Three-dimensional evaluation on digital casts of maxillary palatal size and morphology in patients with functional posterior crossbite

BACKGROUND AND OBJECTIVES: Some authors have recently postulated the possibility of a unilateral contraction of the palate in patients with crossbite. This study aimed to investigate palatal dimension size and morphology in subjects with functional posterior crossbite and to localize location of the contraction through a 3D analysis procedure. MATERIALS AND METHODS: A study sample (SS) of 35 subjects (mean age 9.2 ± 0.8 years), diagnosed with functional crossbite, and a control sample (CS) of 35 subjects (mean age 9.4 ± 0.9 years) without crossbite were selected for this study. The digital models of each patient were analysed to assess palatal dimension size and symmetry by measuring linear distances between primary canines (D1) and fist molars (D2) to the median palatine plane and by performing and analysing the 3D deviation between the two specular models of the palatal vault for each patient. RESULTS: Our findings demonstrate a significantly narrower dimension of D2 for the crossbite side than at the non-crossbite side. The 3D deviation analysis demonstrates a lower matching percentage of the palatal vault models in the SS (83.36%) compared with the CS (92.82%) and a location of that the palatal contraction is at the alveolar bone level. CONCLUSIONS: It can be assumed that there is a bilateral symmetrical contraction of the palatal vault and an asymmetric contraction of the alveolar process, but further studies are needed to corroborate this hypothesis.