Assessment of Vertical Skeletal Patterns using a New Cephalometric Parameter: The Dhaval—Rohan Angle

Abstract

Introduction The aim of this study was to establish a new cephalometric parameter, named the Dhaval—Rohan angle (DR), to assess the vertical skeletal patterns on a lateral cephalogram with accuracy and reproducibility. Materials and methods One hundred and twenty pretreatment lateral cephalograms of the patients visiting the department of orthodontics and dentofacial orthopedics for treatment were obtained and divided into three groups. i.e., horizontal growth pattern, average growth pattern, and vertical growth pattern cases based on the routinely used cephalometric parameters; FMA, SN-GoGn, Y-axis angle and Jarabak ratio. This angle uses three skeletal landmarks, the point C (center of the condyle), point M (midpoint of premaxilla), and point G (center of the largest circle that is tangent to the internal inferior, anterior, and posterior surfaces of the mandibular symphysis). Results The one-way analysis of variance (ANOVA) test showed that the three groups studied were not the same for DR angle and the post hoc Tukey test found the groups to be significantly different. According to the Student's t-test, there was no statistically significant difference in mean values of DR angle between males and females. Conclusion Cephalometric evaluation of young adults shows that the DR angle below 28.5° indicates a horizontal growth pattern, between 28.5 and 32.5° indicate an average growth pattern and above 32.5° indicate a vertical growth pattern. How to cite this article Lekhadia DR, Rai R, Hegde N, Hegde G, Sorake A, Kumar A. Assessment of Vertical Skeletal Patterns using a New Cephalometric Parameter: The Dhaval—Rohan Angle. J Postgrad Med Edu Res 2017;51(1):7-11.

Comparative Assessment of Various Cephalometric Parameters Used for Determining Vertical Skeletal Dysplasia

“…New parameters, the R angle and the DR angle, were developed in 2013 and 2017, respectively, in an effort to address the above-mentioned shortcomings. The intersection of the C-N and C-Me axes forms the R angle Additionally, lines connecting Point M, the pre-maxilla centre, and Point G, the centre of the largest circle tangent to the internal inferior, anterior, and posterior surfaces of the mandibular symphysis, form the DR angle [17] at Point C, the condyle centre. A vertical growth pattern is indicated by the DR angle above 32.5°, an average growth pattern is indicated between 28.5 and 32.5°, and a growth pattern is indicated below 28.5°.…”

Yüzün Verti̇kal Yön Değerlendi̇rmesi̇nde Kullanilan R-Açisinin Güveni̇li̇rli̇ği̇

“…12 Lekhadia ve ark., lateral sefalometrik radyografilerde vertikal yön değerlendirmesinde yeni bir ölçüm olan Dhaval-Rohan açısını (DR açısı) tanıtmıştır. 13 DR açısı 28,5 ̊ 'nin altında olan vakaların hipodiverjan, 28,5-32,5 ̊ arasındaki vakaların ortalama, 32,5 ̊ 'nin üzerindeki vakaların hiperdiverjan büyüme yönüne sahip olduklarını belirtmişlerdir. DR açısının yüzün vertikal büyüme yönü hakkında değerlendirme sağlayarak teşhis ve tedavi planında kullanılabileceğini belirtmişlerdir.…”