A Class I Malocclusion describes a bite where your upper teeth slightly overlap your lower teeth. This is the most common type of malocclusion found in most people, where the bite is normal and the overlap is slight. There are many factors that your Orthodontist needs to consider when treating a Class I malocclusion, such as: your vertical facial pattern and facial aesthetics, teeth crowding or gaps, overbite, position of your lips, and overall relationship between your teeth.
Edward Angle, the father of modern orthodontics, was the first to classify malocclusion types. He based his classifications on the relative position of the top first molar to the other teeth. In cases where the first molars are missing, Orthodontists use canine teeth to determine the relationship.
Illustration courtesy of dentodontics.com