What is the primary way to differentiate between maxillary and mandibular molars when mounting?

The primary way to differentiate between maxillary and mandibular molars when mounting is indeed by the number of roots present in the molars.

Maxillary molars typically have three roots: two buccal roots (mesiobuccal and distobuccal) and one palatal root. This structure allows for a wider occlusal surface and distinctly identifies them from mandibular molars, which usually possess two roots – one mesial and one distal. Understanding this root morphology is crucial for accurate mounting and interpretation of radiographs. It ensures clarity in identifying the type of molar, which is essential for diagnosis and treatment planning.

While factors such as the number of cusps, overall size, and position within the arch can help provide additional context for identification, they are not as definitive or reliable as the root count. The complexity and specific anatomical variations in root morphology offer the clearest distinction between the two types of molars in practice.