| Popis: |
The literature lacks reports on measurement-based investigations of the sagittal curve of the mandibular ridge. The prosthetic significance of that curve is a debated issue even today. Our investigations have been carried out on functional samples of randomly selected edentulous patients (55 females and 17 males) treated at the Department of Prosthodontics of the Semmelweis University, Budapest. We made photographs using a Polaroid MACRO 5 SLR camera on a squared factory-made film, under standard circumstances, from both right and left directions. The photographs were then scanned with 600 dpi resolution and saved as non-compressed tif files (Tag Image File Format). The evaluation of the digitalized photographs has been carried out using a specifically developed computer program. On the four-times enlarged pictures, we made three measurements at each point; the arithmetical means of those sets of three figures served as a basis for statistical analysis. The data were analysed by gender and by side, using the SPSS program package (t-test). Our measurements showed that the sagittal curve is characteristic of the edentulous mandibular ridge as well. However, it does not exhibit significant differences by gender, individual, or side. The average value of the lowest point of the sagittal curve was 5.78 mm, s +/- 1.96 mm, minimum = 1.83 mm, maximum = 11.12 mm. It was concluded from our measurements and comparative anatomical data--clinical observations, as well as measurement-based investigations--that the Spee-curve of the healthy dentition and the sagittal curve of the edentulous mandibular ridge are formed by the same forces. If, in everyday practice, sagittal curves of the occlusion surfaces of complete lower dentures are set parallel with the mandibular edge, this is the most preferable solution with respect to both the stability of complete lower dentures and the optimal functioning of constrictor muscles. |
