Definitions

Question 1

Molar Relationship
Class 1

Answer 1

The mesiobuccal cusp of the upper first molar occludes in the buccal groove on the lower fist molar.

Question 2

Molar Relationship
Class lll

Answer 2

The mesiobuccal cusp of the upper first molar occludes anterior (forward) to the buccal groove of the lower first molar.

Question 3

Molar relationship
Class ll

Answer 3

The mesiobuccal cusp of the UPPER first molar occludes posterior (behind) to the buccal groove of the lower first molar.

Question 4

Incisor Relationship
Class l

Answer 4

The LOWER incisor edges occlude with, or lie immediately below the cingulum plateau of the UPPER central incisors.

Question 5

Incisor Relationship
Class ll div l

Answer 5

The LOWER incisor edges occlude posterior to the cingulum plateau of the UPPER central incisors. The UPPER central imcisors are PROCLINED and there is an INCREASE in the overjet.

Question 6

Incisor Relationship
Class ll div ll

Answer 6

The LOWER incisor edges occlude posterior (behind) to the cingulum plateau of the UPPER central incisors. The UPPER central incisors are RETROCLINED and there is REDUCED or INCREASED overjet.
The common feature is proclined latetal incisors.

Question 7

Incisor Relationship
Class lll

Answer 7

The LOWER incisor edges occlude ANTERIOR (infront) to the cingulum plateau of the UPPER central incisors.
The overjet is REDUCED or REVERSED.

Question 8

Canine Relationship
Class l

Answer 8

The UPPER canine occludes and lies in the embrasure between the LOWER lateral incisors and canine.

Question 9

Canine Relationship
Class ll

Answer 9

The UPPER canine occludes anterior or lies in the embrasure between the LOWER lateral incisors and canine..

Question 10

Canine Relationship
Class lll

Answer 10

The UPPER canine occludes posterior (behind) and lies in the embrasure between the LOWER first and second premolars.

Question 11

Hypodontia

Answer 11

Missing teeth, used when there is congenital absence of one or more primary or secondary teeth.

Causes: can be genetic, with a family history of hypodontia.

Common missing teeth are:
Upper third molars (U8’s)
Lower third molars (L8’s)
Upper premolars (5’s)
Lower premolars (L5’s)
Upper lateral incisors (U2’s)
Lower cental incisors (L1’s)

Question 12

Oligodontia

Answer 12

More than 6 missing teeth

Question 13

Anodontia

Answer 13

Total loss of teeth

Question 14

Supernumerary

Answer 14

AN extra tooth found when there are excess teeth of the normal series.

Most commonly found supernumerary is in the anterior (front) maxillary region.

Types:
*Conical, known as mesiodens.
*Tuberculate
*Supplemental
*Odontomes

Question 15

Impaction

Answer 15

Failure of eruption of a tooth/canine due to crowding or an obstruction within the dental arch.

Question 16

Deepbite

Answer 16

Vertical overlap of UPPER incisors OVER LOWER incisors when posterior segment is in occlusion.

UPPER incisors OVERLAP LOWER incisors in excess of 4mm or more.

Question 17

Normal Overbite

Answer 17

UPPER incisors COVER one-third of LOWER incisors with posterior (back) segment in occlusion.

Question 18

Increased Overbite

Answer 18

UPPER incisors COVER, MORE than one-third of LOWER incisors when posterior segment is in occlusion.

Question 19

Decreased Overbite

Answer 19

UPPER incisors cover LESS than one-third of LOWER incisors when posterior segment is in occlusion.

Question 20

Incomplete Overbite

Answer 20

LOWER incisors DO NOT come into contact with hard or soft tissue.

Question 21

Complete Overbite

Answer 21

LOWER incisors DO come into contact with hard or soft tissues.

Question 22

Anterior openbite (AOB)

Answer 22

No vertical overlap of the upper & lower incisors when posterior segment is in occlusion.

Question 23

Posterior openbite (POB)

Answer 23

No vertical overlap of upper & lower posterior teeth when posterior segment teeth are in occlusion.

Question 24

Crossbites

Answer 24

An abnormal relationship between opposing teeth in buccopalatal or buccolingual direction.

Question 25

Posterior crossbite

Answer 25

Buccal cusps of lower teeth occlude buccal to buccal cusps of upper teeth when patient is in full
occlusion.

Question 26

Anterior crossbite

Answer 26

One or more of the maxillary incisors occlude lingual to lower incisors with posterior terth in occlusion.

Question 27

Lingual crossbite

Answer 27

Buccal cusps off lower teeth occlude palatalto palatal cusps of upper teeth when patient is in full occlusion.

Question 28

Overjet

Answer 28

Distance between upper & lower incisors in horizontal plane.
Normal overjet is 2-4mm.

Question 29

Bimaxillary proclination

Answer 29

Occlusions where both upper & lower incisors are proclined.

Question 30

Centre of resistance

Answer 30

Point in the body where resistance to movement is concentrated.

Question 31

Force movement

Answer 31

The component found within a force that causes rotational movement only.

Question 32

Force couple

Answer 32

In fixed appliances, when an archwire connects into the bracket slot a force couple is created, which will achieve rotation, inclination of teeth & torque.

Question 33

Dental panoramic tomography (DPT)

Answer 33

A radiograph that gives a two-dimensional view of the upper and lower jaws (maxilla & mandible)

Question 34

Cephalometric radiograph

Answer 34

A true lateral view of the skull, a two-dimensional image of a three-dimensional object presenting the skull & facial bones.

Question 35

Upper standard occlusal radiograph (USO)

Answer 35

A radiograph of the anterior part of the maxilla and anterior teeth.

Question 36

Parallax

Answer 36

A technique used when assessing or localising the position of unerupted tooth/teeth.