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The oral cavity is densely populated with microorganisms. As a result, intraoral surgical sites are prone to contamination by pathogens, potentially triggering surgical site infections (SSIs). Prophylactic antibiotics have proven beneficial in reducing the rate of SSIs. However, no consensus has been reached regarding the most effective regimen. The purpose of this study was to investigate two different antibiotic regimens – single-dose and prolonged antibiotic prophylaxis – regarding the rate and severity of postoperative SSIs in patients undergoing orthognathic surgery. Data were analysed retrospectively. Patients who underwent bilateral sagittal split ramus osteotomy or bimaxillary surgery in the study department in 2017 were screened for eligibility. Ninety-nine patients were included in the study and were divided into two groups. The prolonged-antibiotic prophylaxis group (PAP; n = 49) received a 5-day antibiotic prophylaxis regimen, while the single-dose antibiotic prophylaxis group (SDAP; n = 50) received single-dose antibiotic prophylaxis. The groups were assessed for the rate and severity of SSIs following orthognathic surgery. Five patients (10.2%) in the PAP group and seven (14%) in the SDAP group developed infections; no statistically significant difference in the occurrence of SSIs was found (P = 0.380). Single-dose antibiotic prophylaxis is as effective as a 5-day antibiotic prophylaxis regimen in preventing SSIs in orthognathic surgery and is a suitable antibiotic prophylaxis option when considering the risk of antibiotic resistance.
Orthognathic surgical procedures are common surgical interventions in the field of maxillofacial surgery that allow the correction of skeletal malocclusion to improve occlusal function, facial harmony, and aesthetics.
Orthognathic surgery is generally considered safe, however it continues to be associated with numerous complications. What is more, postoperative wound infections are amongst the most common and most severe sequelae that may potentially impair a patient’s wellbeing and jeopardize the surgical outcome. These wound infections particularly occur with intraoral surgical approaches used in orthognathic surgery.
The advantages of intraoral approaches include the avoidance of extraoral scarring while maintaining adequate visibility and surgical access to the operating area. Additionally, the risk of injury to the facial nerve and regional blood vessels is minimized. However, the oral cavity is densely populated with bacteria, which may favour the occurrence of surgical site infections (SSIs). This issue has been highlighted by the American Society of Health System Pharmacists (ASHP), and as a result, orthognathic surgery has been categorized as clean-contaminated surgery.
Possible consequences of SSIs include negative effects on the surgical outcome, a prolonged inpatient stay, re-hospitalization, and increased costs. Considering the highly elective nature of orthognathic surgical procedures, avoiding SSIs is of enormous importance.
estimated the rate of SSIs to amount to 10–15% without antibiotic prophylaxis. This rate was reduced to 1% when perioperative antibiotic prophylaxis was administered. These results correspond to those of Flynn and Lawrence,
who described a significantly increased risk of SSIs after orthognathic surgery without antibiotic prophylaxis. This is consistent with other research on this topic, which has shown a reduction in the infection rate when antibiotic prophylaxis was used, regardless of the regimen applied.
Hence, the clinical guidelines published by the American and British associations of oral and maxillofacial surgeons (AAOMS, BAOMS) recommend the judicious use of antibiotic prophylaxis to reduce the risk of postoperative complications.
Moreover, the use of antibiotics should be minimized to prevent antimicrobial resistance and side effects (e.g. anaphylaxis and serum sickness), while ensuring the optimal efficacy for the prevention of SSIs.
The purpose of this study was to compare two common antibiotic regimens for the prevention of postoperative SSIs in orthognathic surgery. The aim is to reduce the antibiotic medication to a necessary minimum while still guaranteeing optimal SSI prophylaxis.
Materials and methods
This retrospective study was conducted in the Division of Oral and Maxillofacial Surgery at the Medical University of Graz in 2017 as part of a quality improvement project that aims to reduce the amount of prophylactic antibiotics administered in orthognathic surgery (ethical approval, 30–356 ek17/18). In this regard, the standard perioperative antibiotic regimen deployed in the study department was changed from a prolonged 5-day antibiotic prophylaxis regimen to a single-dose regimen.
To identify possible differences in the efficacy of prophylactic antibiotics in preventing SSIs, these antibiotic regimens were compared by means of well-defined primary and secondary outcome measures. Patients who met defined inclusion criteria and who had received single-dose antibiotic prophylaxis (SDAP group) were matched to a control group of patients who had received prolonged antibiotic prophylaxis (PAP group); the groups were similar in sample size and surgical techniques applied.
Male and female patients who underwent bilateral sagittal split ramus osteotomy (BSSO) or bimaxillary surgery (BIMAX) during the 5 months before or after the change in antibiotic protocol were screened for eligibility. Only patients who were classified as either ASA I or ASA II according to the physical status classification of the American Society of Anesthesiologists (ASA), were included in the study. Reasons for patient exclusion included the following: incomplete follow-up (less than 6 months), additional surgical procedures performed in the same operative session (e.g. genioplasty, rhinoplasty), systemic diseases associated with reduced immunity (e.g. lupus erythematosus or HIV), and diabetes mellitus.
Perioperative management and surgical procedure
In both the PAP and SDAP groups, intravenous (IV) antibiotic prophylaxis was started within 60 min before mucosal incision. Further information on the regimens applied is given in Table 1.
Table 1The antibiotic regimens used in the two study groups. The first dose was given within 60 min before mucosal incision in both groups.
Antibiotic regimen (including dosage)
Amoxicillin–clavulanate or ampicillin–sulbactam: IV twice daily on days 1–2 (AMC 2.2 g; SAM 3 g), orally three times daily on days 3–5 (AMC 625 mg; SAM 625 mg) Clindamycin (in the case of penicillin allergy): IV three times daily on days 1–2 (600 mg), orally three times daily on days 3–5 (300 mg)
Amoxicillin–clavulanate or ampicillin–sulbactam: IV single dose (AMC 2.2 g; SAM 3 g) Clindamycin (in the case of penicillin allergy): IV single dose (600 mg)
Preparation of the intraoral surgical site was performed using chlorhexidine gluconate 0.1%; for extraoral prepping, octenidine dihydrochloride was used.
All operations were performed by experienced maxillofacial surgeons in accordance with the standard operating procedures established in the department. The Le Fort I osteotomy was performed as described by Bell and Schendel.
Mandibular fixation involved the placement of three bicortical screws on each side via an extraoral (transmasseteric) approach using a trocar. Wound closure was achieved with resorbable sutures; no tissue glue or surgical drains were used.
Specific instructions on how to maintain adequate postoperative oral hygiene were given to each patient (e.g. the use of antiseptic mouthwash (chlorhexidine gluconate 0.1%), a soft toothbrush etc.). Pain management included ibuprofen IV and oral metamizole as basic analgesia and piritramide IV as an add-on for 3 days.
The patients were examined on a daily basis during their inpatient stay. Once discharged, weekly follow-up appointments were arranged over a period of 6 weeks to check healing, signs of infection, oral hygiene, and occlusion.
The primary outcome measure was the overall SSI rate over a period of 6 months. Furthermore, the severity of the SSIs was quantified using the Clavien–Dindo classification.
This well-validated tool defines complications as any deviation from the normal postoperative course. Depending on the need for a therapeutic intervention and the level of that intervention, the classification differentiates five grades, of which grades III and IV are each divided into subgrades a and b (Table 2).
Secondary outcomes included the localization of the SSI, duration of surgery, length of in-hospital stay (LOS), and time to onset of infection.
The statistical analysis was conducted using IBM SPSS Statistics software version 26 (IBM Corp., Armonk, NY, USA). Fisher’s exact test and the Mann–Whitney U-test were applied to compare the demographic data between the PAP and SDAP groups and to investigate potential differences in the rate and severity of SSIs. Parameters such as the operation time needed and the localization of the SSIs were also analysed using these tests. The χ2 test was used to analyse the SSI rate in relation to the various antibiotic agents used.
A total of 99 patients (68 female, 31 male; mean age 30.1 ± 8.6 years) were included in the final analysis, 50 of whom received single-dose antibiotic prophylaxis (SDAP group) and 49 of whom received a prolonged 5-day antibiotic prophylaxis regimen (PAP group). There was no significant difference between the two groups in terms of age, sex, the duration of surgery, or the length of inpatient stay (Table 3, Table 4). In terms of the surgical techniques applied, 55 of the 99 study patients underwent BIMAX and 44 received a BSSO. BIMAX was performed in 27 patients in the PAP group and 28 patients in the SDAP group, while 22 patients in each group underwent BSSO.
Table 3Relevant patient data for the study cohort. There was no statistically significant difference between the PAP and SDAP groups for any of the parameters assessed.
Overall, 12 infections were observed when analysing the data without subgrouping patients according to the antibiotic regimen applied. This equates to an SSI rate of 12.1%. When comparing the SSI rate between the PAP group and SDAP group, no statistically significant difference was observed between the two antibiotic regimens (P = 0.380): five infections (10.2%) occurred in the PAP group, while seven infections (14%) occurred in the SDAP group.
SSI rate according to the antibiotic agent
Amoxicillin–clavulanate was the most common antibiotic administered (80/99: 35/49 in the PAP group, 45/50 in the SDAP group). Ampicillin–sulbactam was given to 11 patients (10/49 in the PAP group, 1/50 in the SDAP group) and eight patients were given clindamycin (four patients in each group). Ten of the 12 SSIs occurred in patients on amoxicillin–clavulanate (10/80, 12.5%). Two infections were found in patients on clindamycin (2/8, 25%). There was no statistically significant difference in the occurrence of SSIs between the antibiotics used (P = 0.215).
Within the PAP group, four SSIs occurred in patients on amoxicillin–clavulanate (4/35, 11.4%) and one SSI in a patient on clindamycin (1/4, 25%). Regarding the SDAP group, six SSIs were seen in patients who had received amoxicillin–clavulanate (6/45, 13.3%) and one SSI in a patient on clindamycin (1/4, 25%).
Severity of the SSIs
The 12 SSIs included three cases of persistent swelling (25%), one sinusitis (8.3%), four cases of wound dehiscence (33.3%), and four abscesses (33.3%) (Fig. 1).
Regarding the Clavien–Dindo classification, three complications (3/12) were rated as mild and were categorized as grade I; a further three complications (3/12) were classified as grade II. No surgical intervention was required with regard to any of these SSIs. However, systemic antibiotics had to be re-introduced as a therapeutic measure in the grade II cases. Six SSIs (6/12, 50%) met the criteria for grade IIIa of the Clavien–Dindo classification, as surgical treatment under local anaesthesia was deemed necessary: an intraoral mucosal incision was required to ensure adequate drainage of the surgical site.
The prevalence of grade I and grade II complications within the entire study population was 3.0% and 3.0%, respectively, while the prevalence of grade IIIa complications was 6.1%.
The severity of the SSIs did not differ significantly between the PAP and SDAP groups (P = 0.842).
Secondary outcomes—the SSI rate according to the localization of the SSI, surgical procedure, and duration of surgery
Regarding the localization of the 12 SSIs, nine (75%) were located in the lower jaw and three were situated in the upper jaw (25%). This disparity in the SSI rate between mandibular and maxillary surgical sites was not statistically significant (P = 0.583). In the PAP group, four of the five SSIs (80%) were located in the mandible and one (20%) was located in the maxilla. In the SDAP group, five of the seven SSIs (71.4%) affected the mandible and two (28.6%) were located in the maxilla.
Nine of the 12 SSIs (75%) occurred in patients who underwent BIMAX and three (25%) occurred in individuals who received a BSSO. Within the PAP group, all five SSIs (100%) were associated with BIMAX. Regarding the SDAP group, four of seven infections (57.1%) occurred following BIMAX and three (42.9%) following BSSO.
The average duration of surgery amounted to 117.4 ± 69.8 min. No statistically significant difference in operating time was seen when comparing the PAP group with the SDAP group: 125.2 ± 79.3 min vs 111.7 ± 59.0 min, respectively (P = 0.353). Unsurprisingly, BIMAX was associated with a significantly longer operating time in comparison to BSSO: 149.6 ± 73.9 min vs 80.7 ± 39.0 min, respectively (P < 0.001). The occurrence of SSIs was not associated with a significantly longer operating time: 150.1 ± 71.8 min in those with SSIs vs 113.4 ± 68.2 min in those without SSIs (P = 0.088) (Table 4). However, within the PAP group, a significantly longer operating time was detected in cases where SSIs were observed in comparison to those where no infection was reported: 200.2 ± 79.2 min vs 115.6 ± 75.0 min (P = 0.023).
Onset of the SSIs
The SSIs occurred on average 37.4 ± 42.6 days after surgery. In the PAP group, SSIs were found to occur 23.1 ± 30.5 days postoperatively, whereas in the SDAP group the SSIs were noted to occur 57.4 ± 52.3 days after surgery. No statistically significant difference was observed when comparing the two groups (P = 0.181) (Fig. 2).
Duration of hospitalization (LOS)
LOS amounted to an average of 5.4 ± 1.1 days in the PAP group and 5.3 ± 1.2 days in the SDAP group (Fig. 3). No statistically significant difference was found with respect to this parameter (P = 0.863). Patients with SSIs had a mean LOS of 5.9 days, whereas patients without SSIs were hospitalized for a mean 5.3 days (P = 0.251).
Due to the highly elective nature of orthognathic surgery, reducing the rate of complications to a minimum is paramount. Besides haemorrhage, nerve transection, and nasal septum deviations, SSIs are amongst the most frequent complications.
Among other reasons, this can be attributed to the use of intraoral surgical approaches in orthognathic surgery, which may result in contamination with endogenous bacteria. The prevalence of SSIs ranges between 1% and 33.4%.
described a significant reduction in SSIs with a 3-day regimen when compared to a 1-day regimen. Moreover, prolonged antibiotic prophylaxis has been described as advantageous in reducing the infection rate compared to preoperative single-dose antibiotic prophylaxis.
compared a prolonged 5-day regimen to single-dose antibiotic prophylaxis, which yielded no statistically significant differences between the two groups. As a result, their study group cautiously proposed a reduction in antibiotic administration in healthy patients. Lindeboom et al.
Prophylactic single-dose administration of 600 mg clindamycin versus 4-time administration of 600 mg clindamycin in orthognathic surgery: a prospective randomized study in bilateral mandibular sagittal ramus osteotomies.
found no significant difference either, when comparing a single-dose and four-time administration of clindamycin. In addition, several other authors have noted no benefit for extended postoperative antibiotic prophylaxis.
reported no significant difference between single-dose antibiotic prophylaxis and prolonged application of prophylactic antibiotics. Similarly, no statistically significant difference in the occurrence of SSIs was found in the present study when comparing a prolonged 5-day regimen to single-dose antibiotic prophylaxis.
argue against the need for prolonged antibiotic prophylaxis as it is associated with numerous drawbacks, such as disruption of the patient microbial flora, pharmacological adverse events, economic consequences, and, particularly, antibiotic resistance. In fact, multiple trials have shown that even single-dose or short-term application (3 days) of amoxicillin increases the load of resource-resistant viridans streptococci in saliva.
the lowest postoperative infection rate is possible when antibiotics are given within 2 h prior to the skin incision. The World Health Organization guidelines from 2016 recommend performing antimicrobial shielding 120 min before mucosal incision. For antibiotics with a short half-life (cephalosporins, penicillins), which are often used in maxillofacial surgery, administration less than 60 min before the start of the procedure is recommended.
In addressing the first point of criticism, this study strictly adhered to the stated inclusion and exclusion criteria to ensure that only healthy patients (i.e., ASA I or ASA II) were included in the study. Regarding the second point of criticism, the severity of the SSIs was defined by means of the Clavien–Dindo classification.
Thus, any deviation from the normal postoperative course (longer-lasting swelling) was rated as an SSI. It is probable, however, that this led to the higher incidence rate of SSIs reported in this study in comparison to other studies in the field (12.1%).
Furthermore, it is acknowledged that the selection of antibiotics used might have affected the SSI rate in this study. Barrier et al.
inferred that first-generation cephalosporins were more effective than penicillin and clindamycin for the prevention of SSIs. As well as amoxicillin–clavulanate, ampicillin–sulbactam and clindamycin were also used in the current study. However, it was not possible to demonstrate an association between the occurrence of SSIs and any of the antibiotics used.
Previous publications have reported an increased occurrence of SSIs in the mandible. It was hypothesized that this is due to the mandible’s poorer blood supply together with the issue of gravity, which favours an accumulation of saliva and food residues in the lower jaw.
demonstrated that the longer hospitalization as well as additional diagnostic and therapeutic measures following SSIs result in an approximate doubling of the costs on average when compared to patients without SSIs. Data on the extent of the increased LOS associated with SSIs in maxillofacial surgery, let alone orthognathic surgery, are unfortunately lacking. Across multiple surgical disciplines, the duration of hospitalization is expected to increase by 176% with SSIs.
In the present study, SSIs had no statistically significant impact on LOS (5.9 vs 5.3 days; P = 0.251). Regarding the study population, complications took more time until they developed. Thus, they usually emerged after patient discharge and, subsequently, had little effect on the LOS.
Possible limitations of this study include the fact that more than one senior surgeon performed the surgeries. However, all surgeons followed the departmental standard operating procedures. Furthermore, differences in patient oral hygiene may have had an impact on the outcomes. Additionally, studies investigating SSIs in orthognathic surgery should follow up on patients for at least 1 year, since SSIs are defined as infections that occur either within 30 days after surgery or within 1 year after the implantation of foreign material.
Thus, the chosen follow-up period of 6 months in this study leaves further room for improvement. In contrast to extending the follow-up period, however, it is proposed that the rate of SSIs would have been underreported if the study had solely focused on the first 30 days after surgery. Reasons for a later onset of infection (after 30 days) are multifactorial and may also be related to other contributing factors such as screw loosening and non-union.
This, however, was not found to be the case in the study cohort. Furthermore, no statistically significant difference between the groups compared in terms of the onset of infection was found when assessing the cohort over the defined follow-up period. Lastly, it is acknowledged that this work, being retrospective in nature, may show susceptibility to intrinsic bias. Therefore, further prospective studies are needed.
Based on the study results, single-dose antibiotic prophylaxis was statistically as effective as a perioperative 5-day antibiotic prophylaxis regimen in preventing SSIs. Taking into account the issue of increasing antimicrobial drug resistance, a timewise reduction of antibiotic prophylaxis for young, healthy adults undergoing standardized orthognathic surgical procedures is proposed.
The authors wish to thank Dipl.-Ing.in Irene Mischak (Department of Dental Medicine and Oral Health, Medical University of Graz) for her support in the statistical analysis. Special thanks also go to Sophie Krebs MD.
Ethical approval was obtained from the Ethics Committee of the Medical University of Graz (30–356 ek17/18).
Long-term antibiotic prophylaxis regimen compared to short-term antibiotic prophylaxis regimen in patients undergoing orthognathic surgery.
Prophylactic single-dose administration of 600 mg clindamycin versus 4-time administration of 600 mg clindamycin in orthognathic surgery: a prospective randomized study in bilateral mandibular sagittal ramus osteotomies.