[Complications in surgical treatment of malocclusions. Report of 50 years experience]

The neurosensory deficit of inferior alveolar nerve following bilateral sagittal split osteotomy: a prospective study

OBJECTIVES

Investigation in Saudi Arabia or the Arab Gulf States to assess the unfavorable impacts of the bilateral sagittal split osteotomy (BSSO) is non-existent, so questions have been raised about the success rate of this operation and the frequency of unwilling outcome. To address these worries, we directed a case series study to evaluate the hypoesthesia, a type of neurosensory deficit (NSD) of the inferior alveolar nerve (IAN) after BSSO, and if the hypoesthesia outcome will improve if the surgeries performed by a single surgeon.

PATIENTS AND METHODS

This was a prospective case series study for the patient who underwent BSSO in a medical complex that is considered one of the largest in Saudi Arabia (Riyadh). The inclusion criteria include patient aged 18-40 years, any gender, and American Society of Anesthesiologists (ASA) class I. They will undergo BSSO for either mandibular, retrognathia, prognathic, or to follow the maxilla. The outcome will be measured after evaluating the neurosensory by four means light touch (LT), pinprick (PP), 2-point discrimination (2PD), and thermal sensations (TT) in four repeated measurements (preoperatively, 1 week, 1 month, 3 months postoperatively) as the primary outcome. Other confounding factors were the secondary outcome (age, gender, visualization of the I.A.N, the type of mandibular movement, split favorability, mandibular canal location, and patient reports about paresthesia or dysesthesia on any given side); these data analyses were carried out using SPSS ver. 25 data processing software.

RESULTS

The nerve was visible in 93% of cases. During the operation, none of the nerves was transected. Hypoesthesia on the first follow-up was 94% of cases for LT, 92% for PP, 82% for TT, and 100% for the 2PD. On the last follow-up, the patients still had hypoesthesia for the LT 51%, PP 35%, TT41%, and 2PD 55%; age and sex did not significantly affect hypoesthesia outcomes. Nerve visibility and inferior alveolar nerve canal (IAC) distance did not influence the results. The level of confidence for all tests was set at p < 0.05.

CONCLUSIONS

The 2PD sensation was the most affected sense on the last visit, and the right side of the chin and lower lip was affected most both on early and long-term follow-up due to several reasons. A 3-month period was enough as a recovery time to restore 100% of neurological sensation for 45% of the sample, which is similar to several studies in the literature. A single surgeon did not show superior result compared to two surgeons' literature papers. Advancement movement was associated with a high percentage of hypoesthesia.

Pediatric Orthognathic Surgery: National Analysis of Perioperative Complications

BACKGROUND

Orthognathic surgery has traditionally been performed after skeletal maturity. Although these procedures are also being performed in children, the implications of earlier intervention and specific risk factors in this younger population remain unknown.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Pediatric dataset was queried for orthognathic procedures performed in 2018. Complications, readmissions, and reoperations were analyzed with appropriate statistics.

RESULTS

Overall adverse event rate after orthognathic surgery in pediatric patients was 7.8% (n = 22 of 281), which were associated with having any comorbidity (P < 0.001), overall respiratory comorbidities (P = 0.004), structural pulmonary abnormality (P < 0.001), developmental delay (P = 0.035), structural central nervous system abnormality (P < 0.001), and neuromuscular disorder (P = 0.035). Most common complications were excessive bleeding (2.5%), surgical site infection (1.1%), and pneumonia (0.7%). Orthognathic surgery in children below 6 years of age is associated with significantly increased adverse events (P < 0.001), including surgical site infection (P < 0.001), pneumonia (P = 0.022), readmission (P < 0.001), and reoperation (P < 0.001). Le Fort I osteotomies (P < 0.001) and bilateral sagittal split osteotomies (P = 0.009) took significantly longer for older patients in the years of permanent dentition than younger patients in the years of deciduous dentition. Single- and double-jaw procedures in pediatric patients have similarly low adverse events (P all ≥0.130). Interestingly, bilateral sagittal split osteotomies performed before 13.5 years of age were associated with a higher risk of adverse events (P = 0.012), such that these younger patients were 7.1 times more likely to experience adverse events if their procedure was performed earlier.

CONCLUSIONS

Orthognathic surgery is relatively safe, but children in the years of deciduous dentition under 6 years of age have significantly increased risk of adverse events.

Relapse and temporomandibular joint dysfunction (TMD) as postoperative complication in skeletal class III patients undergoing bimaxillary orthognathic surgery: A systematic review

Objectives

The aim of this study was to determine Relapse and TMD as postoperative complication in skeletal class III patients undergoing bimaxillary orthognathic surgery.

Materials and methods

Data was obtained by database searching using The Cochrane Central Register of Controlled Trials (central), PUBMED, SCOPUS, EMBASE, Google scholar, National Medical library, New Delhi. The titles and abstracts of the electronic search results were screened and evaluated by two observers for eligibility according to the inclusion and exclusion criteria.

Results

5261 articles were retrieved for the review. Among these, 3474 duplicate articles were removed. 418 studies were selected based on the eligibility criteria. For the present review, 30 articles were included after elimination according to the inclusion criteria. The Prisma diagram flowchart demonstrates our selection scheme. Quality assessment criteria to evaluate the studies were decided by two review authors in accordance with CONSORT guidelines. Each study was assessed using the evaluation method described in the Cochrane Handbook for Systematic Reviews. Among the 30 studies included in the review, marked degree of relapse in the mandible was noted from 3 months - 1 year postoperatively in 8 studies, 5 studies reported both TMD prevalence and relapse, whereas only 4 studies reported TMD disorder alone.

Conclusion

Complications of relapse and TMD are associated with bimaxillary orthognathic surgery procedures. More RCTs and CCTs are needed in this regard to get better quality evidence. This review was registered with PROSPERO: CRD42020211342.

Intra- and Postoperative Complications of Le Fort I Maxillary Osteotomy

BACKGROUND

The Le Fort I maxillary osteotomy is a versatile and simple procedure, which has gained popularity nowadays, to correct a wide range of malocclusion and maxillofacial deformities. This procedure is often associated with significant but rare postoperative complications. The aim of this study was to evaluate the types and frequencies of intra- and perioperative complications related to Le Fort I osteotomies in noncleft Iranian patients.

MATERIALS AND METHODS

In this prospective study, all the healthy systemic patients, (ASA I, II) with the age range of 18 to 30 years from both genders, who had the skeletal class II or III deformities and required only isolated 1-piece maxillary Le Fort I osteotomy, were included in this study. These patients had no craniofacial cleft history and were candidates for orthognathic surgery in Maxillofacial Surgery Department of Qaem Hospital of Mashhad (Iran), 2015 to 2017. All of the operations were carried out or supervised by a single surgeon and anesthesiologist using the same protocol. The patients were monitored for occurrence of intra- or postoperative complications till 6 months. The t-test, Chi-squared test, and Fisher exact test were performed for data analysis using SPSS version 16 (SPSS Inc, Chicago, IL).

RESULTS

In the present study, a total of 114 consecutive patients with the average age of 22 ± 5 years from October 2015 to November 2017 were recruited. About 77 (67.54%) patients were presented skeletal class III deformity and 37 (32.46%) were class II. The most prevalent maxillary movement after Le Fort I osteotomy was identified to be isolated maxillary advancement in 51 (44.75%) patients. Only 10 (8.77%) of all 114 patients confronted surgical complications. Hemorrhagic complication (arterial bleeding from descending palatine artery and epistaxis) and anatomic complications (septal deviation and bad fracture) would be the most prevalent complications with the frequency of 5.25% and 3.5% in total. Maxillary setback with impaction presented the highest rate (36.4%) of complications compared to other maxillary movement types. On balance, there was a significant association between Le Fort I surgery complications and maxillary movement types in our research (P = 0.002).

CONCLUSION

The rate of intra- and postoperative complications following Le Fort I osteotomy for healthy noncleft adults in our center was low. Therefore, it can be concluded that this technique is safe and reliable. The maxillofacial surgeon should pay more attention for prevention or even management of the risk of intra- and perioperative complications in patients with anatomic irregularities (previous craniofacial cleft or trauma history) and those who required maxillary setback concomitant with impaction movements.

Major Complications and 30-Day Morbidity for Single Jaw Versus Bimaxillary Orthognathic Surgery as Reported by NSQIP

OBJECTIVE

Acute complications in orthognathic surgery are reported in single-institution studies with small sample sizes. We aimed to analyze risk factors for acute complications using a national data set to better inform surgical decision-making.

METHODS

2005-2015 National Surgical Quality Improvement Program (NSQIP) data sets were analyzed for patients undergoing Le Fort 1 and/or bilateral sagittal split osteotomies (BSSO) for nontraumatic indications. Demographics, comorbidities, medical, and surgical 30-day complications were tabulated. A logistic regression model was used to determine predictors of complications.

RESULTS

Five hundred eight patients met the inclusion criteria: 228 underwent Le Fort I osteotomies, 152 BSSO, and 128 patients underwent both during a single surgical encounter. Overall complication rate was 4.5% (23/508). Superficial infection was the most common complication (11 in BSSO and 2 in Le Fort I cohorts). Increasing age and undergoing BSSO alone were associated with higher overall complication rates (P < .05) and surgical complications specifically (P < .05). Patients undergoing the combined procedure had shorter operative time (208 minutes) than the times for Le Fort I osteotomies alone (177 minutes) and BSSO alone (155 minutes) added together and did not have a longer hospital stay (P = .608) or increased need for transfusion (P = 1.0) compared to the surgeries being done separately.

CONCLUSION

This is the first complication risk factor analysis for Le Fort I osteotomy and BSSO using the multi-institutional NSQIP data set. Combining BSSO and Le Fort I osteotomy leads to a shorter overall operative time and does not increase hospital stay duration or 30-day complication rate when compared to the 2 procedures being done separately.

Bad splits in bilateral sagittal split osteotomy: systematic review and meta-analysis of reported risk factors

An unfavourable and unanticipated pattern of the bilateral sagittal split osteotomy (BSSO) is generally referred to as a 'bad split'. Patient factors predictive of a bad split reported in the literature are controversial. Suggested risk factors are reviewed in this article. A systematic review was undertaken, yielding a total of 30 studies published between 1971 and 2015 reporting the incidence of bad split and patient age, and/or surgical technique employed, and/or the presence of third molars. These included 22 retrospective cohort studies, six prospective cohort studies, one matched-pair analysis, and one case series. Spearman's rank correlation showed a statistically significant but weak correlation between increasing average age and increasing occurrence of bad splits in 18 studies (ρ=0.229; P<0.01). No comparative studies were found that assessed the incidence of bad split among the different splitting techniques. A meta-analysis pooling the effect sizes of seven cohort studies showed no significant difference in the incidence of bad split between cohorts of patients with third molars present and concomitantly removed during surgery, and patients in whom third molars were removed at least 6 months preoperatively (odds ratio 1.16, 95% confidence interval 0.73-1.85, Z=0.64, P=0.52). In summary, there is no robust evidence to date to show that any risk factor influences the incidence of bad split.

Bad splits in bilateral sagittal split osteotomy: systematic review of fracture patterns

An unfavourable and unanticipated pattern of the mandibular sagittal split osteotomy is generally referred to as a 'bad split'. Few restorative techniques to manage the situation have been described. In this article, a classification of reported bad split pattern types is proposed and appropriate salvage procedures to manage the different types of undesired fracture are presented. A systematic review was undertaken, yielding a total of 33 studies published between 1971 and 2015. These reported a total of 458 cases of bad splits among 19,527 sagittal ramus osteotomies in 10,271 patients. The total reported incidence of bad split was 2.3% of sagittal splits. The most frequently encountered were buccal plate fractures of the proximal segment (types 1A-F) and lingual fractures of the distal segment (types 2A and 2B). Coronoid fractures (type 3) and condylar neck fractures (type 4) have seldom been reported. The various types of bad split may require different salvage approaches.

Technical and surgical aspects of the sphenopalatine ganglion (SPG) microstimulator insertion procedure

Cluster headache (CH) is a debilitating, severe form of headache. A novel non-systemic therapy has been developed that produces therapeutic electrical stimulation to the sphenopalatine ganglion (SPG). A transoral surgical technique for inserting the Pulsante SPG Microstimulator into the pterygopalatine fossa (PPF) is presented herein. Technical aspects include detailed descriptions of the preoperative planning using computed tomography or cone beam computed tomography scans for presurgical digital microstimulator insertion into the patient-specific anatomy and intraoperative verification of microstimulator placement. Surgical aspects include techniques to insert the microstimulator into the proper midface location atraumatically. During the Pathway CH-1 and Pathway R-1 studies, 99 CH patients received an SPG microstimulator. Ninety-six had a microstimulator placed within the PPF during their initial procedure. Perioperative surgical sequelae included sensory disturbances, pain, and swelling. Follow-up procedures included placement of a second microstimulator on the opposite side (n=2), adjustment of the microstimulator lead location (n=13), re-placement after initial unsuccessful placement (n=1), and removal (n=5). This SPG microstimulator insertion procedure has sequelae comparable to other oral cavity procedures including tooth extractions, sinus surgery, and dental implant placement. Twenty-five of 29 subjects (86%) completing a self-assessment questionnaire indicated that the surgical effects were tolerable and 90% would make the same decision again.

Does the Type of Maxillomandibular Deformity Influence Complication Rate in Orthognathic Surgery?

PURPOSE

Patients may encounter various complications during and after orthognathic surgery. The aim of this study was to compare the prevalence of complications in various skeletal deformities to see if an association exists.

MATERIALS AND METHODS

This retrospective cohort study assessed patients in 2 groups. Group 1 had class III skeletal deformity and group 2 had class II skeletal deformity with vertical maxillary excess (VME). Complications were studied in 2 stages: Stage 1 included perioperative and immediate (first 24 hours) postoperative complications namely difficult intubation, blood transfusion, bad splits, pain, and postoperative airway problems. Stage 2 included postoperative complications (from 24 hours up to 6 months after surgery namely bad splits and relapse). Age, sex, operation time, and the amount of jaw movements were considered as variables. Types of skeletal deformity were predictive factor of the study.

RESULTS

The authors studied 248 patients in 2 groups. In group 1, 13 (8.2%) patients needed blood transfusion during surgery up to 24 hours after operation and 27 (30%) patients in group 2. Analysis of data demonstrated a significant difference for blood transfusion between 2 groups (P = 0.001). In group 1, 8 (5.1%) patients had a difficult intubation compared with 13 (14.4%) patients in group 2.Comparison of mandibular movement and maximum mouth opening (MMO) did not show significant differences between 2 groups (P > 0.05). The amount of maxillary movement and horizontal discrepancy were different statistically in 2 groups (P < 0.05). Analysis of the data showed a significant difference in intubation between the 2 groups (P < 0.05). There were no differences between the 2 groups for bad splits, postoperative airway problems, or paresthesia (P > 0.05). Results did not demonstrate a significant difference for pain between the 2 groups (P > 0.05).

CONCLUSIONS

Patients with class II skeletal deformity and VME may have higher risk of perioperative blood loss and difficult intubation compared with patients with class III skeletal deformity.

Low to high oblique ramus piezoosteotomy: a pilot study

Two major drawbacks of classical bilateral sagittal split osteotomy (BSSO) are occasional inferior alveolar nerve damage and bad splits. In order to avoid these two well-known disadvantages and benefit from ultrasonic bone cutting, a low-to-high oblique piezoosteotomy (LHO) was developed from Schlössmann's 1922 high oblique osteotomy, clinically evaluated with a standard and a novel osteosynthesis system. Eighty-five patients were retrospectively evaluated, 23 with an LHO osteotomy with standard osteosynthesis, 33 LHO with a dedicated plate osteosynthesis and compared to 29 patients with BSSO and standard osteosyntheses. The mean mandibular advancement in the LHO standard osteosynthesis/LHO dedicated plate osteosynthesis/BSSO collectives was 4.7 ± 2.5/7.8 ± 7.1/4.1 ± 2.8 mm, the mean one year relapse 2.6 ± 0.8 (p = 0.58)/1.4 ± 1.4 (p = 0.28)/2.1 ± 1.4 mm; the mean mandibular setback was 6.9 ± 3.6/7.7 ± 4.1/8.1 ± 4.9 mm and the one year relapse 2.9 ± 2.9 (p = 0.16)/1.4 ± 1.0 (p = 0.38)/1.5 ± 1.9 mm; clockwise rotation of the mandible was 5.2 ± 3.2/6.3 ± 5.1/10.2 ± 6.9°, the one year relapse 2.7 ± 1.2 (p = 0.18)/2.1 ± 1.7 (p = 0.09)/11.4 ± 9.3°; counterclockwise rotation averaged 6.4 ± 3.2/6.5 ± 7.9/6.5 ± 6.1° with a mean one year relapse of 3.3 ± 0.6 (p = 0.37)/3.7 ± 1.9 (p = 0.21)/4.5 ± 6.2°. LHO had 3%, BSSO 5% three months postoperative inferior alveolar nerve deficit (p = 0.17). The operation time was significantly shorter when LHO and dedicated plates were used compared to BSSO. Two broken conventional plates occurred in LHO, which stimulated the development of the dedicated plates used, one in BSSO; four bad splits in BSSO and two in LHO. Reosteosyntheses were performed using the newly developed dedicated "orthognathics" plate. LHO was successfully performed, easier and faster than BSSO. Gonial angle modifications were possible due to the oblique cut. Postoperative stability appears sufficient for moderate repositioning with a lower incidence of bad split and inferior alveolar nerve irritation, moreover blood loss was reduced. Since 2 standard miniplate fractures occurred in LHO, the "orthognathics" osteosynthesis was developed, applied and no further osteosynthesis fractures were seen.

Risk factors and prevention of bad splits during sagittal split osteotomy

PURPOSE

One of the operative complications of the sagittal split osteotomy of the mandible is a bad split, which describes an unfavorable or irregular fracture of the mandible in the course of the osteotomy. The purpose of this study is to identify previous studies which reported incidences of bad split occurrence during sagittal split osteotomy and to discuss its mechanisms and risk factors, based on a literature review, in order to minimize their occurrence. A few illustrative cases are also presented.

METHODS

An electronic search was undertaken in January 2011. The titles and abstracts from these results (n = 363) were read for identifying studies which reported incidences of bad split occurrence during sagittal split osteotomy procedures.

RESULTS

Twenty-one studies were identified and assessed. The incidence of bad splits from these studies varied between 0.21% and 22.72%. The buccal plate of the proximal segment and the posterior aspect of the distal segment were the most affected areas.

DISCUSSION

The surgical patient should be evaluated according to age and the presence of unerupted/impacted third molars. Prevention is focused on adequate osteotomy design, eliminating sharp angle where abnormal stress occurs on bony segments, completion of adequate cuts into the retrolingular depression and through the inferior border, and careful separation of the segments. The SSO is an extremely technical and sensitive procedure, and careful attention will probably prevent most unfavorable splits. If a fracture occurs, the fractured segments should be incorporated into the fixation scheme if possible. The occurrence of bad splits cannot always be avoided. When adequately treated the chances of functional success are good.

Surgical risk factors and maxillary nerve function after Le Fort I osteotomy

PURPOSE

Data on intraoperative risk factors for long-term postoperative complications after Le Fort I osteotomy (LFO) are limited. The aim of this study was to describe prospectively the overall postoperative changes in maxillary nerve function after LFO, and to correlate these changes with a number of possible intraoperative risk factors.

PATIENTS AND METHODS

Twelve men and 13 women (mean +/- standard deviation: aged 25+/-10 years) participated in 4 sessions: 1 before LFO (baseline), and the rest at 3, 6, and 12 months after LFO. At each session, somatosensory sensitivity was assessed for the skin, oral mucosa, and teeth, using quantitative sensory tests at either 1 cutaneous point or on a 5 x 5 point matrix reproduced on the skin. In addition, all patients were asked to report their perceived differences in somatosensory sensitivity and their overall satisfaction with the LFO.

RESULTS

The thresholds of tactile stimuli on the gingiva and palate were increased 12 months after LFO (P< .001). Significant increases in 2-point discrimination detection thresholds (P< .01) and increased sensitivity to heat (P< .01) and cold (P< .001) in the infraorbital region were also recorded 12 months after LFO. Correspondingly, self-reported complaints of changed sensation under the eyes (P< .01), upper lip (P< .01), gingiva (P< .001), palate (P< .01), and teeth (P< .01) were reported during the entire postoperative period. Intraoperative risk factors were identified and correlated with postoperative changes in somatosensory sensitivity. Segmentation of the maxilla was associated with an increase in tactile thresholds at the palate and gingiva (P< .05), as were self-reported complaints involving the palate and gingiva (P< .001), whereas maxillary impaction was related to lower-tooth pulp pain thresholds when compared with maxillary lowering (P< .01). All patients expressed satisfaction with LFO, despite signs of somatosensory disturbances in up to 64% of patients.

CONCLUSION

Numerous changes in postoperative somatosensory function are to be expected after LFO. In most patients, these changes are minor, and some are dependent on intraoperative procedures. Nonetheless, all patients reported satisfaction with the surgical results, and would recommend the procedure to others.

Sensory action potentials of the maxillary nerve: a methodologic study with clinical implications

PURPOSE

Recently, recording of sensory nerve action potentials (SNAPs) of the inferior alveolar nerve (IAN) was described and is used as a diagnostic test of traumatic neuropathic trigeminal disorders. The technique is limited to IAN damage; therefore, we adapted the technique to the maxillary nerve, which is also frequently injured by either trauma or orthognathic surgery.

PATIENTS AND METHODS

Fourteen healthy volunteers participated in this methodologic study in which the infraorbital nerve (ION) was stimulated with 2 needle electrodes. The SNAPs were recorded from the maxillary nerve with a unipolar needle electrode close to the foramen rotundum.

RESULTS

The mean latency of the SNAPs was 0.73 ms (95% CI, 0.55 to 0.85 ms) with a 0.08+/-0.09 ms interside difference. The mean baseline to peak amplitude was 31.3+/-7.0 microV (95% CI, 24.2 to 38.3 microV) with a 6.5+/-32.4 microV interside difference. Repeated tests within a session test demonstrated no significant differences in the latency data (ANOVA: P= .225) or amplitude data (ANOVA: P= .44). Stimulus-response curves indicated that the SNAPs saturated at 5.1+/-4.4 mA stimulus intensity. In 1 subject, stimulation of the mental nerve elicited SNAPs (latency: 1.6 ms; amplitude 38 microV) in accordance with published values. A local anesthetic block of the ION was associated with a distinct decay of the SNAP in 1 subject.

CONCLUSION

We suggest that SNAPs of the maxillary nerve can be a valuable technique for a comprehensive examination of the trigeminal system.

Neurosensory disturbances one year after bilateral sagittal split mandibular ramus osteotomy performed with separators

BACKGROUND

The most frequently performed osteotomy for correction of mandibular retrognathia is a bilateral sagittal split ramus osteotomy. Permanent neurosensory disturbance of the inferior alveolar nerve is one of the most frequently and severe complications. Many authors have reported this, but the incidence differs widely. In the recent literature, only four authors have reported a percentage of less than 10% after 1 year follow-up.

OBJECTIVE

To determine the incidence of permanent neurosensory disturbance of the inferior alveolar nerve after bilateral sagittal split ramus osteotomy, and possible influences of the technique used.

PATIENTS AND METHODS

A series of 109 patients is reported who underwent a bilateral sagittal split mandibular ramus osteotomy with the use of separators and without the use of chisels. The segments were hold by rigid transbuccal screw fixation.

RESULTS

The incidence of neurosensory disturbances 1 year after surgery was 8.3%.

CONCLUSION

The use of sagittal split separators without the use of chisels, may play an important role in the relatively low percentage of persistent hypoaesthesia of the inferior alveolar nerve.

[Quantitative determination of thermosensitivity after mandibular sagittal split osteotomy]

BACKGROUND

To determine the temperature- and pain thresholds of patients (n=20) who had undergone mandibular sagittal split osteotomy (MSSO), we developed a specific thermal probe to evaluate the neurosensory disturbances of the inferior alveolar nerve under prospective study conditions.

METHODS

Measurements were performed prior to surgery and postoperatively up to 6 months. Thermal probe test results were compared to the results of the usual two-point discrimination test and the sharp/blunt test. Furthermore we took the subjective neurosensory perception of each patient into account.

RESULTS

With focus on our newly developed thermal probe and under comparison with the preoperative results, the postoperative neurosensory tests revealed increased thresholds of up to 12.7 degrees C. Between 3 and 6 months postoperatively, quantitative resensitization could be evaluated. In contrast, the usual testing methods were not accurate enough to give valuable significant data within 3 and 6 months postoperatively. Our evaluation could also show that after 6 months thermal thresholds were up 1.5 degrees C as compared with the preoperative status.

CONCLUSION

Base on our data we conclude that the newly developed thermal probe is accurate to determine neurosensory disturbances of the alveolar inferior nerve after sagittal split osteotomy. As compared with the more common testing methods, an advantage of our contemporary measurement device is the quantitative analysis of nerval function.

Perioperative complications following sagittal split osteotomy of the mandible

INTRODUCTION

The aim of this study was to review complications in a series of 1264 consecutive patients who were operated in a single centre during a 20-year-period.

MATERIAL AND METHODS

Complications were documented, their incidences calculated and compared with data from the literature.

RESULTS

In 35 patients (2.8%) infection developed requiring extraoral incision and drainage; in 27 patients (2.1%) the inferior alveolar nerve was inadvertently cut; 18 patients (1.4%) had to undergo re-operation due to bending or fracture of osteosynthesis material; 15 patients (1.2%) suffered from bleeding complications; in 12 patients (0.9%) an unfavourable split occurred. In 8 patients (0.6%) foreign bodies were left in situ; in 7 patients a partial weakness of the facial nerve occurred, which was permanent in 1 patient. Six patients (0.5%) with a significantly higher age than average (mean: 33.6 years in comparison with 23.1 years) developed non-union at the site of osteotomy, and the mandible had to be bone grafted. Two patients (0.2%) developed osteomyelitis, and in one patient airway problems led to a need for tracheostomy (0.1%).

CONCLUSION

Although some of these complications of bilateral sagittal split with osteotomy carry severe limitations in health related quality of life, it remains an overall safe procedure, demanding, however, comprehensive informed consent. Good knowledge of technical reasons for these complications should help to reduce their incidence.

Stabilisation of sagittal split set-back osteotomies with miniplates: a prospective, multicentre study with 2-year follow-up

The aim of this study was to assess post-operative stability of bilateral sagittal split set-back osteotomies using two miniplates and clinical parameters including nerve function, TMJ function, occlusal relapse and patient satisfaction. The stability was measured on cephalometric radiographs and possible condylar alterations on orthopantomograms. This prospective study implied a 2-year follow-up on a group of 24 patients. The same protocol was used at six participating institutions at which the patients were treated. A stable occlusion without appreciable relapse was seen in 91% after 2-year follow-up. Only two patients in this study had mild occlusal relapse. The mean skeletal horizontal relapse at pogonion of the whole group, after 2 years was 1.1mm and appeared to be directed backwards. At occlusal level, however, the mean relapse was 1.2mm forwards. The function of the inferior alveolar nerve 2 years post-operatively was reported to be normal in approximately 70% of the patients, yet 80% had no complaints about nerve dysaesthesia. In approximately 21% of the patients, signs and symptoms of TMJ dysfunction had disappeared. Another group (10%), however, without pre-operative signs and symptoms of TMJ dysfunction developed these signs or symptoms post-operatively. No condylar remodelling or resorption was seen in this group of patients. The sagittal split set-back osteotomy fixed with miniplates appeared to be a relatively save and reliable procedure giving rise to adequate results and a high degree of patients satisfaction.

Intra- and perioperative complications of the LeFort I osteotomy: a prospective evaluation of 1000 patients

The LeFort I osteotomy has become a routine procedure in elective orthognathic surgery. The authors report the occurrence of intra- or perioperative complications in a series of 1000 consecutive LeFort I osteotomies performed within a 20-year period. In total, 64 (6.4%) patients experienced complications. Anatomical complications affected 26 (2.6%), patients, including 16 (1.6%) with a deviation of the nasal septum and 10 (1.0%) with non-union of the osteotomy gap. Extensive bleeding that required blood transfusion occurred in 11 (1.1%) patients exclusively after bimaxillary corrections; in 1 patient a ligation of the external carotid artery became necessary. Significant infections such as abscesses or maxillary sinusitis occurred in 11 (1.1%) patients. No patient experienced an osteomyelitis. Ischemic complications affected 10 (1.0%) patients, including 2 (0.2%) who experienced an aseptic necrosis of the alveolar process and 8 (0.8%) who, under critical revision, were affected by retractions of the gingiva. Five (0.5%) patients experienced an insufficient fixation of the osteosynthesis material. The risk and the extent of complications was enhanced in patients with anatomical irregularities (eg, in patients with craniofacial dysplasias, orofacial clefts, or vascular anomalies). The risk of ischemic complications was enhanced in extensive dislocations or transversal segmentation of the maxilla. The authors conclude that patients with major anatomical irregularities should be informed about an enhanced risk of Le-Fort I osteotomies. Preoperative planning avoiding transversal segmentation or extensive dislocations of the maxilla should reduce the occurrence of complications. For healthy individuals, the risk of complications with the LeFort I osteotomy is considered low.

[Preoperative determination of the position of mandibular canal for planning sagittal ramus osteotomy of the mandible]

BACKGROUND

In the literature the incidence of permanent nerve lesions ranges from 3 to 39%. Therefore, we think that it is necessary to discuss the procedure of individual risk assessment and management. Standard imaging techniques for the preoperative planning and preparation of a sagittal split osteotomy usually include a panoramic radiograph and lateral cephalometric radiograph. If an assessment of the transversal thickness of the lower jaw and cortical substance is required, or the position of the inferior alveolar nerve needs to be determined for preoperative planning, computed tomography of the viscerocranium has to be performed. By employing the conventional computed tomographic X-ray imaging system CommCAT, we are able to determine preoperatively both the transversal thickness of the lower jaw including the cortical substance and the diameter of the ascending ramus of the mandible at the proximal osteotomy site.

PATIENTS AND METHOD

We examined prospectively the value of these additional investigations and compared them with the intraoperative findings in 29 patients. With these tomograms, the relation between the position of the inferior alveolar nerve and the vestibular cortical bone was metrically evaluated. In 17 of 58 jaw sides we detected the nerve at a distance from the outer cortical bone of 2 mm or less. The situation for the upper osteotomy was critical in eight cases where the thickness of the mandibular ramus was only 3 mm.

RESULTS

By using of the conventional computed tomography system CommCAT, we have the preoperative opportunity to determine the transversal thickness of the mandibular ramus as well as the exact position of the inferior alveolar nerve and its distance from the cortical bone of the mandibular corpus. By predicting the nerve's position and its relation to the osteotomy site, we are able to individualize the operation procedure so that a high standard of safety can be achieved.