Overbite is the extent of vertical (superior-inferior) overlap of the maxillary central incisors over the mandibular central incisors, measured relative to the incisal ridges.
The term overbite does not refer to a specific condition, nor is it a form of malocclusion. Rather an absent or excess overbite would be a malocclusion. Normal overbite is not measured in exact terms, but as a proportion (approximately 30–50% of the height of the mandibular incisors) and is commonly expressed as a percentage.