Tooth development

Baby teeth. How and when will your baby's teeth come through? The average baby gets his first tooth at around six months, but this quite variable. One baby may get her first tooth at three months, another not until eighteen months. Both may be perfectly healthy, normal infants. It is true that certain diseases can influence the age of teething, but this is rare. For most children the age of teething is simply a matter of the pattern of development the child was born with.
Usually the first two teeth to appear are the lower central incisor is the name given to the eight front teeth (four on the bottom and four on the top) that have sharp cutting edges. After a few months come the four upper incisors, so the everage baby has these six teeth, four above, two below, at about a year old. After this, there's usually a lull of several months before the next onslaught. Then six more teeth quickly appear: the two remaining lower incisors and all four first primary (baby) molars. The molars don't come in next to the incisor teeth but farther back, leaving space for the canine teeth.
After the first molars appear, there is a pause of several months before the canines (the pointed dog or eye teeth) erupt in the spaces between the incisors and the molars. The most common time for this to happen is in the second half of the second year. The last four teth in the baby set are the second primary molars, which come in right behind the first primary molars, usually in the first half of the third year. Remember that these ages are all averages. Don't worry if your baby is ahead of or behind the schedule.

Permanent teeth. permanent teeth begin to appear at about six years of age. The six-year (first permanent) molars come through behind the baby molars. The baby teeth lost first are usually the lower central incisors. The permanent incisors, pushing up underneath, come into position where the baby tooth roots have been dissolved away. Eventually, all the primary teeth become loose and fall out. The baby teeth are lost in about the same order in which they came in. Your toughest decision may be order in which they came in. Your toughest decision may be figuring out the monetary value of these baby teeth when the Tooth Fairy makes her appointed rounds.
The permanent teeth that take the place of the baby molars are called bicuspids or premolars. The twelve-year molars (second permanent molars) come in behind the six -year molars. The third molars (eighteen-year molars or wisdom teeth) may be impacted in the jaw. Sometimes they need to be removed so they won't do any damage to neighbouring teeth or the bone of jaws. Permanent teeth often appear with jagged edges (called mammelons). They either wear down or the dentist can trim them. Also, permanent teeth are more yellow than primary teeth.
Permanent teeth sometimes come through crooked or out of place. They may eventually straighten out by the muscular action of the tongue, lips and cheecks. If they don't straighten out or are crowded or crooked or if the jaw alignment is abnormal orthodontic treatment (braces) may be required for bite improvement.