Dental Anatomy: Mandibular Central and Lateral Incisors (Wk3)

Table of Contents: • Eruption time, form and function • Location in the dental arch, relationship with the adjacent tooth in the dental arch and the opposing teeth • Morphology of each surface of the crown and root and tooth identification • Anatomy of the pulp cavity and pulp tissues of each tooth • Comparison between the permanent mandibular central and lateral incisors

#31 #32 #41 #42

In the FDI system, what tooth numbers are the mandibular central and lateral incisors

moderate to severe overbite obscuring the mandibular incisors

esthetic of the mandibular incisors

tetracycline staining of teeth

use of antibiotic during childhood that bonds to calcium ions needed for enamel development in growing children

mandibular crowding

• tooth size arch length deficiency

• due to insufficient jaw size to accommodate teeth size (ie. change in distance between the lower canines)

• happens in adult

6-7 years

when does the mandibular central incisor erupt?

• active eruption of teeth occurs after 2/3 of the root is formed

• the root is not formed until 2-3 years after eruption

• the mandibular central incisors are the first succedaneous teeth to erupt (along with the 1st molars, both upper and lower)

7-8 years

when does the mandibular lateral incisors erupt?

centered

where is the cingulum in the mandibular central incisor positioned?

off-center distally

where is the cingulum positioned on the mandibular lateral incisor?

sharp, right angle

what is the outline form of the mesioincisal angle for the mandibular right central incisor?

sharp, right angle

what is the outline form of the distoincisal angle of the mandibular right central incisor?

straight

what is the mesial outline of the mandibular right central incisor?

straight

what is the distal outline for the mandibular central incisor?

straight

what is the outline of the incisal edge of the mandibular central incisor?

trapezoid

what is the GEOMETRIC outline for the facial and lingual aspect of the mandibular right central incisor?

triangle

what is the GEOMETRIC outline for the mesial and distal view of the mandibular right central incisor?

diamond

what is the geometric outline for the incisal view of the mandibular central incisor?

incisal third

what is the contact area of the mesial and distal side of the mandibular central incisor?

[special notes]

• only the central incisors (on both maxillary and mandibular) teeth have mesial to mesial contact

• the mesial and distal contacts of the mandibular central incisor are at the same incisocervical position

distal

in what direction does the pointed apex of the root for he mandibular central incisor curve towards to?

• this helps you distinguish the left from the right mandibular central incisor

• one root and one canal

• narrow

• pointed apex curved to the distal

• small mesiodistal dimension

• large labiolingual dimension

• pulp horn is not prominent

• mandibular central and lateral incisors do not have proximal root cavities/depressions, but usually more pronounced on the distal aspect.

what is the root structure of the mandibular central incisor?

mandibular central incisor

what is the smallest tooth in the mouth

sharp

what is the outline forms for the mesioincisal angle for the mandibular right lateral incisor?

round

what is the outline form for the disto-incisal angle of the mandibular right lateral incisor?

straight

what is the outline form for the mesial and distal side of the mandibular right lateral incisor?

straight

what is the outline of the incisal edge of the mandibular right lateral incisors?

trapezoid

what is the GEOMETRIC outline for the labial and lingual view of the mandibular right lateral incisors?

triangle

what is the GEOMETRIC outlines for the mesial and distal view of the mandibular right lateral incisors?

triangle or diamond

what is the GEOMETRIC shape of the incisal view of the mandibular right lateral incisors?

incisal third

what is the proximal contact/contact areas of the mesial side of the mandibular right lateral incisors?

incisal third

what is the contact area of the distal side of the mandibular right lateral incisors?

*contact point between the tooth and its neighbor on the distal side is located slightly closer to the root (more apical) than the contact point on the mesial side, which is positioned closer to the crown (or more toward the incisal/occlusal edge).

• one root, one canal

• narrow

• pointed apex that may curve towards the distal

• narrow mesiodistal dimension

• large labiolingual dimension

• pulp horns not prominent

• have a proximal root concavities/depressions but usually more pronounced on the distal aspect.

list the root forms of the mandibular lateral incisor

cervical third

what is the height of contour for the labial and lingual surface of all anterior teeth?

• on the lingual side, the HOC is on the cingulum

mandibular incisors has no distinct grooves or pits on the lingual surface

how is the lingual surfaces of the mandibular incisors different than the maxillary incisors?

mandibular incisors’ cingula are indistinct with smooth lingual anatomy (maxillary is more rough and pronounced with distinct lingual anatomy)

what is the difference between the cingula of the mandibular incisors and maxillary incisors?

greater

fill in the blank: the mandibular incisors (both central and lateral) have incisocervical dimension ____ than mesiodistal dimension.

incisal embrasure

v shaped space between the curved proximal surfaces of adjacent anterior teeth (incisal to proximal contact)

• shape of the embrasure is determined by the morphology of the teeth

1. between the mandibular centrals

2. between the mandibular lateral and central

3. between the maxillary centrals

what are the three smallest embrasures?

• lateral incisor is overall larger

• the mesial side of the root of the lateral incisor is more convex

• mesial marginal ride is slightly longer than the distal marginal ridge (same as on the central)

• the root of the lateral incisor is longer

• the crown of the central incisor is symmetric and the cingulum is located centrally; the crown tip of the lateral incisors is slightly toward the distal and the cingulum is located to the distal.

how to distinguish between mandibular central and lateral incisor

maxillary central incisor

which teeth does the mandibular central incisor occludes with?

*unique: it only occludes with only one tooth

the maxillary central and lateral incisors

which teeth does the mandibular lateral incisor teeth occludes with?