On another thread related to human explosions and lead and stuff like that, Magetout provided the following link:
http://www.corsinet.com/trivia/h-triv.html
Where I read the two following incredible ‘fact’
Can anyone enlighten me on what happens to the 94 extra bones that a baby has? Do they just become muscles or just dissapear or fuse together or what?:confused
Babies have more bones, but many times three ore more fuse into a single bone. For example, the illium, ischium, and pubic bones are seperate in babies, but fuse together to form the os coxae in adults. Here, six bones become two.
I put the words ‘baby adult number bones’ into Google and found this site here which agrees…
Search engines, dontcha just luv 'em 
On the other hand, you tend to add bones as you get older, then lose them as you get older. These are the bones known as teeth.
In children, the ends of the long bones are separated from the shaft by a thin layer of cartilage, which allows the bones to grow in length. When growth ceases in adulthood, the ends fuse producing a single unified bone. Therefore infants may be said to have more bones, if one counts these end plates separately. On the other hand, they do not have knee caps which ossify out of cartilage later on.
de trop, teeth are not considered “bones,” as their composition is quite different.
That depends which expert you cite. Most archeologists include teeth with bones.
Teeth are not included among the 206 adult bones mentioned in the OP (and obviously not among the 300 infant bones). In an anatomical sense, teeth are definitely not bones. Please provide a citation for your allegation regarding acheological usage.
At birth, the skull is composed of separate plates which fuse together later (this allows the head to deform and pass through the birth canal more readily).
All of the sesamoid bones typically ossify late, if I am not mistaken. The pisiform in the wrist, for example, doesn’t tend to ossify until about the 12th year in males, 9th year in females.
Also, even in cases of fusion, the bones are often joined by sutures (as in the skull), leaving each individual bone still readily identifiable. At this point, it becomes more a matter of nomenclature than any real ‘disappearance’; the ilium, pubis and ischium are still present, but the whole structure is given a separate working name.
The accepted number of ‘bones’ in an adult is rather ambiguous anyway. Included among the 206 are 33 vertebrae; however, in adults the 4 coxygial vertebrae are fused, as well as the 5 sacral.