|Year : 2015 | Volume
| Issue : 4 | Page : 532-538
Digital cephalometric analysis illustrating morphological variation of the soft palate
Tanya Khaitan1, Ramaswamy Pachigolla2, Ginjupally Uday3, Praveen Kumar Balmuri4, Sai Kiran Chennoju2, Sreenivasulu Pattipati2
1 Department of Oral Medicine and Radiology, Haldia Institute of Dental Sciences and Research, Haldia, West Bengal, India
2 Department of Oral Medicine and Radiology, St. Joseph Dental College and Hospital, Eluru, Andhra Pradesh, India
3 Department of Oral Medicine and Radiology, Kamineni Institute of Dental Sciences, Telangana, India
4 Department of Oral Medicine and Radiology, G Pulla Reddy Dental College and Hospital, Kurnool, Andhra Pradesh, India
|Date of Submission||13-Jan-2015|
|Date of Acceptance||08-Nov-2015|
|Date of Web Publication||19-Aug-2016|
Dr. Tanya Khaitan
30A/162, Dr. PT Laha Street, Bangur Park, Rishra - 712 248, Hooghly, West Bengal
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction and Objectives: The soft palate plays a vital role in velopharyngeal closure which is strongly dependent on a close coordination of the velum and the contiguous pharyngeal structures. It is reasonable to hypothesize that these structures may have different characteristics to match up to different soft palate morphologies. Considering this, the present study was done to investigate the variation in the morphology of the soft palate. Materials and Methods: A total of 200 patients belonging to both the genders, in the age group 5-55 years, were selected from the outpatients visiting the Department of Oral Medicine and Radiology. All the study samples were subjected to lateral cephalogram and the morphology of the soft palate was categorized as described by You et al. Any additional finding was further differentiated as type 7 and so on. The length of soft palate was also evaluated using Sidexis next generation software. The data obtained were tabulated and subjected to statistical analysis. Results: The morphology of soft palate was categorized into eight types. Type 1 was the commonest type observed. The relationship between the different types of soft palate in various age groups was found to be non-significant. The mean length of the soft palate was found to be more in group V (46-55 years). The mean length of soft palate was found to be higher in males. There was a positive correlation between age and type of soft palate. Conclusion: The present study draws a new set of morphological classification for the soft palate.
Keywords: Lateral cephalogram, obstructive sleep apnea, velopharyngeal closure, velopharyngeal incompetence, velum
|How to cite this article:|
Khaitan T, Pachigolla R, Uday G, Balmuri PK, Chennoju SK, Pattipati S. Digital cephalometric analysis illustrating morphological variation of the soft palate. J Indian Acad Oral Med Radiol 2015;27:532-8
|How to cite this URL:|
Khaitan T, Pachigolla R, Uday G, Balmuri PK, Chennoju SK, Pattipati S. Digital cephalometric analysis illustrating morphological variation of the soft palate. J Indian Acad Oral Med Radiol [serial online] 2015 [cited 2020 May 29];27:532-8. Available from: http://www.jiaomr.in/text.asp?2015/27/4/532/188745
| Introduction|| |
The oral cavity is an intricate phenomenon with sophisticated details and varied functions. It is limited by the palate, the base of the mouth, the cheeks, and the lips, as well as by the uvula and the palatine arches on each side of the uvula. , The soft palate plays a vital role in velopharyngeal closure and, thus, aids in normal physiologic functions like sucking, swallowing, and pronunciation.  The velopharyngeal adequacy is strongly dependent on a close coordination of the anatomic parts: The soft palate and contiguous pharyngeal structures. So, it is reasonable to hypothesize that the contiguous pharyngeal structures may have different characteristics to match up to different velar morphologies. 
Clinical visualization of the soft palate becomes inadequate due to limited accessibility of the velopharyngeal region; therefore, it becomes mandatory to rely on other diagnostic methods for complete evaluation. Radiographic examination of the soft palate has been largely ignored, perhaps because it can be easily inspected on its inferior surface and visualized on its superior surface with a flexible nasopharyngoscope. , The lateral skull view is by far the most valuable view for evaluation of the soft palate as it shows extensive bone and soft tissue images. Other views such as anteroposterior view, however, are useful in evaluation of the lateral pharyngeal walls and uvular deviation, but with the head in extension, the soft palate is projected above the hard palate.  Therefore, lateral cephalometry is one such radiograph which is relatively inexpensive and one of the most common screening radiographs for evaluation of the sagittal plane. 
Earlier references concerning the objective measurements of the soft palate using lateral cephalogram with different morphologies have not contributed much information.  Thus, the present study was undertaken to understand the various morphologies of the soft palate and its dimension.
| Materials and Methods|| |
The study was initiated after the protocol had been approved by the Institutional Ethical Committee. A total of 200 patients belonging to both genders, in the age group 5-55 years, attending the outpatient department of Oral Medicine and Radiology were selected for the study by simple random sampling. The selected sample was subdivided into five groups: Group I, 5-15 years; Group II, 16-25 years; Group III, 26-35 years; Group IV, 36-45 years; and Group V, 46-55 years, with 40 individuals in each group. Patients with normal speech function were considered for the study. Patients with any developmental anomalies of maxillary alveolus, palate including hard and soft palate, fractures of head and neck region, any history of surgery in the oropharyngeal and nasopharyngeal region, systemic diseases such as stroke and paralysis, and local diseases such as oral submucous fibrosis were excluded from the study. The importance and need for the study was explained to each individual. An informed consent was obtained from the study subjects and in case of patients less than 18 years, consent was taken from the guardian.
All the selected subjects were instructed to remove any dental appliances and metal objects from the head and neck region. The subjects were explained about the procedure and subjected to digital lateral cephalogram (Sirona Orthophos XG Model 6229343 D3352, SN 05685) under exposure factors as applicable to their age. The radiographs were stored with patients' details incorporated. All radiographs were interpreted using Sidexis next generation software (version 2.5, Sirona, Bensheim, Germany) and the morphology of the soft palate was categorized into six types as described by You et al. as follows: type 1- "leaf shaped" (lanceolate), the middle portion of the soft palate is elevated to both naso- and oro-sides; type 2- "rat-tail shaped," the anterior portion is inflated and the free margin has an obvious coarctation; type 3- "butt-like shaped," shorter and fatter velum appearance and the width has almost no distinct difference from the anterior portion to the free margin; type 4- "straight line shaped;" type 5- distorted soft palate, which presents the "S shape;" and type 6- "crook-shaped" appearance, in which the posterior portion of the soft palate crooks anteriosuperiorly. Any additional finding which does not fit in the above said types was noted and classified as type 7 and so on, if required.
The radiographic images were magnified to an extent that the soft palate was clearly visualized and analyzed by using the measuring tools provided in the software. The length of soft palate was determined by measuring the linear distance from the posterior nasal spine to the tip of uvula of the resting soft palate. The measurements obtained were recorded and entered in the proforma specially designed for the study. The results obtained were subjected to statistical analysis applying Chi-square test and one-way analysis of variance (ANOVA) using SPSS version 16.01 (Statistical package for social sciences) software. Significance level was based on P-value <0.05.
| Results|| |
Overall distribution of the various types of soft palate
The different types of soft palate were categorized according to You et al.  Type 1 was the most common type observed in 95 cases (47.5%) followed by type 2 in 67 cases (33.5%), type 3 in 15 cases (7.5%), type 4 in 9 cases (4.5%), type 5 in 3 cases (1.5%), and type 6 in 3 cases (1.5%) [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]. In addition to the above-mentioned types, two other types were also noted in the present study and they were differentiated as type 7 and type 8, respectively: type 7- "triangular shaped" soft palate, which appeared bulged in the center and sharp toward the extremities which was observed in 4 cases (2%), and type 8- "bifid-shaped" soft palate which was seen in 4 cases (2%) [Figure 7] and [Figure 8].
Overall distribution of soft palate morphology according to various age groups
The relationship between the different types of soft palate in various age groups was found to be non-significant with a P value of 0.490 [Table 1].
|Table 1: Distribution of soft palate morphology types according to various age groups |
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Overall distribution of soft palate morphology with respect to gender
On comparison between males and females, type 1 (57 cases) was commonly seen in males and type 2 (41 cases) in females [Table 2]. The relationship between the different types of soft palate with respect to gender was found to be statistically non-significant (P = 0.055).
|Table 2: Distribution of soft palate morphology types with respect to gender |
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Measurement of the length of soft palate
The overall mean length of the soft palate was 33.80 mm. The length of the soft palate varied from a minimum of 20.15 mm to maximum of 44.62 mm in the fourth age group.
Overall comparison of the mean length of soft palate with respect to gender
On comparison of the mean lengths of the soft palate in males and females, the length of the soft palate was found to be more in males (34.59 mm) than in females (33.01 mm). The mean difference was found to be 1.58 mm, which was statistically significant with a P value of 0.011 [Table 3].
|Table 3: Overall mean comparison of length of soft palate with respect to gender|
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Comparison of the mean length of soft palate among the age groups in different types
The mean length of the soft palate was found to be highest in type 6 (41.81 mm) followed by type 5 (37.90 ± 0.16 mm), and it was found in group V [Table 4]. Multiple comparisons of the means between each two types of soft palate were found to be statistically significant with a P value of 0.040.
|Table 4: Comparison of the mean length of soft palate among age groups in different types |
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Correlation between age and length of soft palate
A positive correlation was obtained between the age and length of the soft palate, which was found to be statistically significant (P = 0.001). This suggests that as age increases, the length of the soft palate increases [Figure 9].
| Discussion|| |
Since the harmony of the velum and surrounding pharyngeal structures seems to be indispensable for velopharyngeal closure, it is rational to theorize that the contiguous pharyngeal structures may have diverse distinctiveness to match up to varied velar morphology.  The velopharyngeal morphology of adults with velopharyngeal incompetency (VPI) after cleft palate repair is characterized by a shorter palate and superiorly positioned posterior pharyngeal wall.  Cohen et al. (1993) suggested that one of the several explanations for the surgically successful, yet functionally compromised repair may be due to the differences in the morphology of the soft palate and other associated structures.  Thus, even after the closure of the soft tissue defect in case of cleft patients, the normal function of the soft palate is frequently not achieved, and velopharyngeal insufficiency with hypernasal speech ensues.  The variation of the soft palate morphology may be a new explanation for surgical failure and the soft palate might be repaired in various patterns. Over the years, the variation in the velar morphology was analyzed by many authors as one to few, and very few have made an effort to categorize them.
Pepin et al. (1992) observed a peculiar hooking of the soft palate which is described to have an angulation of 30° or greater between the distal part of the uvula and the longitudinal axis of the soft palate. Later, the same authors in 1999 determined the hooked appearance of the soft palate in 131 awake patients with snoring, with or without obstructive sleep apnea syndrome (OSAS), on cephalometric radiographs and computed tomography (CT). They concluded that both cephalometric radiography and CT demonstrated hooking of the soft palate only in 9 of 96 patients with OSAS.  Furthermore, in 2006, Niu et al. evaluated the morphology of the soft palate in 106 normal individuals and visualized static and dynamic images of the soft palate. The authors suggested that all static images of soft palate could be divided into six shapes: Shuttle-shaped, crescent-shaped, strip-shaped, S-shaped, hamulus-shaped, and anomalous-shaped, and the dynamic image was described as knee-shaped.  A similar study was done by Guo et al. in the year 2011 to investigate the morphology of the soft palate when pronouncing the high vowel of "i" and found knee-shaped morphology in all the individuals.  You et al. were the first to categorize the morphology of the soft palate into six different types.  Guttal et al. had described two additional types along with the above-mentioned six variants: Type 7- U-shaped soft palate as the possible variant of the rat-tail shape and type 8- bifid-shaped soft palate. 
The finding of the present study was also in concordance with the above study where type 1 was found to be the most common in 47.5% of cases. This was also in agreement with other studies done by Kumar and Gopal  and Guttal et al.  However, our results were contrary to the study conducted by Praveen et al. (2011) who observed type 2, i.e. rat-tail shaped soft palate, as the most common type (55%).  Type 2, type 3, and type 4 soft palate were the next common types seen in the present study. These results were in agreement with the results of studies done by You et al. and Kumar et al. , The hooked appearance of the soft palate found by Pepin et al. (1992) was described as distorted shape (S-shape or type 5) by You et al. , This variant was present in only 3 (1.5%) cases in the present study. Type 6 or crook-shaped soft palate was observed in only some individuals (1.5%). This was also in accordance with the study results of You et al. (1.5%), Kumar et al. (3%), and Guttal et al. (6.5%). ,, In addition to the six types mentioned by You et al., two more variants were noted in the present study and were differentiated as types 7 and 8. Type 7 was described as triangular-shaped soft palate and type 8 as bifid-shaped soft palate, and were observed in 4 cases (2%) each. The U-shaped soft palate (type 7), as described by Guttal et al., was not found in the present study.  Instead, a completely new variant, triangular-shaped soft palate (type 7), was noted in our study, which has not described in the literature elsewhere. With regard to the comparison of the soft palate among various age groups, type 1 soft palate was the most common type seen in the present study. This was in agreement with the study results of You et al. 
When the dimension of the soft palate was analyzed, it was found to be maximum in group V (35.13 ± 4.71 mm). There was a weak positive correlation noted between age and length of the soft palate, which suggests that as age increases, the length of soft palate increases. Taylor et al. had observed 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.  Similar observations were made by Johnston and Richardson wherein the soft palate became longer and thicker with advancement of age.  While lengthening of the soft palate appears to be a normal feature of aging, it may also be an important factor in individuals otherwise predisposed to OSAS. Studies conducted by Petrou-Amerikanou et al. showed retropositioned or narrow hard palate with a vertically positioned soft palate and an enlarged uvula in subjects with OSAS.  Johnston et al. (1999) also observed a longer and thicker soft palate and narrower oropharynx during adulthood, which could be an explanation for the increased prevalence of OSAS and related disorders in later life. 
In the present study, with regard to the gender differences in the soft palate, there was increased length of soft palate in males when compared to females. This was in agreement with the results of studies conducted by Kollias and Krogstad  and Guttal et al.  Shankar et al. conducted an analogous study in patients with oral submucous fibrosis. They observed that as the oral submucous fibrosis advanced, there was a gradual change from type 1 and type 2 variety of soft palate to type 3 and type 6 variety of soft palate. 
| Conclusion|| |
Thus, it is imperative to postulate that the morphology of the soft palate can be manifold and there could be a possible existence of some more variants. Further studies with larger samples and focused toward the search of newer morphological variants should be done, in order to facilitate wider research in the field of systemic and local conditions affecting the oropharyngeal region.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3], [Table 4]