Palatal plane inclination on vertical growth pattern among Indians

Abstract

The skeletal discrepancies in the vertical dimensions can either lead to a long face or a short face. The palatal plane inclination is one such contributing factor. The study sample comprised of 15 lateral cephalograms collected between the time period of June 2019 - March 2020 with 5 cephalograms belonging to skeletal Class I, II and III respectively. The inclination angle and mandibular plane angle were measured using the FACAD software. The obtained results were tabulated and statistically analysed using Pearson's correlation test to determine the correlation between the two variables. There was a statistically significant negative correlation between the skeletal malocclusions with a p value of 0.011. Thus, palatal plane inclination is not a major contributing factor for vertical growth pattern and it is suggestive of a multifactorial influence.

Keywords: Inclination angle; mandibular plane; palatal plane; vertical growth pattern.

Figure 1

Bar chart showing mean value of mandibular plane angle and inclination angle in Class I, II and III malocclusion. Mean of the mandibular plane is 40.3° and the mean for inclination angle is 85.5° for Class I. For Class II, the mean of mandibular plane is 39.5° and the mean for inclination angle is 87.8°.The mean of mandibular plane is 38.2° and the mean for inclination angle is 86.3° for Class III. The mandibular plane angle is largest in Class I skeletal malocclusion, followed by Class II and then least in Class III. The inclination angle is maximum in Class II skeletal malocclusion, followed by Class III and then least in Class I. ( x axis - Skeletal relationship, y axis - Mean of mandibular plane angle and inclination angle; blue colour - mandibular plane angle, yellow colour - Inclination angle)

Figure 2

Scatter dot graph showing the results for Pearson's correlation test between mandibular plane angle and inclination angle in all 3 skeletal malocclusions. Figure shows a moderate negative correlation between the two angles, which is statistically significant as P value is 0.011. (x axis - mandibular plane angle; y axis - inclination angle)