Clinical Development of the Dentition

Question 1

what is orthodontics?

Answer 1

the branch of dentistry concerned with facial growth with development of the dentition and occlusion and with the diagnosis, interception and treatment of occlusal anomalies

Question 2

what are the 4 stages of development?

Answer 2

newborn, deciduous dentition, mixed dentition and permanent dentition

Question 3

what does the dentition of a newborn look like?

Answer 3

gum pads, upper rounded and lower U shaped, anterior open bite, skeletal class 2, mandible set back

Question 4

what is skeletal class 1?

Answer 4

mandible is 2-3mm posterior to the maxilla

Question 5

what is skeletal class 2?

Answer 5

mandible is retruded relative to the maxilla

Question 6

what is skeletal class 3?

Answer 6

mandible is protruded relative to the maxilla

Question 7

what is cleft lip and palate?

Answer 7

congenital defect with a large impact on the development of the dentition

Question 8

what does the dentition appear as in a child with cleft lip and palate?

Answer 8

narrow maxilla, lateral incisor possible absent, crowding of teeth

Question 9

when is the eruption of the primary dentition?

Answer 9

6 months - 3 years

Question 10

what erupts first lowers or uppers?

Answer 10

lowers

Question 11

what is the order of erupting teeth?

Answer 11

a-b-d-c-e

Question 12

what is the first tooth to erupt and when?

Answer 12

central incisor (a) at 6-7 months

Question 13

what is the second tooth erupt and when?

Answer 13

lateral incisor (b) at 7-8 months

Question 14

what is the third tooth to erupt and when?

Answer 14

first molar (d) at 12-15 months

Question 15

what is the fourth tooth to erupt and when?

Answer 15

canine (c) at 18-20 months

Question 16

what is the fifth tooth to erupt and when?

Answer 16

second molar (e) at 24-36 months

Question 17

what is characteristic of the primary dentition?

Answer 17

incisors more upright, spacing, marked wear towards the end, smaller and occupy less space, increasing overlap with front teeth

Question 18

what are the quadrants of the primary dentiton?

Answer 18

5,6,7,8

Question 19

why is it good to have more spacing in the primary dentition?

Answer 19

because the permanent dentition occupies more space

Question 20

what is the mixed dentition?

Answer 20

mixture of primary and permanent teeth

Question 21

what age does the mixed dentition present?

Answer 21

6-13

Question 22

what age does the eruption of first molars and incisors take place?

Answer 22

6 - 8.5

Question 23

what age does the eruption of canines, premolars and second molars take place?

Answer 23

10 - 12.5

Question 24

what is supernumerary?

Answer 24

an extra tooth preventing the permanent tooth from erupting

Question 25

what is microdontia?

Answer 25

permanent teeth that are quite small

Question 26

what is macrodontia?

Answer 26

permanent teeth that are too big?

Question 27

what is an anterior crossbite?

Answer 27

a single upper stuck being the lowers

Question 28

what is increased overjet?

Answer 28

uppers stick out a bit so there is an increased risk of trauma

Question 29

what is reversed overjet?

Answer 29

lowers over uppers resulting in wear of front teeth

Question 30

what is posterior crossbite?

Answer 30

transverse problem, teeth shifted to one side and sometimes have a displacement

Question 31

what is the eruption pattern of lower canines, premolars and second molars?

Answer 31

3,4,5

Question 32

what is the eruption pattern of upper canines, premolars and second molars?

Answer 32

4,5,3

Question 33

why do canines take longer to come into the mouth?

Answer 33

they develop under the orbit and must travel further

Question 34

why does the arch increase posteriorly in length?

Answer 34

to accomodate the 6,7,8

Question 35

what is leeway space?

Answer 35

the difference in size between e,d,c and 3,4,5 typically in the maxilla

Question 36

what is transposition and where is it most common?

Answer 36

two permanent teeth become swapped over and almost always involves the upper canine due to it forming further up. most common between the 3 and 4

Question 37

what is a palatal ectopic canine?

Answer 37

the canine is unerupted and is under the palatal surface behind the 2

Question 38

what are the features of an ideal static occlusion in the permanent dentition?

Answer 38

incisors slightly proclined with lower incisal edge in contact with the cingulum of upper teeth, mesio-buccal cusp of upper permanent molar occludes with the buccal groove of he mandibular first molar, long axis of the teeth has a slight mesial inclination except the lower incisors, tight approximal contact, flat occlusal plane

Question 39

what are the four different incisor classifications?

Answer 39

class 1, class 2 division 1, class 2 division 2, class 3

Question 40

what is class 1 incisor classification?

Answer 40

the lower incisal edges occlude with or lie immediately belwo the cingulum plateau of the upper central incisors

Question 41

what is class 2 division 1 classification?

Answer 41

the lower incisor edges lie posterior to the cingulum plateau of the upper incisors, the upper centrals are proclined or of average inclination, the overjet is increased

Question 42

what is class 2 division 2 classification?

Answer 42

lower incisal edge lies posterior to the cingulum plateau of the upper incisors, upper incisors are retroclined, the overjet is usually minimal but can be increased

Question 43

what is class 3 classification?

Answer 43

lower incisal edge lies anterior to the cingulum plateau of the upper incisors, overjet is reduced or reversed

Question 44

what is overbite?

Answer 44

vertical overlap of the upper and lower incisors when viewed anteriorly. one third to one half coverage of the lower incisors is normal

Question 45

what is crowding?

Answer 45

when there is insufficient space to accommodate the teeth in perfect alignment

Question 46

what is hypodontia?

Answer 46

congenital absence of one or more teeth

Question 47

what is reverse overjet?

Answer 47

lower incisors lie anterior to upper incisors

Question 48

what is a supernumerary tooth?

Answer 48

an additional tooth to the normal series

Question 49

what is malocclusion?

Answer 49

variation from ideal occlusion which has dental health and/or psychosocial implications for the individual

Question 50

what is ideal occlusion?

Answer 50

anatomically perfect arrangement of the teeth

Question 51

what is normal occlusion?

Answer 51

acceptable variation from ideal occlusion

Question 52

what is a buccal crossbite?

Answer 52

the buccal cusps of the lower premolars and/or molars occlude buccally to the buccal cusps of the upper premolars and/or molars

Question 53

what are natal teeth?

Answer 53

a tooth which is present at birth or erupts soon after

Question 54

what is a macrodont

Answer 54

abnormally large tooth