Home | About us | Editorial board | Search | Ahead of print | Current issue | Archives | Submit article | Instructions| Reviewers

Login 
  Home Print this page Email this page Small font sizeDefault font sizeIncrease font size Users Online: 738    
     


 
Table of Contents   
ORIGINAL ARTICLE
Year : 2016  |  Volume : 6  |  Issue : 9  |  Page : 205-212
Prevalence of facial asymmetry in Tirupati population: A posteroanterior cephalometric and photographic study


1 Department of Orthodontics, Meghana Institute of Dental Sciences, Nizamabad, India
2 Department of Orthodontics, Sri Balaji Dental College and Hospital, Moinabad, India
3 Department of Orthodontics, Anantapur, India
4 Department of Orthodontics, Mallareddy Institute of Dental Sciences, Hyderabad, India
5 Department of Orthodontics, Hyderabad, Telangana, India
6 Department of Orthodontics, Gitam Dental College, Vishakhapatnam, Andhra Pradesh, India

Date of Submission24-Jun-2016
Date of Acceptance01-Dec-2016
Date of Web Publication30-Dec-2016

Correspondence Address:
M Radhika Reddy
Department of Orthodontics, Meghana Institute of Dental Sciences, Nizamabad, Telangana
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2231-0762.197194

Rights and Permissions

   Abstract 

Aims and Objective: The human face is the most prominent aspect in human social interactions, and therefore, it seems reasonable opting for orthodontic treatment is to overcome psychosocial difficulties relating to facial and dental appearance and enhance the quality of life in doing so. Materials and Methods: Posteroanterior cephalograms and frontal photographs of 100 participants (50 males and 50 females) were analyzed to evaluate skeletal asymmetry by the analysis suggested by Grummons. Soft tissue facial asymmetry was analyzed by composite photographic analysis. The data were statistically analyzed using the Statistical Package for the Social Sciences version 16.0 software. Independent t-test was used to find the differences between different measurements. Results: All participants showed mild asymmetry and right-sided laterality. The difference between the right and left sides were statistically insignificant (P > 0.01). The test revealed that only Co distance was statistically significant (P < 0.01), and all the other values are not statistically significant. Conclusion: Composite photographs of hundred participants revealed that facedness is towards the right, however, this laterality was not statistically significant. Both posteroanterior cephalograms and composite photographs showed right-sided laterality. Gender difference in both skeletal and soft tissue asymmetry is not statistically significant.


Keywords: Composite photographs, facial asymmetry, frontal photographs, Grummon′s analysis, photographic evaluation, posteroanterior cephalometry


How to cite this article:
Reddy M R, Bogavilli SR, Raghavendra V, Polina VS, Basha SZ, Preetham R. Prevalence of facial asymmetry in Tirupati population: A posteroanterior cephalometric and photographic study. J Int Soc Prevent Communit Dent 2016;6, Suppl S3:205-12

How to cite this URL:
Reddy M R, Bogavilli SR, Raghavendra V, Polina VS, Basha SZ, Preetham R. Prevalence of facial asymmetry in Tirupati population: A posteroanterior cephalometric and photographic study. J Int Soc Prevent Communit Dent [serial online] 2016 [cited 2019 Oct 16];6, Suppl S3:205-12. Available from: http://www.jispcd.org/text.asp?2016/6/9/205/197194



   Introduction Top


From early times, human beauty has puzzled mankind for its variety and peculiarities. It has been argued that the degree of asymmetry in bilateral features is one of the fundamental factors underlying human attractiveness. [1]

Many Epidemiological studies pertaining to facial asymmetry have been conducted across the globe. One such study was done by Goel et al. [2] to detect the asymmetries and their correlation with malocclusions in Karnataka population. They concluded that there was decrease in magnitude of the asymmetry as higher regions of craniofacial skeleton was approached. Studies conducted by Profitt and Severt [3],[4] assessing facial asymmetries in orthodontic patients clinically found a prevalence ranging from 12% to 37% in North Carolina, United States, 23% in Belgium, and 21% in Hong Kong. Radiographic examinations reveal values higher than 50%. [5]

Mossey et al. [6] performed a similar study to evaluate the size and shape-related craniofacial skeletal asymmetries, and concluded wider left side of the face and a shorter vertical dimension on the right side. Kowner in a classic experiment on the perception of attractiveness based on symmetry conducted in Japan concluded that limited asymmetry may be simply more aesthetic, regardless of its function. [7] Fong et al. in a study conducted in Taiwan concluded that 68% of the study population showed chin deviation to the left side and (32%) to the right side. [8]

In another study, Anistoroaei et al. concluded that facial asymmetry was present in 4.7% of patients; they also concluded that a significant correlation was evidenced between facial asymmetry and type of malocclusions, age, and type of dentition. [9]

While most of the studies have concluded that no quantitative differences in different types of measurements of face exists in relation to face, [10],[11] some studies, such as the one conducted by Ercan et al., concluded that the number of significantly asymmetric linear distances between the two halves of the face was greater in females than that in males. [12] Cheng in his review concluded the symmetry of the face is highly influenced by soft tissue landmarks. [13]

The purpose of the present study was to evaluate the prevalence of skeletal facial asymmetry using frontal cephalograms and frontal photographs among the adults of Tirupati, Andhra Pradesh, hitherto assessing the correlation of skeletal facial asymmetry and soft tissue facial asymmetry as well as to assess the gender differences in the prevalence of facial asymmetry.


   Materials And Methods Top


A total of 100 residents (50 males and 50 females) of Tirupati, Andhra Pradesh in the age group of 18-25 years were selected for the study through randomized sampling [Table 1] and [Table 2]. Before commencement of the study, a written informed consent was taken from all the participants of the study. Ethical approval was obtained from the ethical committee. The study was planned and done over a period of 3 months.
Table 1: Sample size and mean age group of the sample


Click here to view
Table 2: Mean age group of the study groups


Click here to view


The inclusion criteria were clinically acceptable facial symmetry, presence of full complement of teeth, no history of pathology/trauma/surgical intervention or orthodontic treatment, and no congenital abnormalities in the maxillofacial region.

The sample size was calculated using the following  formula: E=Zα/2 σ/√n

Facial photographs were taken with a Canon Power Shot A 650 IS camera and by the same photographer. Participants were made to stand and assume natural head position, so that their  Frankfurt horizontal (FH) planes will be parallel to the floor. The cephalograms were taken in the posteroanterior projection.

The analysis for assessment of transverse frontal facial asymmetry was done by using frontal asymmetry analysis suggested by Grummons [Figure 1]. [1] For subjective evaluation, frontal photographs were assessed by using composite photographs. [2],[3]
Figure 1: List of Land marks used in this study

Click here to view


Mid sagittal reference

This is a vertical reference line. According to Grummons, mid sagittal reference (MSR) closely follows visual plane formed by subnasale and the midpoint between the eyes and eyebrows, and hence MSR was selected as the key reference line [Figure 2] and [Figure 3].
Figure 2: Midsagital reference line

Click here to view
Figure 3: Alternate methods of constructing. (a) Line from midpoint of Z plane through ANS, (b) Line from midpoint of Z plane through Fr-Fr line

Click here to view


Horizontal planes

Four planes were drawn to show the degree of parallelism and symmetry of the facial structures. Three planes connected the medial aspects of the zygomatic frontal sutures (ZZ), the centers of the zygomatic arches (ZA), and the medial aspects of the jugal processes (J). Another plane was drawn at menton parallel to the Z plane [Figure 4].
Figure 4: Horizontal plane

Click here to view


Mandibular morphology

Two triangles (right and left) were formed by joining the AG, Me, and Co points on both sides, representing the mandibular morphology. The linear measurements for all the three sides of the triangles were recorded along with the measurements of the angles formed by joining Co, Go, and Me points on both sides [Figure 5].
Figure 5: Mandibular morphology

Click here to view


Linear asymmetry (transverse)

The vertical offset as well as the linear distance was measured from MSR to Co, NC, J, Ag, Go, and Me were measured. The linear distance to MSR from the land marks Co, Nc, J, Ag, Go, U, L, and Me was calculated for paired structures, the distance away from the midline was determined for both landmarks, and the difference between the distances was calculated. For unpaired points, the horizontal distance to the midline will be determined [Figure 6].
Figure 6: Linear asymmetries

Click here to view


Frontal photographs of the participants were taken and each photograph is divided into left and right sides and left half of the face and its mirror image are joined together and similarly right half of the face and its mirror image were joined to form two facial composites, i.e., L-L (left composite) and R-R (right composite). Facedness of the sample or population refers to the side with highest total prevalence [Figure 7].
Figure 7: Composite photographs

Click here to view



   Results Top


The data were statistically collected and tabulated in Microsoft excel. The data was stastically analyzed using the Statistical Package for the Social Sciences (SPSS) version 16.0 program statistical analysis package software. Independent t-test was used to find the differences between different measurements and the significance in the measurements of the right and left side dimensions, if any. The data was checked for the normal distribution using t-statistics and then the correlation coefficients between the various parameters were calculated using Pearson's correlation to determine which would produce a higher value.

Linear asymmetries (transverse)

[Table 3] shows the bilateral facial widths observed at Z, Co, Za, J, Nc, Ag, Go distances, as total widths, right side, and left side. [Table 4] shows total bilateral facial widths observed at Z, Co, Za, J, Nc, Ag, and Go for males. [Table 5] shows total bilateral facial widths observed at Z, Co, Za, J, Nc, Ag, and Go for females.
Table 3: Bilateral facial widths observed at Z, Co, Za, J, Nc, Ag, and Go distance as total width, right side, and left side


Click here to view
Table 4: Bilateral facial widths observed at Z. Co, Za, J, Nc, Ag, and Go for males


Click here to view
Table 5: Bilateral facial widths observed at Z. Co, Za, J, Nc, Ag, and Go for females


Click here to view


The results showed statistically significant difference between the mean Z, Co, Za, J, Nc, Ag, and Go values of males and females (P < 0.01). The difference between the right and left sides were statistically insignificant (P > 0.01). The test revealed that only Co distance was statistically significant (P < 0.01). The means and standard deviation of vertical distances from the right and left Z, Co, Za, J, Nc, Ag, and Go to the MSR on both groups are shown in [Table 6]. No significant difference was observed between males and females (P > 0.01).
Table 6: Vertical offset of Z. Co, Za, J, Nc, Ag, and Go


Click here to view


[Table 6], [Table 7] and [Table 8] shows bilateral widths of Co-Go, Go-Me, Co-Me, and gonial Angle to assess the mandibular morphology (P < 0.05). There was statistically significant difference between the mean Co-Me value and gonial angle of the right and left sides.
Table 7: Total bilateral widths and gonial angle to assess the mandibular morphology


Click here to view
Table 8: Bilateral widths and gonial angle to assess the mandibular morphology in males


Click here to view


[Table 9] shows the Bilateral widths and gonial angle to assess the mandibular morphology in females. The results were statstiscally significant for the coronoid and menton distance and the coronoid gonion and menton distance.
Table 9: Bilateral widths and gonial angle to assess the mandibular morphology in females


Click here to view


[Table 10] shows mandibular offset at menton. Menton deviated to the left side in 55% (2.6 ± 1.4 mm) and deviated to right in 3% (1.6 ± 0.28 mm). In 58% males, there was deviation towards left (2.8 ± 1.6). Whereas towards the right in 2% (1.5 mm). In 52% females, deviation was towards left (2.4 ± 1.02) and towards right 4% (1.7 ± 0.3 mm). The difference between males and females is statistically insignificant (P > 0.01).
Table 10: Mandibular offset at menton


Click here to view


[Table 11] shows parallelism of facial structures. Mean angles formed by Z, Za, J, Me, and occlusal planes with MSR shows that there was no statistically significant canting. The difference between males and females was statistically insignificant.
Table 11: Parallelism of facial structures


Click here to view


[Table 12] and [Table 13] show the sidedness of the face by subjective evaluation of composite photographs of 100 participants. Out of a total of 100 participants, it was observed that 81 were right faced (R-R) and 19 were left faced. Thirty-nine males were observed to be right faced (R-R) and 11 were observed to be left faced (L-L). Whereas in females, 42 were observed as right faced (R-R) and 8 were observed to be left faced (L-L). Therefore, in males and females, facedness is towards the right, and female faces were more right faced than males (P > 0.01).
Table 12: Composite photographic analysis - sideness of face


Click here to view
Table 13: Composite photographic analysis in males and females


Click here to view



   Discussion Top


Asymmetries in the human craniofacial skeleton are a rule rather than exception. This has been verified and stressed upon by many researchers dating back from  Shah and Joshi [14] and Peck et al. [15]

A posteronterior cephalometric radiographic study of 100 participants with pleasing symmetrical faces and normal occlusions was conducted with the objective of evaluating the extent of facial asymmetry. Frontal photographs were obtained and studied for subjective evaluation of facial asymmetry seen in the selected Tirupati population.

The frontal analysis suggested by Grummons was used to assess the patients for the transverse (skeletal) facial asymmetries as it provides clinically relevant information regarding specific locations and amounts of facial asymmetry and measures mandibular morphology, which can be seen to play a major role in asymmetries.

The results of the present study [Table 1] showed that the bilateral total widths of Z, Co, Nc, Ag, and Co on the right side was greater than those on the left side, however, the difference was statistically insignificant except for Co. Only the Co distance was statistically significant (P < 0.01). This shows that asymmetry was present more in the condylar region and towards right side. Similar findings were reported by Farkas and Cheung. [4] The difference between the right and left side mean absolute asymmetry for Z, Nc, abd J distances are less than those for Co, Ag, and Go. These are in agreement with findings of Letzer and Kronman [16] and Peck et al. [15]

None of the studies on facial asymmetry measured vertical offsets. In the present study, vertical offsets of Z. Co, Za, J, Nc, Ag, and Go were also measured and no statistical difference between males and females (P > 0.01).

For the assessment of the mandibular morphology, Co-Ag, CO-Me, and Ag-Me and gonial angle were statistically analyzed [Table 2]. Gonial angle (P < 0.001) showed statistically significant value at 1% level length. The possible cause of asymmetry in gonial angle are asymmetry functional patterns such as unilateral chewing patterns, muscular atrophies, etc., as suggested by Shah and Joshi. [14] It shows that gonial angle is the only region where the right side is larger than the left side.

Mandibular length (Co-Me) and Gonial angle (Co-Go, Me) showed statistically significant difference between the right and left sides, with right side being larger in total as well as in males and females. This is in accordance with a similar study conducted by Shah and Joshi [14] and Azevedo et al. [17]

Chin deviations in our study showed a left sidedness, which is in agreement with findings of Severt and profit. [3] The high incidence of chin deviation may be due to the asymmetries of mandibular length, which also showed high incidence. The possible reason given by Woo [18] is the increased size of the right hemisphere of brain. The right side dominance in brain affects the functional activities and facial structures.

The mean values obtained for the angles formed by the various planes used in this analysis were more or less parallel to each other. These findings are in agreement with Ricketts and Grummons. [19]

In our study on composite photographic analysis, it was observed that 81% shows right sidedness and 19% shows left sidedness. The findings in our study are in concordance with Hardie et al. [11] andHaraguchi et al. [10]

Mild asymmetry was observed both in males and females with males having wider faces than females. Co distance showed statistically significant right sidedness (P < 0.01). Me-Co length showed statistically significant right sidedness in total (P < 0.01); males (P < 0.05), females (P < 0.05).The findings in our study are in concordance with many studies, [2],[4],[14],[18],[20],[21] however, left side laterality was observed in few studies. [22],[23]

Seventy-eight percent of males and 88% females were observed as right faced (R-R) on composite photographic analysis. The difference between males and females was statistically insignificant (P > 0.01). The findings in our study are in concordance with those carried out by Farkas and Cheung, [4] and Ferrario Virgilio et al. [24] The findings in our study differ with Smith. [25]

According to Kim et al. [26] generally, skeletal deviation must be greater than 4 mm to render the asymmetry visible in an individual's face. Therefore, other authors consider an asymmetrical face as having bone deviations equal to or greater than 2 mm. This might be the major drawback of the study because the present study utilized photographs also for determining the depth of facial asymmetries.

Other main limitations of the study are the errors in identifying the anatomical landmarks in posteroanterior cephalograms due to superimposition of many craniofacial structures. A three-dimensional topographic study or cone-beam computed tomography (CBCT) could be used in the future to diagnose facial asymmetries. Complete CBCT software to identify different landmarks three dimensionally could also be helpful in marking the facial asymmetries. [27],[28] Other advanced means such as the use of stereophotogrammetry, [29] (three-dimensional photography) or quantifying facial soft tissue asymmetry by a three-dimensional imaging-based method, [30],[31],[32] or use of the Weibull distribution-based comparison of a person's asymmetry with respect to a large sample of symmetrical faces [27],[33],[34] would be more accurate.


   Summary And Conclusions Top


All participants showed mild skeletal asymmetry on posteroanterior cephalograms which was not statistically significant. Composite photographs of hundred participants revealed that facedness is towards right, however, this laterality was not statistically significant. Both posteroanterior cephalograms and composite photographs showed right-sided laterality. Gender difference in both skeletal and soft tissue asymmetry was not statistically significant.

In the evaluation for an orthodontic treatment, asymmetry of the face should be considered and may only be noticed with a morphometric analysis. The present data may be of use for future clinical studies, but studies with larger sample at different geographical locations are warranted. A classification for asymmetry based on the data collected for the Asian group would be useful for future research on this subject.

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

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Grummons DC, Kappeyne MA. A frontal asymmetry analysis. J Clin Orthod 1987;21:448-65.  Back to cited text no. 1
    
2.
Goel S, Ambedkar A, Darda M, Sonar S. An assessment of facial asymmetry in Karnataka population. J Indian Orthod Soc 2003;36:30-8.  Back to cited text no. 2
    
3.
Severt TR, Proffit W. The prevalence of facial asymmetry in the dentofacial deformities in the population at the University of North Carolina. Am J Adult Orthod Orthognath Surg 1997;12:171-6.  Back to cited text no. 3
    
4.
Farkas LG, Cheung G. Facial asymmetry in Healthy North American Caucasians. Angle Orthod 1981;51:76-8.  Back to cited text no. 4
    
5.
Boeck EM, Lunardi N, Pinto AS, Pizzol KEC, Boeck RJ Neto. Occurrence of Skeletal Malocclusions in Brazilian Patients with Dentofacial Deformities. Braz Dent J 2011;22:340-5.  Back to cited text no. 5
    
6.
Mcintyre M. Asymmetry of the parental craniofacial skeleton in orofacial clefting. J Orthod 2002;29:299-34.  Back to cited text no. 6
    
7.
Kowner R. Facial Asymmetry and Attractiveness Judgment in Developmental Perspective. J Exp Psychol Hum Percept Perform 1996:22;662-75.  Back to cited text no. 7
    
8.
Fong JH, Wu HT, Huang MC, Chou YW, Chi LY, Fong Y, et al. Analysis of Facial Skeletal Characteristics in Patients With Chin Deviation. J Chin Med Assoc 2010:73;29-34.  Back to cited text no. 8
    
9.
Anistoroaei D, Golovcencu L, Sãveanu IC, Zegan G. The prevalence of facial asymmetry in preorthodontic treatment. Int J Med Dent 2014:4;210-15.  Back to cited text no. 9
    
10.
Yoshitaka H, Takada K. Asymmetry of the Face in Orthodontic Patients. Angle Orthod 2008;78:421-6.  Back to cited text no. 10
    
11.
Hardie S, Hancock F, Rodway F, Penton-Voak I, Carson D, Wright L. The enigma of facial asymmetry: Is there a gender specific pattern of facedness? Laterality 2005;10:295-304.  Back to cited text no. 11
    
12.
Ercan I, Ozdemir ST, Etoz A, Sigirli D, Tubbs RS, Loukas M, et al. Facial asymmetry in young healthy subjects evaluated by statistical shape analysis. J Anat 2008:213;663-9.  Back to cited text no. 12
    
13.
Cheong YW. Facial Asymmetry: Etiology, Evaluation, and Management. Chang Gung Med J 2011;34:341-51.  Back to cited text no. 13
    
14.
Shah SM, Joshi MR. An assessment of asymmetry in the normal craniofacial complex. Angle Orthod 1978;48:141-8.  Back to cited text no. 14
    
15.
Peck S, Peck L, Kataja M. Skeletal asymmetry in esthetically pleasing faces. Angle Orthod 1991;61(1):43-8.  Back to cited text no. 15
    
16.
Letzer GM, Kronman JH A posteroanterior cephalometric evaluation of craniofacial asymmetry. Angle Orthod 1967;37:205-11.  Back to cited text no. 16
    
17.
Azevedo AR, Janson G, Henriques JF, Freitas MR. Evaluation of asymmetries between subjects with Class II subdivision and apparent facial asymmetry and those with normal occlusion. Am J Orthod Dentofacial Orthop 2006;129:376-83.  Back to cited text no. 17
    
18.
Woo TL. On the asymmetry of the human skull. Biometrika 1931;22:324-2.  Back to cited text no. 18
    
19.
Ricketts RM, Grummons D. Frontal Cephalometrics: Practical Applications, Part I. World J Orthod 2003;4:297-316.  Back to cited text no. 19
    
20.
Arnold TG, Anderson GC, Liljemark WF. Cephalometric norms for cranio-facial asymmetry using submental vertical radiograph. Am J Orthod Dentofac Orthop 1994;106:250-6.  Back to cited text no. 20
    
21.
Ferrario VF, Sforza C, Poggio CE, Serrao G. Facial three-dimensional morphometry. Am J Orthod Dentofac Orthop 1996;109:86-93.  Back to cited text no. 21
    
22.
Vig PS, Hewitt AB. Asymmetry of the human facial skeleton. Angle Orthod 1975;45:125-9.  Back to cited text no. 22
    
23.
Melnick AK. A cephalometric study of mandibular asymmetry in a longitudinally followed sample of growing children. Am J Orthod Dentofac Orthop 1992;101:355-66.  Back to cited text no. 23
    
24.
Ferrario VF, Sforza C, Ciusa V, Dellavia C, Tartaglia GM. The effect of sex and age on facial asymmetry in healthy subjects: A cross section study from adolescence to mid adulthood. J Oral Maxillofac Surg 2001;59:382-8.  Back to cited text no. 24
    
25.
Smith WM. Hemispheric and facial asymmetry: Gender differences. Laterality 2000;5:251-8.  Back to cited text no. 25
    
26.
Kim JY, Jung HD, Jung YS, Hwang CJ, Park HS. A simple classification of facial asymmetry by TML system. J Craniomaxillofac Surg 2014;42:313-20.  Back to cited text no. 26
    
27.
Thiesen G, Gribel BF. Facial asymmetry: A current review. Dent Press J Orthod 2015;20:110-25.  Back to cited text no. 27
    
28.
Bhateja NK, Fida M, Shaikh A. Frequency Of Dentofacial Asymmetries: A Crosssectional Study On Orthodontic Patients. J Ayub Med Coll Abbottabad 2014;26:129-33.  Back to cited text no. 28
    
29.
Minich CM, Araújo EA, Behrents RG, Buschang PH, Tanaka OM, Kim KB. Evaluation of skeletal and dental asymmetries in Angle Class II subdivision malocclusions with cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2013;144:57-66.  Back to cited text no. 29
    
30.
Maheshwari S, Verma SK, Gaur A, Dhiman S. Diagnosis and management of facial asymmetries. J Orthod Res 2015;3:81-7.  Back to cited text no. 30
  Medknow Journal  
31.
Patel A, Islam SM, Murray K, Goonewardene MS. Facial asymmetry assessment in adults using three-dimensional surface imaging. Prog Orthod 2015;16:36.  Back to cited text no. 31
    
32.
Rajpara Y, Shyagali TR, Trivedi K, Kambalyal P, Sha T, Jain V. Evaluation of facial asymmetry in esthetically pleasing faces. J Orthod Res 2014;2:79-8.  Back to cited text no. 32
  Medknow Journal  
33.
Djordjevic J, Toma AM, Zhurov AI, Richmond S. Three-dimensional quantification of facial symmetry in adolescents using laser surface scanning. Eur J Orthod 2014:36;125-32.  Back to cited text no. 33
    
34.
Agrawal M, Agrawal JA, Nanjannawar L, Fulari S, Kagi V. Dentofacial asymmetries: Challenging diagnosis and treatment planning. J Int Oral Health 2015;7:1-4.  Back to cited text no. 34
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13]



 

Top
Print this article  Email this article
 
  Search
 
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (1,416 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
   Introduction
    Materials And Me...
   Results
   Discussion
    Summary And Conc...
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed1414    
    Printed21    
    Emailed0    
    PDF Downloaded107    
    Comments [Add]    

Recommend this journal