Assessment of mandibular symmetry in cleft lip and cleft palate patients

Veerendra Prasad; Priyawati Moungkhom; Arun Kumar Singh; Brijesh Mishra; Divya Narain Upadhyay

doi:10.4103/jclpca.jclpca_37_20

ORIGINAL ARTICLE

Year : 2022 | Volume : 9 | Issue : 1 | Page : 49-54

Assessment of mandibular symmetry in cleft lip and cleft palate patients

Veerendra Prasad, Priyawati Moungkhom, Arun Kumar Singh, Brijesh Mishra, Divya Narain Upadhyay
Department of Plastic Surgery, King George's Medical University, Lucknow, UP, India

Date of Submission	07-Oct-2020
Date of Acceptance	30-Nov-2020
Date of Web Publication	01-Jan-2022

Correspondence Address:
Dr. Veerendra Prasad
Department of Plastic Surgery, King Geoerge's Medical University, Lucknow, Uttar Pradesh, 226003
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jclpca.jclpca_37_20

Abstract

Objective: The objective of this study is to evaluate cleft patients, both unilateral and bilateral clefts and compare them with Skeletal base Class I patients for symmetry using orthopantomogram. Materials and Methods: Three groups of patients within age range of 15–25 years: Group I – Normal participants (mean age = 18.33 ± 2.84); Group II – Unilateral cleft lip and cleft palate participants (mean age = 18.74 ± 3.36); and Group III – Bilateral cleft lip and cleft palate participants (mean age = 17.64 ± 3.10) were assessed and compared to each other. Orthopantomogram was analyzed for vertical symmetry. Habets asymmetry index and the Kjellgren's asymmetry index were applied to assess the relative intensity of asymmetry. Results: Significant difference was seen in condylar height (P = 0.029), ramal height (P = 0.046), mandibular body length (P = 0.014), gonial angle (P = 0.035) and condylion–gonian distance (P = 0.044). Kjellberg's symmetry index/condylar ratio was maximally affected by the groups when compared with the Habets asymmetry index. Conclusion: Mandibular asymmetry has been expressed in unilateral cleft lip and palate (CLP) group. Normal group and bilateral CLP group indicated a symmetrical posterior vertical height of the mandible.

Keywords: Bilateral cleft lip and palate, orthopantomogram, symmetry, unilateral cleft lip and palate

How to cite this article:
Prasad V, Moungkhom P, Singh AK, Mishra B, Upadhyay DN. Assessment of mandibular symmetry in cleft lip and cleft palate patients. J Cleft Lip Palate Craniofac Anomal 2022;9:49-54

How to cite this URL:
Prasad V, Moungkhom P, Singh AK, Mishra B, Upadhyay DN. Assessment of mandibular symmetry in cleft lip and cleft palate patients. J Cleft Lip Palate Craniofac Anomal [serial online] 2022 [cited 2023 Jun 6];9:49-54. Available from: https://www.jclpca.org/text.asp?2022/9/1/49/333651

Introduction

Cleft lip and palate (CLP) is one of the most common congenital anomalies of the craniofacial region with an average incidence of 1 in 700, worldwide (World Health Organization, 2001).^[1] CLP patients have a congenital defect in the face, which expresses itself in the hard as well as in the soft tissues of the face. Growth patterns of dento-maxillofacial tissues in patients affected by CLP are different from their normal peers.^[2] CLP patients generally present anterior and posterior crossbites and mid-face deficiency with a tendency toward a Class III malocclusion. Several studies have reported asymmetrical and distorted features of the naso-maxillary complex with consistent results.^[3] Studies have shown that type of cleft can be of importance when assessing the facial appearance, psychosocial life, and self-concept.^[4] More or less they are associated with fluctuating asymmetry or a definite asymmetry of the face with/without evident chin deviation. The presence of these oro-facial clefts affects the patient psychosocially besides functional problems, especially in young adults. In patients showing mild skeletal discrepancy, orthodontic dental compensation may be beneficial. In patients showing moderate-to-severe skeletal discrepancy, the best esthetic outcomes and function has been achieved through a combination of orthodontic treatment that has been carefully planned with orthognathic surgery.^[5]

Studies have suggested that panoramic radiographs yield acceptable results, are noninvasive, have a favorable cost-benefit relationship, and expose participants to relatively low doses of radiation. Using the 6% cutoff reported in the literature, the sensitivity of the panoramics to diagnose asymmetry for the total height was determined to be 0.62 and the specificity 1.0. From the panoramic radiograph, total ramal height could be used in determining asymmetry.^[6] Panoramic radiography is relatively accessible and provides a bilateral view of the mandible, and has been suggested for measurement of side-to-side height differences. Therefore, orthopantomogram has been used in this study to evaluate participants with CLP for vertical height differences and compare them with Skeletal base Class I patients for symmetry.

Materials and Methods

The patients with unilateral and bilateral cleft lip and cleft palate were evaluated in this study and compared to normal participants with skeletal base Class I with Class I occlusion. The study conducted was an observational study, to study the effect of clefts on the facial symmetry. The symmetry was assessed between the right and left sides of the orthopantomogram radiograph (OPG) within a group, and the groups were compared against each other to observe any difference among them. They were grouped into: Group-I – Normal group (n = 18); Group-II-Unilateral CLP (UCLP) group (n = 36); and Group-III – Bilateral CLP (BCLP) group (n = 17) [Figure 1]. The age group of the patients ranged from 15 –25 years, these were to prevent bias that could occur due to differential growth potential. The inclusion criteria of normal participants are: Skeletal base Class I with Class I occlusion; minimal crowding or spacing maybe present; and pathology limited to missing teeth and impaction of teeth. Exclusion criteria of normal participants are: Any underlying systemic diseases; history of past orthodontic treatment; anterior or posterior crossbite present. The inclusion criteria of cleft participants are: Nonsyndromic craniofacial deformity; UCLP/BCLP. Exclusion criteria of cleft participants are: Participants with syndromic cleft lip and cleft palate; any underlying systemic diseases; history of past orthodontic treatment.

Figure 1: Sample distribution

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Orthopantomogram of the patients were obtained. The patients were positioned upright with the Frankfort Horizontal plane parallel to the floor. The X-rays obtained were of those patients who got the OPG done for the purpose of orthodontic assessment or evaluation of the cleft lip and cleft palate. The obtained X-rays were traced and measurements were carried out manually by the same operator to avoid any error in reference point identification and interpretation. The reference points and reference planes used in this study and the parameters evaluated are as described below ([Table 1], [Table 2] and [Figure 2], [Figure 3])^[7],[8],[9] and asymmetry index and condylar ratio were drawn for each structure by the following formula:

Table 1: Describes the reference points

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Table 2: Describes the parameters used in this study

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Figure 2: Dictates the landmarks and reference lines used in the study

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Figure 3: Dictates the parameters used in the study where, 1-condylar height; 2-ramal height; 3-coronoid height; 4-Co-Go distance; 5-mandibular body length; 6-total mandibular body length; 7-ante-gonial notch; 8-vertical distance of maxilla; 9-gonial angle

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The measurements were done on the OPG tracing, a line tangent to the posterior border of ramus was drawn (A-line) through the lateral most point on the condylar and ascending ramus. O1 and O2 were designated to the points where the line touches the posterior border of the mandible. B-line was drawn tangent to the lower border of the mandible. A line was drawn perpendicular to the A-line from the condylar point (C-line). Another line (D-line) was drawn perpendicular to A-line through the sigmoid notch. H-line (modified Frankfort horizontal line) was constructed through orbitale and condylion.^[10] The parameters measured have been described in [Table 2].

Statistical analysis

Data were summarized as mean ± standard Deviation. The variables were compared between the groups by one-way ANOVA followed by multivariate analysis to see the magnitude of group effect over various parameter symmetries. Symmetries between the left and right sides were tested by paired t-test. A two-sided P < 0.05 was considered statistically significant. All the statistical analysis was performed using IBM SPSS Statistics V21.0, (IBM corporation, Armonk, New York, USA).

Results

[Table 3] shows comparison between the right and left sides among the participants of Group I. No significant difference was found. [Table 4] shows comparison between the right and left sides among the participants of Group II. Significant difference was seen in condylar height (P = 0.029), ramal height (P = 0.046), mandibular body length (P = 0.014), gonial angle (P = 0.035) and condylion–gonian distance (P = 0.044). [Table 5] shows, the right and left sides difference in Group III, no significant difference were found in the parameters evaluated. [Table 6] and [Figure 4] shows intergroup comparison of various asymmetry indices, no significant differences were observed. [Table 7] and [Figure 5] show the intensity of group effect on various asymmetry indices between the parameters Kjellberg's symmetry index/condylar ratio (effect size = 0.043), Asymmetry index condyle (effect size = 0.001), Asymmetry index ramal (effect size = 0.034). The groups showed no significant effect on any of the asymmetry parameters (P > 0.05).

Table 3: Comparison between Right & Left Sides among the Subjects of Normal Group

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Table 4: Comparison between Right & Left Sides among the Subjects of UCLP Group

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Table 5: Comparison between the right and left sides among the subjects of bilateral cleft lip and palate group

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Table 6: Intergroup comparison of various asymmetry indices

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Table 7: Multivariate analysis to find the intensity of group effect on various asymmetry indices

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Figure 4: Intergroup comparison of various asymmetry indices

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Figure 5: Multivariate analysis to find the intensity of group effect on various asymmetry indices

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Discussion

Unilateral/Bilateral cleft lip and/palate participants were analyzed in the study compared to normal participants with skeletal base Class I. Kambylafkas et al. (2006),^[6] in his study concluded that panoramic radiographs can be used for measuring vertical posterior mandibular asymmetry with a cutoff of 6% difference between the left and right sides. OPG is commonly accessible and is used as routine diagnostic aids. OPG has been used to evaluate asymmetry of condylar and ramus process and also evaluate vertical differences between both sides; as it projects a bilateral view and provides adequate information on vertical measurements.^{[7],[11],[12]}

The findings of the study showed that no significant differences were observed between the right and the left sides for all the parameters (P > 0.05) in the control group [Table 3]. These were similar to the findings observed by Sanders et al.,^[13] who found that clinically, symmetric patients do exhibit minor skeletal asymmetries. They stated that small discrepancies exist as a reflection of minute skeletal compensation, dictated by the direction of the growth. These discrepancies are said to be normal and results as a homeostatic mechanism.^{[13],[14],[15],[16]} Therefore, our study also states that a natural compensatory mechanism exists in esthetically pleasing faces.

In the UCLP participants, significant differences were observed between the noncleft and the cleft side [Table 4]. The difference value was calculated by subtracting the cleft side from the noncleft side. Significant differences were observed in the condylar height (P = 0.029), ramal height (P = 0.046), mandibular body length (P = 0.014), gonial angle (P = 0.035) and Co-Go distance (P = 0.044) [Table 4]. Ramus length was shorter on the cleft side and the difference value was in consensus with the study of Jena et al.,^[8] Smahel and Brejha.^[17] Mandibular body length was also shorter on the cleft side than on the noncleft side and was in consensus with the studies done by Kim et al.,^[18] Lin et al.,^[3] The difference value of gonial angle (−0.88) was larger on the cleft side than that of the noncleft side and was in consensus with the studies of Kurt et al.,^[7] Jena et al.,^[8] Lin et al.,^[3] Celikoglu et al.,^[19] found ramal height and ramus plus condylar height to have a significant difference, with lower value in the cleft side of the UCLP participants. Our findings were also similar to their studies.

Therefore, our study is in consensus with the previous study by Kim et al.,^[18] stating that due to directed mandibular growth, mandibular asymmetry may exist and may have been compensated for the already existing asymmetries of the cranial base and the naso-maxillary complex and also as a result of muscular tension due to postoperative scarring.

Comparison of the right and left sides in the BCLP group [Table 5] was nonsignificant, indicating a symmetrical posterior vertical height of the mandible. These findings were similar to the study by Kurt et al.^[7]

According to the multivariate analysis [Table 6] and [Table 7], from the Kjellberg's asymmetry index^[20] and the Habets asymmetry index,^[11],[21] the parameter Kjellberg's symmetry index/condylar ratio was maximally affected, stating that the intergroup difference was maximum for Kjellberg's symmetry index/condylar ratio (effect size = 0.043) that was followed by the asymmetry index ramal (effect size = 0.034). However, the groups showed no significant effect on any of the asymmetry parameter.

Therefore, it was observed that patients with unilateral cleft lip and/palate do exhibit mandibular asymmetry as they correspond to the existing deformity. However, further studies with increased sample size are required to validate the accuracy and reliability of orthopantomogram as an aid to assess asymmetry.

Conclusion

No significant differences were observed between the right and left sides for all the parameters in the normal group
Mandibular asymmetry has been expressed in the UCLP group. Possibly, it may have developed as a compensatory mechanism to the existing deformity in the naso-maxillary complex
BCLP group was nonsignificant, indicating a symmetrical posterior vertical height of the mandible.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	WHO Registry Meeting on Craniofacial Anomalies (2001: Bauru, Brazil), Mossey, Peter A, Catilla, Eduardo E, WHO Human Genetics Programme & WHO Meeting on International Collaborative Research on Craniofacial Anomalies (3^rd: 2001 : Bauru, Brazil). Global registry and database on craniofacial anomalies: report of a WHO Registry Meeting on Craniofacial Anomalies / Main editors: P. Mossey, E. Catilla. World Health Organization 2003.
2.	Shetye PR, Evans CA. Midfacial morphology in adult unoperated complete unilateral cleft lip and palate patients. Angle Orthod 2006;76:810-6.
3.	Lin Y, Chen G, Fu Z, Ma L, Li W. Cone beam computed tomography assessment of lower facial asymmetry in unilateral cleft lip and palate and non-cleft patients with class III skeletal relationship. PLoS One 2015;10:e0130235.
4.	Feragen KJ, Semb G, Magnussen S. Asymmetry of left versus right unilateral cleft impairments: An experimental study of face perception. Cleft Palate Craniofac J 1999;36:527-32.
5.	Shetye PR. Update on treatment of patients with cleft – Timing of orthodontics and surgery. Semin Orthod 2016;22:45-51.
6.	Kambylafkas P, Murdock E, Gilda E, Tallents RH, Kyrkanides S. Validity of panoramic radiographs for measuring mandibular asymmetry. Angle Orthod 2006;76:388-93.
7.	Kurt G, Bayram M, Uysal T, Ozer M. Mandibular asymmetry in cleft lip and palate patients. Eur J Orthod 2010;32:19-23.
8.	Jena AK, Singh SP, Utreja AK. Effects of sagittal maxillary growth hypoplasia severity on mandibular asymmetry in unilateral cleft lip and palate subjects. Angle Orthod 2011;81:872-7.
9.	Hirpara N. Comparative assessment of vertical facial asymmetry using posteroanterior cephalogram and orthopantomogram. J Biomedical Sci 2016;6:1.
10.	Sharma VK, Tandon P, Singh GK, Yadav K, Singh GP. Evaluation of Skeletal Patterns Using Panoramic Radiography. J Adv Res Dent Oral Health 2017;2:1-8.
11.	Habets LL, Bezuur JN, Naeiji M, Hansson TL. The orthopantomogram, an aid in diagnosis of temporomandibular joint problems. II. The vertical symmetry. J Oral Rehabil 1988;15:465-71.
12.	Saglam AA, Sanli G. Condylar asymmetry measurements in patients with temporomandibular disorders. J Contemp Dent Pract 2004;5:59-65.
13.	Sanders DA, Chandhoke TK, Uribe FA, Rigali PH, Nanda R. Quantification of skeletal asymmetries in normal adolescents: Cone-beam computed tomography analysis. Prog Orthod 2014;15:26.
14.	Shah SM, Joshi MR. An assessment of asymmetry in the normal craniofacial complex. Angle Orthod 1978;48:141-8.
15.	Peck S, Peck L, Kataja M. Skeletal asymmetry in esthetically pleasing faces. Angle Orthod 1991;61:43-8.
16.	De moraes ME, Hollender LG, Chen CS, Moraes LC, Balducci I. Evaluating craniofacial asymmetry with digital cephalometric images and cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2011;139:e523-31.
17.	Smahel Z, Brejcha M. Differences in craniofacial morphology between complete and incomplete unilateral cleft lip and palate in adults. Cleft Palate J 1983;20:113-27.
18.	Kim KS, Son WS, Park SB, Kim SS, Kim YI. Relationship between chin deviation and the position and morphology of the mandible in individuals with a unilateral cleft lip and palate. Korean J Orthod 2013;43:168-77.
19.	Celikoglu M, Halicioglu K, Buyuk SK, Sekerci AE, Ucar FI. Condylar and ramal vertical asymmetry in adolescent patients with cleft lip and palate evaluated with cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2013;144:691-7.
20.	Kjellberg H, Ekestubbe A, Kiliaridis S, Thilander B. Condylar height on panoramic radiographs. A methodologic study with a clinical application. Acta Odontol Scand 1994;52:43-50.
21.	Habets LL, Bezuur JN, van Ooij CP, Hansson TL. The orthopantomogram, an aid in diagnosis of temporomandibular joint problems. I. The factor of vertical magnification. J Oral Rehabil 1987;14:475-80.