According to the British Dental Association, there are deciduous molars, all of which eventually fall out by around age 12, and permanent molars, which do not necessarily fall out. All the deciduous molars appear by the time a child is around 2 1/2 years old.
Mascara: Get yourself a pre-wash stain fighter like Shout and apply to the stain using the brush that comes with the pre-wash. Let it sit for about 10-15 minutes, then rinse with hot water. Launder the garment immediately either by hand or in the machine (whichever is most convenient for you).
The stains are a combination sweat and the chemicals in the deodorant. Though the shirt is white, I wouldn't use bleach as this can make such stains worse (actually more yellow.) You can try soaking it in an enzyme pre-soak product such as Oxyclean, you can also rub the stains with white vinegar.