|Year : 2021 | Volume
| Issue : 6 | Page : 1111-1114
Correlation of pharyngeal airway dimensions with maxillomandibular skeletal relation and mandibular morphology in subjects with skeletal Class I and Class II malocclusions and different growth patterns: A cephalometric study in selected local population
Pallavi Jeetesh Jadhav1, Shivprasad Vasant Sonawane2, Nikhil Mahajan3, Bhushan Gorakh Chavan4, Swapnil J Korde5, Naufil Mushtaque Momin5, Priyanka R Mahale5
1 Department of Orthodontics and Dentofacial Orthopedics, Bharati Vidyapeeth (Deemed to be) Dental College and Hospital, Navi Mumbai, Maharashtra, India
2 Department of Orthodontics and Dentofacial Orthopedics, SMBT Institute of Dental Sciences and Research, Nashik, Maharashtra, India
3 Department of Orthodontics and Dentofacial Orthopedics, Sinhgad Dental College and Hospital, Pune, India
4 Department of Orthodontics and Dentofacial Orthopedics, JMF's ACPM Dental College and Hospital, Dhule, Maharashtra, India
5 Head Dentist, Smile Designers Dental Clinic and Orthodontic Care, Nashik, Maharashtra, India
|Date of Submission||16-Apr-2021|
|Date of Decision||26-Apr-2021|
|Date of Acceptance||07-May-2021|
|Date of Web Publication||10-Nov-2021|
Shivprasad Vasant Sonawane
Om Moungiri Bungalow, Hare Krishna Colony, Behind KKW Engg College, Panchavati, Nashik - 422 003, Maharashtra
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Objectives: To test the hypothesis that there is no positive correlation between skeletal Class II and mandibular morphology with pharyngeal dimensions in subjects with different growth patterns. Materials and Methods: Lateral cephalograms of 60 patients were collected and divided into 2 groups, comprising of 30 in each group. Group 1 consisted of cephalograms of patients having Class I malocclusion, and was further divided into subgroups. 1a) Class I with normal growth 1b) Class I with vertical growth. Group 2 consisted of cephalograms of patients having class II malocclusion and was further divided into subgroups 2a) Class II with normal growth, 2b) Class II with vertical growth. Results: The results showed that the estimated marginal mean for upper pharyngeal width in class I malocclusion group was 8.56 mm, for class II malocclusion group was 7.80 mm, for normal growth individuals was 9.73 mm and that for vertical growth individuals was 6.63 mm. The estimated marginal mean for lower pharyngeal width in class I malocclusion group was 9.62 mm, in class II malocclusion group was 9.10 mm, in normal growth individuals was 8.95 mm and that in vertical growth individuals was 9.77 mm. The estimated marginal mean for pharyngeal area in class I malocclusion group is 330.13 sq.mm, in class II malocclusion group is 308.17 sq.mm, in normal growth individuals is 328.47sq.mm and that in vertical growth individuals is 309.83 sq.mm. Conclusions: The null hypothesis for this study, as per the statistical analysis, has been rejected.
Keywords: Pharyngeal airway, Lateral Cephalometry, Growth pattern, Mandibular morphology
|How to cite this article:|
Jadhav PJ, Sonawane SV, Mahajan N, Chavan BG, Korde SJ, Momin NM, Mahale PR. Correlation of pharyngeal airway dimensions with maxillomandibular skeletal relation and mandibular morphology in subjects with skeletal Class I and Class II malocclusions and different growth patterns: A cephalometric study in selected local population. J Pharm Bioall Sci 2021;13, Suppl S2:1111-4
|How to cite this URL:|
Jadhav PJ, Sonawane SV, Mahajan N, Chavan BG, Korde SJ, Momin NM, Mahale PR. Correlation of pharyngeal airway dimensions with maxillomandibular skeletal relation and mandibular morphology in subjects with skeletal Class I and Class II malocclusions and different growth patterns: A cephalometric study in selected local population. J Pharm Bioall Sci [serial online] 2021 [cited 2022 Dec 7];13, Suppl S2:1111-4. Available from: https://www.jpbsonline.org/text.asp?2021/13/6/1111/330100
| Introduction|| |
The size of the nasopharyngeal airway space is of importance in its relationship to the morphology of the face, the mandible included, because with reduction of the nasopharyngeal airway space, nasal breathing becomes difficult or impossible, and mouth breathing becomes necessary.
Some authors associated mouth breathing and Class II malocclusions, and others reported associations of vertical growth patterns with obstruction of the upper and lower pharyngeal airways concurrently with mouth breathing. If this relationship actually exists, Class II malocclusions and vertical growth patterns must have natural anatomical predisposing factors.,,,,
Thus it may be hypothesised that mandibular morphology and position are closely associated with the dimensions of the airway. Taking all the above factors into consideration, it was decided to evaluate the correlation between pharyngeal airway dimensions, mandibular morphology and maxillomandibular skeletal relation
| Aims and Objectives|| |
- Comparative evaluation of pharyngeal width in skeletal class I subjects with that in skeletal Class II subjects,
- Comparative evaluation of pharyngeal width and height with mandibular ramus width and height in subjects with Class I malocclusion and Class II malocclusion and with either normal or vertical growth pattern.
- Comparative evaluation of the area of pharyngeal space in subjects with Class I and Class II malocclusion and with either normal or vertical growth pattern.
| Materials and Method|| |
Lateral cephalograms of 60 patients were collected from the existing records.
Inclusion Criteria: Subjects with no previous orthodontic treatment, Subjects with skeletal Class I malocclusion and skeletal class II malocclusion, 8 to 14 years of age. Selection criteria for Class I malocclusion -ANB of 2° ± 2°, WITS analysis of 2mm to -3mm.Selection criteria for Class II malocclusion- ANB>4°, WITS analysis >2mm. Selection criteria for growth pattern -Angle used to determine the growth pattern was FMA(°) according to Downs analysis - normal growth(17° – 28°), vertical growth pattern ( > 28°). Exclusion Criteria: Craniofacial deformities, Asymmetries, Missing teeth, History of sleep disorders, snoring, sleep apnea, Adenoidectomy, pathology in the pharynx,horizontal growth patterns.
| Method of Study|| |
Group 1 consisted of cephalograms of Class I malocclusion, divided into subgroups as 1a) Class I with normal growth and 1b) Class I with vertical growth
Group 2 consisted of cephalograms of class II malocclusion, divided into subgroups as 2a) Class II with normal growth and 2b) Class II with vertical growth
All the cephalograms were traced manually on acetate paper by 1 investigator using the viewer box in a dark room. Within a week after the first measurement, 20 (5 from each group) randomly selected radiographs were retraced and remeasured by the same examiner. The casual error according to Dahlberg's formula (Se2 = d2/2n) and the systematic error with dependent t tests at P .05 were calculated.
The following cephalometric measurements were selected for pharyngeal dimensions.
- Pharyngeal height (distance Pht) as: between points Pn'and Pp'. [Figure 1]
- Width of pharynx is measured as per McNamara's Analysis. [Figure 1]
- Upper pharyngeal width (distance a) as: distance between a point on the anterior half of posterior outline of soft palate to the closest point on the pharyngeal wall.
- Lower pharyngeal width (distance b) as: distance between a point of intersection of posterior border of tongue and the inferior border of mandible to the closest point on the posterior pharyngeal wall.
Statistical Analysis methods:
Software used for statistical analysis is Windows based statistical package Medcalc® version 184.108.40.206 (MedCalc Software bvba, Ostend, Belgium; http://www.medcalc.org; 2013). Measurement data is expressed as means with SEM. All testing is done using 2-sided tests with alpha 0.05.
The pharyngeal and mandibular dimensions were compared for differences using a Two-Way ANOVA with class as first factor and growth as second factor.
| Results|| |
The findings have been tabulated in [Table 1] and [Table 2], and the significant changes have been highlighted as bold.
|Table 1: Mean upper pharyngeal width (mm) in different classes and growth types|
Click here to view
| Discussion|| |
A number of researchers during the last 50 years used variety of radiographs to study the pharyngeal airway space.,, Cameron et al, in their study compared computed tomography (CT) and cephalometric films in subjects with skeletal malocclusion and found a significant positive relationship between nasopharyngeal airway size on cephalometric films and its true volumetric size as determined from CBCT scan in adolescents. Though, in this day and age, CBCT offers accurate three dimensional information about the extent of the airway, cephalograms are more easily accessible and offer a more economical and reasonably reliable estimate of 2- dimensional pharyngeal space measurements. Also the radiation exposure for CBCT ( 0.15 mSv) is higher as compared to lateral cephalometric exposure (0.03 mSv).
Results showed that subjects with Class I and Class II malocclusions and vertical growth pattern had significantly narrower upper pharyngeal airway [Table 1] than Class I and Class II subjects with normal growth pattern confirming the previous studies.,,, .In subjects with vertical growth pattern the saddle angle is increased which leads to a more downward and forward position of the superior wall of the pharynx resulting in a narrower upper pharyngeal airway measurement.
The upper airway width showed no significant association with type of malocclusion; this corroborated previous findings.
Mandibular ramus width and pharyngeal height showed a more positive correlation for class II malocclusion type and normal growth pattern as the mandibular plane was more horizontal and therefore resulted in a larger measured pharyngeal height.
This study showed that the upper pharyngeal width was found to be narrower in individuals with vertical growth pattern as compared to individuals with normal growth pattern, in both Class I and Class II malocclusions.
| Conclusions|| |
Our results showed that,
- Sagittal malocclusion type does not influence upper pharyngeal width. Malocclusion type and growth pattern do not influence lower pharyngeal airway width
- Mandibular ramus height and pharyngeal height showed a more positive correlation for class I malocclusion type and normal growth pattern. No significant correlation was found between mandibular ramus width and pharyngeal width for malocclusion type in either normal or vertical growth pattern subjects.
The null hypothesis for this study therefore, has been rejected
| References|| |
Functional Matrix Theory. Am J Orthod Dentofacial Orthop 2005; 127:529
Gwendolyn Faye Dunn et al. “Relationships between variation of mandibular morphology and variation of nasopharyngeal airway size in monozygotic twins”.Angle Orthod, 1973;43: no. 2: 129-135.
Freitas MR, Alcazar N, Janson G. Upper and lower pharyngeal airways in subjects with Class I and Class II malocclusions and different growth patterns. Am J Orthod Dentofacial Orthop 2006; 130:742-45.
Mergen DC, Jacobs MR. The size of nasopharynx associated with normal occlusion and Class II malocclusion. Angle Orthod 1970; 40:342-46.
Subtelny JD. Malocclusions, orthodontic corrections and orofacial muscle adaptation. Angle Orthod 1970; 40:170-201.
Paul JL, Nanda RS. Effect of mouth breathing on dental occlusion. Angle Orthod 1973; 43:201-06.
Dahlberg G. Statistical methods for medical and biological students. New York: Interscience; 1940.
Rajat Mangala, Navjot Singh, Vinay Dua, Prajeesh Padmanabhan, and Mannu Khanna. “Evaluation of mandibular morphology in different facial types”. Contemp Clin Dent. 2011 Jul-Sep; 2(3): 200-6
Aboudara C, Nielsen I, Huang JC, Maki K, Miller AJ, Hatcher D. Comparison of airway space with conventional lateral headfilms and 3 dimensional reconstruction from cone beam computed tomography. Am J Orthod Dentofacial Orthop 2009;135:468-79
McNamara JA. Influence of respiratory pattern on craniofacial growth. Angle Orthod 1981;51:269-300.
Tourne LP. The long face syndrome and impairment of the nasopharyngeal airway. Angle Orthod 1990;60:167-76.
Dr Anastacia Bacopulos Marangu Cone Beam Computed Tomography (CBCT) in Orthodontics Australian Society of Orthodontics; 2013. Available from: http://www.aso.org.au
Dunn GF, Green LJ, Cunat JJ. Relationships between variation of mandibular morphology and variation of nasopharyngeal airway size in monozygotic twins. Angle Orthod 1973;43:129-35.
Proffit W. Contemporary Orthodontics. 5th ed. July 4, 2012, Elsevier,India p. 142.
Cetlan I, Oktay H. A study on the pharyngeal size in different skeletal patterns. Am J Orthod Dentofacial Orthop 1995;108:69-75
[Table 1], [Table 2]