ORTHODONTICS
Ideal Occlusion
All teeth are perfectly placed in the arcades of the jaw and have a normal anatomical relationship to each other. When the teeth are brought together into contact the cusp fossa relationship is considered the most perfect anatomic relationship that can be attained.
Occlusion
Occlusion is the contact relationship of the maxillary and mandibular teeth when the mouth is fully closed. In normal occlusion the mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar.
Overjet
THe horizontal overlap of the maxillary central incisors over the mandibular central incisors. Overjet refers to how much the upper teeth front teeth protrude forward in relation to the lower front teeth. The amount of overjet is measured using the probe horizontally. The normal overjet is considered to be 2-3mm.
Overbite
Overbite defines the vertical overlap of the maxillary central incisors over tha mandibular central incisors.
Overjet describes how much the upper front teeth cover the lower front teeth in a vertical dimension. The amount of overbite is measured by the probe vertically.
Normal overbite is considered to be 2-3mm or approximately 20-30% of the height of the mandibular incisors.
Edge To Edge
Sometimes the maxillary teeth do not overlap the mandibular incisors in a vertical or horizontal dimension. As it relates to an edge to edge relationship, the upper and lower front teeth meet in a straight line. Therefore there is no overjet or overbite.
Open Bite
In an open bite relationship, the upper and lower teeth do not meet.
Class 1 malocclusion is similar to normal occlusion but is characterized by crowding , rotations and other positional irregularities
The mesiobuccal cusp of the upper first molar occludes anterior to the buccal groove of the lower first molar. There are two sub types of class 2 malocclusion.
Class 2 Division 1
In division 1 of class 2 malocclusion the upper incisors are tilted outwards , creating significant overjet.
Class 2 Division 2
Upper incisors are labially inclined
The mesiobuccal cusp of the upper first molar occludes posterior to the buccal groove of the lower first molar.
