Protruding upper incisors

Question 1

Many children attend ortho

Answer 1

because their upper front teeth protrude (proline) between their lips. usually arises from a jaw relationship in which upper teeth are too far forwards relative to lower.
commonly associated with open lip posture + called a class 2 division 1 malocclusion

Question 2

why does this tend to occur

Answer 2

because the mandible is too far behind its normal position + not because maxilla is too far forwards. The maxilla is a fixed bone of facial skeleton + cannot alter during growth whereas mandible is only moveable bone of skull + position can alter as it grows + develops

Question 3

When the mandible is not so far posterior to its normal position

Answer 3

so that the jaw relationship is not quite so severe, the upper incisors become trapped behind the tightened lower lip + erupt upright or even pulled back (retroclined) - called class II division 2 malocclusion

Question 4

Prominent lower jaw

Answer 4

the chin is unduly prominent, is called by jaw relationship which the mandible + lower teeth are too far forwards relative to maxilla + upper teeth.
usually results in incisors biting edge to edge; or lowers infront of uppers (Class 3 malocclusion)