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Resident Manual of Trauma to the Face, Head, and Neck

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Chapter 5: Mandibular Trauma

6. Overjet and Overbite

Overjet is anterior vertical overlap, and overbite is anterior horizontal

overlap. Both are measured in millimeters.

7. Skeletal Malocclusion

Skeletal disharmony of the maxillary and mandibular relationship, as

identified on cephalometric assay, produces malocclusion of the upper

and lower dentition. Most skeletal malocclusions can only be treated by

orthognathic surgery.

8. Dental Malocclusion

Dental malocclusion is the misalignment of teeth or incorrect relation

between the teeth of the maxilla and mandible. This term was coined by

Edward Angle, the “father of modern orthodontics,” as a derivative of

occlusion, which refers to the way opposing teeth meet. Most dental

malocclusions are treated by orthodontic movement.

9. Mesial

Mesial refers to the direction toward the anterior midline in a dental

arch. Each tooth can be described as having a mesial surface and, for

posterior teeth, a mesiobuccal and a mesiolingual corner or cusp.

10. Distal

Distal refers to the direction toward the last tooth in each quadrant of a

dental arch. Each tooth can be described as having a distal surface and,

for posterior teeth, a distobuccal and a distolingual corner or cusp.

11. Crossbite

A crossbite is a malocclusion where a single tooth or a group of teeth

has a more buccal or lingual position and can be classified in anterior or

posterior and bilateral or unilateral. Anterior crossbite is seen in Angle

Class III skeletal malocclusion, while posterior crossbite correlates to a

narrow maxilla.

12. Centric Occlusion and Centric Relation

Centric occlusion is the occlusion of opposing teeth when the mandible

is in centric relation to the maxilla. Centric occlusion is the first tooth

contact and may or may not coincide with maximum intercuspation. It

is also referred to as a person’s habitual bite position. Centric relation

should not be confused with centric occlusion, which is the relationship

between the maxilla and mandible.

13. Vertical Dimension of Occlusion

This term is used in dentistry to indicate the superior-inferior relation-

ship (height) of the maxilla and the mandible when the teeth are