The most common occlusal feature of Class I malocclusion is crowding. Crowded and irregular teeth occur in a majority of the population and are the most common complication in adults. This is a case report of a 21-year-old woman with moderate crowding and a missing lower left first molar. The first permanent molars are sometimes unnoticed by the child or their parents and bring a risk of caries to the first permanent molar. Caries in the first molars that persist without any treatment will give a poor prognosis. Treatment was performed using a fixed orthodontic appliance with the extraction of the two upper and one lower first premolars.
Angle Class I ; malocclusion ; tooth crowding ; tooth loss