CRANIOMAXILLOFACIAL DEFORMITIES/COSMETIC SURGERY
Nerve Manipulation During Bilateral Sagittal Split Osteotomy Increases Neurosensory Disturbance and Decreases Patient Satisfaction Marina Kuhlefelt, DDS,* Pekka Laine, DDS, PhD,y Anna L. Suominen, DDS, MSc, PhD,z Christian Lindqvist, DDS, MD, PhD,x and Hanna Thoren, DDS, MD, PhDk Purpose:
The extent to which neurosensory disturbance (NSD) affects patients after bilateral sagittal split osteotomy (BSSO) was investigated 1 year postoperatively. An additional aim was to identify related factors.
Materials and Methods:
In this prospective study, the fate of the mandibular nerve during BSSO was recorded. The predictor variable was the degree of nerve injury during BSSO, and the outcome variable was the effect of NSD 1 year postoperatively. Statistics were computed and a P value less than .05 was considered significant.
Results:
Forty-one patients (27 women; average age, 37 yr) completed the study. Of these patients, 90.2% had NSD, but most (89.2%) were satisfied with the treatment and would choose it again. The NSD was greater when the nerve had been manipulated more during surgery. The 4 patients with visible nerve lacerations had severe NSD and were unsatisfied with the treatment at the endpoint.
Conclusions: Although NSD was frequent 1 year after BSSO, most patients were satisfied with the treatment. However, a risk for severe NSD or neuropathic pain does exist in a small group of patients. These patients should be identified at an early stage so that proper medical and supportive treatment can be initiated. If necessary, a multidisciplinary pain center should be consulted. The importance of accurate patient information preoperatively cannot be overstated. Ó 2014 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 72:2052.e1-2052.e5, 2014
Correction of mandibular deformities using bilateral sagittal split osteotomy (BSSO) is a basic procedure in oral and maxillofacial surgery. The great majority of patients undergoing orthognathic surgery are young healthy adults who are motivated and compliant to treatment. However, patients are likely to have high expectations with regard to function and esthetics, and,
as before any surgery, patients should be well informed about possible complications. The main complication after jaw osteotomies is neurosensory disturbance (NSD) of the branches of the trigeminal nerve. A small group of these patients will develop neuropathic pain. NSD has been reported to occur in 25 to 98% of patients immediately or up to 1 month after BSSO1-4 and
*Consultant, Department of Oral and Maxillofacial Diseases,
Oral and Maxillofacial Diseases, Helsinki University Central
Helsinki University Central Hospital, Helsinki, Finland.
Hospital, Helsinki, Finland.
yProfessor and Head, Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland.
Address correspondence and reprint requests to Dr Kuhlefelt: Department of Oral and Maxillofacial Diseases, Helsinki University
zHead, Department of Oral Public Health, Institute of Dentistry,
Central Hospital, Kasarmikatu 11-13, 00130 Helsinki, PO Box 263,
University of Eastern Finland, Kuopio, Finland; Department of Oral
00029 HUS Helsinki, Finland; e-mail: [email protected]
and Maxillofacial Surgery, Kuopio University Hospital, Kuopio, Finland. xProfessor and Head, Department of Oral and Maxillofacial
Received November 27 2013 Accepted June 23 2014
Surgery, Institute of Dentistry, University of Helsinki, Helsinki,
Ó 2014 American Association of Oral and Maxillofacial Surgeons
Finland; Department of Oral and Maxillofacial Diseases, Helsinki
0278-2391/14/01103-3
University Central Hospital, Helsinki, Finland.
http://dx.doi.org/10.1016/j.joms.2014.06.444
kHead, Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Helsinki, Helsinki, Finland; Department of
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in 11.7 to 85.0% at least 6 months after BSSO.1,3-6 Several factors predisposing to NSD have been identified,1,6-9 such as older age, large mandibular advancements, a lateral course of the mandibular canal, a long mandibular angle, and manipulation of the inferior alveolar nerve (IAN). Many of these factors cannot be modified by the surgeon. Although altered sensation often recovers with time,10 some patients are evidently left with permanent NSD or even neuropathic pain. How much NSD actually affects patients remains unknown. Because this question has received little attention in the literature, the main aim was to clarify the extent to which NSD affects patients 1 year after BSSO. An additional aim was to elucidate the effect of the degree of manipulation of the IAN on the occurrence of NSD.
Materials and Methods STUDY DESIGN
The authors designed and implemented a prospective 18-month study of adult patients ($18 yr old) with skeletal Class II malocclusion who were scheduled to undergo mandibular advancement using standard BSSO. Fixation with titanium miniplates and monocortical screws was performed in all patients. According to the protocol of the authors’ department, possible retained third molars had been removed at least 6 months before surgery. A 1-year follow-up was required for the patient to be included in the final analysis. Patients who underwent any further surgical procedures of the mandible or maxilla primarily or during the first postoperative year were excluded. The study protocol was approved by the ethics committee of the Department of Surgery and the internal review board of the Division of Musculoskeletal Surgery, Helsinki University Central Hospital (Helsinki, Finland). All patients signed a written informed consent. The study followed the ethical principles of the Declaration of Helsinki. All patients were administered dexamethasone perioperatively according to the following scheme: 10 mg on the evening before surgery, 10 mg every 8 hours on the day of surgery, 10 mg on the first postoperative morning and then 5 mg in the evening, and 5 mg on the second postoperative morning. After the surgical procedure, patients were administered painkillers (ibuprofen or paracetamol) for as long as they subjectively benefitted from them. Additional pain medication during the immediate postoperative recovery included codeine phosphate or tramadol when needed. All patients also received antibiotics until postoperative days 7 to 10, usually penicillin or first-generation cephalosporin or, in the event of penicillin allergy, clindamycin. All enrolled patients were interviewed according to a standard protocol 1 year after surgery by one of the
authors (M.K.). The patients were asked whether they experienced NSD. The patients who had NSD were asked about the degree of harm caused by NSD. Degree of harm was categorized as 1) no harm, 2) slight harm, 3) moderate harm, and 4) major harm. After this, patients with NSD were asked about their overall satisfaction, which was categorized as 1) satisfied, 2) fairly satisfied, and 3) not satisfied. Patients with NSD also were asked whether they would be prepared to undergo the same treatment again. DATA ANALYSIS
In the statistical analysis, the main outcome variable was NSD 1 year after surgery. Patients with neuropathic pain also were identified. The main predictor variable was degree of manipulation of the IAN. Based on intraoperative observations, the degree of manipulation of the IAN was recorded as 1) IAN not exposed, 2) IAN exposed, 3) IAN dissected from the underlying bone, 4) IAN lacerated, and 5) loss of continuity of the IAN. Other predictor variables included in the analysis were gender, age at time of surgery, smoking habit (smoker vs nonsmoker), degree of mandibular advancement (7 mm), and duration of surgery (minutes). The c2 test was used to evaluate the statistical significance of the associations between the predictor variables and the dichotomous outcome variable. A P value less than .05 was considered significant.
Results Forty-three patients met the inclusion criteria and all agreed to participate in the study. Two patients did not appear at the 1-year follow-up, leaving 41 completers for the present analysis. Twenty-seven patients (65.9%) were women. The average age of all patients was 37.0 years (range, 22.2 to 59.5 yr). Six patients (14.6%) were smokers. The average operation time was 127 minutes (range, 75 to 240 minutes). As presented in Table 1, the IAN was frequently exposed during surgery. Of the total of 82 nerves, 50 were exposed, 8 had to be dissected from the underlying bone, and 4 were lacerated during the procedure. No nerve was transected and no nerve continuity was lost. The lacerated nerves were not repaired in any way; no epineural suture or fibrin glue was used. At the 1-year examination, 37 patients (90.2%) had NSD. In 2 (4.9%) of the 41 patients, the NSD was severe and classified as neuropathic pain. NSD tended to be more frequent when the IAN had been exposed, dissected, or lacerated than when it had not been exposed, but the difference was not important (Table 2). NSD tended to be more frequent in women, in patients at least 30 years old, and in smokers, but the differences were not important.
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NERVE MANIPULATION DURING OSTEOTOMY
Table 1. DEGREE OF IAN MANIPULATION IN 41 PATIENTS (82 NERVES) DURING BILATERAL SAGITTAL SPLIT OSTEOTOMY
Table 3. RELATION BETWEEN NSD AND GENDER, AGE, SMOKING HABIT, DURATION OF SURGERY, AND AMOUNT OF MANDIBULAR ADVANCEMENT 1 YEAR AFTER BILATERAL SAGITTAL SPLIT OSTEOTOMY
Not Exposed Exposed Dissected Lacerated Total IAN right IAN left Total
13 7 20
22 28 50
4 4 8
2 2 4
41 41 82
Abbreviation: IAN, inferior alveolar nerve. Kuhlefelt et al. Nerve Manipulation During Osteotomy. J Oral Maxillofac Surg 2014.
The magnitude of mandibular advancement did not have an influence on the occurrence of NSD (Table 3). Table 4 presents the degree of harm from NSD and overall satisfaction in those 37 patients who had NSD 1 year after surgery. Twenty-five patients (67.5%) experienced some degree of harm from NSD. Of these 25 patients, 14 (56%) experienced the harm as slight and 9 (36%) as moderate. Major harm was experienced by the 2 patients who had neuropathic pain. Most patients with NSD were satisfied (27.0%) or fairly satisfied (62.2%) with the treatment result. In all 4 patients who were not satisfied, the IAN had been lacerated during surgery. Two of these patients had neuropathic pain. Thirty-three (89.2%) of the 37 patients with NSD (89.2%) said that they would go through the treatment again.
Discussion The main aim of this study was to clarify the extent to which NSD affects patients 1 year after BSSO. An additional aim was to determine the effect of the degree of manipulation of the IAN on the occurrence of NSD. Of the 41 patients, 37 (90.2%) had NSD. Of these 37 patients, 25 (67.5%) experienced some degree of harm from NSD. Despite NSD, 89.2% were satisfied or fairly satisfied with treatment and would choose it again.
Patients P With NSD, n (%) Value Gender Male (n = 14) Female (n = 27) Age (yr)
Nerve Manipulation During Bilateral Sagittal Split Osteotomy Increases Neurosensory Disturbance and Decreases Patient Satisfaction Marina Kuhlefelt, DDS,* Pekka Laine, DDS, PhD,y Anna L. Suominen, DDS, MSc, PhD,z Christian Lindqvist, DDS, MD, PhD,x and Hanna Thoren, DDS, MD, PhDk Purpose:
The extent to which neurosensory disturbance (NSD) affects patients after bilateral sagittal split osteotomy (BSSO) was investigated 1 year postoperatively. An additional aim was to identify related factors.
Materials and Methods:
In this prospective study, the fate of the mandibular nerve during BSSO was recorded. The predictor variable was the degree of nerve injury during BSSO, and the outcome variable was the effect of NSD 1 year postoperatively. Statistics were computed and a P value less than .05 was considered significant.
Results:
Forty-one patients (27 women; average age, 37 yr) completed the study. Of these patients, 90.2% had NSD, but most (89.2%) were satisfied with the treatment and would choose it again. The NSD was greater when the nerve had been manipulated more during surgery. The 4 patients with visible nerve lacerations had severe NSD and were unsatisfied with the treatment at the endpoint.
Conclusions: Although NSD was frequent 1 year after BSSO, most patients were satisfied with the treatment. However, a risk for severe NSD or neuropathic pain does exist in a small group of patients. These patients should be identified at an early stage so that proper medical and supportive treatment can be initiated. If necessary, a multidisciplinary pain center should be consulted. The importance of accurate patient information preoperatively cannot be overstated. Ó 2014 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 72:2052.e1-2052.e5, 2014
Correction of mandibular deformities using bilateral sagittal split osteotomy (BSSO) is a basic procedure in oral and maxillofacial surgery. The great majority of patients undergoing orthognathic surgery are young healthy adults who are motivated and compliant to treatment. However, patients are likely to have high expectations with regard to function and esthetics, and,
as before any surgery, patients should be well informed about possible complications. The main complication after jaw osteotomies is neurosensory disturbance (NSD) of the branches of the trigeminal nerve. A small group of these patients will develop neuropathic pain. NSD has been reported to occur in 25 to 98% of patients immediately or up to 1 month after BSSO1-4 and
*Consultant, Department of Oral and Maxillofacial Diseases,
Oral and Maxillofacial Diseases, Helsinki University Central
Helsinki University Central Hospital, Helsinki, Finland.
Hospital, Helsinki, Finland.
yProfessor and Head, Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland.
Address correspondence and reprint requests to Dr Kuhlefelt: Department of Oral and Maxillofacial Diseases, Helsinki University
zHead, Department of Oral Public Health, Institute of Dentistry,
Central Hospital, Kasarmikatu 11-13, 00130 Helsinki, PO Box 263,
University of Eastern Finland, Kuopio, Finland; Department of Oral
00029 HUS Helsinki, Finland; e-mail: [email protected]
and Maxillofacial Surgery, Kuopio University Hospital, Kuopio, Finland. xProfessor and Head, Department of Oral and Maxillofacial
Received November 27 2013 Accepted June 23 2014
Surgery, Institute of Dentistry, University of Helsinki, Helsinki,
Ó 2014 American Association of Oral and Maxillofacial Surgeons
Finland; Department of Oral and Maxillofacial Diseases, Helsinki
0278-2391/14/01103-3
University Central Hospital, Helsinki, Finland.
http://dx.doi.org/10.1016/j.joms.2014.06.444
kHead, Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Helsinki, Helsinki, Finland; Department of
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in 11.7 to 85.0% at least 6 months after BSSO.1,3-6 Several factors predisposing to NSD have been identified,1,6-9 such as older age, large mandibular advancements, a lateral course of the mandibular canal, a long mandibular angle, and manipulation of the inferior alveolar nerve (IAN). Many of these factors cannot be modified by the surgeon. Although altered sensation often recovers with time,10 some patients are evidently left with permanent NSD or even neuropathic pain. How much NSD actually affects patients remains unknown. Because this question has received little attention in the literature, the main aim was to clarify the extent to which NSD affects patients 1 year after BSSO. An additional aim was to elucidate the effect of the degree of manipulation of the IAN on the occurrence of NSD.
Materials and Methods STUDY DESIGN
The authors designed and implemented a prospective 18-month study of adult patients ($18 yr old) with skeletal Class II malocclusion who were scheduled to undergo mandibular advancement using standard BSSO. Fixation with titanium miniplates and monocortical screws was performed in all patients. According to the protocol of the authors’ department, possible retained third molars had been removed at least 6 months before surgery. A 1-year follow-up was required for the patient to be included in the final analysis. Patients who underwent any further surgical procedures of the mandible or maxilla primarily or during the first postoperative year were excluded. The study protocol was approved by the ethics committee of the Department of Surgery and the internal review board of the Division of Musculoskeletal Surgery, Helsinki University Central Hospital (Helsinki, Finland). All patients signed a written informed consent. The study followed the ethical principles of the Declaration of Helsinki. All patients were administered dexamethasone perioperatively according to the following scheme: 10 mg on the evening before surgery, 10 mg every 8 hours on the day of surgery, 10 mg on the first postoperative morning and then 5 mg in the evening, and 5 mg on the second postoperative morning. After the surgical procedure, patients were administered painkillers (ibuprofen or paracetamol) for as long as they subjectively benefitted from them. Additional pain medication during the immediate postoperative recovery included codeine phosphate or tramadol when needed. All patients also received antibiotics until postoperative days 7 to 10, usually penicillin or first-generation cephalosporin or, in the event of penicillin allergy, clindamycin. All enrolled patients were interviewed according to a standard protocol 1 year after surgery by one of the
authors (M.K.). The patients were asked whether they experienced NSD. The patients who had NSD were asked about the degree of harm caused by NSD. Degree of harm was categorized as 1) no harm, 2) slight harm, 3) moderate harm, and 4) major harm. After this, patients with NSD were asked about their overall satisfaction, which was categorized as 1) satisfied, 2) fairly satisfied, and 3) not satisfied. Patients with NSD also were asked whether they would be prepared to undergo the same treatment again. DATA ANALYSIS
In the statistical analysis, the main outcome variable was NSD 1 year after surgery. Patients with neuropathic pain also were identified. The main predictor variable was degree of manipulation of the IAN. Based on intraoperative observations, the degree of manipulation of the IAN was recorded as 1) IAN not exposed, 2) IAN exposed, 3) IAN dissected from the underlying bone, 4) IAN lacerated, and 5) loss of continuity of the IAN. Other predictor variables included in the analysis were gender, age at time of surgery, smoking habit (smoker vs nonsmoker), degree of mandibular advancement (7 mm), and duration of surgery (minutes). The c2 test was used to evaluate the statistical significance of the associations between the predictor variables and the dichotomous outcome variable. A P value less than .05 was considered significant.
Results Forty-three patients met the inclusion criteria and all agreed to participate in the study. Two patients did not appear at the 1-year follow-up, leaving 41 completers for the present analysis. Twenty-seven patients (65.9%) were women. The average age of all patients was 37.0 years (range, 22.2 to 59.5 yr). Six patients (14.6%) were smokers. The average operation time was 127 minutes (range, 75 to 240 minutes). As presented in Table 1, the IAN was frequently exposed during surgery. Of the total of 82 nerves, 50 were exposed, 8 had to be dissected from the underlying bone, and 4 were lacerated during the procedure. No nerve was transected and no nerve continuity was lost. The lacerated nerves were not repaired in any way; no epineural suture or fibrin glue was used. At the 1-year examination, 37 patients (90.2%) had NSD. In 2 (4.9%) of the 41 patients, the NSD was severe and classified as neuropathic pain. NSD tended to be more frequent when the IAN had been exposed, dissected, or lacerated than when it had not been exposed, but the difference was not important (Table 2). NSD tended to be more frequent in women, in patients at least 30 years old, and in smokers, but the differences were not important.
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NERVE MANIPULATION DURING OSTEOTOMY
Table 1. DEGREE OF IAN MANIPULATION IN 41 PATIENTS (82 NERVES) DURING BILATERAL SAGITTAL SPLIT OSTEOTOMY
Table 3. RELATION BETWEEN NSD AND GENDER, AGE, SMOKING HABIT, DURATION OF SURGERY, AND AMOUNT OF MANDIBULAR ADVANCEMENT 1 YEAR AFTER BILATERAL SAGITTAL SPLIT OSTEOTOMY
Not Exposed Exposed Dissected Lacerated Total IAN right IAN left Total
13 7 20
22 28 50
4 4 8
2 2 4
41 41 82
Abbreviation: IAN, inferior alveolar nerve. Kuhlefelt et al. Nerve Manipulation During Osteotomy. J Oral Maxillofac Surg 2014.
The magnitude of mandibular advancement did not have an influence on the occurrence of NSD (Table 3). Table 4 presents the degree of harm from NSD and overall satisfaction in those 37 patients who had NSD 1 year after surgery. Twenty-five patients (67.5%) experienced some degree of harm from NSD. Of these 25 patients, 14 (56%) experienced the harm as slight and 9 (36%) as moderate. Major harm was experienced by the 2 patients who had neuropathic pain. Most patients with NSD were satisfied (27.0%) or fairly satisfied (62.2%) with the treatment result. In all 4 patients who were not satisfied, the IAN had been lacerated during surgery. Two of these patients had neuropathic pain. Thirty-three (89.2%) of the 37 patients with NSD (89.2%) said that they would go through the treatment again.
Discussion The main aim of this study was to clarify the extent to which NSD affects patients 1 year after BSSO. An additional aim was to determine the effect of the degree of manipulation of the IAN on the occurrence of NSD. Of the 41 patients, 37 (90.2%) had NSD. Of these 37 patients, 25 (67.5%) experienced some degree of harm from NSD. Despite NSD, 89.2% were satisfied or fairly satisfied with treatment and would choose it again.
Patients P With NSD, n (%) Value Gender Male (n = 14) Female (n = 27) Age (yr)
