##  [Overjet](/overjet-0) 

 Definition

The horizontal (sagittal) distance measured in centric occlusion between the labial surface or incisal edge of the most protruded maxillary anterior tooth(s) and the labial surface or incisal edge of the opposing mandibular anterior tooth(s), expressed in millimetres; commonly referred to as overjet.

 

 

 

 

 

 





## Principle

Principle

Overjet quantifies anterior–posterior tooth position and contributes to the dental classification of sagittal relationships; it reflects dental alignment, dental compensation for skeletal relationships and must be measured in centric occlusion with a defined horizontal reference plane for reproducibility.

 

 

 

 

 





## Demonstration

Demonstration

Situation: Orthodontic record-taking. Recognition: With teeth in centric occlusion, align a millimetre ruler or caliper parallel to occlusal plane at the incisal edges. Action: Measure the horizontal projection from the labial surface/incisal edge of the lower incisor to the incisal edge or labial surface of the upper incisor; report in mm. Consequence: Measured overjet informs treatment need (e.g., correction of increased overjet) and appliance selection.

 

 

 

 

## Misapplication

Misapplication

Confusing overjet with overbite (vertical overlap) or measuring during mandibular protrusion or retrusion rather than true centric occlusion; such errors produce clinically misleading values.

 

 

 

 

 





## Consequence

Consequence

Accurate overjet measurement affects orthodontic diagnosis, risk assessment for trauma to protrusive incisors, and treatment planning; inaccurate measures can misclassify sagittal relationship and lead to inappropriate appliance design or timing.

 

 

 

 

## Reversal

Reversal

When dental compensation masks an underlying skeletal discrepancy (e.g., proclined lower incisors compensating a skeletal Class III), overjet may understate or overstate skeletal abnormalities; in mixed dentition transient measurements may not predict final relationships.

 

 

 

 

 





## Boundary

Boundary

Clearly within: Horizontal interincisal distance measured in centric occlusion between anterior teeth. Boundary case: Asymmetric incisor positions where measurement depends on choosing the most protruded tooth. Clearly outside: Molar sagittal relationship measurements alone or anterior crossbite situations where overjet is negative and requires sign convention.

 

 

 

 

 





## Semantic Tension

Semantic Tension

Dental tooth alignment metric versus skeletal jaw relationship: overjet is a dental measurement that may or may not reflect underlying skeletal class, creating tension in diagnosis and treatment planning.

 

 

 

 

 





## Synthesis

Synthesis

Overjet is a standardized horizontal tooth-position measure; its interpretation requires concurrent assessment of dental compensation, occlusal contacts and skeletal relationships rather than reliance on the numeric value alone.