The minimum phonetic dimension in total edentulous patients: a different method for determining the vertical dimension of occlusion

literature since there is no reliable and universally accepted method for resolving it (Bratu et al 2003, Sigurd et al 1983, Lejoyeux 1968). As it is a step of major importance, which precedes the correct account of the centric relation (CR), there is currently still high interest in finding new approaches. The current methodology involves two branches: (1) using physiological methods at the expense of anthropometric (mechanical) ones, and (2) optimal timing determination in successive stages of treatment (Negucioiu 2004, Păuna et al 2005, Klein 1974). Some of the ideas shared at the Cluj School of Dental Prosthetics focus on finding dynamic functional methods for determining the VDO, complementing the functional static methods used to date. At the national level, for the first time, we encounter the use of phonation in determining the VDO. We believe that an in-depth analysis of this valuable approach could bring new therapeutic benefits for total edentulous patients. It is generally agreed that there is a corresponding position of the mandible in the relation to the maxilla for each sound. According to Survin (Survin 1988) “M”, “F” and “S” are the most appropriate consonants for testing. Head position has a significant impact on the size of free interocclusal space if VDO is determined by facial aspect, while using the phonetic method, Introduction It is well known that for a successful treatment of bimaxilary edentation, one of the milestones is a correct determination of the vertical dimension of occlusion, which has to be the same as before edentation occurred. The vertical dimension of occlusion (VDO) is an essential parameter in dentistry, in particular for prosthetics. The vertical dimension of occlusion refers to the vertical position of the mandible in relation to the maxilla when the upper and lower teeth are intercuspated at the most closed position. The repetitive contracted length of the elevator muscles determines the vertical dimension of occlusion (Dawson 2006). Methods for determining vertical dimension of occlusion mostly date back to the early 20th century (Pound 1976). Techniques for determining VDO are numerous and are based on the determination of the rest vertical dimension (RVD) (Niswonger 1934, Pleasure 1951), speaking methods (Pound 1977, Silverman 1953, Silverman 1956) preextraction registration techniques (Smith 1971), photographs (Bliss 1935) measurements of face and intraoral measurements (Willis 1935), cephalometric radiographs (Pyott et al 1954) etc. Determination of the dimension of vertical occlusion in total edentulous patients continues to be a hotly discussed topic in Abstract. Introduction: The vertical dimension of occlusion, describing the vertical position of the mandible with respect to the maxilla when the upper and lower teeth are intercuspated at the most closed position, is an essential parameter in dentistry, in particular for prosthetics. The classic method to determine the vertical dimension of occlusion is a static one, based on the determination of the rest vertical dimension, which is imposed by the balance between the two opposite muscle groups of the mandibula (elevators and depressors). The aim of the present work is to probe a new method based on dynamic principles, using phonation for determination of the vertical dimension of occlusion in total edentulous patient. Materials and methods: This method consists in using hard material custom trays. The maxillary custom tray is bearing an occlusion rim made of pink wax which assures the vestibular curvature according to aesthetic criteria and the occlusal plane. The mandibular tray will be used with a soft roll of material to take impressions during phonation. Special sounds are used during the procedure in order to obtain the minimal phonetic vertical dimension. The proposed method had been tested on a group of ten denture-bearing patients having total bi-maxillary edentation. Results: After treatment, facial aspects showed that lip contours are improved, the facial ratios appear to be proportional and the speech was similar to persons with natural teeth. Conclusion: The minimum vertical dimension has been proven to be a valuable method. This method eliminates the evaluation errors, reduces treatment time and demonstrates practical feasibility.