A possible biomechanical role of occlusal cusp–fossa contact relationships

Abstract

Biomechanical features of occlusal contacts are important in understanding the role of the occlusion contributing to masticatory function. Cusp-fossa contact is the typical pattern of occlusion between upper and lower teeth. This includes static relations, such as that during clenching, and dynamic relations when mandibular teeth contact in function along the maxillary occlusal pathways, as during mastication. During clenching in the maximum intercuspal position (ICP), cuspal inclines may take the role of distributing the occlusal forces in multi-directions thus preventing excessive point pressures on the individual tooth involved. During chewing movement on the functional side, the mandible moves slightly from buccal through the maximum ICP to the contralateral side. The part of the chewing cycle where occlusal contacts occur and the pathways taken by the mandible with teeth in occlusal contacts are determined by the morphology of the teeth. The degree of contact is associated with the activity of the jaw muscles. To obtain repeatable static and dynamic occlusal contact information provided by the morphology of the teeth, maximum voluntary clenching and chewing movements with maximum range are needed. In conclusion, in addition to the standard occlusal concepts of centric relation/centric occlusion and group function/cuspid protection relation, biomechanics in static and dynamic cusp-fossa relationships should be included to develop an understanding of occlusal harmony which includes no interfering or deflective contacts in functional occlusal contact.

Reproducibility of habitual intercuspation in vivo

“…Possible reasons for that could be a main focus in the literature on the dynamic aspects and concepts about functional occlusion in connection with static investigations. [27][28][29] Thus, based on this little scientific information, it was difficult to evaluate comparable results. Utz et al 14 Furthermore, the above-mentioned study shows the distinctions of the results between the different clinicians, which however were not evident within the actual study.…”

The influence of occlusal morphology on occlusion time

“…The dental arches sustain loads from jaw closing muscles contracting when upper and lower teeth come into contact. 19 The ICP, commonly used in kinematic analyses, marks the beginning and the end of the chewing movement where most tooth contact occurs. 20 Cusp-fossa contact is one of…”

Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness

“…The progressive and rapid reduction of contact area with increasing excursion confirms the observed changes in contact number. A larger contact area in the initial stages of excursion reflects greater jaw stability, as broader contact areas during chewing cycles may aid in evenly distributing occlusal forces (1,11).…”

“…However, fixed prosthodontic treatment usually affects the static and dynamic occlusal relationship. Occlusion scheme, contact number, contact area, and occlusion steepness may be altered by complex prosthodontic treatment (1,2). The lateral occlusion scheme has been extensively studied, as it is believed to control mandibular movement, chewing efficiency, restoration longevity, and patient comfort (2).…”

“…59, No. 3,[431][432][433][434][435][436][437][438]2017 Original Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness (1,11). Occlusal steepness is part of mandibular border movement and may affect the design of prostheses, the smoothness of gliding movement, and patient comfort (12)(13)(14).…”