D.K.Singh, Lav Kumar, Haripal

ABSTRACT

AIM: To assess difference in the position of posterior mandibular teeth as dictated by existing anatomical landmarks on the cast and that attained physiologically by neutral zone recording. OBJECTIVES –To assess: (1) Deviation (buccal/lingual) of the potential space for the placement of posterior teeth in atrophic mandibular ridges. (2) The period of edentulousness and the condition of surrounding tissues affecting relative position of the teeth. Materials and Methods: The study included 8 edentulous patients, previous denture wearer, with atrophied mandibular residual ridges and a variable period of edentulous equal or more than 5 years. Neutral zone recording was performed for each patient and the bucco-lingual relationship of the crest of the mandibular alveolar ridge and position of the neutral zone was examined. Results:The results suggested that the location of the neutral zone varies from individual to individual depending on their musculature and that there is a significant relation to the duration of edentulousness. As edentulousness increases, there is more lingual positioning of the neutral zone at the molar region of both sides of the arch. At the premolar region, there is no change in position of the neutral zone; it remains constant as resorption of the alveolar ridge is directly under the buttress. In the anterior region, there is more labial positioning of the neutral zone as edentulousness increases. Conclusions:This technique proves itself to be an easy and inexpensive way to determine the relationship between the crest of alveolar ridge and neutral zone. Incorporating this technique into practice will be a great aid that can be exploited by the clinicians for functional and psychological comfort of the patients.