Overjet

Overjet

Diagram illustrating overjet and overbite

Overjet refers to the horizontal distance between the upper front teeth (maxillary incisors) and the lower front teeth (mandibular incisors). It is a common dental measurement used to assess the alignment and occlusion of teeth.

Definition

In dental terms, overjet is the extent of horizontal (anterior-posterior) overlap of the maxillary central incisors over the mandibular central incisors. It is typically measured in millimeters using a periodontal probe or a ruler.

Normal Overjet

A normal overjet is considered to be around 2 to 3 millimeters. This allows for proper function and aesthetics of the teeth. A normal overjet ensures that the teeth can effectively cut and chew food, and it also contributes to the overall appearance of the smile.

Increased Overjet

An increased overjet, often referred to as "protrusion," occurs when the maxillary incisors are significantly forward of the mandibular incisors. This condition can be caused by:

• Genetics
• Thumb sucking
• Tongue thrusting
• Skeletal discrepancies

Increased overjet can lead to functional problems such as difficulty in biting and increased risk of trauma to the protruded teeth.

Decreased Overjet

A decreased overjet, sometimes called "reverse overjet" or "anterior crossbite," occurs when the mandibular incisors are positioned in front of the maxillary incisors. This condition can be associated with:

• Class III malocclusion
• Mandibular prognathism
• Maxillary retrusion

Decreased overjet can affect the aesthetics of the smile and may lead to functional issues such as improper incisal guidance.

Clinical Significance

Assessing overjet is crucial in orthodontic diagnosis and treatment planning. It helps in determining the type of malocclusion and the appropriate treatment approach, which may include:

• Orthodontic braces
• Functional appliances
• Orthognathic surgery

Related Pages

• Overbite
• Malocclusion
• Orthodontics
• Dental occlusion