International Journal of Dentistry and Oral Science (IJDOS) / IJDOS-2377-8075-08-8060

Comparison of Linear Measurements of Tongue and Lower Airway in Skeletal Class Ii with Various Growth Pattern

H. Sruthi1, Navaneethan. R2*, Sri Rengalakshmi3

1,2 Department of Orthodontics and Dentofacial Orthopaedics, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, India.
3 Senior Lecturer, Department of Orthodontics and Dentofacial Orthopaedics, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, India.

*Corresponding Author

Navaneethan. R,
Reader, Department of Orthodontics and Dentofacial Orthopaedics, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, 162, Poonamallee High Road, Velappanchavadi, Chennai, Tamil Nadu, India-600077.
Tel: 9962787531
E-mail: navaneethan@saveetha.com

Received: July 30, 2021; Accepted: August 10, 2021; Published: August 17, 2021

Citation:H. Sruthi, Navaneethan. R, Sri Rengalakshmi. Comparison of Linear Measurements of Tongue and Lower Airway in Skeletal Class Ii with Various Growth Pattern. Int J Dentistry Oral Sci. 2021;8(8):3861-3865. doi: dx.doi.org/10.19070/2377-8075-21000790

Copyright: Navaneethan. R�2021. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.

Abstract

The volume of functional spaces such as Oral, Nasal and Pharyngeal spaces and the patency of the Orofacial area is maintained due to the postural activity of the Orofacial musculature and soft tissue wall formed by lips, cheeks, floor of the mouth, tongue, soft palate. According to Functional matrix theory form and function are interrelated. Tongue and Airway also plays a major role in Normal growth and development of craniofacial structures. Their dimensions have been shown to alter in various studies in Skeletal class II patients. The aim of this present research is to compare and evaluate the linear measurement of tongue and lower airway in skeletal Class II patients with various skeletal growth patterns. 60 Lateral Cephalograms which matched the inclusion criteria were selected from the case records of patients who reported for orthodontic treatment in a university hospital. They were grouped equally among the three growth patterns. All linear measurements of tongue and lower oropharyngeal airway were measured. The result shows that there is no significant difference in the linear measurement of width of the lower pharyngeal airway (p-0.49) and Tongue length in Skeletal class two patients with various growth patterns (p-0.88).

Full Text -HTML

1.Keywords
2.Introduction
3.Conclusion
4.References

Keywords

Tongue; Lower Oropharyngeal Airway; Growth Pattern; Skeletal Class II.

Introduction

The Orofacial region is responsible for several vital functions such as deglutition, respiration, and gustation. The volume of functional spaces such as Oral, Nasal and Pharyngeal spaces and the patency of the Orofacial area is maintained due to the postural activity of the Orofacial musculature and soft tissue wall formed by lips, cheeks, floor of the mouth, tongue, soft palate This Interaction interdependence between the Form and function has been stated by the Functional matrix theory (Melvin L. Moss, 1997a, 1997b, 1997c; M. L. Moss, 1997) and is widely accepted in orthodontics. Has been shown to be interdependent. Tongue is the largest organ in the oral cavity. Any abnormalities in its growth, position and function has been shown to be associated with Malocclusion in several studies [35, 13, 38]. Similarly Airway also plays a major role in Normal growth and development of craniofacial structures. Mouth breathing and Obstructive sleep apnea OSA has been found to be associated with Narrow pharyngeal airway. A reduction of 25% in oropharyngeal and hypopharyngeal airway has been reported in OSA patients [6].

A skeletal class two malocclusion can be caused by protrusive maxilla, retrusive mandible, or a combination of both [30]. Balter�s philosophy states that, Class II malocclusion can occur as a consequence of backward position of a tongue. Pharyngeal airway space has been shown to be largest in mandibular prognathism and least in mandibular retrognathism [29]. There are several studies which have shown that Pharyngeal airway dimensions decreases in Class II patients [23, 19]. Thus, Any changes in spatial relationship in the tongue, airway have wide functional importance and reciprocal consequences. This necessitates assessment of tongue and airway as a routine in orthodontic diagnosis and treatment planning as a functional, positional and structural assessment of dentofacial pattern. Previously our team has a rich experience in working on various research projects across multiple disciplines [40, 15, 53, 33, 31, 47, 28, 14, 5, 37, 48, 36, 2, 55, 1]. Now the growing trend in this area motivated us to pursue this project.

The aim of this present research is to compare and evaluate the linear measurement of tongue and lower airway in skeletal Class II patient patients between various growth patterns of the mandible in the vertical dimension.

Materials And Methods

Our sample size was calculated to be 60 using G power software version 3.1 [4]. Ethical committee clearance approval was obtained from the Institutional review board. This retrospective study was carried out in several stages. The patients were selected from the patients who had reported to the Department of Orthodontics at Saveetha dental college, Chennai for orthodontic treatment between March 2020- March 2019.

Inclusion criteria:

1. All permanent teeth were present (3rd molars were excluded).
2. ANB angle >4 degree.(Skeletal class two pattern)
3. All patients had either horizontal, vertical growth pattern or Average growth pattern.
4. Clear lateral cephalograms with adequate contrast.

Exclusion criteria:

1. Patients with missing teeth or impacted teeth.
2. History of orthodontic treatment.
3. Cleft lip & palate.
4. Craniofacial anomalies or syndromes.
5. TMJ disorders.
6. Trauma to face.

Mandibular Plane angle formed by Sella-Nasion & Gonion- Gnathion planes were used to analyse growth pattern of the mandible from the Lateral Cephalograms and segregate them into various growth patterns namely Average growth pattern where the angle is between 30-320, Horizontal growth where the angle is pattern <300 and Vertical growth pattern where the angle is >340. All Cephalometric analysis were made using FACAD software. 60 Lateral Cephalogram were sorted into 3 groups with 20 in each growth pattern.

Linear dimensions of Tongue and Lower oropharyngeal airway were measured in all 60 lateral cephalograms. Tongue length -Linear distance between the deepest point on epiglottis and center of the tip of the tongue and the width of the lower oropharyngeal airway was measured as the Distance between po89\int on the posterior pharyngeal wall and point on the tongue along the mandibular lower border were measured (Figure 1).

Previously our team had conducted numerous clinical trials (Kamisetty et al., 2015 [18]; Krishnan, Pandian and Kumar S, 2015 [21]; Viswanath et al., 2015 [54]; Sivamurthy and Sundari, 2016 [49]; Felicita, 2017b [10]; Samantha et al., 2017 [45]; Vikram et al., 2017 [53]) and lab animal studies (Ramesh Kumar et al., 2011 [42]; Felicita, Chandrasekar and Shanthasundari, 2012 [12]; Rubika, Sumathi Felicita and Sivambiga, 2015 [44]; Felicita, 2017a [9]; Pandian, Krishnan and Kumar, 2018 [32]) and in-vitro (Dinesh et al., 2013 [7]; Jain, Kumar and Manjula, 2014 [17]; Felicita, 2018 [11]) studies over the past 5 years. The idea for this study stemmed from the current interest regarding the airway in class II patients. Hence this study was conducted to evaluate the airway and tongue in Class II individuals.

Statistical Analysis

For all growth patterns 2 different parameters i.e. Length of the tongue and Width of the lower oropharyngeal airway were measured separately for 60 lateral cephalogram samples. To know if there was any association between the three growth patterns i.e. Horizontal, vertical and average facial growth patterns and Linear dimension of tongue and lower oropharyngeal airway one way -ANOVA was performed with 95% confidence level and 1 degree of freedom to cross tabulate data.

Results & Discussion

Figure 2 shows Mean value of Length of the tongue and Width of the lower oropharyngeal airway measured in various growth patterns. The legends in the bar graph (red) shows the mean Length of the tongue in horizontal growth pattern is 80.7mm, in vertical growth pattern is 80.1mm and in average growth pattern is 81mm.The legends in (grey) bar graph shows the mean width of the lower oropharyngeal airway in horizontal growth pattern is 13.3mm, in vertical growth pattern is 13.3mm and in average growth pattern is 12.8mm.

One-way ANOVA comparing Width of the lower oropharynx among various growth patterns showed no significant difference between the groups (p-0.49) (Refer Table 1). One-way ANOVA comparing Length of the tongue among various growth patterns showed no significant difference between the groups (p-0.88) Refer Table 1.

In the present study linear measurement - Length of the tongue and width of the lower pharyngeal airway showed no significant difference in skeletal class two patients with various growth patterns. In a previous study by Chauhan et al. [4] where they compared the pharyngeal airway dimensions between Class II and Class I patients showed that the mean linear and angular measurement were lower in skeletal class II patients but were not significantly different between the Groups. Similarly in the present study the lower airway dimension showed that the mean values are reduced in average growth pattern and almost similar in horizontal and vertical growth pattern. However there was no statistically significant difference between the groups. In a study by Kirjavainen et al. [20]. It was shown that Class II patients have narrow oropharyngeal and hypopharyngeal space. In a study by Sukniyom et al. [51]. They assessed the various treatment modality effects on class II patient airways and concluded that Non-extraction treatment with Class II traction showed significant increase in the pharyngeal airway. In a cephalometric evaluation of pharyngeal airway by muto et al. [29] Mandibular retrognathism is the major risk factor for narrowing of pharyngeal airway.

Chauhan et al. [4] showed that mean tongue length decreased in Class II patients than class I but were not statistically significant between the groups but showed inferior positioning of the tongue. Similarly in the present study mean tongue lengths decreased in Vertical growth pattern but were not statistically significant. In a study by Ihan et al(Ihan Hren and Barbic, 2016) [16] using three dimensional Ultrasound showed that tongue volume increases in skeletal class III patients. In a study by Yoo et al. [56] concluded that tongue volume is dependent on the horizontal and vertical location of the Chin and symphysis and does not increase only because of mandibular prognathism.

The limitations of this study include Retrospective study design, Two Dimensional Imaging technique, smaller sample size and other parameters are not assessed. Future scope involves a multicentric study design with other parameters assessed simultaneously in three dimensions would provide better results.

Our institution is passionate about high quality evidence based research and has excelled in various fields ( (Pc, Marimuthu and Devadoss, 2018 [34]; Priyadharsini et al., 2018 [36]; Ramesh et al., 2018 [41]; Ezhilarasan, Apoorva and Ashok Vardhan, 2019 [8]; Ramadurai et al., 2019 [39]; Sridharan et al., 2019 [50]; Vijayashree Priyadharsini, 2019 [52]; Chandrasekar et al., 2020 [3]; Mathew et al., 2020 [2]; R et al., 2020 [43]; Samuel, 2021 [46]). We hope this study adds to this rich legacy.

Figure 1:Depicts the various Linear measurements, Length of the tongue-Linear distance between the deepest point on epiglottis and center of the tip of the tongue and Width of the lower oropharyngeal airway -Distance between point on the posterior pharyngeal wall and point on the tongue along the mandibular lower border.

Figure 2: Bar graph depicting the mean values of linear dimensions measured-Length of the tongue (red) and Width of the lower oropharyngeal airway (grey) measured in various growth patterns. X axis represents the various growth patterns and the Y axis the linear measurements. The legends in the bar graph (red) shows the mean Length of the tongue in horizontal growth pattern is 80.7mm, in vertical growth pattern is 80.1mm and in average growth pattern is 81mm.The legends in (grey) bar graph shows the mean width of the lower oropharyngeal airway in horizontal growth pattern is 13.3mm,in vertical growth pattern is 13.3mm and in average growth pattern is 12.8mm.It could be inferred from the graph that both the width of the lower oropharyngeal airway and the length of the tongue did not show much variation among various growth pattern.

Table 1: Table depicting the association between the various growth patterns and the linear measurement -Length of the tongue, width of lower oropharyngeal airway. One-way ANOVA comparing length of the tongue among various growth patterns showed no significant difference between the groups (p-0.498). One-way ANOVA comparing width of the lower oropharyngeal airway dimension among Various growth patterns showed no significant difference between the groups (p-0.887).(>0.05) ,hence statistically not significant.

Conclusion

Within the limitation of the study it was concluded that the growth pattern does not alter the linear measurement of width Lower pharyngeal airway and tongue length in skeletal class II skeletal pattern.

References