Morphological Diversity of Soft Palate in Nepalese Population: A Retrospective Cephalometric Study

Introduction: Soft palate is a fibromuscular portion constituting the back of roof of the mouth which is essential for phonation, deglutition, respiration and velopharyngeal competence. Objective: To study various morphologies of soft palate, difference in proportion of each type and their differencesamong gender and agegroups in Nepalese sample. Materials & Method: Aretrospective study was conducted on patients seeking orthodontic treatment. 263 lateral cephalograms were classified on the basis of radiographic appearance. Analysis was done using SPSS (version 20.0). Pearson chi square and descriptive statistics were performed and level of significance was set at p<0.05. Result: In the order of occurrence; rat tail type of soft palate was most prevalent followed by leaf type, butt type, straightline, crooked type and S shaped. There was no significant difference between male and female subjects (p=0.338) and through age groups (p=0.998). Conclusion: The study highlights various types of soft palate present in Nepalese sample which will help as a reference for research pertaining to cleft palate/ velopharyngeal closure and in obstructive sleep apnoea syndrome in Nepalese population. Key-words: digital lateral cephalometry, morphology, soft palate lateral and posterior pharyngeal walls fails to separate two cavities, velopharyngeal incompetence (VPI) occurs. It participates in many oral functions especially velopharyngeal closure which is related to normal function of sucking, swallowing, and pronunciation.6 This incompetency can result into many malfunctions especially Obstructive Sleep Apnoea (OSA). You M et al documented the variation in normal velar morphology and classified them into six different categories;7 which have been employed in the present study. The objective of this study is to classify various morphologies of soft palate, difference in proportion of each type and also the difference between gender and age groups in Nepalese sample. MATERIALS AND METHOD The retrospective study was conducted from July 2016 to February 2017. A total of 263 lateral cephalograms were collected randomly from patients who had visited Department of Orthodontics and Department of Oral


INTRODUCTION
The oral cavity has various functions including respiratory, nutritional and communicative.The palate is the roof of the mouth and comprises of an anterior bony hard palate and posterior muscular portion.Soft palate is a fibromuscular portion constituting the back of roof of the mouth and does not contain bone.The hard and soft palate are easily palpable and identified by change in colour. 1 Soft palate plays an important role in phonation, deglutition, respiration and velo-pharyngeal competence. 2 The palate is formed by the fusion two palatal processes and fronto-nasal process.[5] Theanatomy of the soft palate plays animportant role in velopharyngeal closure which is a sphincteric mechanism constituting of velar and pharyngeal components.The movement separates the oral cavity from nasal cavity during deglutition and speech.When the velum and occurs.It participates in many oral functions especially velopharyngeal closure which is related to normal function of sucking, swallowing, and pronunciation. 6is incompetency can result into many malfunctions especially Obstructive Sleep Apnoea (OSA).

MATERIALS AND METHOD
The retrospective study was conducted from July 2016 to February 2017.A total of 263 lateral cephalograms

RESULT
In the present study, the age group of patient ranged from 18-40 years with the mean age of 27.70 years.
The gender comparison showed almost equal proportion of male and female in each type of soft palate with no significant difference between the groups (p=0.338)(Table 2).
The age-wise comparison (<20 years, 21-30 years and 31-40 years) showed almost equal proportions in each type of soft palate with no significant differences among the groups (p=0.988)(Table 3).

DISCUSSION
[11][12] One of the several hypotheses proposed by Cohen et al suggested that; this surgically successful yet functionally compromised repair may be the difference in morphology of the soft palate and other associated structures in these patients from that of the normal subjects.[15][16] In the present study, Type 2 rat tail shape was most frequent type (35.0%), which is similar to study done by Samdani et al. 17 This was followed bythe prevalence of Type 1 Leaf shaped (20.2%).However in many studies; most common type of soft palate reported was Leaf type. 18,19,4The leaf shape which is found as second common in our study was previously described as classic velar morphology in literature.This variation could be due to the fact that most of our study cases had malocclusions requiring orthodontic treatment.
In other studies; the most common type of morphological variant of soft palate was reported to be butt-shape and S shaped.

YouM
et al documented the variation in normal velar morphology and classified them into six different categories; 7 which have been employed in the present study.The objective of this study is to classify various morphologies of soft palate, difference in proportion of each type and also the difference between gender and age groups in Nepalese sample.

Table 1 : Distribution of various types of soft palate
lateral cephalogram is the most common diagnostic radiograph used in clinical orthodontics.Cephalometric

Table 3 : Comparison of type of soft palate with age group
Upadhyaya C, Neupane I, Sapkota B, Srivastava S: Morphological Diversity of Soft Palate in Nepalese Population: A Retrospective Cephalometric Study soft palate has frequently been left unexplored.Even after closure of the soft tissue defect in cleft patients, normal function of the softpalate is frequently not achieved and velopharyngeal insufficiency (VPI) with hypernasal NS: Not significant Orthodontic Journal of Nepal, Vol. 7 No. 1, June 2017 19,18,23se variations in types of soft palate could Pepin et al was found in 6.5%of our cases.They found the "hooked" appearance of soft palate in patients who were awake and this appearance of soft palate is associated with high risk of obstructive sleep apnea syndrome (OSAS).22The diffence among age and gender groups with different shapes of soft palate was not statistically significant in the present study, conforming to other studies as well.19,18,23 CONCLUSIONSoft palate is an important structure in velopharyngeal closure and provides information for diagnosis, prognosis and treatment in individuals with cleft palate and in obstructive sleep apnoea syndrome.The present study helps as a reference for research pertaining to cleft palate/ velopharyngeal closure and in obstructive sleep apnoea syndrome in Nepali population.OJN