What Is Occlusal Vertical Dimensions?

Introduction: Occlusal vertical dimension (VD) can be defined as the distance measured between two points when the occluding members are in contact or it can be defined as the distance between any two points measured in the maxilla and the mandible when the teeth are in maximum contact. A loss of OVD can significantly have in impact on the function, aesthetics and comfort of the patient. Comprehension of altering vertical dimensional effects on facial aesthetics, diagnose of the causative factors accurately and determination of the original vertical dimension are essential for a convenient treatment planning. A thorough intra-oral combined with an extra-oral assessment is essential since increasing the OVD is normally part of a comprehensive
(Figure 2) The original OVD is very often matching the following dimensions: (3)(5)
1. The horizontal distance between the pupils.
2. The vertical distance from the external canthus or the pupil to the cheilion.
3. The vertical distance from the eyebrow to the ala of the nose.
4. The vertical distance from subnasion to glabella at the midline.
5. The distance from one cheilion to the other cheilion, following the curvature of the lip border.
6. The distance from the eyebrow line to the hair line (in females) (Da Vinci).
7. The distance from the external canthus to the internal canthus (Da Vinci).
8. The vertical height of the ear (Da Vinci).
9. The distance between tips of the thumb and the index finger when the fingers are pressed together (Da Vinci).
10. The length of an eye x 2
11. The distance between the internal canthus of both eyes x 2
12. The distance between the external canthus and the ear (Da Vinci).
Depending on facial measurements to determine OVD presents obvious prosthetic advantages. (3)(5)
Figure 2: Face and body dimensions used to determine OVD.
Extra-oral
Interocclusal rest space (IORS) is defined as the difference in vertical dimension between rest position and occlusion of the mandible. For dentate patients, the foremost guide is the OVD of the present teeth. Therefore, the vertical dimension when the mandible is at rest can be evaluated clinically in order to determine the desired increase the OVD. An IORS of 2 mm has been described as the physiological space, as a result, 2 mm or more of IORS designates that the OVD can be safely increased. The available clinical trials that increased the OVD beyond IORS did not show any pathological consequences. On this basis, it could be stated that the determination of the OVD increase should not be based on IORS values. The availability of several identical measurements which match the original OVD allows the dentist to record an accurate average of multiple measures in order to determine OVD loss. So, the facial and body dimensions are desirable because there is no particular modality to determine OVD for all patients.