• Users Online: 1693
  • Print this page
  • Email this page


 
 
Table of Contents
ORIGINAL ARTICLE
Year : 2022  |  Volume : 11  |  Issue : 1  |  Page : 14-20

Knowledge and attitude of elementary school health-care providers with regard to emergency management of traumatic dental injuries in Kashan city


1 Department of General Dentistry, School of Dentistry, Kashan University of Medical Sciences, Kashan, Iran
2 Department of Pediatric Dentistry, School of Dentistry, Kashan University of Medical Sciences, Kashan, Iran
3 Department of Epidemiology and Biostatistics, School of Health, Kashan University of Medical Sciences, Kashan, Iran

Date of Submission24-Feb-2021
Date of Decision17-Jan-2022
Date of Acceptance10-Mar-2022
Date of Web Publication31-Jul-2022

Correspondence Address:
Mohammadreza Molaee
Department of General Dentistry, No. 5th of Qotb–e Ravandi Blvd. Kashan University of Medical Sciences, P.O. Box: 8715988141, Kashan
Iran
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/atr.atr_18_21

Rights and Permissions
  Abstract 


Background and Objectives: Dental trauma is a common problem seen in children. Since schools are one of the main places where traumatic dental injuries (TDIs) occur, school health care providers have an important role to reduce the possible consequences. The study aimed at examining the awareness and attitudes of elementary school health-care providers about the emergency management of TDIs in children. Methods: This cross-sectional study was conducted on all health-care providers of elementary schools in Kashan, Iran. Data were collected using a four-part questionnaire. The collected data were analyzed using descriptive statistics (percentage, frequency, mean, and standard deviation) by the SPSS 26 software. Results: Regarding emergency management of traumatic dental injures, the scores of health care providers' knowledge and health care providers' attitude were 65% and 86.5%, respectively. There was no statistically significant association between the level of knowledge and a length of service, gender, and the educational level. Conclusions: The elementary school health-care providers did not have a high level of awareness about how to deal with TDIs.

Keywords: Attitude, knowledge, tooth avulsion, tooth injuries, trauma


How to cite this article:
Hosseinpoor S, Kashani AT, Akbari H, Molaee M. Knowledge and attitude of elementary school health-care providers with regard to emergency management of traumatic dental injuries in Kashan city. Arch Trauma Res 2022;11:14-20

How to cite this URL:
Hosseinpoor S, Kashani AT, Akbari H, Molaee M. Knowledge and attitude of elementary school health-care providers with regard to emergency management of traumatic dental injuries in Kashan city. Arch Trauma Res [serial online] 2022 [cited 2024 Mar 28];11:14-20. Available from: https://www.archtrauma.com/text.asp?2022/11/1/14/353054




  Introduction Top


Traumatic dental injuries (TDIs) in children are a significant oral health issue worldwide.[1] The world TDI prevalence among 12-year-old children[2] and the prevalence of TDIs in East Iranian school children[3] have been reported 18.1% and 22.9%, respectively. The results of a similar study conducted in Hamedan showed that more than half of TDIs occur at schools.[4]

Falls and collisions, sporting activities, violence, and traffic accidents are the main cause of TDIs.[5] Traumatic injuries are an upsetting experience on a physical level which may also affect emotional and psychological levels.[6] The physical impacts of TDIs may cause pain, loss of function, and it could adversely affect the developing occlusion and esthetics.[7] The psychosocial impacts of a TDIs are unique to each patient, influencing their treatment preferences, resilience, and ultimate recovery.[8] Thus, these situations can have a negative impact on the life of children.

Although TDIs are not entirely preventable, there are some ways to minimize the risk. For young children, child-proofing home safety tips can be effective to decrease the risk of falls and injury. For older children who participate in sports, the use of protective gear-like mouth guards and helmets can minimize the risk of TDIs.[9]

When a tooth is avulsed during trauma, tooth replantation is a technique by which a dentist or an informed and capable person can put a tooth back in its place. Today, it has been proven that the best primary treatment for an avulsed tooth is immediate replantation within 60 min after an injury. If school teachers cannot do replantation, the tooth should be kept in special solutions such as cold milk, normal saline, the patient's saliva, or egg white, and then, the patient should be immediately referred to a dentist.[10],[11],[12],[13] Therefore, the prognosis for success often depends on the rapidity of treatment, irrespective of whether the procedure is involving protecting a large area of exposed dentin or treating a vital pulp exposure.[14]

As mentioned, one of the common places where TDIs occur is in school.[14],[15] Since teachers are frequently dealing with TDIs among children in schools, they are considered as the first immediate seniors for children when an accident occurs.[16] Therefore, their knowledge about the emergency management of TDIs is a vital factor for the prognosis of injured teeth and in assisting the injured person to receive an immediately appropriate first-aid treatment.[15]

Numerous studies have been conducted to determine the level of knowledge and attitude of school teachers that some of them are elementary school health-care providers (ESHCPs) regarding emergency management of TDIs in different countries, which shows the inadequacy of knowledge in this field.[15],[17],[18],[19],[20],[21],[22] Furthermore, other studies have been conducted in different cities of Iran that show school teachers did not have sufficient knowledge about emergency management of TDIs.[4],[23],[24],[25],[26]

According to the results of studies conducted in different cities of Iran and abroad which show the low level of knowledge of teachers and ESHCPs with regard to Emergency Management of TDIs and also the lack of research and statistical studies in this field in Kashan city, the authors decided to perform this research. Hence, this study aimed at evaluating the knowledge and attitude of ESHCPs in Kashan regarding an emergency management of TDIs using a four-part questionnaire.


  Methods Top


This cross-sectional study was conducted on 46 school health-care providers employed by the Kashan Education Department in 2020. The inclusion criteria were considered as part-time or full-time employment and willingness to cooperate and participate in the research. The exclusion criteria were considered as the incompleteness of the questionnaire. This study was adherent to the Strengthening the Reporting of Observational Studies in Epidemiology statement. The flowchart of the study steps is shown in [Figure 1].
Figure 1: Flowchart of study steps

Click here to view


Data were collected using Porsline as an online survey because of school closures, due to the COVID-19 virus pandemic. Data collection occurred for 1 month starting from May 2020.

After obtaining the research ethical license by the Ethics Committee of Kashan University of Medical Sciences (IR.KAUMS.MEDNT.REC.1398.138), by referring to the Kashan Education Department, the list and phone number of individuals were extracted and the study objectives and individuals were described through phone and they were invited to cooperate in the study. Then, verbal consent was obtained from all participants. They were informed that they could withdraw from the study at any time. All questionnaires were anonymous and the participants were assured of the confidentiality of their information.

In this study, a researcher-made questionnaire was used. In order to develop the questionnaire, a review of previous studies[1],[4],[14],[18],[23],[27],[28] and an evaluation of existing tools were conducted. The basic items of the questionnaire were extracted with the aim of assessing the current knowledge and attitude of ESHCPs regarding the emergency management of TDIs. To assess the content validity of the questionnaire, the opinions of five health education specialists with master's degrees and over along with five dental specialists were applied. To calculate the content validity index, relevance, clarity, and simplicity of all items were investigated using a 4-point Likert scale with 0.8 and more cutoff. The questionnaire was distributed to five random ESHCPs for face validation, and it was evaluated using a 5-point Likert scale.

The questionnaire consisted of four parts. The first part had seven questions about personal data included age, gender, educational level, history of job, dental trauma first-aid training background, having any experience of tooth injury in school, and a type of school where they work. The second part consisted of eight questions about the attitude of ESHCPs in the emergency management of TDIs. The third part contained 18 multiple-choice questions about the knowledge of ESHCPs about emergency management of TDIs. It consisted of two case scenarios and some general questions. The first case consisted of questions regarding moderate trauma involving partial crown fracture and the second case comprised questions regarding tooth avulsion. The fourth part of the questionnaire included three questions about self-assessment and the source of information on ESHCPs regarding emergency management of TDIs in school.

Ultimately, there are two total scores, one of which indicates the knowledge and level of awareness of ESHCPs about TDIs, and the other shows their attitude toward gaining knowledge about TDIs, performing the assigned task, and their responsibility. For statistical analysis, answers to the 18 knowledge questions were collected as correct or incorrect, and each of the correct answers was given a score of 1, and the wrong answer a score of 0. Similarly, a score of 1 was assigned for a positive attitude and a score of 0 for a negative attitude with regard to the 8 questions of the attitude part.[1],[4],[14],[23],[24] Therefore, in the knowledge section, the maximum score is 18 (the highest level of knowledge) and the minimum score is zero (the lowest level of knowledge). In the attitude section, the maximum score is 8 (the best attitude) and the minimum score is zero (the worst attitude).

Statistical analysis was performed by the SPSS software version 26 (IBM Corp, University of Chicago, Illinois, USA). Descriptive statistics included percentages, frequencies, mean and standard deviation were used. To compare between-group comparisons, after checking normality with the appropriate test, the independent t-test and one-way ANOVA were used and in cases, with skewed distributions, the nonparametric Mann–Whitney and Kruskal–Wallis tests were used. The level of significance was set at 0.05.


  Results Top


A total of 46 questionnaires were distributed and all the questionnaires were filled with 100% response rate. Of 46 participants, 58.7% (n = 27) were female and 41.3% (n = 19) were males. The age ranged from 25 to 58 years. Demographic data of the participants and their relationship with their level of knowledge and attitude are provided in [Table 1].
Table 1: Demographic data of the participants and their relationship with their level of knowledge and attitude

Click here to view


The questionnaire consisted of four parts with Cronbach's alpha 0.81. The first part includes seven questions about demographic data. The second part consists of eight questions about attitude. The third part contains 18 multiple-choice questions about the knowledge. The fourth part of the questionnaire considers three questions about self-assessment and the source of information on ESHCPs regarding emergency management of TDIs in school. [Figure 2] shows the relationship among the mentioned parts. The demographic data is the baseline. Attitude and knowledge are considered as screen parameters. Thus, each arrow shows the relation between base/screen or screen/screen parameters.
Figure 2: Diagram of relationship among the base and screen parameters

Click here to view


The mean and standard deviation of the “attitude” part was 6.92 ± 1.2 out of 8 (86.5%). All of the ESHCPs believed that “time” is an important factor in saving a damaged tooth. Furthermore, “gaining skills” in emergency management of TDIs should be considered as an educational priority; thus, these two factors got the highest score 100% (n = 46). In contrast, the lowest score with 63% (n = 29) belonged to this item; “Due to some legal considerations, ESHCPs should refrain from interfering in the management of dental trauma.” More details are shown in [Table 2].
Table 2: Distribution of responses regarding attitude for management of traumatic dental injuries

Click here to view


The result of the third part of the questionnaire is indicated in [Table 3], [Table 4], [Table 5]. The result of an imaginary case is presented in [Table 3] as a mild TDI and also the result of an imaginary case regarding tooth avulsion has been shown in [Table 4]. [Table 5] also shows the general questions about ESHCPs' knowledge. The knowledge questions of the three cases consist of 18 questions. The mean and standard deviation of the knowledge score for all the ESHCPs were obtained 11.7 ± 2.8 out of 18 (65%). When it comes to genders, there was no significant difference between males and females. The age group <30 years experienced the highest score of knowledge compared with other groups (P < 0.05).
Table 3: Responses of elementary school health care providers regarding knowledge of mild traumatic dental injuries (case scenario 1)

Click here to view
Table 4: Responses of elementary school health-care providers regarding knowledge of tooth avulsion (case scenario 2)

Click here to view
Table 5: Responses of elementary school health care providers regarding knowledge (general questions)

Click here to view


The last part of the questionnaire indicates the distribution of responses regarding “self-assessment and the source of information”. In this study, 89.1% (n = 41) of ESHCPs declared a lack of knowledge in the realm of emergency management of TDIs and expressed their desire to participate in any related workshops. Moreover, according to the participants' answers, the majority order of collecting information about TDIs is as dentists >social networks (Telegram, Instagram, etc.) >retraining and workshops >and other people working in the health sector [Table 6].
Table 6: Distribution of responses regarding self-assessment and the source of information

Click here to view



  Discussion Top


In the present study, the participants' knowledge score (65%) indicates the lack of awareness among ESHCPs concerning how to deal with emergency TDIs. This finding was similar to the other studies conducted by Nirwan et al.[29] and Mehrabkhani et al.[24] that reported scores of 67.1% and 53.3%, respectively. The similar results in these studies probably are due to a worldwide lack of instruction in TDIs, which shows the necessity for critical revision in instruction methods and opportunities.

Moreover, there was no significant relationship between the participants' level of knowledge and their gender. Although Pithon et al. indicated female school teachers had more knowledge and this difference was statistically significant,[30] in some other studies, no significant relationship was observed between the participants' level of knowledge and their gender.[4],[17],[29],[31] In all of these studies, there was no significant difference in the number of responders based on their gender and also two genders had equal training opportunities. Therefore, if there are equal educational and employment opportunities for men and women, an equal level of knowledge and performance can be expected to face TDIs.

According to the findings of the present study, a higher level of knowledge was found among ESHCPs in the age group <30 years. Furthermore, the use of social networks to obtain information about the emergency management of TDIs among ESHCPs got the second rank after dentists. In this regard, Rouhani et al.[26] also reported a significant association between knowledge and the age group and found that the most correct answers belonged to the 20-to-30-year age group. Considering the more tendency of young people to use social networks, the higher level of awareness can be justified among ESHCPs <30 years.

Participants showed a high level of attitude regarding emergency management of TDIs. This result is comparatively higher than the other study conducted by Sharma et al.[14] Unlike the current study in which 73.6 (n = 34) of individuals had a bachelor's degree or higher, the majority of participants in the Sharma et al. study had diploma degrees which could be the probable reason leading to lower attitude scores. It suggests having a higher degree could play a positive role in improving an individual's attitudes towards the emergency management of TDIs. Moreover, comparison of the age groups indicated that the individuals under the age of 30 had the highest attitude and, as mentioned, these individuals also had the highest level of knowledge. Therefore, raising the level of knowledge may improve the level of attitudes of individuals towards TDIs.

When ESHCPs were asked if you cannot put the avulsed tooth back in its place, in what environment you send it to the dentist, only 47.8% responded correctly in a liquid such as milk. In Mehrabkhani et al.[24] study, only 33.1% selected milk as the best storage media for an avulsed tooth; In Blakytny et al.[32] study, 45.6% of the participants chose milk as a suitable media and in McIntyre study,[33] 34% of the participants selected milk. Although the knowledge of our participants in this field does not seem to be sufficient, it is higher than other similar studies. In most of these studies, participants were school teachers but only a special part of the school teachers who were health care providers have been evaluated in this study. Given the connection of their work and study field to the management of traumatic injuries, a higher level of knowledge is probably not unexpected.

The majority of respondents (89.1%) expressed an interest to participate in retraining workshops about emergency management of TDIs. A similar finding was observed in some studies conducted by Al-Jundi et al.[18] and Sharma et al.[14] Since 89.1% of the participants also declared a lack of knowledge toward the emergency management of TDIs, the desirability to take training courses is compatible with feeling the lack of information, which is shown in all studies.

Concerning the increasing use of social networks for getting information among people,[34] it seems helpful to use this source for informing ESHCPs. Social networks can be effective for instruction by making animations, short educational videos, podcasts, etc., and transfer them to the target groups besides holding continuous retraining courses seems suitable. It is suggested that in future studies, the impact of using social networks to improve the knowledge of ESHCPs with regard to emergency management of TDIs be examined and studied.

Since in this study a researcher-made questionnaire was used, it was not possible to compare the results of this study results with those of other studies, as the main limitation. Moreover, the absence of control and experimental groups due to the COVID-19 virus pandemic was the other limitation of the current study, which led us to implement an online survey.


  Conclusions Top


Findings of the present study show that the knowledge of ESHCPs about the emergency management of TDIs in Kashan does not adequately meet the professional demands. Thus, increasing the health care providers' knowledge using extra dental trauma management courses is a must. Moreover, providing comprehensive and sufficient information has a positive effect on attitude and self-assessed competence. To achieve adequate awareness, the distribution of brochures, posters, and educational handouts in the schools can be helpful.

Acknowledgments

The authors would like to express sincere gratitude to Kashan Education Department and also the representative of the Kashan Education Department, Ms. Blour for their support of this work.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Yassen GH, Chin JR, Younus MS, Eckert GJ. Knowledge and attitude of dental trauma among mothers in Iraq. Eur Arch Paediatr Dent 2013;14:259-65.  Back to cited text no. 1
    
2.
Petti S, Glendor U, Andersson L. World traumatic dental injury prevalence and incidence, a meta-analysis – One billion living people have had traumatic dental injuries. Dent Traumatol 2018;34:71-86.  Back to cited text no. 2
    
3.
Rouhani A, Movahhed T, Ghoddusi J, Mohiti Y, Banihashemi E, Akbari M. Anterior traumatic dental injuries in East Iranian school children: Prevalence and risk factors. Iran Endod J 2015;10:35-8.  Back to cited text no. 3
    
4.
Kamali A, Kashani AT, Hydarpoor M. Primary school health teachers' knowledge regarding the emergency treatment of avulsed permanent teeth in Hamadan. J Dent Med 2016;29:129-35.  Back to cited text no. 4
    
5.
Dua R, Sharma S. Prevalence, causes, and correlates of traumatic dental injuries among seven-to-twelve-year-old school children in Dera Bassi. Contemp Clin Dent 2012;3:38-41.  Back to cited text no. 5
[PUBMED]  [Full text]  
6.
Diab M, elBadrawy HE. Intrusion injuries of primary incisors. Part I: Review and management. Quintessence Int 2000;31:327-34.  Back to cited text no. 6
    
7.
Aldrigui JM, Abanto J, Carvalho TS, Mendes FM, Wanderley MT, Bönecker M, et al. Impact of traumatic dental injuries and malocclusions on quality of life of young children. Health Qual Life Outcomes 2011;9:78.  Back to cited text no. 7
    
8.
Rodd H, Noble F. Psychosocial impacts relating to dental injuries in childhood: The bigger picture. Dent J (Basel) 2019;7:23.  Back to cited text no. 8
    
9.
Slayton RL, Palmer EA. Prevention of traumatic dental injuries. In: Traumatic Dental Injuries in Children. Cham: Springer; 2020. p. 167-78.  Back to cited text no. 9
    
10.
Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth. Wiley-Blackwell: John Wiley & Sons; 2018.  Back to cited text no. 10
    
11.
Bhayya DP, Shyagali TR. Traumatic injuries in the primary teeth of 4- to 6-year-old school children in Gulbarga city, India. A prevalence study. Oral Health Dent Manag 2013;12:17-23.  Back to cited text no. 11
    
12.
Blokland A, Watt RG, Tsakos G, Heilmann A. Traumatic dental injuries and socioeconomic position – Findings from the children's dental health survey 2013. Community Dent Oral Epidemiol 2016;44:586-91.  Back to cited text no. 12
    
13.
Dean JA, Avery DR, McDonald RE, editors. McDonald and Avery's Dentistry for the Child and Adolescent. 10th ed. Mosby: Elsevier, Inc; 2016.  Back to cited text no. 13
    
14.
Sharma R, Mallaiah P, Kadalur U, Verma S. Knowledge and attitude of school teachers with regard to emergency management of dental trauma in Bangalore city. Int J Oral Health Med Res 2016;3:38-43.  Back to cited text no. 14
    
15.
Young C, Wong KY, Cheung LK. Emergency management of dental trauma: Knowledge of Hong Kong primary and secondary school teachers. Hong Kong Med J 2012;18:362-70.  Back to cited text no. 15
    
16.
Krishnan B, Joseph J. Knowledge of basic dental physiology among teachers can improve preliminary management of acute dental avulsion in school children. Int J Clin Exp Physiol 2014;1:63-7.  Back to cited text no. 16
  [Full text]  
17.
Al-Asfour A, Andersson L, Al-Jame Q. School teachers' knowledge of tooth avulsion and dental first aid before and after receiving information about avulsed teeth and replantation. Dent Traumatol 2008;24:43-9.  Back to cited text no. 17
    
18.
Al-Jundi SH, Al-Waeili H, Khairalah K. Knowledge and attitude of Jordanian school health teachers with regards to emergency management of dental trauma. Dent Traumatol 2005;21:183-7.  Back to cited text no. 18
    
19.
Caglar E, Ferreira LP, Kargul B. Dental trauma management knowledge among a group of teachers in two south European cities. Dent Traumatol 2005;21:258-62.  Back to cited text no. 19
    
20.
Chandukutty D, Peedikayil FC, Premkumar CT, Narasimhan D, Jose D. Awareness of dental trauma management among school teachers of Kannur, Kerala, India. J Clin Diagn Res 2017;11:C08-12.  Back to cited text no. 20
    
21.
Prathyusha P, Harshini T, Haripriya B, Pramod IJ, Swathi K, Samyuktha CL. Knowledge and awareness regarding avulsion and its immediate treatment in school teachers in Bangalore city (South). J Int Oral Health 2015;7:93-7.  Back to cited text no. 21
    
22.
Sae-Lim V, Lim LP. Dental trauma management awareness of Singapore pre-school teachers. Dent Traumatol 2001;17:71-6.  Back to cited text no. 22
    
23.
Karame M, Moradi M, Shafiee F. Evaluating the knowledge of elementary school health teachers of Sanandaj about traumatic dental injuries in year 2017-2018. J Dent Med 2019;31:239-48.  Back to cited text no. 23
    
24.
Mehrabkhani M, Ajami B, Parisay I, Bolboli A, Akbarian G. Knowledge of emergency management of traumatized teeth among schoolteachers in Mashhad, Iran. J Dent Res Dent Clin Dent Prospects 2015;9:121-5.  Back to cited text no. 24
    
25.
Mesgarzadeh AH, Shahamfar M, Hefzollesan A. Evaluating knowledge and attitudes of elementary school teachers on emergency management of traumatic dental injuries: A study in an Iranian urban area. Oral Health Prev Dent 2009;7:297-308.  Back to cited text no. 25
    
26.
Rouhani A, Movahhed T, Mohiti Y, Banihashemi E, Akbari M. Knowledge and attitude of primary school staff to management of dental trauma in North-East of Iran in 2015. J Dent Mater Tech 2017;6:67-72.  Back to cited text no. 26
    
27.
Chan AW, Wong TK, Cheung GS. Lay knowledge of physical education teachers about the emergency management of dental trauma in Hong Kong. Dent Traumatol 2001;17:77-85.  Back to cited text no. 27
    
28.
Farzandipour M, Mohamadian H, Akbari H, Safari S, Sharif R. Designing a national model for assessment of nursing informatics competency. BMC Med Inform Decis Mak 2021;21:35.  Back to cited text no. 28
    
29.
Nirwan M, Syed AA, Chaturvedi S, Goenka P, Sharma S. Awareness in primary school teachers regarding traumatic dental injuries in children and their emergency management: A survey in South Jaipur. Int J Clin Pediatr Dent 2016;9:62-6.  Back to cited text no. 29
    
30.
Pithon MM, dos Santos RL, Magalhães PH, Coqueiro Rda S. Brazilian primary school teachers' knowledge about immediate management of dental trauma. Dental Press J Orthod 2014;19:110-5.  Back to cited text no. 30
    
31.
Fux-Noy A, Sarnat H, Amir E. Knowledge of elementary school teachers in Tel-Aviv, Israel, regarding emergency care of dental injuries. Dent Traumatol 2011;27:252-6.  Back to cited text no. 31
    
32.
Blakytny C, Surbuts C, Thomas A, Hunter ML. Avulsed permanent incisors: Knowledge and attitudes of primary school teachers with regard to emergency management. Int J Paediatr Dent 2001;11:327-32.  Back to cited text no. 32
    
33.
McIntyre JD, Lee JY, Trope M, Vann WF Jr. Elementary school staff knowledge about dental injuries. Dent Traumatol 2008;24:289-98.  Back to cited text no. 33
    
34.
Tiryakioglu F, Erzurum F. Use of social networks as an education tool. Contemp Educ Technol 2011;2:135-50.  Back to cited text no. 34
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
Abstract
Introduction
Methods
Results
Discussion
Conclusions
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed2552    
    Printed242    
    Emailed0    
    PDF Downloaded206    
    Comments [Add]    

Recommend this journal