NMDA Journal Summer 2018

14 New Mexico Dental Journal, Summer 2018 In the course of our life and dental practice, we inevitably meet people with whom we don't feel comfortable for a variety of reasons. There are those who may feel the same way about us. In either case, it is a serious mistake to accept such an individual as a patient. This concept is particularly true when you are confronted with people of “importance,” whether real or self-designated. Should any disagreement arise—whether with regard to communication, quality of care, or result of treatment—it is likely to be more difficult than one might expect under normal circumstances. Many dentists have found that the opinions of their staff in the office can be constructive in assessing who is or is not a potentially troublesome patient. Such opinions can certainly serve to augment or confirm your impression on the basis of the consultation. Lingualized Occlusion The search for the ideal denture occlusion has been going on for many decades in an effort to find the tooth formwhich provides maximum denture stability and masticatory efficiency without compromising the health of the underlying bone. Concern about ridge resorption started a trend toward the use of non-anatomic occlusal forms in the 1920s. A monoplane occlusal scheme limits aesthetic results in the premolar region and diffuses the forces of mastication over the entire occlusal surface of the tooth. This diffusion of forces reduces the patient’s ability to incise food. Alfred Gysi (1927), a dentist in Zurich, was the first to report the biomechanical advantages of lingualized tooth forms. Gysi noted that 60% of his denture patients had developed reverse articulations (i.e., cross-bite) due to common resorptive patterns. He also recognized the advantages associated with a balanced occlusion but encountered difficulties while attempting to create such occlusions with the prosthetic teeth of the era. The basic concepts of lingualized occlusion were first suggested by Payne (1941). Earl Pound (1973) discussed a similar occlusal concept and used the term “lingualized occlusion.” Ortman (1971), Murrell (1974), and Becker (1977) provided additional support for this occlusal concept. In the lingualized occlusion concept, only the lingual cusps of the posterior teeth of the maxillary denture make contact in an acquired centric relation in the central fossa of the lower posterior teeth. All of the maxillary and mandibular buccal cusps are out of contact. There is therefore only one “centric stop” between upper and lower antagonistic pair of posterior teeth (Fig 1). Fig 1—Lingualized occlusion During protrusive balance, anterior teeth should be out of contact. If anterior interference occurs, either move or grind the opposing lower anterior teeth slightly or increase the distal incline on the lower molars by increasing the compensating (Curve of Spee) curve. We use a semi-anatomical shallow 22° cusp tooth. This prosthetic tooth offers minimal interference and interacting ridges with clearance spaces to enhance chewing efficiency. This tooth is Ideal for use with full dentures when ease of set-up and uninterrupted function is desired. Lingualized occlusion is an attempt to maintain the aesthetic and food-penetration advantages of the anatomic form while maintaining the mechanical freedom of the non-anatomic form. Pound’s Triangle A successful denture is built on a firm foundation. In this nugget, the firm foundation is the set-up of the mandibular posterior teeth. It is vital for the stability of the mandibular denture that the force is distributed over the residual ridge. The maxillary posterior tooth set-up is then dictated by this mandibular set-up. Earl Pound (Fig 2) showed that the buccolingual position of maxillary teeth is controlled by the position of posterior mandibular teeth. He recommended that the lingual surfaces of mandibular posterior denture teeth should occupy an area continued from page 13 Fig 2—Earl Pound DDS (1971) Annual Meeting of the American College o f P r o s t h o d o n t i c s , Houston, Texas. “Seven Nuggets” for the Successful Denture