PERMANENT DENTITION

PERMANENT DENTITION

second set of teeth formed in human

PERMANENT DENTITION

32 in total

ERUPTION

the developmental process that moves a tooth from its crypt position

6 1 2 4 5 3 7 8

Maxillary sequence of eruption

6 1 2 3 4 5 7 8

Mandibular sequence of eruption

2 to 5 years

the time it takes for the posterior teeth to reach the alveolar crest following the completion of their crowns

12 to 20 months

the time it takes to reach the occlusion after reaching the alveolar margin

Second molar

has a strong tendency to shorten the arch perimeter and may create space difficulties

i. Presence of mesiodens ii. Presence of lowly attached labial frenulum iii. Cystic lesions iv. Juvenile periodontitis

FACTORS THAT PREVENTS CLOSURE OF CENTRAL INCISORS

ARCH PERIMETER/CIRCUMFERENCE

the most important of the dental arch dimension

ARCH PERIMETER/CIRCUMFERENCE

measured from the distal surface of the second primary molar around the arch to the distal surface of the second primary molar or first permanent molar of the opposite side

ARCH PERIMETER/CIRCUMFERENCE

is subjected to crowding or interdental space

Crowding

decreases the arch perimeter

Interdental space

increases the arch perimeter

ARCH LENGTH OR DEPTH

measured from a contact point between 2 central incisors perpendicular

ARCH LENGTH OR DEPTH

considered about ½ of the arch perimeter

BIMOLAR WIDTH

a measure of an arch width

BIMOLAR WIDTH

measured from the central fossa of 1 molar to the central fossa of another molar

ATTRITION

physiologic wearing away of teeth due to mastication

ABRASION

pathologic wearing away of teeth due to mechanical wear

MAMELONS

three rounded protuberances which are present on the cutting edge of an incisor tooth when it first erupts though the gum