|Year : 2022 | Volume
| Issue : 2 | Page : 213-217
Assessment of the morphology of soft palate by using cone-beam computed tomography
Gargi Sen. Gupta1, HC Meghana2, Ujwala S Shetty2, Devishree V Rai2, Prasanna K Rao2, Raghavendra Kini2
1 Oral Medicine and Maxillofacial Radiology, Bangalore, Karnataka, India
2 Department of Oral Medicine and Radiology, A J Institute of Dental Sciences, Mangalore, Karnataka, India
|Date of Submission||21-Feb-2022|
|Date of Decision||20-May-2022|
|Date of Acceptance||21-May-2022|
|Date of Web Publication||22-Jun-2022|
H C Meghana
Assistant Professor, Department of Oral Medicine and Radiology, A.J Institute of Dental Sciences, NH 66, Kuntikana, Mangalore - 575 004, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Soft palate is an anatomical structure that helps modify the quality of voice and breath while swallowing. In patients with cleft palate, obstructive sleep apnea, oral submucous fibrosis, and skeletal craniofacial malocclusions, soft palate dysfunctions are frequently seen. Knowing the soft palate's morphological variations thus helps us to assess and manage such patients better. Aims: To assess the morphology of the Soft Palate in Cone-Beam Computed Tomography in different age and gender groups and to find its association with: Need's ratio, Velar Length, Width, and Pharyngeal Depth in different morphological velar types. Methods and Material: The study sample consisted of 60 patients aged 20-50 years. Patients who underwent Cone Beam Computed Tomography scans of the whole maxilla (16X16 FOV) were taken up for the study. Measurements and Interpretation of Velar Length, Width, and Pharyngeal Depth were made. Results: A statistically significant correlation was observed in Velar width with an R-value of 0.04. An increase in velar width was noted with an increase in age. Leaf shape soft palate was the more prevalent type, followed by rat tail and butt shape. In male patients, the velar length and pharyngeal depth were significantly greater compared to female patients. Conclusion: By knowing different types of the soft palate and all the variations in the parameters as the reference, the dental surgeon can plan any invasive surgical procedure related to velopharyngeal dysfunctions better and avoid any complications arising from velopharyngeal dysfunctions.
Keywords: Dysfunctions, types of the soft palate, velar morphology, velar length, velopharyngeal
|How to cite this article:|
Gupta GS, Meghana H C, Shetty US, Rai DV, Rao PK, Kini R. Assessment of the morphology of soft palate by using cone-beam computed tomography. J Indian Acad Oral Med Radiol 2022;34:213-7
|How to cite this URL:|
Gupta GS, Meghana H C, Shetty US, Rai DV, Rao PK, Kini R. Assessment of the morphology of soft palate by using cone-beam computed tomography. J Indian Acad Oral Med Radiol [serial online] 2022 [cited 2022 Jun 29];34:213-7. Available from: https://www.jiaomr.in/text.asp?2022/34/2/213/347930
| Introduction|| |
The soft palate is the soft tissue constituting the back of the roof of the mouth. It plays an essential role in blocking food and other substances from entering the nasal passages during swallowing., It participates in velopharyngeal closure related to normal functions of sucking, swallowing, and pronunciation.
The mouth is isolated from the oropharynx during swallowing by the soft palate without altering the breath pattern. At the same time, velopharyngeal closure helps in the correct pronunciation of consonants with further modification in voice quality. The air and sound must be directed into the mouth and blocked from entering the nasal cavity to produce the most speech sounds. This is done through the closure of the velopharyngeal valve with the help of the soft palate. So many variations in the soft palate morphology can result in velopharyngeal insufficiency. Through the variants of the soft palate, we can also assess the age and gender of an individual.
So this study was conducted to assess the variation in morphology of soft palate in cone-beam computed tomography (CBCT) in different age and gender groups and also to find its association with Need's ratio (NR), Velar Width (VW), and Pharyngeal Depth (PD) in different morphological velar types among Mangalore population.
| Subjects and Methods|| |
A study design involved 60 patients between 20 and 50 years who had undergone CBCT in the Oral Medicine and Radiology department from November 2016 to August 2018. The study was sanctioned by the Institutional Ethics committee (AJEC/REV/D/04/2016 on 8/11/2016). Before including them in the study, prior intimation and informed consent were secured from all the patients. The study was conducted under standardized ethical principles with 'Helsinki Declaration.' Also, cases in which CBCT was simultaneously advised were considered. Any pathologies, developmental defects, trauma, or injury affecting the maxilla extending to the soft palate of the maxillary jaw were excluded from the study.
CBCT scans were done using NewTom VGievo Machine under 110 kvp, 5.3 mA, exposure time of 18 seconds, and FOV 16X16. While exposing the patients to CBCT scans, the patient's tongue position played a role in the exposure area, so they were instructed to place their lips closed together and position the tip of the tongue to the roof of the mouth. A personal computer with a 27-inch LED monitor display with installed and integrated NNT viewer software was used for interpretations of scans. Parameters were similarly measured according to Priyal Agrawal and Anjali Gupta et al., measurement of angulation between the Posterior Nasal Spine (PNS) and Velar length (VL) was added to this study.
- Two points were marked from the posterior nasal spine (PNS) to the tip of the uvula of the resting soft palate, linear distance – velar length (VL) [Figure 1].
- Thickest section of velum – velar width (VW) was measured [Figure 2].
- Two points were marked on the posterior surface of the nasal spine and posterior pharyngeal wall and the palate linear distance – Pharyngeal Depth (PD) [Figure 3].
- Mathematical calculation – Need's ratio: PD/VL.
- PNS, Velar length angulation [Figure 4] were measured.
- Interpretations of scans for soft palate morphology were made, and the following six shapes were identified, i.e., Rat tail, Butt shape, Leaf shape, Handle shape, S-shape, and Crook shape [Figure 5].
Sample size estimation
The sample size was calculated using a power analysis by G*power, version 3.0.1 (Franz Faul Universitat, Kiel, Germany). A sample size of 60 subjects (20 in each group) would yield 80% power to detect significant differences, with an effect size of 0.42 and a significance level of 0.05.
Data was entered in the excel spreadsheet. Mean, standard deviation, and percentages were calculated from the data. Inferential statistics like ANOVA with the post hoc Bonferroni test were applied to compute the statistical difference among the groups; Pearson's correlation was used to find the correlation between velar length, pharyngeal depth, and velar width, angulation with age using SPSS (Statistical Package for Social Sciences) version 20. IBM SPSS statistics [IBM corp. Released 2011].
| Results|| |
The present study consists of a sample size of 60 patients; the mean age of these patients and standard deviation (SD) of all subjects were 35.96 ± 4.077 years. There were 29 males (48.33%) and 31 females (51.6%) participants; divided into three groups, according to age (A, B, C) with equal numbers of participants [20 participants]. It was observed that the minimum and maximum mean velar length of the soft palate among the total sample was 32.26 mm and 34.35 mm, pharyngeal depth minimum and the maximum mean 25.51 and 27.88 mm, respectively, and velar width maximum of 15.60 mm, and a minimum of 5.30 mm. Angulation among age groups was analyzed using the ANOVA test, t, and the result showed that the values were statistically insignificant (p > 0.05).
On the Pearson's Chi-square test, there was a negative correlation with velar width among the 21-30 years observed. A similar correlation was observed between velar lengths between 31-40 years. Velar length, pharyngeal depth, and angulations also show a weak correlation among the 41-50 years age group. A positive correlation was observed in velar width among the 41-50 years age group with an R-value of 0.04, making it statistically significant [p < 0.05] [Table 1]. An increase with a small variation in mean velar width was thus noted with an increase in age, while the velar length, pharyngeal depth, and angulation showed no significant difference.
The co-relation of pharyngeal depth and velar length among genders was analyzed using the independent sample t-test, and it was statistically significant (p < 0.001) [Table 2]. In male patients, the velar length and pharyngeal depth were significantly greater compared to female patients.
|Table 2: Comparison of the parameters in gender using independent sample t-Test|
Click here to view
The correlation of types of the soft palate with age group was analyzed by using the Chi-square test and was statistically not significant (p > 0.05) [Table 3].
All the scans were interpreted for soft palate morphology, and the following six shapes were identified, that is, Rattail, Butt shape, Leaf shape, Handle shape, S-shape, and Crook shape. The leaf shape was most common in 17 (28.3%), i.e., 8 (47.05%) females and 9 (52.94%) males. The second common type of soft palate was rat tail shape 14 (23.3%) reported in 8 (57.14%) males and 6 (42.85%) females and followed by butt shape 12 (20%) noted in 5 (41.66%) males and 7 (58.33%) females. The least common type of soft palate was crook and handle shape 4 (6.7%) with 2 (50%) males and 2 (50%) females, while handle shape was absent in group C. Leaf shape was the more prevalent type in all age groups and followed by rat tail. In the statistical agreement using the Chi-square test, the P value was little, which concluded that types of the soft palate could not be determined according to age.
The mean velar length and pharyngeal depth were smallest in handle shape and butt shape with 31.17 mm and 25.97 mm, respectively, while maximum in S shape and crook shape soft palates with 35.46 mm 28.5 mm, respectively. The mean velar width was shortest in S shape (6.94 mm) and maximum in leaf shape with 174.89 mm, whereas angulation was found to be lowest in leaf shape (174.89 mm) and highest in handle shape (178.12 mm). The statistical agreement based on Kruskal–Wallis highlighted that the mean difference in morphological variants: velar length, pharyngeal depth, angulation, and needs ratio was not significant (p > 0.05) among morphological types of the soft palate, but it did say how significant the difference concerning velar width among different shapes [Table 4] and [Table 5]. So, it was concluded that types of the soft palate could not be identified by calculating velar length, pharyngeal depth, and angulation, but velar width can be considered for identifying different types of the soft palate.
|Table 4: Comparison of the velar width (in mm) based on soft palate shape|
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| Discussion|| |
The velopharyngeal valve consists of a soft palate anteriorly, bounded laterally and posteriorly by the lateral and posterior pharyngeal walls. Normal velopharyngeal function depends on normal structure (anatomy), normal movement (neurophysiology), and normal articulation learning. The soft palate has variable radiographic appearances. The classification system and proportional findings here may research velopharyngeal closure in cleft palate individuals and the aetiological study of obstructive sleep apnea syndrome and other dysfunctional conditions.
CBCT typically delivers less radiation than conventional CT, and magnification or distortion of images is less likely than two-dimensional (2D) radiographic images. Designating the measuring points in a multi-planar reconstruction (MPR) view is highly reproducible and reliable. On the other hand, considering the large amount of information that CBCT provides, its utilization is limited, and it still cannot replace the widely used lateral cephalometric radiography (LCR).
According to the study done by Nagaraj T., a significant increase in the soft palate length was observed with an increase in age. The dimensional changes of velar morphology were compared between male and female subjects. It was concluded that the increase in thickness and sagittal area of the soft palate was equal among males and females. It was noted that velar length was significantly greater in males than in females. In the present study, no significant increase in velar length was observed as age increased. But in male patients, the velar length and pharyngeal depth were significantly greater than in female patients.
Subramaniam N et al. observed that the frequency of the rat tail (40.4%) type of soft palate was seen in the highest proportion, whereas the distorted s-shaped and butt-shaped (5.8%) soft palate frequency was the least. In the present study, leaf shape was most common (28.3%) in our subjects, followed by rat tail shape (23.3%) and butt shape (20%). Pradhuman Verma and Kanika Gupta et al. indicated that the most frequent velar among subjects was leaf type (48.7%), followed by rat-tail type (31.0%), straight-line type (8.7%), and S-shaped (4%), with the least common type crook shape (3%). A consistent increase was noted with an increase in age, while VW, PD, and Need's ratios showed an inconsistent pattern. In the present study, leaf shape was most common (28.3%) in our subjects followed by rat tail shape (23.3%) and butt shape (20%). The least common type of soft palate was crook and handle shape. A consistent increase was noted with an increase in age with VW, while VL, PD, and Need's ratios showed an inconsistent pattern. So it was concluded that types of the soft palate could not be identified by calculating velar length, pharyngeal depth, and angulation—still, velar width can be considered for identifying different types of the soft palate.
Limitations and future study prospects
The major limitations of the present study would be restricted to the sample size. So, further studies would be recommended with a larger sample size, which would help better understand the morphological variations of the soft palate and their association with velar length, pharyngeal depth, PNS-velar length angulation, and Needs ratio. Prospects of this study could be extended to patients with cleft lip, cleft palate, obstructive sleep apnea, and skeletal craniofacial malocclusions, which will aid in better assessment and management of such conditions.
| Conclusion|| |
Leaf shape was a more prevalent type in all age groups, followed by rat tail and butt shape. In male patients, the velar length and pharyngeal depth were significantly greater compared to female patients. A significant increase in velar width was noted with an increase in age. The results revealed the mean difference in morphological variants: velar length, pharyngeal depth, angulation between PNS and VL, and needs ratio was not significant (p > 0.05) among morphological types of the soft palate, but it showed a significant difference concerning velar width among different shapes. So, it was concluded that types of the soft palate cannot be identified by calculating velar length, pharyngeal depth, angulation between PNS-VL, and needs ratio, but velar width can be considered.
Thus, using these parameters as the reference, the dental surgeon can better plan any invasive surgical procedure related to velopharyngeal dysfunctions and avoid complications arising from velopharyngeal dysfunctions.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]