Study of Soft Palate Dimension and Nasopharyngeal Depth (Need’s Ratio) Using Lateral Cephalometrics X- Ray

Abstract

Background: Soft palate is a tissue mass that hangs behind the hard palate mainly to seal the pharyngeal airway. The length of the soft palate should be adequate to close the pharyngeal depth. Failure to completely seal leads to velopharyngeal insufficiency while longer palatal length leads to obstructive sleep apnea. This study aimed to find the need’s ratio among the general Nepalese population. Methods: Lateral cephalograms of 591 of 17 years and above cases without any history of palatal surgery, orthodontic treatment or congenital defect were studied. The length of the soft palate, pharyngeal depth and thickness of the palatal tissue was measured using VLX computer program in lateral cephalograms obtained from gendex orthoralix 9200. The ratio of palatal length pharyngeal depth was calculated as Need’s ratio. Results: Soft palate length was 33.27 + 7.74 and 24.82 + 4.53 respectively. The Need’s ratio calculated is 0.75. The rat tail shape of soft palate was highly prevalent 173 (28.3%) while S shape was least 51 (8.6%) . Crook type of soft palate has highest Need’s ratio. Conclusions: The mean Need’s ratio of Nepalese population is 0.75. Need’s ratio also varies from shape of the soft palate.