Bisshöhe

Bisshöhe, known in English as the occlusal vertical dimension (VDO), is the vertical distance between the maxilla and the mandible when the teeth are in contact in centric occlusion. It is a fundamental parameter of dental occlusion and influences chewing efficiency, speech, facial aesthetics, and the health of the temporomandibular joints.

This dimension is not fixed and varies widely between individuals. It is shaped by factors such as tooth wear, tooth loss, aging, and previous restorative or orthodontic work. In addition, there is a rest position in which the jaw is separated, called the rest vertical dimension (RVD); the difference between RVD and VDO is the freeway space, typically around 2 to 4 millimeters.

Clinically, Bisshöhe is established and adjusted during diagnosis, planning, and restoration. In patients with natural teeth, clinicians assess VDO through facial proportions, phonetics, and functional testing. In edentulous patients or those needing dentures, wax rims mounted on articulators are used to simulate VDO, with guidance from phonetic cues (such as the way sounds are formed), esthetics, and swallowing patterns. The goal is to reproduce a comfortable and functional bite that supports normal function and appearance.

Both excessive and insufficient Bisshöhe can cause problems. A bite that is too high can produce muscle fatigue, TMJ strain, restricted opening, and speech difficulties; a bite that is too low can reduce lower facial height, lip support, and masticatory efficiency. Restoration and occlusal adjustment typically involve incremental changes and careful reassessment to maintain or restore stable occlusion and patient comfort.