Dental Anatomy + Morphology

Question 1

what is the universal numbering system?

Answer 1

what we use at school and in the US
Succedaneuous / permanent / secondary dentition
-1-16 from UR to UL, 17-32 from LL to LR

Primary/deciduous dentition:
-A->J is UR to UL, K->T is LL to LR

Question 2

what is the palmer notation system?

Answer 2

used by specialists and oral surgeons sometimes

• succedaneous / permanent / secondary dentition:
• • counting from midline to third molar (1->8) with the notation of | and | for upper right and upper left respectively, and downward for the LL and LR
• deciduous/primary dentition :
• -counting from midline using the brackets, goes from A to E in each quadrant

Question 3

what is the international numbering system?

Answer 3

• succedaneous /secondary/ permanent dentition
• • quadrants are UR (1) , UL (2), LL (3), LR (4) , and then midline counting from 1->8, putting the quadrant number first. so right maxillary canine would be 13, etc.
• deciduous, primary dentition
• • quadrants are UR (5), UL (6), LL (7), LR (8) and we use NUMBERS for it counting 1->5 from the midline!

Question 4

what is the other word for secondary dentition?

Answer 4

succedaneous

Question 5

what are the different types of trait categories and what they mean

Answer 5

set trait: primary vs secondary dentition
arch trait: maxillary vs mandibular
class trait: canine vs molar or incisor vs canine etc.
type trait: first molar vs second molar

Question 6

what is the enamel made up of (%s) and cover

Answer 6

95% calcium hydroxyapatite
4% water
1% organic matter
enamel is highly calcified and inorganic (only 1% organic matter)

covers the CROWN of the tooth

Question 7

what does enamel develop from

Answer 7

ectoderm, product of ameloblast cells.

Question 8

what is dentin made up of (%s)

Answer 8

12% water, 18% organic matter, 70% calcium hydroxyapatite

Question 9

what does dentin develop from

Answer 9

mesoderm and its the product of odontoblast cells

-calcified and inorganic but much softer than enamel!

Question 10

what does cementum develop from?

Answer 10

(external layer of anatomical root)

mesoderm, product of cementoblast cells.

Question 11

what is cementum made up of (%s), what are its features?

Answer 11

65% hydroxyapatite, 23% organic matter, 12% water

• dull yellow color, its slightly softer than dentin and about as hard as bone is.
• calcified and inorganic!

Question 12

what is the clinical crown and root

Answer 12

the clinical crown is the part of the tooth that is visible. This could include the anatomical root!
The clinical root is the part of the tooth that is not visible

Question 13

what separates the anatomic crown and anatomic root?

Answer 13

The CERVICAL LINE, which is the cementoenamel junction (CEJ)

Question 14

what are the junctions in the tooth and are they visible?

Answer 14

• cementoenamel junction (CEJ) where cementum meets enamel (cervical line)
• Dentinoenamel junction (DEJ) where dentin meets enamel, visible on xrays! Visible in cross section or badly worn teeth
• cementodentinal junction (CDJ) where cementum meets dentin- visible in cross section or badly worn teeth/broken

Question 15

what are the surfaces of the teeth

Answer 15

facial - includes buccal (for posterior) and labial (for anterior) both maxillary and mandibular

lingual- closest to tongue (mandibular AND maxillary)

palatal- another term for closest to tongue (maxillary ONLY)

proximal - includes mesial (towards midline) and distal (away from midline)

occlusal - chewing surface of the posterior teeth, has cusps , cusp slopes / ridges

incisal edge - cutting surface on incisors

canine has a cusp tip!

Question 16

what are the divisions of the crown and root

Answer 16

crown: cervical, medial, and occlusal (posterior teeth) or incisal (anterior teeth-including canines)
root: cervical, medial, apical

vertically you have 3 more sections- mesial, middle and distal (creating 9 squares on the crown)

Question 17

what is the labial ridge

Answer 17

the ridge that runs along the canine crown cervico-incisally (vertical, about middle of it) on labial side

Question 18

what is the buccal ridge

Answer 18

ridge that runs along premolars cervico-occlusally (vertical, mid tooth) on buccal side

Question 19

what is a marginal ridge

Answer 19

on incisors and canines- located on both mesial and distal borders of the lingual surface
on posterior teeth , located on mesial and distal borders of occlusal surface

Question 20

what is the cervical ridge (***)

Answer 20

ridge running mesiodistally on the cervival third of the crown on the buccal surface. On all deciduous teeth, but ONLY on permanent molars!!

Question 21

what is the triangular ridge (***)

Answer 21

on occlusal surface of posterior teeth, going from any cusp tip to the center of the occlusal surface, with the groove as the base of the triangle.

Question 22

what is a transverse ridge?

Answer 22

crosses occlusal surface buccal to lingual , made of two connecting (at the base) triangular ridges
-posterior teeth

Question 23

what is an oblique ridge?

Answer 23

found only on maxillary molars!! made up of the triangular ridges from the mesiolingual + distobuccal cusps (slide 54)

Question 24

what is a developmental groove

Answer 24

sharply defined narrow and linear depression formed during tooth development , separating lobes (major teeth portions).

Question 25

Fissure

Answer 25

may be found at the depth of developmental grooves, imperfect union of lobes during development

Question 26

supplemental groove

Answer 26

small, less deep grooves, irregularly placed- not at junction of lobes or major portions of the teeth

Question 27

fossa

Answer 27

depression or hollow found on lingual side of anterior teeth and occlusal side of posterior teeth

Question 28

pit

Answer 28

pit occurs at the depths of fossa where two or more grooves join

Question 29

what surrounds the pulp chamber and canal

Answer 29

dentin except at the apical foramen

Question 30

what does pulp derive from and whats in it

Answer 30

mesoderm , its soft and not calcified

Question 31

what is a cingulum

Answer 31

the enlargement or bulge on the cervical third of the lingual surface of the crown of anterior teeth (more info later?)

Question 32

which teeth have incisal edge?

Answer 32

all of the anterior teeth!

-for canines, incisal edge is the two cusp ridges i think