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ORIGINAL ARTICLE
Year : 2019  |  Volume : 8  |  Issue : 3  |  Page : 198-205

Bacteriology of orofacial space infections-A retrospective study


1 Department of Oral and Maxillofacial Surgery, Drs. Sudha and Nageswara Rao Siddhartha Institutes of Dental Sciences, Chinaoutapalli, Gannavaram (M), Krishna District, Andhra Pradesh, India
2 Vishnu Dental College and Hospital, West Godavari, Bhimavaram, Andhra Pradesh, India
3 Dr. PSIMS and RF, Chinaoutapalli, Gannavaram (M), Andhra Pradesh, India

Date of Submission29-Jan-2018
Date of Acceptance01-Aug-2019
Date of Web Publication17-Oct-2019

Correspondence Address:
Dr. Uppaluru Vijaya Lakshmi
Department of Oral and Maxillofacial Surgery, Drs. Sudha and Nageswara Rao Siddhartha Institutes of Dental Sciences, Chinaoutapalli, Gannavaram (M), Krishna District, Andhra Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/JDRNTRUHS.JDRNTRUHS_9_18

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  Abstract 


Aim: The purpose of this study was to assess causative micro-organisms responsible for Orofacial space infections of odontogenic origin, and to evaluate their sensitivity to various antibiotics used in the treatment of these infections.
Methods: The bacteriology and antimicrobial susceptibility of major pathogens in 30 patients with orofacial odontogenic infections were examined excluding the patients who were on prior antibiotic therapy, who were diagnosed to be immunocompromised and the patients were on immunosuppressants and the following patients underwent incision and drainage and received IV antibiotics.
Results: A total of 46 bacterial strains were isolated from 30 patients out of which five patients' culture results were sterile. The most common aerobic bacteria isolated were Viridans Streptococci, Klebsiella Pneumonia and Streptococcus Pyogens, and anaerobic bacteria were Porphyromonas Gingivalis, Streptococci, Fusobacterium and Prevotella Melanogenicus. As per our study, Gentamycin (84%) and Cefotaxime (80%) were the most effective antibiotics.
Conclusion: In conclusion, the surgical treatment incision and drainage must always be in the foreground for the therapy of orofacial space infections of odontogenic origin. Cultures and sensitivities commonly showed greater growth in aerobes (76%) than in anaerobes (23.9%).

Keywords: Abscess, incision and drainage, odontogenic infection, space infection


How to cite this article:
Lakshmi UV, Rayalu KP, Moturi K, Yelamolu R, Prakash CS. Bacteriology of orofacial space infections-A retrospective study. J NTR Univ Health Sci 2019;8:198-205

How to cite this URL:
Lakshmi UV, Rayalu KP, Moturi K, Yelamolu R, Prakash CS. Bacteriology of orofacial space infections-A retrospective study. J NTR Univ Health Sci [serial online] 2019 [cited 2019 Nov 15];8:198-205. Available from: http://www.jdrntruhs.org/text.asp?2019/8/3/198/269494




  Introduction Top


Odontogenic infection refers to an infection that originates in the dental pulp, periodontium, jawbones, or in the tissues that closely surround it, which may spread locally or generally along the path of least resistance and may involve the potential spaces of head and neck, causing considerable morbidity and mortality. However, these odontogenic infections are frequently encountered in our day to day practice.[1],[2]

Early diagnosis, identification of microorganisms through culture and antibiotic sensitivity, prompt antibiotic treatment together with early removal of cause should prevent most complications and resulting in early recovery. Therefore, management of these infections involves both surgical and supportive therapy.

Most of the odontogenic infections resolve with little consequences or may lead to life threatening complications compromising vital structures, namely, airway compromise, jugular vein thrombosis, mediastinal involvement, pericarditis, pneumonia, emphysema, arterial erosion, and extracranial and intracranial extensions due to delay in diagnosis and treatment.[2],[3],[4] These severe head and neck infections have increased potential risk in immunocompromised host. In normal host, orofacial infections are usually polymicrobial infections. These can be produced by organisms that may not be infectious in pure culture, but that become infectious through microbial synergism.[5]

However, recent studies performed with advanced microbial techniques under strict anaerobic conditions have produced a different picture of flora causing these infections, approximately 5% of aerobic bacteria, 35% are due to anaerobic bacteria and remaining 60% are caused by both aerobic and anaerobic bacteria. The most common organisms are Streptococcus, Peptostreptococcus, Eubacterium, Porphyromonas, Prevotella and Fusobacterium. The infections caused by these microorganisms follow a well-defined pattern of evolution. Entry of bacteria into deep tissues to cause an infection results from invasive aerobic bacteria gaining access through a necrotic pulp. The aerobic bacteria serves as an initiator of the infection preparing the local environment for anaerobic bacterial infection. The anaerobic becomes predominant since the reduction oxidation potential favors the anaerobic growth.

Antibiotics are necessary as a primary treatment to eliminate the invading microorganisms. The choice of the antibiotic should be with a clear idea of antibiotic susceptibility of bacteria causing infection. Penicillin have historically been used as a first line therapy against streptococcal organisms, but increasing rate of resistance have lowered their usefulness. The addition of metronidazole to penicillin has become popular recently in treatment of odontogenic infections. Broad spectrum antibiotics should be kept reserved for serious life threatening infections.[6]

With this background, the study has been designed to obtain the valuable information regarding early diagnosis, microbiology and antimicrobial susceptibility of microorganisms causing orofacial space infection of odontogenic origin. Therefore, management of these infections involve both surgical and supportive therapy.[6]


  Methods Top


A retrospective descriptive study was made from the hospital records in the period between 2010 August to 2011 September; 30 patients were selected randomly who reported to the Department of Oral and Maxillofacial Surgery, Vishnu Dental College, Bhimavaram, West Godavari District, Andhra Pradesh, and were diagnosed with Orofacial space infections of odontogenic origin. All patients in the study were examined, and pus sample was collected prior to antibiotic therapy (excluding the patients with immunocompromised condition and the patients who are on immunosuppressant drugs) and all these patients underwent surgical incision and drainage, received Intravenous antibiotics in the operating room. Pus samples were collected and processed in the microbiology laboratory prior to definitive management. The samples were inoculated for both aerobic and anaerobic culturing and antibiotic sensitivity was performed. Patient demographics gender, age, fascial spaces, nature of micro-organisms and culture and sensitivity reports were reviewed in [Table 1], [Graph 1] Informed consent was taken from all the patients prior to the study. Duration or course of infection varied for each patient (Approx. from 4-10 days).
Table 1: Demographic Data: Distribution Of Patients According To Age Groups & Sex

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Bacteriologic examination

After taking a detailed history, each patient was thoroughly examined. To identify the causative agents, pus specimens were sampled from the tissues before commencing of antibiotic therapy. The extra-oral sites were prepared with 5% Betadine solution. The pus sample from these sites were aspirated with sterile disposable syringes (10 ml) and with disposable 18 gauze wide bore needles. After aspirating the specimen was immediately inoculated in sterile thyoglycollate media with Hemin and vitK, under special care the media along with specimen was transported to the department of microbiology, Maratha Mandal's Nethajirao G. Halgekar institute of dental sciences and research centre, Belgaum for further investigation.

Bacteriological examination was performed immediately as follows: for aerobic culture a portion of each specimen was incubated on Mac-Conkey and chocolate agar. (Mac-Conkey is a semiselective media). Colonies formed were lactose fermenting pink color (LF) and Non-lactose fermenting (NLF) pale color. After incubating at 37°C overnight on chocolate agar, they were observed for colony formation Holt JG et al. 1994.[7] The colonies were identified by gram staining and biochemical tests. If no growth was observed after the first culture, subcultures from nutrient broth was made on Mac-Conkey agar, blood agar and looked for growth after overnight incubation. Aerobic and micro-aerophilic bacteria were identified by using conventional methods for 48 hrs.[8],[9] For anaerobic culture, the samples were inoculated and cultured on Kanamycin blood agar using gas pack, in the anaerobic jar for 48-72 hrs. The plates were observed for colony formation. The colonies were identified by gram staining morphology, hemolysis and biochemical tests. If no growth was observed after first culture, subculture was done from Thyogylcolate media with Hemin and vit K on plain blood agar, bile esculin agar and identified as mentioned above. For Facultative Anaerobes, the samples were inoculated in Dentaid agar, which is selective media for Actinomycetem comitans and incubated in Co2 jar for 48-72 hrs.[8],[10] Antibiotic sensitivity was done by Kirby-Bauer disk diffusion method.[10] [Figure 1].
Figure 1: Armamentarium for Culture and Sensitivity Test. (a) Transport media: Thyogylcolate media with hemin & vit k. (b) Inoculation loop. (c) Bunsen burner. (d) Mac-conkey Agar for Aerobic Culture. (e) Blood Agar for Anaerobic Culture. (f) Anaerobic jar (g) Incubator

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Based on this background, a new research on orofacial abscess and celluloid has been SPARSE-DNA sequencing of the PCR product was performed with an Automated Perkin Elmer ABD 377 (PERKIN ELMER CORP FOSTER CITY, Calif). Identification of bacteria associated with spreading odontogenic infections by 16SrRNA gene sequencing to determine the bacterial species associated with spreading odontogenic infections (SOIs). PCR amplification, cloning and sequencing of bacteria 16SrRNA genes.[4]

Antibiotic sensitivity is a term used to describe the susceptibility of bacteria to antibiotics. Antibiotic susceptibility testing (AST) is usually carried out to determine which antibiotic will be most successful in treating a bacterial infection in vivo. Testing for antibiotic sensitivity is often done by the Kirby-Bauer method. Small wafers containing antibiotics are placed on to a plate up on which bacteria are growing. If the bacteria are sensitive to the antibiotic, a clear ring, or zone of inhibition, is seen around the wafer indicating poor growth.[11]


  Results Top


Out of 30 patients, 19 male (63.33%) and 11 female (36.67%) with odontogenic infections, 23 patients were identified with single space infections (76.67%) and were categorized as follows in [Table 1] Single Spaces were identified in 23 patients; the following were 7 patients with canine space infections, 6 patients with buccal space, 5 patients with submandibular space, 2 patients with sub-masseteric space, 2 patients with dentoalveolar abscess and one patient with Pterygomandibular space infection [Table 2] and [Graph 2].
Table 2: Single-Space Abscess

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Multiple space infections were identified in 7 patients as follows; 2 patients with ludwig's angina, 2 patients with Buccal and submandibular space infection, 1 patient with canine and buccal space, 1 patient with submasseteric, pterygomandibular space and left parapharnygeal spaces and 1 patient with submasseteric and infratemporal space infection [Table 3] and [Graph 3].
Table 3: Multiple-Space Abscess

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A total of 46 bacterial strains were isolated from 30 patients. 5 patients showed no growth from cultures. Candida Albicans (1 isolate) and Aspergillus Niger (1 isolate) were also identified. There were 35 aerobes (strict and facultative) (76%) and 11 anaerobes (23.9%) isolated [Table 4]. The bacteria were found to be 52.18% Gram-positive and 47.71% Gram-negative. Gram-positive cocci were isolated in 18.18% and Gram-positive bacilli (34%) of specimens and Gram-negative cocci were isolated in 22.72% and Gram-negative bacilli were isolated in 24.99% of cultures. The most common bacteria isolated were Streptococcus Viridians accounted for 33.33% (10 isolates), Klebsiella Pneumonia and Streptococcus Pyogens for 13.33% (4 isolates), streptococci for 10% (3 isolates), Staphylococcus Aureus and Actinomycetem Comitans for 6.67% (2 isolates) from total aerobic isolates and  Porphyromonas gingivalis Scientific Name Search unted for 23.33% (7 isolates) from total anaerobic isolates. The most common type of isolates were Pure aerobes accounted for 33.33%, followed by 23.3% mixed Aerobic + Anaerobic organisms, 20% mixed aerobes and 6.67% of pure anaerobes and 5 patients (16.67%) culture results were sterile [Table 5] and [Graph 4].
Table 4: Organisms Isolated From Orofacial Odontogenic Infections

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Table 5: Types Of Isolates

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As mentioned earlier, in inclusion criteria, only the patients who were not on any medications regarding tooth ache and swelling were accepted, and for these patients initially pus sample were collected for culture and sensitivity testing after which patients were kept under Empirical therapy, IV medication, incision and drainage and extraction of offending tooth was the treatment protocol. After three days, patients were kept under therapeutic treatment.


  Discussion Top


Odontogenic infections are among the conditions most commonly treated by Oral and Maxillofacial Surgeons. The classic signs of maxillofacial infections include pain, swelling, fever, dysphagia and dehydration. Odontogenic infections have the potential to spread via fascial spaces in Head and Neck region to compromise vital structures such as airway, mediastinum and cavernous sinus. Untreated or rapidly spreading odontogenic infections[12] can be potentially life threatening leading to airway compromise, septicemia and finally death. This makes a situation for maxillofacial surgeons to take a timely decision and surgical intervention. These decisions can be lifesaving. In our study, the incidence of odontogenic orofacial space infections was high in people with low socio-economic status and poor oral hygiene.[1],[3],[13]

Thirty patients were selected randomly for the study. Age groups most commonly involved were in the VI decade of life. The mean age group was 42.80 ± 16.74 years, out of which male patients were more commonly involved than female patients.[8] Clinical and radiographic examinations were undertaken to evaluate the patient's oro-dental status and to confirm the diagnosis.[14] All the patients were clinically, radiographically diagnosed and hematologically diagnosed based on which the immunocompromised patients were excluded. Since most patients had poor oral intake for several days secondary to pain and dysphagia, intravenous hydration was initiated and monitored by the normalization of vital signs and urine output.[15],[16]

Out of 30 patients with odontogenic infections, 23 patients were identified with single space infections and 7 patients were identified with multiple space infections. The most commonly involved sites were on left side of face than right side. Mandibular first molars were most common causative teeth.[17] This may be due to the anatomical relationship of odontogenic infections and close relationship to the affected space (s). Most organisms involved in infections of the head and neck are odontogenic origin.[18] Bacteria that were isolated consisted of both aerobic and anaerobic organisms.[8]

In our study, empirical antibiotic therapy against both aerobes and anaerobes was initiated in all cases before culture and sensitivity test results were obtained, and subsequent antibiotic therapy was based on culture and sensitivity test results.[19] In addition to administration of appropriate antibiotics, 93.33% of the cases in our study required prompt incision and drainage and 6.67% removal of the source of infection (offending tooth) during the first appointment for early resolution.

Microbiology of orofacial infections has been studied widely and various forms of both aerobic and anaerobic microorganisms reflective of normal oral flora have been isolated. Infections due to anaerobic and gram negative organisms have increased in comparison with past reports in medical and dental literature. This may be related to improvements in isolating and culture methods of anaerobic organisms.[17] The key to effective anaerobic bacterial culture includes collecting a contamination- free specimen and protecting it from oxygen exposure by avoiding Swabs as cotton fibers may be detrimental to anaerobes.[16],[20] Abscess or fluids can be aspirated using a sterile syringe that is then tightly capped to prevent entry of air. The specimens should be plated as rapidly as possible on to culture media that has been prepared. Culture should be placed in an environment that is free of oxygen, at 95°F (35°C) for at least 48 hrs before the plates are examined for growth. Gram staining is performed on the specimens at the time of culture. Biochemical identifications are used for primary speciation of individual isolates.

In our study, pus samples were aspirated before incision and drainage with 10 ml sterile disposable syringes and 18 G wide bore needle. Before sampling, the surgical site was disinfected with solution of 5% Betadine solution. Specimens were collected into an anaerobically pre-reduced transport medium (Thyogylcolate media with Hemin and Vit K) and sealed tightly with sterile plaster. Specimens were transported to Dept. of Microbiology, Belgaum and specimens were immediately cultured for both aerobic and anaerobic organisms.

However, recent studies performed with advanced microbial techniques under strict anaerobic conditions have produced a different picture of flora causing these infections, approximately 5% of aerobic bacteria, 35% are due to anaerobic bacteria and remaining 60% are caused by both aerobic and anaerobic bacteria.[9] [Table 6].
Table 6: Normal Mouth Flora

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The study shows 46 bacterial strains that were isolated from 25 patients and 5 patients showed no growth from cultures. Candida albicans (1 isolate) and Aspergillus niger (1 isolate) were also identified. There were thirty five aerobes (strict and facultative) shows 76% and eleven anaerobes (23.9%) isolated. Pure aerobes were commonly isolated, followed by mixed aerobic + anaerobic organisms, mixed aerobes and 2 were pure anaerobes and 5 patients' culture results were sterile. In our study streptococci viridians, aerobic streptococci, streptococci epidermidis were more commonly isolated in Aerobic bacteria. Porphyromonas gingivalis, Fusobacterium and Prevotella were more commonly isolated in Anaerobic bacteria.

The treatment protocol used in our study includes empirical antibiotics in the form of oral Cap. Amoxicillin 500 mg TID and Tab. Metronidazole 400 mg TID post-operatively. Severely ill patients were started with Inj. Augmentin (Amoxycillin and clavulanic acid) – 1.2 g B.D I.V and Metranidazole 500 mg/100 ml TID I.V, followed by therapeutic antibiotics prescribed according to culture and sensitivity test results. The results were statistically analysed and the study shows high sensitivity to Gentamycin (84%), followed by Cefotaxime (80%), Ciprofloxacin (76%), Azithromycin (76%), Cefuroxime (72%), Amoxicillin (72%), Augmentin (72%) and Penicillin (36%). The most common isolates were sensitive to [Table 7].
Table 7: Most Common Sensitive Aerobic And Anaerobic Isolates

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On discharge, all these patients were followed up every week for 15 days. They were prescribed oral antibiotics for up to 5 days, no complications were noted at follow up visits, in any of these 30 patients [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d.
Figure 2: (a) A 32-year-old female patient diagnosed with buccal and submandibular space infection with restricted mouth opening, measuring 1 cm. (b) 1. Showing vestibular obliterence in right lower back teeth region. 2. Sample collected with disposable dispovan syringe and transferred in Transport media for culture and sensitivity test. 3. Proceeding extraction and incision and drainage mouth opening improved to 3 cm. (c) Incision and Drainage. (d) Pre and Post-operative procedure

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  Conclusion Top


In conclusion, the mainstay of the study was to assess the incidence of orofacial space infection, to identify the causative organism and to modulate the treatment protocol. Based on this background, surgical management i.e. incision and drainage[21] must always be in the foreground for the therapy of orofacial space infections of odontogenic origin. Culture and antibiotic sensitivity tests commonly showed greater growth in aerobes (76%) than in anaerobes (23.9%). Gram-positive bacilli and gram-negative bacilli had the greatest growth percentage in cultures. As per our study, almost all the organisms were more sensitive to Gentamycin (84%) and Cefotaxime (80%).

Indiscriminate use of antibiotics alone in treating orofacial space infections results in creating resistant strains of microbes. The appropriate antibiotics with the correct dosage in addition to the surgical intervention helps not only in complete resolution of the infection but also prevents resistant strains in the population [Table 8].
Table 8: Advantages And Disadvantages Of The Study

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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.



 
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Rega AJ, Aziz SR, Ziccardi VB. Microbiology and antibiotic sensitivities of head and neck space infections of odontogenic origin. J Oral Maxillofac Surg 2006;64:1377-80.  Back to cited text no. 16
    
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Ndukwe KC, Okeke IN, Akinwande JA, Aboderin AO, Lamikanra A. Bacteriology and antimicrobial susceptibility profiles of agents of orofacial infections in Nigerans. Am J Clin Exp Microbiol 2004;5:272-7.  Back to cited text no. 17
    
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Chow AW, Roser SM, Brady FA. Orofacial odontogenic infections. Ann Intern Med 1978;88:392-402.  Back to cited text no. 18
    
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Flynn TR, Halpern LR, Antibiotic Selection in head and neck infections. Oral Maxillofacial Surg Clin N Am 2003;15:17-38.  Back to cited text no. 19
    
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    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]



 

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