Evaluation of dentistry students' knowledge on hematologic disorders

Objective To determine the knowledge level of undergraduate dentistry students of UESB on hematological disorders and their implications in the treatment of the patient. Methods This is a descriptive, quantitative and cross-sectional study in which a questionnaire with 16 questions was used as a data collection instrument. The study subjects were 192 students enrolled at UESB Dentistry Course. For data analysis, SPSS statistical software (version 16.0) was used. Results The response rate was 87.5%. Only 54.2% of respondents reported having information about blood disorders and 78% considered themselves not enough informed, fact observed through the low percentage of right answers in a knowledge test. Conclusion The level of knowledge of UESB Dentistry academics on hematological disorders is insufficient and there isn't a gradual increment of this knowledge throughout the semesters, polarized mainly in the 6th and 10th semester. Indexing terms: Anemia, sickle cell. Hemophilia A. Hemophilia B. Knowledge. Leukemia. Students dental.


INTRODUCTION
Hemopathies or hematological disfunctions are constituted of a group of diseases related to blood that can present a number of different etiologies and clinical features.They may be classified as anemia, coagulopathies, and malignant blood diseases 1 .
Some of these disfunctions present buccal and/ or maxillofacial manifestations that are directly related to the surgeon-dentist working field.Given the prevalence within each group, sickle cell anemia, hemophilia and leukemia are prominent.
Sickle cell anemia is one of the most common hereditary pathologies in Brazil.It is estimated that about 3,550 children are born per year with falciform disease and 200,000 trace bearers.Such scenario calls for this pathology to be treated as a public health issue 2 .
Leukemia is the most common malignant disease in infancy, corresponding approximately to 30% of cancer cases in children.In Brazil, the estimate for 2016 is 10,070 new cases 3 .
According to the Brazilian Federation of Hemophilia, Brazil is the third largest population worldwide of patients with hereditary genetic disorders with 9,122 cases of Hemophilia A; 1,801 cases of Hemophilia B; 5,445 cases of Von Willebrand and 1,851 of other hereditary hemorrhagic coagulopathies.Hemophilia incidence is one case for each 5.000 males born alive 4 .
Given what was stated above, it must be highlighted that in addition to such pathologies, typical buccal manifestations, dental procedures are able to exude blood, a number of medications must be administered with restriction in such patients.Thus, it is fundamentally important knowledge diffusion with regards to hematologic disfunctions even in the undergraduate level, since these patients must receive special attention in accordance with their health status.Moreover, the current literature doesn't offer studies similar to the current study, which keeps knowledge from teaching reality with regards to this theme.
The objective of this paper was to verify the knowledge level of Dentistry students at the Southwest Bahia State University (UESB) with regards to the approach of hematological disfunctions and its interference in Dentistry and to identify the mode of operating of information diffusion.

METHODS
A transversal quantitative descriptive research was performed.The study sample was the student body of the Course of Dentistry at UESB with 192 students regularly enrolled in the period of 2013.2 and disposed in 10 semesters that integrate the course.
The data collection instrument was a questionary divided in three blocks.Block I: containing three questions regarding identification (age, gender and attending semester).Block II: containing ten questions regarding knowledge of hematological disfunctions and their interference in Dentistry, and how information was obtained.Block III: containing one question regarding transmission of information by the professor of the course, whether there is or not.If the answer is affirmative, which transmission form was employed?
Data collection was carried out during September and October 2013.It was initiated only after the research project approval by the Ethics in Research Committee of UESB (protocol 365.284,CAAE: 19707913.8.0000.0055).The research subjects were approached in the class room.Prior to answering the questionary, objectives and procedures of the study were explained, and the Free and Clarified Consent Term (TCLE) was signed.
Descriptive statistics (relative and absolute frequency) was employed in the data analysis.Data were analyzed with statistic software: Statistical Package for the Social Sciences -SPSS (version 16.0).

RESULTS
Among the 192 regularly enrolled academics, 168 accepted to participate in this research, that represents a response rate of 87.5%.In the group that joined the research, 65.5% were females and 61.3% were in the agegroup from 21 to 25 years.
When asked if they were aware of implications of hematologic disorders in Dentistry, 54.1% (n=91) of academics asserted that they were partially informed.On the other hand, 45.8% informed that they had not obtain this information yet; 70% (n=54) pointed out as a motive the lack of opportunity; 0.7% (n=1) were not interested in the subject and 29% (n=22) other reasons.Most students that indicated 'other' as to the reason of their unfamiliarity believe that the content will be approached in the next semesters.Among those who had some information, the majority (78%) considered themselves insufficiently informed about the theme; 22% sufficiently informed and none were fully informed, as shown in Figure 1.
When questioned about the exams that must be prescribed in order to evaluate the patient condition with abnormal bleeding after any cut or surgery, 31.5% of the academics marked the correct option.
Dentistry; 66% appointed that during classes they were told about the possibility of complications caused by these dysfunctions; 8% asserted that they comment about hematologic dysfunction.They also own/suggest didactic material which informs odontological complications, as well as attending protocol for patients presenting hematologic alterations and 18% marked a combination of these options.
Within the academics group who marked negatively, 12% believe that the subject is distant from graduation reality; 63% believe that the information is intended to a specific discipline; 2% think that the information is disposable, given that these informations are dispensable due to its low practical utility; and 23% marked other reasons.Among the latter, some believe that this content will be approached in posterior semesters and others pointed the need to adapt the course curricular adequateness, so that this theme be adapted in order to the theme be contemplated.

DISCUSSION
Sickle cell anemia is a hereditary chronic hemolytic disease 5 caused by a punctual mutation of chromosome 11.As a result, the substitution of glutamic acid by valine in the position 6 of the β hemoglobin chain originates hemoglobin S 6 .This structural alteration is accountable for the modification in stability, solubility and erythrocyte structure.The latter, in hypoxia conditions, assume a form similar to a sickle.Thereof, the word sickle derived from polymerization of hemoglobin S 7- 8 .Corroborating with such information, 44% of the students answered correctly the question that referred to Sickle Cell Anemia etiology.
In relation to Sickle Cell Anemia oral manifestations, the success rate was even smaller.Only 30.4% of the research subjects agreed with the alternative in which the main signs of the disease are mucosa paleness, yellow coloration of tissues, radiographic alterations, delay of teeth eruption, and enamel and dentine disorder, malocclusion, hyper-cementosis and a degree of periodontitis uncommon in children [9][10] .
In some cases, the pulp chamber shows calcifications similar to denticles that might be the result of blood vessel thrombosis that irrigate the affected area.The most common oral complications are due to the development of sickle cells with ischemia of the bone marrow and adjacent bone structures.Among them, there are osteomyelitis, nerve neuropathies of the mandibular and mentonian nerves, asymptomatic pulp necrosis and orofacial pain 2 .When asked if the professors have the habit to inform hematologic dysfunctions and their implication in Dentistry, 35.1% said no, 48.2% indicated yes, only in the specific area of the discipline content and 16.7% marked yes in a general manner in their commitment in procedures of several specialties.
According to the graduands who marked positively, 8% indicated that the professors stimulate article readings about hematologic dysfunction and its implication in Graduate students' knowledge on hematologic disorders Hemophilia is a congenital hereditary disease.Hemophilia A or classic is the result of deficiency of coagulation factor VIII, while hemophilia B is caused by a qualitative or quantitative alteration of the coagulation factor IX.Both present themselves with higher prevalence in the male gender.Their bearers suffer hemorrhages that are difficult to control and they can occur spontaneously as well as through small traumatisms 1,[11][12] .Although only 27.4% marked this alternative which contained the information, a slightly higher number knew Hemophilia oral manifestations.
Some Hemophilia oral manifestations are: petechiae and ecchymosis localized on the mucosa surface; prolonged gingival bleeding, spontaneous or provoked by traumatism and, rarely, hemarthrosis of temporomandibular articulation [13][14] .In this sense, 38.1% of the academics agreed with such information.
Leukemia is a group of complex malignant cells with differences among them, characterized by excessive and progressive production of leukocytes that appear in the blood in immature forms 13 .According to the original cell, leukemia can be classified as myeloid or lymphocytic.Both can be acute or chronic, thus there are four types of Leukemia 14 .
Oral complications due to leukemia can be classified in primary, secondary and tertiary.The primary lesions are the result of oral tissues infiltration by leukemic cells, standing out gingival hyperplasia and gingivitis.The secondary lesions are associated to thrombocytopenia and granulocytopenia that lead to a greater tendency of gingival bleeding and increase of susceptibility to infections, as candidiasis and herpes simplex; the tertiary lesions are consequences of the adopted therapeutics and are characterized by oral mucosa scurf and painful ulcerations which can generalize and xerostomia 15 .
Similar indexes of correct answers were obtained regarding Leukemia etiology and their buccal manifestation: 28% and 26.2%, respectively.
Acknowledging the inception of a bleeding disturbance that may indicate the presence of a systemic pathological process might occur in odontological practice.Moreover, odontological prophylactic, restoring and surgical treatment of patients with hemorrhagic disturbance is better performed by professionals who have knowledge of pathology, complications and treatment options associated to these conditions.
A good anamnesis is essential to the dentist know the health status of the patient.When facing an abnormal situation indicating an hematological disfunction, the complementary exams are fundamental for a correct diagnosis.Almost all hemorrhagic disorders can be diagnosed performing the task of triage with platelets count, BT (bleeding time), PT (prothrombin time) and PTT (partial thromboplastin time).If the values found are not within normality, the patient must be referred to the hematologist 16 .Only 31.5% of the academics would request all these exams to evaluate the condition of a patient with abnormal bleeding after any cut or surgery.
Given what was exposed it is possible to infer that the knowledge of the academics attending the course of Dentistry at UESB regarding hematologic disorders is quite deficient.This result is in accordance with auto-perception over their knowledge level, given that despite 54.2% of academics assert that they are informed, most of them (79%), considered that they are insufficiently informed.
It is concerning the fact that 45.8% of those who have not obtained this information, 70% pointed as a motive the lack of opportunity, given that they believe that the content will be approached in posterior semesters.Notwithstanding, although 67% students indicated classes as means to obtain information about hematologic disturbances and their implications in Dentistry, this content seems to be solely a roll of the discipline Integrated Clinic IV that approaches Dentistry for Patients with Special Needs.Although within the Hemopathies approached, Sickle Cell Anemia and Leukemia were not contemplated.
In the disciplines Oral Diagnosis and Odontological Clinic I, the content was approached sporadically in some semesters through seminar presentations and article readings.Information about etiology/ physiology regarding these disturbances were presented in Histology, Biochemistry, Pathology and Physiology.This explains the fact of lack of progress of knowledge throughout the semesters, given that for most students information was not communicated nor received.
Despite the few studies about this theme in the literature, studies performed with Iranian dentists points out that their knowledge about hemorrhagic disturbance is not at an ideal level and demands planning continued education courses [17][18][19] .According to Robati & Farokhi 17 , the lack of knowledge of dentists seems to result from the limited number of credits and insufficient hours dedicated to the course of "systemic diseases" (including blood and hemorrhagic diseases).This is why the curriculum review was approved, and the authors' expectations are that the knowledge level of future Dentistry students of the Iranian society be promoted through the implementation of a new curriculum.
Corroborating this idea, it is assumed that a reformulation of the curriculum will be necessary, given that teaching hematologic disorders in the Dentistry course at UESB was deficient, oscillating between semesters.Thus, these issues must be corrected so that knowledge be accumulated throughout the semester.Being part of a specific discipline, as asserted by 63% of students that didn't read this content nor distributed in several disciplines that are part of the course, this topic must be contemplated.

CONCLUSION
The level of knowledge of academics of Dentistry at UESB about hematological disturbances was insufficient.Moreover, It was noticed that gradual growth of knowledge throughout the semesters is polarized, especially in the 6th and 10th semesters.Transmission of information about this content occurred in most cases during classes of Oral Diagnosis, Odontological Clinic I and Integrated Clinic IV.

Collaborators
CA SILVA, CL SANTANA, RCDV ANDRADE, TL FRAGA e FO PRADO collaborated on the development of the research project, collecting and analyzing data and composing the manuscript.