Class I Molar Relationship
The standard occlusal relationship, defined by Angle, in which the mesiobuccal cusp of the upper first molar occludes in the buccal groove of the lower first molar.
Full Definition
Described by Edward H. Angle in 1899, the Class I molar relationship is the normative reference standard for dental occlusion against which Class II and Class III deviations are measured. In a Class I relationship, the mesiobuccal cusp of the maxillary first permanent molar aligns with the buccal groove of the mandibular first permanent molar. Editors should note that Angle's classification is strictly dental (dentoalveolar) and does not describe the underlying skeletal relationship; a patient with a Class I molar relationship may still have a skeletal discrepancy. The term is styled with roman numerals and is capitalised as a proper classification system.
Usage
Usage note: Always use roman numerals (I, II, III) when styling Angle's molar classification. Clearly distinguish dental (Angle) classification from skeletal classification in reports.
In Context
- "Despite the underlying Skeletal Class II pattern, a Class I molar relationship was maintained through dentoalveolar compensation." — Orthodontic case report
- "Editors should use roman numeral 'I' rather than Arabic '1' when styling Angle's classifications." — Style guide for orthodontic journals