[Criteria for applying lingualized occlusion by the condition of residual alveolar ridge]

Lingualized occlusion is applied to patients with alveolar ridge resorption, and it is considered that this occlusion is functionally useful and should be applied to cases with alveolar ridge resorption. However, selection criteria supported by evidence for what conditions of the alveolar ridge lingualized occlusion should be selected do not exist. For that reason, we conducted an investigation on choosing lingualized occlusion. As a result, no differences were noted in subjects with a good alveolar ridge condition while a sufficient lingualized occlusion effect was obtained in subjects with a poor alveolar ridge condition, suggesting that efficient mastication could be attained. The following indexes were examined as the criteria for applying lingualized occlusion: The ratio of the residual alveolar ridge should be less than approximately 0.5, in which the distance between the inferior border of the mental foramen and the superior border of the mandibular bone should be less than half the distance between the inferior border of the mental foramen and the inferior border of the mandibular bone. The supporting area of the denture base should be less than approximately 2,000 mm(2). Though the effect can be expected when applying lingualized occlusion under these criteria, they are one standard, and cannot be applied in all cases. In clinical cases, it is important to grasp the local and the whole-body conditions of the patient in order to choose denture occlusion.