Acquisition of the 3D surface of the palate by in-vivo digitization with Wave

An accurate characterization of the morphology of the hard palate is essential for understanding its role in human speech. The position of the tongue is adjusted in the oral cavity, of which the hard palate is a key anatomical structure. Methods for modeling the palate are limited at present. This paper evaluated the use of a thin plate spline (TPS) technique for reconstructing the palate surface from a series of in-vivo tracings obtained with electromagnetic articulography using Wave (NDI). Twenty-four individuals (13 females and 11 males) provided upper dental casts and in-vivo tracings. Models of the palate surfaces were derived from data acquired in-vivo and compared to the scanned casts. The optimal value for the smoothness parameter for the TPS technique, which provided the smallest error of fit between the modeled and scanned surfaces, was determined empirically (the value of 0.05). Significant predictors of the quality of the fit were determined and included the individuals’ palate characteristics such as palate slope and curvature. The tracing protocol composed of four different traces produced the best palate models for the in-vivo procedure. Evidence demonstrated that the TPS procedure as a whole is suitable for modeling the palate surface using a small number of in-vivo tracings.

► TPS is suitable for modeling the palate surface using a small number of in-vivo tracings.
► The TPS smoothness parameter that yielded the lowest error was determined empirically to be 0.05.
► Four traces added complimentary data to the TPS surface.
► Palatal anatomy needs to be taken into account when tracing the hard palate.