Introduction
Infective endocarditis is a serious infection occurring on the endothelial surfaces of the heart, especially at the valves. Oral commensal bacteria are the important etiologic agents in this disease. Common dental procedures, even non-surgical dental procedures, can often cause bacteremia of oral commensals. Infective endocarditis is a rare, but has very serious complication during dental treatment. One necessary prerequisite for the development of infective endocarditis is a bacteraemia, which can develop as a result of dental treatment. Patients with conditions that predispose to the development of infective endocarditis need to be identified and given prophylactic antibiotics before dental treatment known to generate a bacteraemia. Most types of dental procedures, which are known to cause bacteraemias, have been investigated and guidelines for the prevention of infective endocarditis have been published.1, 2 However, there is still confusion, about what types of orthodontic procedures generate bacteraemias which could cause endocarditis in a susceptible patient. This has leaded some orthodontists to be ultra-cautious and to not carry out orthodontic treatment in susceptible patients. The purpose of this paper was to examine the link between orthodontic procedures and infective endocarditis, and to make practical recommendations for practitioners.
The link between orthodontic treatment and infective endocarditis
The link between orthodontics and infective endocarditishas not been fully defined.3, 4 Hobson and Clark, in a survey of 1038orthodontists, found only eight cases of infective endocarditisdiagnosed during or immediately after orthodontictreatment involving both fixed and removable appliances.4 The paucity of reported cases could reflect the fact that very limited orthodontic treatment has been done for patientsconverseis true, orthodontics is widely practicedon patients susceptibleto infective endocarditis both in Europe andU.S.A. It would be necessarily follow that, since there is apaucity of cases, the risk between infective endocarditisand orthodontics must be very small. However, it isas yet unclear which clinical procedures in orthodonticscould potentially result in the development of endocarditis.
It has been postulated that placement of orthodonticbands could result in a bacteraemia. McLaughlin et al. were able to detect bacteraemias in 10 per cent of blood samples taken during band placement. 5 One other study did not detect micro-organisms in the bloodstream duringbanding. 6 This apparent contradiction indetection rates may be a result of difficulties in the techniques of bacteraemia detection. It could also (andmore likely) be due to the fact that banding does not always produce detectable bacteraemias that could cause infective endocarditis.
Cleaning and polishing of teeth has been associated with bacteraemias and infective endocarditis.7, 8 Therefore, this procedure could predispose patient at risk of infective endocarditis. Therefore according to literature antibiotic prophylaxis is required in susceptible patients for the placement and removal of bands, and any polishing of the teeth. The adjustment of fixed or removable orthodontic appliances has never been associated with a risk of a significant bacteraemia or a proven case of infective endocarditis. It is for this reason that the American Heart Association, in their recent guidelines did not recommend prophylaxis for adjustment of orthodontic appliances.9 Similarly, the taking of impressions for study models is notassociated with a significant bacteraemia (that could cause infective endocarditis) and does not require prophylactic antibiotics. The exposure of teeth (particularly palatal canines) is asurgical procedure that would generate a bacteraemia and requires prophylactic antibiotics in patients susceptible to infective endocarditis. Once the tooth is exposed, the operative site may be considered in the same manner as anextraction site or erupting tooth, and does not require any further antibiotics. It has been argued that traction following excisional exposure may result in a reduced risk of bacteraemia compared to traction following replaced flaptechniques.4 This recommendation may be based on the potential for bacteraemia during the period of traction. In our opinion any tooth movement through a replaced flap is analogous to accelerated tootheruption and should not require prophylactic antibiotics.
Principles of prophylaxis
Prophylaxis is sometimes interpreted as only antibiotic cover; however, it should also be concerned with the maintenance of good oral hygiene and prevention of oral disease. Poor oral hygiene results in plaque accumulationand a resultant quantitative increase in plaque bacteria. The subsequent gingival inflammation and spontaneous bleeding caused by broken capillaries will lead to transitory bacteraemias. Hence, placement of orthodontic appliances and gingival inflammation in such a situation will result in an increase in bacteraemic episodes.
Transitory bacteraemias have been induced in patients with clinically healthy gingivae.10 Bacteraemias have also been demonstrated with tooth brushing in the presence of inflammation and plaque, but the significant factor is that the bacteraemic load is reduced when oral hygiene is good.11 Silver et al also showed that the percentage of positive cultures (ameasure of the number of micro-organisms isolated)increased with increasing severity of inflammation. 10 Thereare no reports of infective endocarditis being precipitatedby oral hygiene procedures in patients with mouths that have a good gingival condition. The number of micro-organisms in a bacteraemia is also influenced by the degree of trauma after a particular manipulative procedure.12 Therefore, antibiotic cover is recommended for some procedures and not others. 1
An effective method for reducing the level of bacteraemia is to use an oral rinse of 0·2 per cent (w/v) chlorhexidine solution.13, 14 Repeated applications of chlorhexidine have not been found to result in changes in sensitivity to thisdisinfectant. 15, 16 This isdistinct from patients who have received long termantibiotics where resistant strains of oral Streptococci, the most common bacteria identified in bacterial endocarditis, tend to be present in the mouth.17
Patients at risk from infective endocarditis
The most important factor in the assessment of patient’s at risk from infective endocarditis is the patient’s medical history. Patients can be divided into three type’s high, moderate or negligible risk. The medical conditions that are in each of the three categories are shown in Table 1. Patients at high risk can potentially undergo orthodontic treatment, but the patient’s cardiologist should be consultedto assess risk before treatment. If, after consultation with the patient’s physician, the risk of infective endocarditisis considered to be high then treatment should not be undertaken. Patients at moderate risk of endocarditiscan receive orthodontic treatment and they will need antibiotic cover for procedures that cause bacteraemia. Patients at negligible risk can be treated without antibiotic prophylaxis, but again, the precise nature of the patient’s condition should be confirmed with the physician prior to the start of treatment. Many potential orthodontic patients give a history of a heart murmur. This requires investigation and clarification of whether the murmur is innocent, prior to undertaking any orthodontic treatment.
Table 1
Cardiac conditions associated with endocarditis (Dajaniet al., 1997) 9
Antibiotic prophylaxis is recommended for the ‘high’ and ‘moderate’ risk categories, but not for the ‘negligible’ risk category. This latter category lists cardiac conditions inwhich the development of endocarditis is not higher than in the general population.
Special Risk Patients
The British Society of Antimicrobial Chemotherapy have recognized a group of patients, with endocardial disease, who they consider as ‘special risk’; these are considered to be particularly susceptible to infective endocarditis. Special risk patients are classified as those patients with endocarp dial disease who have had infective endocarditis or require a general an aesthetic and
The practicalities of orthodontic treatment in patients at risk from infective endocarditis and management recommendations
The patient’s condition should be accurately understood before any treatment is stated and this may involve further confirmatory tests by the cardiologist (e.g. echocardiography).When the orthodontist is in possession of all this information then informed consent should be obtained from the patient and/or guardian as appropriate. Figure 1 shows a practical scheme for treating orthodontic patients at risk from endocarditis. In the opinion of the authors, the treatment formulated in patients at high risk of endocarditis should be practical, achievable, and not over ambitious. As with all orthodontic patients, oral hygiene should be impeccable before any treatment is started. Oral hygiene of a high standard is especially important in patients at risk from infective endocarditis since the accumulation of plaque increases the risk of significant bacteraemias during treatment. If the patient’s oral hygiene lapses during treatment then consideration must be given to the abandoning of the appliance treatment if the hygiene does not rapidly improve. Patients at ‘high’ or‘ moderate’ risk should receive prophylactic antibiotics for procedures known to be associated with a bacteraemia.
Figure 1
Chematic representation of management of orthodontic patient at risk for infective endocarditis
Table 2 Lists orthodontic procedures and the need forantibiotic prophylaxis in the ‘high’ and ‘moderate’ risk categories.
Table 2
Requirement for prophylactic antibiotics for orthodontic procedures in patients at high or moderate risk of infective endocarditis
etails the currently recommended regimen for the prophylaxis of infective endocarditis. Any orthodontic procedure in patients under any of the three risk categories should be done following a preliminaryrinse with 0·2 per cent chlorhexidine mouthwash. Daily chlorhexidine rinsing should also be advised if mucosal irritation occurs which results in bleeding from the appliance. For effective prophylaxis, antibiotic therapy ideally should be administered within 2 hours of the procedure. In order to reduce the number of prophylaxis courses, fixed appliance placement should be completed in one visit. This is possible with banding and bonding without separation or preferably, the bonding of brackets on all teeth.
Table 3
Antibiotic regimens recommended for the prophylaxis of dentally-induced infective endocarditis (adapted from the Endocarditis Working Party of the British Society for Antimicrobial Chemotherapy, 1992, 1998). 1, 2
In all of the ‘risk’ categories, the patient must be instructed to report back any unexplained illness after the orthodontic procedure has been conducted.18 There is still a possibility that infective endocarditis may occur despite appropriate antibiotic prophylaxis. 19, 20 This is said to be most likely within the first 30 days of the procedure, but due to the protracted nature of orthodontic treatment, the clinician should remain vigilant.21
Antibiotic management (points to remember)
Clindamycin tablets should be swallowed with a glass of water to prevent oesophageal irritation.
Children under 10 years of age half the adult dose of amoxycillin or clindamycin is recommended and children under 5 years a quarter of the adult dose. For children under 10 years of age, 20 mg of vancomycin should be used and 2 mg of gentamycin. Children under 14 years of age should be given 6 mg/kg of teicoplanin plus 2mg/kg of gentamycin.
For those patients not at special risk amoxycillin maybe given twice in 1 month as it is unlikely that proliferationof clinically significant amoxycillin resistantstrains will occur after one 3-g dose of amoxycillin. Athird dose of amoxycillin, however, should not be givenuntil after an interval of 1 month. A time interval of atleast 2 weeks is required before clindamycin can beagain used for prophylaxis.
Conclusion
The lack of reported cases in the literature, suggests that infective endocarditis associated with orthodontic treatmentis extremely rare. Nevertheless, guidelines arenecessarily based on the available scientific evidence, butunfortunately such evidence is scarce.
Patients can be divided into high, moderate, and negligiblerisk of infective endocarditis based on their medicalcondition.
Patients with a ‘high’ predisposition to infective endocarditisshould only be treated after consultation withtheir supervising physician.
Patients at ‘medium’ risk can be treated but antibioticprophylaxis should be considered only for procedures causing bacteraemias.
In the opinion of the authors, based on the availableevidence, patients with a ‘low’ risk of infective endocarditiscan be safely treated, usually without antibioticprophylaxis. All patients should have a 0·2 per cent w/vchlorhexidine mouthwash prior to each adjustment.
Certain procedures are known to be associated with bacteraemias, these include band placement, removalof bands, and surgical exposure of teeth. Such procedures require antibiotic prophylaxis in ‘at-risk’patients.
