Tuesday, May 31, 2011

Teeth

Well, his little tooth just keeps growing.  It hasn't been joined by any others yet, but to hear him cry about it you'd think all 20 were poking through at the same second.

(That's right, babies have 20 primary teeth (also called milk teeth or deciduous teeth).  The internet has taught me that Elliot will eventually grow 8 incisors, 4 canines, and 8 molars. You might think that it would be the molars that babies don't get, but it's actually PRE-molars they lack.)

He's been a good sport about it overall.  No more fevers, although he seems more sweaty than he used to.  It's getting summery, so that could be another reason for his discomfort.  Basically, there's a constant low-grade whine in the apartment most of the time these days, unless we give in and squirt him with Tylenol (which we try to limit to 2-3 times daily). 

(By the way, if you're really interested in teeth, here's more information than you could ever use:

The number of teeth of each type is written as a dental formula for one side of the mouth, with the upper and lower teeth shown on separate rows. The number of teeth in a mouth is twice that listed as there are two sides. In each set, the first number indicates incisors, the second, canines, the third, premolars, and the last, molars. For example, the formula 2.1.2.3 for upper teeth indicates 2 incisors, 1 canine, 2 premolars, and 3 molars on one side of the upper mouth.

The human dental formula is:

2.1.2.3
2.1.2.3

Of cats it is:

3.1.3.1
3.1.2.1

The last upper premolar and first lower molar of the cat, since it is a carnivore, are called carnassials and are used to slice meat and skin. The armadillo, being homodont, has a dental formula that is simply 7/7.

The maximum dental formula for placental mammals is:

3.1.4.3
3.1.4.3

Non-placental mammals such as marsupials can have more teeth than placentals. The opossum's dental formula is:

5.1.3.4
4.1.3.4

In many mammals the children have a set of teeth that fall out and are replaced by adult teeth. These are called deciduous teeth, baby teeth or milk teeth. Animals that have two sets of teeth, one followed by the other, are said to be diphyodont. Normally the formula for milk teeth is the same as for adult teeth except that the premolars are missing.

The milk tooth formula for humans is:

2.1.0.2
2.1.0.2 )

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