|Year : 2015 | Volume
| Issue : 2 | Page : 48-51
Normative Soft Palate Dimensions and Morphology in a Subset of Indian Population: A Digital Cephalometric Study
Vasavi Krishnamurthy Santosh, Pooja Singh, Sandeep S Pagare
Department of Oral Medicine and Radiology, D. Y. Patil University, School of Dentistry, Navi Mumbai, Maharashtra, India
|Date of Web Publication||17-Dec-2015|
Vasavi Krishnamurthy Santosh
701, Gurusamridhi Heights, Plot No. 2, Sector 14, Sanpada, Navi Mumbai - 400 705, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: The variations in the morphology of the soft palate in normal patients help to establish the variations in morphology in various diseases. The classification system and statistical findings help to research velopharyngeal closure in cleft palate individuals and etiological study of obstructive sleep apnea syndrome and other conditions. The aim of our study was to investigate the variations in the velar morphology and to analyze the variations of length and density of the soft palate. Materials and Methods: In this study, a sample of 100 normal digital lateral cephalograms was analyzed for the variations in morphology of the soft palate and evaluated for analysis of length and density of the soft palate. Results: The morphology of the soft palate showed seven different morphological types. There was a significant difference in length of the soft palate between preadult and adult age groups. Males showed significantly longer and denser soft palate than the females. Conclusion: There was a significant difference in length of the soft palate between preadult and adult age groups. Males showed signifi cantly longer and denser soft palate than the females
Keywords: Digital lateral cephalogram, soft palate morphology, velar morphology
|How to cite this article:|
Santosh VK, Singh P, Pagare SS. Normative Soft Palate Dimensions and Morphology in a Subset of Indian Population: A Digital Cephalometric Study. Indian J Oral Health Res 2015;1:48-51
|How to cite this URL:|
Santosh VK, Singh P, Pagare SS. Normative Soft Palate Dimensions and Morphology in a Subset of Indian Population: A Digital Cephalometric Study. Indian J Oral Health Res [serial online] 2015 [cited 2019 Mar 19];1:48-51. Available from: http://www.ijohr.org/text.asp?2015/1/2/48/172022
| Introduction|| |
The soft palate is the posterior fibromuscular part of the palate that is attached to the posterior edge of the hard palate. The soft palate plays a large role in velopharyngeal closure, which refers to the normal apposition of soft palate with posterior and lateral pharyngeal walls. It participates in most oral functions, especially velopharyngeal closure which is related to the normal function of sucking, swallowing, and pronunciation. 
The variations in the morphology, length, and density of the soft palate in normal patients help to establish the variations in morphology in various diseases. Few studies in literature describe the normal variations of the soft palate.
The soft palate function and development can be monitored and recorded using a nasopharyngeal fiberscope and magnetic resonance imaging methods. ,
On the other hand, cephalometry is easy to use, economical, and can provide definite and quantitative information about the soft palate. The objective measurements of the soft palate have been contributed by investigators interested in speech function and upper airway structures. Recently, there has been renewed interest in the soft tissues of the oral and nasal pharynx. This increased interest stems from a potential relationship between the size and shape of the oral/nasal airway and sleep disordered breathing.
Hence, this study was designed with the aim to assess the variations of soft palate morphology in a subset of the Indian population, and to determine the difference in dimension and density of the soft palate across the different age and gender groups. This study can be helpful for understanding the various morphologies and length of the soft palate in the median sagittal plane on lateral cephalogram.
| Materials and methods|| |
One hundred digital lateral cephalograms of normal Indian subjects (41 males and 59 females with age ranging from 15 to 25 years) were derived from the Department of Oral and Maxillofacial Radiology from 2012 to 2013. All the subjects had normal speech and had no history of cleft palate, systemic diseases, or fracture of head and neck region. All the cephalograms were taken using XRTOPAN 2000. The tube potential was adjusted to optimize the contrast of both the hard and soft tissues (85 kV). Digital radiographs were processed and viewed by KODAK CR 7400 system.
Tracing was done on butter paper with a pencil to evaluate the morphology of the soft palate and were categorized according to the differences in the morphological pattern, based on the criteria given by You et al.  and modified by Guttal et al. 
- Type I: Leaf shaped/lanceolate-shaped - the middle portion of the soft palate elevated to both the naso and the oral side [Figure 1]a and b
- Type II: Rat-tail shaped: The soft palate which showed inflated anterior portion and free margin with an obvious coarctation [Figure 2]a and b
- Type III: Butt like - soft palate which showed a shorter and fatter velum appearance with no distinct difference of width of the anterior portion to the free margin [Figure 3]a and b
- Type IV: Straight line shaped [Figure 4]a and b
- Type V: S-shaped/distorted soft palate [Figure 5]a and b
- Type VI: U-shaped soft palate - variant of rat-tail shape with blunt end [Figure 6]a and b
- Type VII: Bifid shape - where the tip of the soft palate has a cleavage and splits into two [Figure 7]a and b
- All the radiographs were observed and categorized into seven types by two senior oral radiologists who did the examination separately. Since there was no difference in their classification, reliability was considered to be adequate for the purpose of this study.
The length of the soft palate was obtained by measuring the linear distance from the posterior nasal spine to tip of the uvula of the resting soft palate using the measurement tool of Kodak Trophy 6.04 software (Carestream Kodak UK).
Density of the soft palate was measured by densitometric analysis tool of Kodak Trophy 6.04 software.
All statistical procedures were carried out using SPSS software version 10.0 (SPSS for Windows, Version 10.0, Chicago SPSS Inc.). A cross-tab was composed by dividing the subjects into four age groups (of 3 years interval) for comparing the length and density constituents between the groups. The same constituents were compared in another cross-tab composed by dividing the subjects according to the gender. Data of the velar length and density in each type are reported as mean + standard error. Student's t-test was performed on both cross-tabs to evaluate for significant relationships among variables in the tables.
| Results|| |
The distribution and proportion of various morphological types of soft palate of our study population are shown in [Table 1]. Type I (leaf shape) had the highest incidence among the subjects, i.e., 47%, followed by type III which showed an incidence of 16%, 12% showed type IV, 10% were type II, 8% were type VI, 5% were type VII, and 2% were type V. Leaf shape showed highest and S-shape showed the lowest percentage, respectively.
|Table 1: Frequency distribution of morphological types of soft palate among male and females|
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A significant increase in velar length was noted with increasing age [Table 2]. The velar length was found to be significantly greater in males than in females [Table 3]. On comparison of density of the soft palate and age, the density, however, did not show any consistent increase or decrease with age [Table 4]. It showed different incoherent values in different age groups. However, velar density was found to be significantly greater in males than in females as seen in [Table 5].
| Discussion|| |
Cephalometric analysis is one of the most commonly accepted techniques for evaluating the soft palate in both normal individuals and those with cleft palate. Cephalometry is relatively inexpensive method and permits a good assessment of the soft tissue elements that define the soft palate and its surrounding structures.  Morphometric assessment of the nasopharynx or the configuration of adjacent structures can be defined in terms of depth and height in the median sagittal plane on lateral cephalogram. The dimensional analysis of the soft palate and its surrounding structures, especially the velar length and width, has been studied by many investigators,  but You et al.  gave classification system based on the morphological patterns. In addition, in our study, we defined the density of soft palate as given by the Kodak dental imaging software, which would indirectly represent the thickness of the soft palate. The density has not been analyzed by any of the previous studies in the literature.
The digital radiographic technique, used in the current study, is based on the principle of slit radiography. We were able to take the image scanning from posterior to anterior in the sagittal plane, and adjust and optimize the contrast and the gradation with Kodak Trophy 6.04 software. Therefore, the soft palate appearance and diagnostic information could be enhanced and elicited which benefits the investigation and measurement. 
In our study, the leaf shaped soft palate was the most frequent type which is an expected finding since this type has been previously described as a classic velar morphology in the literature. These findings are in correlation with that of Guttal et al.  and You et al. 
The S-shape, which was described as a hooked appearance of the soft palate by Pépin et al.  was found in two cases in our study. Hooking of the soft palate was defined by Pépin et al.  as an angulation of about 30° between the distal part of the uvula and the longitudinal axis of the soft palate. They hypothesized that soft palate hooking plays a key role in pharyngeal collapse since hooking results in a sudden and major reduction in the oropharyngeal dimensions, which therefore dramatically increases upper airway resistance and the transpharyngeal pressure gradient. Pépin et al. therefore concluded that hooking of the soft palate in awake patients indicates a high risk for obstructive sleep apnea syndrome. 
The bifid type of soft palate which has been identified as a normal variant by Guttal et al.  could be a very mild representation of cleft of the soft palate.
An increase in the length of the soft palate has been found in all time periods. In this study, also it was not surprising to find that the mean length of the soft palate was greater in the adult age group (20-25 years) than in the preadult group (15-20 years). Authors have hypothesized the potential possibility that as the age grows and the velar length increases, the velar features of some primary "butt-like" soft palates may gradually present as the other types, such as types I and II which show a longer velar length. 
Taylor et al.  have concluded in their study that there was 1 mm increase in length of soft palate and 0.5 mm increase in thickness of soft palate every 3 years after the age of 9 years. The findings in our study in relation to length are almost similar to this inference as we noted an increase in the length of around 1.5-2 mm in age intervals of 3 years. The density of the soft palate which could be an indirect reference to the thickness of the uvula, however, did not show any coherent values with increasing age. This could be due to the small sample size and age range.
Kollias and Krogstad  in their study compared increase in length and thickness and found no difference between male and female, but in the present study it was noted that velar length and density are significantly greater in males than the females.
The ratio between the soft palate and the sagittal depth of the nasopharyngeal airway is of prime importance in the resonance of speech.  You et al.  indicated that an adequate velar length/depth would be 1.3-1.4, which would be the level of standard relation for the normal subjects to enable them to maintain velopharyngeal closure during speech.
Longitudinal studies are required to establish the parameters of the nasopharynx as soft tissue changes in the velopharyngeal complex with age have been recorded by authors.  These changes may be important particularly in explaining the increased incidence of obstructive sleep apnea and related disorders which occur during later life.
| Conclusion|| |
The morphology of soft palate could be divided into seven types according to their feature on lateral cephalometry. The classification can help us better understand the diversity of velar morphology in the median sagittal plane. Normative palatal data permit greater anatomic understanding when undertaking surgical manipulation of the palate such as to reduce snoring or sleep apnea. These findings can also be used as a reference for research of velopharngeal closure in cleft palate individual and for etiological research.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]