Activity 5D: Casting Teeth

Give each student a copy of the plaster cast activity. Allow the students enough time to make a cast of their teeth with plaster of Paris in order for them to get a good look at the anatomy of their teeth.

Warning to Teachers: This activity is a possible choking hazard. Use caution.

If you are unable to make plaster casts of the teeth, you can give each student a mirror to use for their observations. This activity is best done with additional dental mirrors, which are set at an angle. However, pocket mirrors are sufficient. Students will record the different kinds of teeth they see in their mouth and how many of each kind on a sheet of paper. Next have the students share their observations with the class. (Due to a potential lack of mirrors, this may be used as a homework assignment.)

After students collect their data, have them respond to the following question. “Do you have a complete set of teeth? If there are less than 28–32 teeth, explain the reasons why this is so.” (Possible explanations for having less than 28–32 teeth include a lack of development, some people have congenital absence, i.e., they may not have wisdom teeth), and tooth loss.

Tooth loss may be the result of:

1. a natural loss of childhood teeth being replaced by permanent teeth
2. trauma, i.e., football, accidents
3. disease, i.e., caries, periodontal disease
4. planned extractions by dentist

Point out that the loss of teeth due to sports accidents may be preventable by using mouthguards.