Incisor Relationship
The antero-posterior relationship of the upper and lower incisor teeth as defined by the British Standards Institute classification into Classes I, II Division 1, II Division 2, and III.
Full Definition
The incisor relationship describes the vertical and horizontal overlap between the upper and lower incisor teeth and is used by UK orthodontists as the primary basis for classifying malocclusion, according to the British Standards Institute (BSI) system. Class I denotes a normal relationship; Class II Division 1 indicates proclined upper incisors with an increased overjet; Class II Division 2 involves retroclined upper incisors; and Class III presents with a reverse overjet. Editors should note that 'Division' is capitalised as part of the proper classification designation and Roman numerals are used. This classification differs from Angle's molar-based system used more commonly in North America.
Usage
Usage note: Capitalise 'Class', 'Division', and use Roman numerals. The BSI classification is standard in UK orthodontic practice; do not substitute with Angle's classification without context.
In Context
- "The patient presented with a Class II Division 1 incisor relationship and an overjet of 9 mm." — Referral letter
- "Following treatment, a Class I incisor relationship was established." — Completion summary