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Revista Facultad de Odontología Universidad de Antioquia

Print version ISSN 0121-246X

Rev Fac Odontol Univ Antioq vol.29 no.1 Medellín July/Dec. 2017 

Original article












1 DDM. Specialist in Pediatric Dentistry and Community Health. Specialist in Methodology of Research in Health Sciences. School of Dentistry. Universidad del Pacífico Privada, Paraguay.

2 DDM. Specialist in Methodology of Research in Health Sciences. School of Dentistry. Universidad del Pacífico Privada, Paraguay.

3 DDM. MA in Statistics. MA in Research Methodology for Health Sciences. School of Dentistry. Universidad del Pacífico Privada, Paraguay.

4 DDM. Specialist in Cosmetic Dentistry. School of Dentistry. Universidad del Pacífico Privada, Paraguay.

5 DDM. MA in Public Health. School of Dentistry. Universidad del Pacífico Privada, Paraguay.

6 Student. School of Dentistry. Universidad del Pacífico Privada, Paraguay.



oral health in patients with disabilities represents a great challenge in dentistry, as motor, sensory, cognitive, behavioral, and emotional limitations influence oral hygiene, leading to the development of certain diseases in this population. The aim of the present study was to analyze the oral health conditions of school children with disabilities aged 12 to 18 years attending Centro de Educación Especial San Miguel, in the city of Guarambaré, in 2013.


this was a descriptive cross-sectional study. A survey was applied to 20 schoolchildren who met the inclusion criteria. Oral health was assessed using the DMFT index, as well as the dental plaque, tartar, gingival indices and occlusal anomalies.


the DMFT index was 5.5 (SD = 4.38), dental plaque index was 1.15, tartar was 0.53 and gingival index was 0.68. There was malocclusion in 50% of cases, of which 35% were class II and 15% class III.


the school children participating in this study do not enjoy good health conditions because of the high rate of tooth decay, high percentages of dental plaque, and a large percentage of preventive and restorative needs.

Key words: health of persons with disabilities; oral hygiene; oral health; public health



la salud bucal en pacientes con discapacidad representa un gran desafío en la odontología, pues las limitaciones motoras, sensoriales, cognitivas, conductuales y emocionales inciden en la higiene oral, lo cual lleva al desarrollo de ciertas enfermedades en esta población. El objetivo del presente estudio consistió en analizar el estado de salud bucal de escolares de 12 a 18 años con discapacidad, que asistieron al Centro de Educación Especial San Miguel, de la ciudad de Guarambaré, en el año 2013.


estudio descriptivo de corte transversal. Se realizó un censo en el que participaron 20 escolares que cumplían con los criterios de inclusión. La salud bucal se evaluó mediante los índices CPO-D, placa dental, sarro, gingival y anomalías de oclusión.


el índice CPO-D fue de 5,5 (DE = 4,38), el índice de placa dental fue de 1,15, el de sarro fue de 0,53 y el gingival de 0,68. Se presentó maloclusión en el 50%, de los cuales 35% correspondieron a la clase II y el 15% a la clase III.


no existen condiciones aceptables de salud bucal en los escolares de este estudio debido al elevado índice de caries, a los altos porcentajes de placa dental, y a un gran porcentaje de necesidades preventivas y restauradoras.

Palabras clave: salud de la persona con discapacidad; higiene bucal; salud bucal; salud pública


Persons with disabilities are described as those with any motor, sensory, cognitive, behavioral or emotional limitation, requiring assistance and specialized health programs. Disabilities include, but are not limited to, learning difficulties, autism, Down Syndrome (DS), short-sightedness, intellectual disabilities or mental retardation (MR), selective mutism, and motor dysfunction.(1)

According to the World Health Organization (WHO), more than 1 billion people in the world live with some sort of disability, and according to various studies the poverty rates of these people are higher than those of individuals with no disabilities, and therefore they are less likely to access health care services in comparison with others.(2) According to the WHO and the United Nations, 10% of people in Paraguay have a disability, with limited opportunities to adequately access health services to improve their standards of living.(3)

Due to the problems posed by these limitations, persons with disabilities require more care and specialized treatment, since many depend on others to achieve and maintain good health in general and oral health in particular,(4)which is defined as the absence of diseases and disorders affecting the elements of the oral cavity.(5)

Oral health in these patients represents a major challenge for dentists because the aforementioned limitations prevent proper oral hygiene, leading to the development of certain diseases that are prevalent in this population, such as tooth decay and periodontal disease.(6)

Several factors contribute to poor oral health in patients with disabilities, including oral conditions, physical limitations that make brushing difficult, reduced saliva flow, medications, and restricted or precarious diets.(4)

One of the main disabilities is Down syndrome (DS) or trisomy 21, a chromosomal disorder that affects males more frequently, causing disorders that can range from mild to severe; in addition, mental and physical development in these patients tends to be slower.(7) The orofacial alterations in this syndrome promote the development of respiratory infections and dryness of mucous membranes, and therefore the tonsils and adenoids tend to increase in size. The lower lips are hypotonic, the hard palate tends to be arched and high, and the presence of mandibular subluxation is common, usually associated with hypotonia of the temporomandibdular joint ligaments. The mandible is usually protruded with a tendency to Angle Class III.(8) Certain tooth anomalies can be seen, such as delayed eruption (both in primary and permanent dentition), agenesis, anomalies in position and occlusion, anomalies in structure, form and size of teeth, as well as a decrease in saliva flow and poor articulation of language.(9)

Another common disability is autism, affecting the individuals’ social and affective relationships and their communication capabilities; it is congenital in most cases, and is not considered a disease.(10) The way autism expresses itself varies greatly from one individual to another, but there are certain symptoms common to all, such as atypical development of social and language skills and limited and repetitive behaviors.(11)

Mental retardation (MR) is a disorder that typically starts between birth and the age of 18 years, more frequently in males. Its main features include below-average intellectual functioning and a lack of skills needed for everyday life. In general, individuals who suffer from MR do not possess sufficient motor or linguistic abilities, and show deficiencies in communication, self-care and social adaptations.(12) The risk factors of these limitations include infections, chromosomal, environmental, and genetic anomalies, and metabolic, nutritional, toxic and traumatic (prenatal and postnatal) disorders. The signs and symptoms of MR are: continuous infantile behavior, decreased learning abilities, inability to comply with the guidelines of intellectual development, inability to meet the educational needs at school, and lack of curiosity.(13) Dental care for these patients is therefore complex, since they usually have poor oral hygiene, which may cause deterioration of the oral cavity tissues. According to some studies, the most common disorders in these patients are dental caries, teeth loss, and periodontal disease.(14)

Short-sightedness refers to a reduction in central visual acuity or loss of visual field, which results in low vision, even with the best optical correction provided by conventional lenses.(15) Short-sighted children perceive things differently compared to other children since they have visual-motor coordination difficulties and problems to recognize the objects surrounding them or to distinguish the concepts of right and left. All this hinders their learning, not only in terms of literacy but also in personal hygiene and oral hygiene.(16)

Learning disabilities (LD) is one of the neurological alterations increasingly occurring in our society because of the diversity of distractions, such as technology, parents’ separation, children’s lack of attention, loss of close relatives, inadequate teaching, and bullying, just to name a few reasons, that distract and create continuous stress in children at the time of learning. These difficulties can be classified as primary and secondary. Primary learning disabilities include cognitive disorders such as dyslexia, dyspraxia, dysphasia, dysgraphia, and dyscalculia. Secondary disabilities include learning difficulties due to a known factor that distracts children when they are studying, but they can learn normally once the factor disappears.(17)

Deafness or hearing loss is a decrease in hearing acuity or the inability of the ear to capture sounds. Patients who suffer from it not only have problems hearing but also talking. The causes of hearing loss can be either congenital, which serious neurotic and emotional disorders that cause deep insulation, or acquired, causing hearing loss during the first years of life; if it is not treated early, patients will have big difficulties to develop language and speech, which in turn will cause emotional and social problems and will have a severe impact on their education.(18)

Selective mutism (SM) is a psychological condition with clinical manifestations such as remaining silent or avoiding speaking in situations in which children are normally expected to speak, even though they can do it otherwise, which may hinder communication with dental professionals while teaching hygiene techniques.(19)

For these reasons, patients with disabilities can suffer from or acquire oral diseases due to the various factors that affect their health in general. These conditions do not change the protocol dentists follow to treat oral diseases, but these patients do need comprehensive care including the training of parents, teachers and relatives, as well as therapy sessions to improve their manual skills.

Some schools in Paraguay respond to the needs of integrating this population to the education system, with special programs and learning methods adapted to their disabilities. One of these is Centro de Educación Especial San Miguel, located in the city of Guarambaré. It began operations after the creation of a special class in 1991 in a property of the municipality and under the administration of Educational Center No. 91, Medalla Milagrosa. This center operates in its own property since the year 2000 and has 6 teachers, 2 psychologists, 1 physiotherapist, 1 sign language auxiliary, 2 physical education teachers, and 93 schoolchildren with autism, hearing impairment, DS, MR, and cerebral palsy.

The aim of this study was to determine the oral health condition of children with disabilities aged 12 to 18 years attending the Centro de Educación Especial San Miguel of the city of Guarambaré in 2013.

The information provided in this study can help guide the development of intervention plans in oral health to improve the current situation and to promote the inclusion of preventive habits, so that the multiple disadvantages of disabilities do not add up to the pain and costs of oral pathologies.


A descriptive, cross-sectional study was conducted to evaluate the oral health status of 20 schoolchildren with disabilities aged 12 to 18 years attending the Centro de Educación Especial San Miguel of the city of Guarambaré in 2013.

The study included a survey that was applied to all students, prior authorization of parents or guardians. All participants agreed to be examined and were present on the days of data collection.

This study was approved by the Ethics and Research Committee of Universidad del Pacífico Privada. To access the study population, authorization was obtained from the directors of Centro de Educación Especial San Miguel. A list of participants was compiled once all the consents were signed and each participant was called for an assessment session.

Some instruments were designed to register the health status of participants. The clinical record included four sections: one section was used to register the participants’ sociodemographic data; another section included an odontogram to enter dental data; a third section was used for assessing soft tissues and other supporting tissues, and the last section was used for data referring to occlusion. To fill out the forms, the researchers held a meeting with the parents in one of the classrooms of the institution, where they explained the objectives and scope of the research project, emphasizing on the anonymity of data. The parents who agreed to participate and signed an authorization form were given a questionnaire and all questions were clarified.

The clinical examination was conducted at the school, in a classroom with natural and artificial light for the clinical evaluation of participants. Each child was examined by a calibrated dentist and a dental student in charge of registering the data. Each child was evaluated in supine position on a table for oral examination or, in some cases, on the individuals’ wheel chairs. A Hu-Friedy© periodontal probe and a flat oral mirror #5 were used for the examination.

The schoolchildren who were waiting for the evaluation were accompanied by a student in another room, where brushing techniques were taught using macro-models and macro-brushes to optimize the teaching, making the explanations about the importance of oral hygiene more effective.

The obtained data were entered in a 2007 Microsoft Office Excel© electronic worksheet. Descriptive statistics were used for data analysis. Measures of central tendency and dispersion were used for the quantitative variables; distribution of frequencies was used for the qualitative variables, and the results were registered in tables.


The Centro de Educación Especial San Miguel accepts students with learning disabilities or other differences that prevent their inclusion in mainstream schools. It is a public institution, certified by the Ministerio de Educación y Cultura (MEC) since the year 2000. The students are provided with psychological and physiotherapeutic care, and a sign language auxiliary is available to them. They attend the school four hours a day and are given a school meal.

This study evaluated the oral health status of 20 schoolchildren aged 12 to 18 years (median = 15 years) attending the Centro de Educación Especial San Miguel, in the city of Guarambaré. Half of the population were females, 45% had learning difficulties, and all came from urban environments. Fifty percent of participants were enrolled in the functional program, and the rest were distributed among levels 1, 2 and 3. Seventy-five percent of mothers had primary education only (Table 1).

Table 1 Socio-demographic characteristics of schoolchildren with disabilities. Centro de Educación Especial San Miguel of the city of Guarambaré. Paraguay, 2013 

Demographic characteristics N %
12 to 15 years 11 55
16 to 18 years 9 45
Female 10 50
Male 10 50
Level of education of schoolchildren with disabilities
Level 1 1 5
Level 2 3 15
Level 3 6 30
Functional Program 10 50
Education level of mothers (n = 16)
Primary 12 75
Secondary 4 25
Clinical condition
Mental retardation 8 40
Learning disability 9 45
Selective mutism 1 5
Cerebral palsy 1 5
Down syndrome 1 5

Regarding the DMFT index, the male students with learning disability aged 16 to 18 years had the highest rates of decayed, missing or filled teeth (Table 2).

DMFT index according to socio-demographic and clinical variables. Centro de Educación Especial San Miguel of the city of Guarambaré. Paraguay, 2013 

Demographic characteristics DMFT
X σ
12 to 15 years 4.9 4.5
16 to 18 years 6.4 5.7
Female 5.0 4.5
Male 6.0 5.4
Mental retardation 4.4 3.7
Learning disability 6.7 6.4

This population has a high prevalence of mild gingivitis, most frequently in male schoolchildren with mental retardation aged 12 to 15 years. The presence of gingival overgrowth and hypotonic lip was mostly observed in males and in patients with mental retardation. Three male adolescents with mental retardation had hypotonic lip, while 5 adolescents had gingival overgrowth (Table 3).

Table 3 Diseases of the soft tissues according to demographic and clinical variables. Centro de Educación Especial San Miguel of the city of Guarambaré. Paraguay, 2013 

Demographic characteristics Gingivitis
Healthy Mild Moderate Severe
N % N % N % N %
12 to 15 years 4 36 6 55 0 0 1 9
16 to 18 years 2 22 4 45 2 22 1 11
Female 4 40 4 40 1 10 1 10
Male 2 20 6 60 1 10 1 10
Mental retardation 2 20 6 60 1 10 1 10
Learning disability 4 40 4 40 1 10 1 10

Regarding molar class, the schoolchildren with the highest prevalence of class I were the females aged 12 to 15 years with learning disabilities, while males aged 16 to 18 with mental retardation were the ones with the highest prevalence of class II. In terms of posterior bite, most kids showed normal posterior bite, except for those aged 16 to 18 years, who had unilateral crossbite by 55%. Regarding overbite and overjet, all showed a high prevalence of normality, except for those aged 16 to 18, who, with respect to overjet, had a higher prevalence of edge-to-edge ratio, and those with mental retardation, who showed increased overjet. The schoolchildren with the highest prevalence of crowding were the males aged 12 to 15 and those with learning difficulties (Table 4).

Table 4 Occlusal anomalies according to demographic and clinical variables. Centro de Educación Especial San Miguel of the city of Guarambaré. Paraguay, 2013 

Occlusal anomalies Age (years) Sex Clinical condition
12-15 16-18 Female Male MR LD
N % N % N % N % N % N %
Molar class
Class I 5 55 1 11 5 50 1 10 2 20 4 40
Class II 3 45 4 44 2 20 5 50 4 40 3 30
Class III 1 9 2 22 1 10 2 20 1 10 2 20
Posterior bite
Normal 7 63 3 33 6 60 5 50 5 50 6 60
Unilateral crossbite 1 9 5 55 4 40 2 20 4 40 2 20
Bilateral crossbite 2 18 1 11 0 0 3 30 1 10 2 20
Normal 6 54 5 55 6 60 5 50 4 40 7 70
Open 1 9 1 11 0 0 2 20 2 20 0 0
Edge-to-edge 3 45 2 22 3 30 2 20 2 20 3 30
Deep 0 0 1 11 1 10 0 1 10 0 0
Covered 1 9 0 0 0 0 1 10 1 10 0 0
Normal 7 63 2 22 5 50 4 40 2 20 7 70
Edge-to-edge 2 18 3 33 4 40 1 10 2 20 3 30
Inverted 0 0 2 22 0 0 2 20 2 20 0 0
Increased 2 18 2 22 1 10 3 30 4 40 0 0
Crowding 4 36 3 33 3 30 4 40 3 30 4 40

* MR = Mental retardation, LD = Learning disabilities

The DMFT index was 5.5, which is considered not compatible with health, while the PMA index was 0.53, considered compatible with health.


The present study found a DMFT index of 5.5, differing from the findings by Calderón(18) in 66 children with congenital hearing impairment and by Giménez et al(19) in 103 kids with cerebral palsy aged 5 to 20 years, who showed considerably higher rates, of 6.23 and 6.7 respectively. Serrano et al,(20) however, found substantially lower rates in 51 children with intellectual disabilities whose DMFT index was 0.70.

On the other hand, dental caries was observed in 80% of the schoolchildren, differing from the reports by Dávila et al(21) and León,(22) who found lower values of decayed teeth. As for lost and filled teeth, these values were 25% and 20% respectively, contrasting with León,(22) who reported lower percentages of missing and filled teeth in 50 children with hearing impairments.

Seventy percent of the subjects in this study showed dental plaque, with grade 1 (mild) being the most frequent, with a 35%. The average value was 1.15, while other authors report higher rates, such as Córdoba et al,(23) who observed an average of 1.4 in 33 people with mild intellectual disabilities, and Mogollón et al,(24) who with the same scale reported a plaque rate of 2.6 in 35 schoolchildren.

Similarly, regarding gingivitis, grade 1 was the one with the highest frequency, agreeing with the study by Garcés et al(25) in 195 children and adolescents with intellectual disabilities, but differing with these authors in that only 2.6% of their participants showed 0 gingivitis, in contrast to 30% of the kids in the present study who had 0 gingivitis. Motta(26) also reported a mild gingival index in 88 students with intellectual disabilities, with an average of 0.43, which is slightly lower in comparison to the average of the present study, with 0.68.

Thirty-five percent of the students in the present study had crowding, while Caballero et al(27) reported a prevalence relatively higher (42%) in 24 children aged 7 to 18 years with different disabilities.

Regarding malocclusions in the studied population, 35% showed Angle class II malocclusion, followed by 30% of Angle class I malocclusion, differing to the report by Mogollón et al,(24) who found a high prevalence of Angle class III malocclusion in children with Down syndrome.


The oral health status of schoolchildren from the Centro de Educación Especial San Miguel is poor. The quality of oral hygiene is poor or bad, since more than half of the population showed plaque, tartar, and gingivitis. In addition, a large percentage of the studied population had a high index of active caries but few filled teeth, suggesting a higher incidence of decayed and lost teeth. The conclusion is then that there is a need to educate parents, teachers, and schoolchildren and to carry out preventive and restorative treatments in this population, in order to reduce the prevalent diseases and associated risk factors.


1. Organización Mundial de la Salud. Salud bucodental. Nota Informativa No. 318, abril de 2012 [Internet]. Disponible en: ]

2. Martínez-Menchaca HR, Treviño-Alanís MG, Rivera- Silva G. Guía para el cuidado de la salud oral en pacientes con necesidad de cuidados especiales de salud en México. Rev ADM. 2011; 68(5): 222-228. [ Links ]

3. Arias S, Muñoz L, Romero C, Espeso N. Propuesta de comunicación en salud bucal para niños con retraso mental ligero, padres y educadores. Arch Med Camagüey. 2005; 9(6); 44-45. [ Links ]

4. University of California. California Childcare Health Program. Notas sobre salud y seguridad California Childcare Health Program: salud bucal para niños con discapacidades y necesidades especiales. Berkeley: California Childcare Health Program; 2007. [ Links ]

5. World Health Organization. Discapacidad y rehabilitación: informe mundial sobre la discapacidad [Internet]. Malta: WHO; 2011. Disponible en: ]

6. Khan R, Abdallah AI, Virginia-Antony V. Síndrome de Down: reporte de un caso [Internet]. The OrthonticCyberjournal. 2009; Enero; Disponible en: ]

7. Marulanda J, Betancur JD, Espinosa S, Gómez JL, Tapias A. Salud oral en discapacitados. Rev CES Odont. 2011; 24(1): 71-76. [ Links ]

8. Republica del Paraguay. Ministerio de salud pública y bienestar social. Resolución S.G. No. 352, Por la cual se incorporan las normas paraguayas en aplicación, dictadas por el instituto nacional de tecnologia, normalización y metrología, sobre “accesibilidad de las personas al medio físico”, para el acceso y la utilización de los espacios y edifícios de los servicios del Ministeriode Salud Pública y Bienestar Social. (May 11 2011). Disponible en: ]

9. Urdiales J, Galindo F, Torres C, Avilés S. Síndrome de Down: caso clínico. Odontol Actual. 2008; 5(57): 22-28. [ Links ]

10. Horruitiner L. Manejo del paciente autista en el consultorio odontológico. Odontol Pediatr. 2008; 7(2): 34-35. [ Links ]

11. Gómez B, Badillo V, Martínez E, Planells P. Intervención odontológica actual en niños con autismo. La desensibilización sistemática. Cient Dent. 2009; 6(3): 207- 215. [ Links ]

12. Vasconcelos MM. Retardo mental. J Pediatr (Rio J). 2004; 80(2 Supl): S71-S82. [ Links ]

13. MedlinePlus. Discapacidad intelectual [Internet]. Disponible en: ]

14. Córdoba D, España S, Tapia G. Conocimientos y actitud de los odontólogos en la atención de personas con discapacidad intelectual. Rev Univ Salud. 2012; 14(1): 78- 86. [ Links ]

15. Osorio L, Hitchman D, Pérez J, Padilla C. Prevalencia de baja visión y ceguera en un área de salud. Rev Cubana Med Gen Integr. 2003; 19(5). [ Links ]

16. Ortega L. Dificultades de aprendizaje [Internet]. Innovación y Experiencias Educativas. 2008; (12): Disponible en: ]

17. Rebollo MA, Rodríguez S. El aprendizaje y sus dificultades. Rev Neurol. 2006; 42(Suppl 2): S139-S142 [ Links ]

18. Madrigal G, Martínez B, Teja E, Canto D. Manejo estomatológico del niño sordo o con hipoacusia. Rev Mex Odon Clin. 2006; 1(8): 26-32. [ Links ]

19. Calderón-Cortez I. Experiencia de caries dental e higiene oral en niños con deficiencias auditivas congénitas [Trabajo de grado Cirujano Dentista]. Lima: Universidad Nacional Mayor de San Marcos; 2009. [ Links ]

20. Giménez-Prat MJ, López-Jiménez J, Boj-Quesada JR. Estudio epidemiológico de la caries en un grupo de niños con parálisis cerebral. Med Oral. 2003;8:45-50. [ Links ]

21. Serrano M, Torrelles A, Simancas YC. Estado de salud bucodental en niños con discapacidad intelectual. Acta Odontológica Venezolana. 2012; 50(3). [ Links ]

22. Dávila ME, Gil M, Daza D, Bullones X, Ugel E. Caries dental en personas con retraso mental y síndrome de Down. Rev Salud Pública. 2006; 8(3): 207-213. [ Links ]

23. León N. Experiencia de caries dental en niños con deficiencias auditivas en dos escuelas del área metropolitana de Caracas, Venezuela. 2001. Acta Odontológica Venezolana. 2003; 41(1). [ Links ]

24. Córdoba D, Portilla M, Arteaga G. Dinámica familiar interna e higiene bucal en personas con discapacidad intelectual leve. Revista Hacia la Promoción de la Salud. 2010; 15(2): 81-93. [ Links ]

25. Mogollón-Pocaterra J, Navas-Perozo R, Rojas-Morales T, Álvarez CJ. Condiciones de salud-enfermedad bucal de niños y adolescentes con síndrome de Down. Salud bucal en niños con síndrome de Down. Rev Cuba Estomatol. 2008; 45(1). [ Links ]

26. Garcés C, Barrera M, Ortiz M, Rosas C. Estado de Salud Oral de niños y adolescentes con discapacidad intelectual en una población chilena, 2012. J Oral Res. 2013; 2(2): 59-63. DOI:10.17126/joralres.2013.013 [ Links ]

27. Motta-Candela AP. Higiene bucal y gingivitis en alumnos con discapacidades intelectuales del Colegio Especial “Santa Teresa De Courdec” mayo-junio 2011 [Trabajo de grado Cirujano dentista]. Lima: Universidad de San Martín de Porres; 2011. [ Links ]

28. Caballero Y, Vega K, Ávila Y, Pérez M, Santiesteban I, Lora C. Salud bucal en niños discapacitados. Revista Electrónica de Portales Médicos. 2009; 4(6): 111. [ Links ]

Pérez-Bejarano NM, Ferreira-Gaona MI, Díaz-Reissner CV, Sanabria-Vázquez DA, Torres-Amarilla CD, Acosta-Parra EB et al. Oral health in adolescents with disabilities from Centro de Educación Especial San Miguel, Guarambaré, Paraguay. Rev Fac Odontol Univ Antioq. 2017; 29(1): 51-64. DOI:

CONFLICT OF INTEREST The authors declare not having any conflicts of interest.

Received: June 07, 2016; Accepted: July 17, 2017

*CORRESPONDING AUTHOR Clarisse V. Díaz Reissner, MSc. Facultad de Odontología. Universidad del Pacífico Privada O’Higgins esquina Austria Asunción, Paraguay

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