is VERY RARE

Question 2

what do we mean by the ‘normal occlusion’

Answer 2

• this is the ACCEPTABLE VARIATION from IDEAL occlusion. All teeth are well aligned, no crowding, class 1 incisor relationship, class 1 molar relationship

Question 3

what does malocclusion mean?

Answer 3

• this is an irregularity in the occlusion beyond the accepted range of normal
• not ALL malocclusions require treatment

Question 4

describe the class 1 malocclusion

Answer 4

• With a Class I malocclusion, the bite is normal in the front-to-back relationship, but teeth are misaligned in some way.

Question 5

describe the class 2 malocclusion

Answer 5

Also known as an overbite/OVERJET, a Class II malocclusion occurs when the upper teeth set forward of the lower teeth, which affects the alignment of the bite

Question 6

describe the class 3 malocclusion

Answer 6

A Class III malocclusion happens when the lower teeth set forward of the upper teeth. This is also called an underbite. This happens because the lower molars are too far forward compared to the upper molars.

Question 7

what are the causes of malocclusion? (3)

Answer 7

GENETIC
- skeletal pattern
- size of jaws and teeth
- syndromes eg cleft lip and palate

ENVIRONMENTAL
- soft tissues
- habits eg thumb sucking
- pathology eg tumour
- trauma
- local factors

Question 8

describe the class 1 skeletal pattern

Answer 8

when the maxilla and mandible are in normal position

Question 9

describe the class 2 skeletal position

Answer 9

an overbite, when the maxilla is slightly over the mandible

Question 10

describe class 3 skeletal pattern

Answer 10

this is when the maxilla is either too small and the mandible is too big or a combo of the both.

Question 11

what is the cause for crowded teeth

Answer 11

BIG TEETH and SMALL JAWS

Question 12

what is the cause for spacing in the dentition

Answer 12

SMALL TEETH, BIG JAWS

Question 13

what are some local factors that could cause a malocclusion

Answer 13

• additional teeth (supernumerary)
• missing teeth (hypodontia)
• fraenum
• retained deciduous tooth
• early loss of deciduous tooth

Question 14

what could having hypodontia mean for a malocclusion

Answer 14

eg missing lateral incisors
maybe replace the missing teeth eg bridge
close spaces

Question 15

what could a fraenum cause in the dentition

Answer 15

may cause a midline diastema

Question 16

what does a retained deciduous tooth mean for the permanent dentition

Answer 16

this will prevent permanent tooth from erupting into correct position

Question 17

what does the early loss of a deciduous tooth mean for the permanent successors

Answer 17

• itll mean there is a loss of space and crowding

Question 18

what does IOTN stand for

Answer 18

INDEX of ORTHODONTIC TREATMENT NEED

Question 19

what does the IOTN measure

Answer 19

• measures the severity of malocclusion
• DENTAL HEALTH COMPONENT
• aesthetic component too!

Question 20

describe the different grades within IOTN (DHC)

Answer 20

grade 1 - no treatment required
grade 2 - little treatment needed
grade 3 - borderline treatment need
grades 4 and 5 - treatment required

Question 21

IOTN (aesthetic component) - describe it

Answer 21

there are 10 pictures as a guideline, 1 being the least severe to 10 being the most severe.