Chronology of the Dent It Ions

CHRONOLOGY OF ERUPTION OF THE DENTITIION

Dental AnatomyDent 201

Summer semester2006/2007

Order of Eruption

6 4 5 3 2

6 4 5 3 1

3 4 8 6 7 1 9 10

2 3 5 7 8 1 9 10

Deciduous Permanent

Maxillary

Mandibular

The contra-lateral side has the same order of eruption

Times of developmental stages

First evidence of calcification Crown completed Afterwards tooth commences movement towards the

occlusal plane until:

Occlusal contact with the opposing tooth What is meant by eruption in the charts? Time needed until root completion

2 - 3 years for permanent 1 - 1.5 years for deciduous

Root completion

Gustafson & Koch Diagram

Can teeth tell the age?

Estimation vs. determinationMeans of investigation Clinical examination Models X-rays (OPG)

Significance Forensic investigations Before confirming an existing abnormality in

tooth development or sequence of development

AGE ESTIMATION

Tips Locate the medline and count the teeth Identify all deciduous and permanent teeth Identify any abnormality

Hint: look at the contra-lateral tooth unless the abnormality is symmetrical

Exclude any abnormal teeth from age estimation Choose teeth close to a “stage” whose age can be known from the

chart In the chart, eruption refers to the last stage of pre-functional eruptive

stage when the occlusal contact is established For root completion consider teeth about to have completed roots not

teeth with completed roots Take as many clues as you can then estimate the average age of all

clues