What defines a class III malocclusion?

A class III malocclusion is characterized by the position of the maxillary and mandibular first molars. Specifically, in a class III situation, the mesiobuccal (MB) cusp of the maxillary first molar is positioned behind the buccal groove of the mandibular first molar. This arrangement indicates a skeletal relationship where the mandible is either positioned forward relative to the maxilla or the maxilla is positioned backward, resulting in a prognathic appearance.

Understanding this classification is essential as class III malocclusion can impact the function and aesthetics of an individual's dentition. It often associates with other characteristics, such as a more pronounced overjet and potential for increased wear on teeth due to the misalignment of the dental arches. This specific relationship of the molars is pivotal for diagnosing malocclusions in dental practice, allowing practitioners to develop appropriate treatment plans for their patients.