engleski

Evaluation of three different methods for the establishment of the inclination of the occlusal plane in complete dentures

Introduction: Inclination of the occlusal plane is responsible for the amount of forces directed towards the denture bearing area, and for the stability of dentures. The artificial occlusal plane should be as close as possible to the position once occupied by the natural teeth in order not to jeopardize proprioceptive and neuro-muscular mechanisms (1-3). Clinically occlusal plane orientation in edentulous patients is established using different soft and hard tissue landmarks (1-7). Aims: To compare the accuracy of three methods for establishment of the occlusal plane inclination: a) parallelism with the Camper’s plane, b) parallelism with the incisive papila-hamular notch plane, and c) termination at the level of the retromolar pad.Methods: Eighty eugnath subjects were photographed with the Fox Plane (44 females, 36 males). The angle between the Camper’s plane and the Fox plane was transferred to the callibrated paper. Alginate impressions were also made and the maxillary casts were mounted in the S.A.M. 2 articulator and the measurements were performed by a precise calliper. The natural occlusal plane was defined as the line connecting incisal margins of the maxillary central incisors and the mesiopalatal cusp sof the first molars. Also the plane connecting the midpoint of the incisive papilla and the hamular notches was defined (IP-HN). All the vertical and the horizontal values were transfered t o the calibrated paper and the inclination between the planes were measured . The third method to establish the artificial occlusal plane was its termination at the insertion of the pterygomolar fold at the retromolar pad. The plane connecting the incisal margins of the lower mandibular incisors and the insertion of the pterygomolar fold was measured and transferred to the calibrated paper. The angles were measured by a precise protractor. The statistical analysis comprised one-way Kolmogorov-Smirnov test, Student’’s t-test and one-way ANOVA. Results: 1.There was a significant difference between the OP determined by the three different methods (p<0.05, one-way ANOVA).2. The Camper’s plane and the Fox plane (representing occlusal plane) were not parallel (mean difference: x= 3.52 degrees, p<0.05) ; 3. The line between the incisal edges of the lower central incisors and the insertion of the pterygomandibular fold at the retromolar pad (RP) was also not parallel with the occlusal plane (mean difference: x= -2.93 degrees ; p<0.05). 4. The Incisive papila-hamular notches plane (IPHN) and the Fox plane were almost parallel (mean difference: x=0.34 degrees, p>0.05). Conclusion: The occlusal plane (OP) determined by the parallelism with the IPHN plane was superior to other two methods

occlusal plane; orientation; clinical methods

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