IADR Abstract Archives
Comparison of palatal vault Characteristics in adult patients with various mandibular divergence patterns
Objectives: Different vertical facial patterns have been associated with variations in maxillary arch width, determined to be narrower in hyperdivergent phenotypes. Compare the anatomy and dimensions of the palatal vault between subjects with different vertical skeletal patterns.
Methods: Pretreatment dental casts of 87 adult patients were stratified into 4 subgroups according to mandibular plane inclination to cranial base (MP/SN): A.Low (MP/SN≤27o;n=21), B.medium-low (27oo;n=21), C.medium-high (32oo;n=20), D.high (MP/SN>37o;n=25). Maxillary arch measurements included palatal width (at level of first molars, premolars and canines) and depth (at level of first molars and premolars), palatal width/depth ratio and characteristics (orientation, shape, strength, length) of the right and left rugae. Statistics included bivariate analysis including t-test and fisher’s exact test for categorical variables; regressions to predict palatal height; and Pearson product moment for associations among variables.
Results: Height/width ratio at the level of molars was higher in the hyperdivergent compared to the hypodivergent group (p=0.04). When the data were pooled in 2 groups (A,B vs C,D), the intercanine and interpremolar widths, and the second right rugae length were significantly higher in the hypodivergent group; shapes of the second left and right rugae were significantly different (p=0.033 and 0.044, respectively). The rugae contributed to predicting palatal height (PH): 11% of the variation in PH at the molar level was predicted by the combination of the 2nd left rugae length, MP/SN and PH at the premolar level (p<0.02); the lengths of both left second and third rugae, along with the intercanine distance, predicted PH at the premolar level (R2=0.19;p<0.02).
Conclusions: Similarity of maxillary vault dimensions in the various mandibular divergence patterns may imply functional adaptation of the nasopharyngeal matrix. The anatomical variation of the seconds palatal rugae, already reported to change with orthodontic treatment, suggests an adaptive nature of the rugae to environmental influences.
Methods: Pretreatment dental casts of 87 adult patients were stratified into 4 subgroups according to mandibular plane inclination to cranial base (MP/SN): A.Low (MP/SN≤27o;n=21), B.medium-low (27o
Results: Height/width ratio at the level of molars was higher in the hyperdivergent compared to the hypodivergent group (p=0.04). When the data were pooled in 2 groups (A,B vs C,D), the intercanine and interpremolar widths, and the second right rugae length were significantly higher in the hypodivergent group; shapes of the second left and right rugae were significantly different (p=0.033 and 0.044, respectively). The rugae contributed to predicting palatal height (PH): 11% of the variation in PH at the molar level was predicted by the combination of the 2nd left rugae length, MP/SN and PH at the premolar level (p<0.02); the lengths of both left second and third rugae, along with the intercanine distance, predicted PH at the premolar level (R2=0.19;p<0.02).
Conclusions: Similarity of maxillary vault dimensions in the various mandibular divergence patterns may imply functional adaptation of the nasopharyngeal matrix. The anatomical variation of the seconds palatal rugae, already reported to change with orthodontic treatment, suggests an adaptive nature of the rugae to environmental influences.