Abstract

Using cinematographic and radiocinematographic recording techniques, the authors studied the movements of inferior prosthesis unstable in the lingual region. Pronunciation of the diphthong La... La... La... causes upward and forward projection of the prosthesis. Electromyography records contraction of the mylo-hyoid during pronunciation of these diphthongs. In the totally edentulous patient, the crest of the mylo-hoid is very close to the alveolar crest. From a clinical standpoint, functional exploration of the mylohyoid is easy, the index finger being placed along the mylo-hyoid crest and the patient asked to say La... La... La... If the index finger is pushed forwards and up, surgical intervention to lower the mylo-hyoid (Trauner's operation) is indicated, in association or not with other procedures designed to treat the other causes of instability or the prosthesis.