Neurosensory changes following orthognathic surgery

Much variability exists among studies of neurosensory disturbance following facial surgery. This diversity of findings may be a function of the different surgical procedures and measurement methods used. The present study compared 3 methods of assessing neurosensory loss following surgical orthodontics. Two objective tests and 1 subjective test were administered to 24 patients preoperatively and 4 weeks postoperatively. These included measures of 2-point discrimination, pressure-pain thresholds, and perceived sensation changes in specific facial regions. Postoperatively, all patients needed greater separation on the 2-point discrimination test in the lower facial regions, but not in the upper regions. Bilateral sagittal split osteotomy patients, especially males, required greater separation on these lower sites. Pressure-pain thresholds were not significantly impaired in most patients. Those who underwent combined maxillary and mandibular procedures experienced lower thresholds on the lower lip, while bilateral sagittal split osteotomy patients reported lower thresholds on the upper lip. The 2-point discrimination test was consistent with patients' self-ratings of neurosensory problems using facial maps, but the pressure-pain test was not. The majority of patients reported changed sensation in the lower facial regions postoperatively, regardless of surgery type. Examiners were less likely to rate these same facial regions as different in sensory acuity. Male patients were more likely to report sensory loss or pain postoperatively. These findings suggest that self-reports of neurosensory change following orthognathic surgery are consistent with tests of 2-point discrimination and somewhat higher than examiner ratings, but the objective test of pressure-pain thresholds in this study was least sensitive to neurosensory changes.     

Treatment-induced errors in occlusion following orthognathic surgery

Posttreatment occlusion following orthognathic surgery is often different from that predicted in the treatment plan. Differences between intended and actual occlusion may be treatment-induced occlusal errors caused by mismatches between the centers of rotation of the mandible and of the articulated models. Discrepancies in the position of the articulator center of rotation (relative to the position of the center of rotation of the patient's mandible) influence the magnitude of occlusal errors. A computer model was developed to quantify these errors. As the center of rotation of the articulated models becomes more divergent from the patient's center of rotation, the magnitude of the occlusal errors increases. This magnitude increases most rapidly along the line that is perpendicular to the line joining the patient's center of rotation and a preselected mandibular landmark (incisor tip or molar cusp, for instance). For small changes in vertical dimension, clinically insignificant errors result, independent of the degree of mismatch between the centers of rotation. Clinical implications of these findings are discussed.     

Masseter muscle changes following orthognathic surgery

Abstract Objective: To evaluate the long-term changes of masseter muscle morphology in skeletal Class III patients with facial asymmetry following two-jaw orthognathic surgery (Le Fort I osteotomy + intraoral vertical ramus osteotomy). Materials and Methods: Using computed tomography (CT), a longitudinal study was conducted on 17 skeletal Class III patients with facial asymmetry. Measurements from the reconstructed three-dimensional (3D) CT images were compared from T1 (before surgery), T2 (1?year after surgery), and T3 (4?years after surgery). The maximum cross-sectional area (CSA), orientation, thickness, and width of the masseter muscle were measured on both the deviated and nondeviated sides. The control group included 17 volunteers with skeletal and dental Class I relationships without dentofacial deformities. Results: At T1, there were no significant differences in CSA, thickness, or width of masseter muscle between the deviated and nondeviated sides. Masseter muscle orientation was significantly more vertical on the nondeviated side than on the deviated side at T1 (P < .01); no significant bilateral differences were noted at T2 and T3. At T1, masseter muscle measurements were significantly lower than controls (P < .01). During T1-T3, a significant increase was noted in CSA, thickness, and width (P < .01) of masseter muscle. At T3, no significant difference was noted between the study and control groups. Conclusion: After surgery, the masseter muscle measurements of skeletal Class III asymmetry patients showed no significant differences compared with the control group within the 4-year follow-up period, indicating adaptation to the new skeletal environments and increased functional demand.     

Recovery of neurosensory function following orthognathic surgery

The purpose of this study was to prospectively define the recovery of touch discrimination following four commonly performed surgical procedures in 22 consecutive patients with no previous maxillofacial surgery. The surgical groups studied were Le Fort I osteotomy (LEFORT; n = 13), sagittal split ramus osteotomy (SSRO; n = 6), intraoral vertical ramus osteotomy (IVRO; n = 9), and isolated genioplasty (GENIO; n = 5). Neurosensory function was assessed by three different testing modalities which included static light touch (SLT), moving touch discrimination (MTD), and two-point discrimination (TPD). Cutaneous sensation of the lower lip and chin were examined for the mandibular procedures, whereas the infraorbital and upper lip regions were evaluated following maxillary surgery. Immediately following surgery, each group varied in both the incidence and magnitude of neurosensory deficits (NSD). The SSRO group had the highest percentage of sites with immediate postsurgical NSD to both SLT (72%) and MTD (67%), followed by the LEFORT (SLT = 50%, MDT = 58%), GENIO (SLT = 27%, MTD = 6%), and IVRO groups (SLT = 11%, MTD = 18%), respectively. Each group also varied in the severity of the initial postoperative deficit as measured by SLT, with the SSRO group showing the greatest deficit followed by the LEFORT, GENIO, and IVRO groups. During the 6-month recovery period each group approached preoperative levels of sensation at a different rate. The LEFORT group recovered most rapidly, with few anatomic sites showing NSD (SLT = 20%, MTD = 5%) at the 1-month postoperative examination, and the majority of the group (96%) returned to preoperative sensation by 3 months following surgery. The SSRO group recovered more slowly, with approximately half of the group demonstrating a deficit (SLT = 50%, MTD = 59%) at 1 month, which diminished to about one fourth of the sites (SLT = 25%, MTD = 5%) by 3 months. Most of the SSRO group (90%) exhibited no residual deficit 6 months following surgery. The IVRO group had few sites with immediate NSD (SLT = 11%, MTD = 15%). In none of the surgical groups was a statistically significant correlation found between the severity of the initial NSD and length of time to complete recovery.     

Postoperative pneumomediastinum and pneumothorax following orthognathic surgery

Pneumomediastinum and pneumothorax are rare complications in the postoperative oral and maxillofacial surgery patient. Review of the sequence of events relating to these two life-threatening conditions emphasizes the importance of awareness of the clinical presentation and pathophysiology of these conditions as well as the need for judicious pulmonary physiotherapy in the intubated patient.     

Recovery of mandibular mobility following orthognathic surgery

The aim of this prospective study was to define the patterns of recovery of mandibular mobility following three commonly performed orthognathic surgical procedures. Twenty-two consecutive patients undergoing either isolated Le Fort I osteotomy (LE FORT; n = 7), sagittal split ramus osteotomies (SSRO; n = 7), or intraoral vertical ramus osteotomies (IVRO; n = 9) were studied. LE FORT and SSRO patients had no mandibular immobilization, whereas IVRO patients were immobilized by dental fixation for 3 weeks. Mandibular mobility was assessed by measurement of maximal mandibular opening (MMO) and lateral and protrusive excursions. No significant difference in MMO was observed between groups prior to surgery (LE FORT, 47.0 mm; SSRO, 50.7 mm; IVRO, 54.5 mm). A significant reduction in MMO occurred immediately after surgery in the LE FORT and SSRO groups and at release of fixation in the IVRO group. Each group returned to presurgical levels of mandibular mobility at a different rate following surgery. LE FORT patients recovered quickly, regaining 83% (mean, 38.7 mm) of MMO by 1 month and exceeded preoperative levels (mean, 49.6 mm) by 6 months. SSRO patients showed hypomobility (mean, 23.5 mm) after 1 month, with significant improvement in MMO (mean, 38.0 mm) at 2 months, and nearly complete recovery (96.2%; mean, 48.8 mm) at 6 months. IVRO patients recovered rapidly after release of dental fixation, achieving 78% (mean, 39.8 mm) of preoperative MMO at 2 months. This study shows that significant differences in recovery patterns of mandibular mobility exist between surgical procedures. The clinician should be aware of these differences in recovery patterns in defining goals for individual patient rehabilitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Patient expectations and satisfaction following orthognathic surgery

Orthognathic surgery aims to correct dentoskeletal and facial discrepancies. Treatment usually requires a minimum of 18 months, necessitating that patients are adequately satisfied with the treatment provided. This study aimed to assess the determinants of patient satisfaction following treatment. One hundred and eighteen patients who had undergone orthognathic surgery were included prospectively. All participants completed a questionnaire regarding their reasons for undergoing treatment, treatment logistics, treatment outcomes, and satisfaction throughout their journey. Most patients were ‘very satisfied’ (71.2%) or ‘satisfied’ (19.5%) with the overall treatment. The majority wished to improve their smile (78.0%); post-treatment, 89.0% of patients reported an improved smile. Almost half of the patients (46.6%) stayed in hospital for only one night, and 41.5% took over 4 weeks off work or school post-surgery. People with postoperative breathing difficulties spent more days in hospital (P = 0.021), but importantly, the duration of hospital stay did not differ between maxillary advancement, bilateral sagittal split osteotomy, and bimaxillary surgery (P = 0.78). In conclusion, patient satisfaction was high following orthognathic treatment. The results highlight areas for improvement, such as information delivery to the patient throughout the treatment journey, and show that the presence of ongoing problems is an important predictor of patient satisfaction.     

Major vascular complications of orthognathic surgery: false aneurysms and arteriovenous fistulas following orthognathic surgery

False aneurysms and arteriovenous fistulas are rare complications of orthognathic surgery. The vessel most commonly involved with false aneurysms following mandibular surgery is the internal maxillary artery, and this vessel, especially the sphenopalatine branch, may also be involved following maxillary surgery. An unusual factor in the presentation of false aneurysms following Le Fort I osteotomies is an initial episode of epistaxis occurring greater than 2 weeks postoperatively. Arteriovenous fistulas following orthognathic surgery are more apt to involve large vessels, especially the internal carotid artery. Embolization procedures are the treatment of choice for false aneurysms and arteriovenous fistulas in the maxillofacial region following orthognathic surgery.     

Adaptations in lip posture and pressure following orthognathic surgery

Lip pressures before and after orthognathic surgery were studied to evaluate the relationship between posttreatment soft-tissue adaptation and incisor stability. After all surgical procedures, physiologic adaptation resulted in the maintenance of pressures during speech and swallowing. When the maxilla was advanced by LeFort I osteotomy, a significant decrease in resting pressure of the upper lip was observed instead of the expected increase and incisor stability did not seem related to soft-tissue influences. When the mandible was advanced by sagittal split osteotomy, resting pressure did not increase as expected, but there was a tendency for incisors to become more upright after fixation release, perhaps as a rebound from labial tipping in fixation. When soft tissues were relaxed as the mandible rotated forward following superior repositioning of the maxilla, resting pressures decreased and lower incisors tended to be positioned forward as predicted by equilibrium theory.     

A survey of extubation practices following orthognathic surgery

The incidence of respiratory complications following orthognathic surgery was investigated by a survey of 234 private oral and maxillofacial surgeons and residency programs to determine if prolonged postoperative intubation is warranted. The results showed no significant increase in such complications when patients were extubated within 8 hours following surgery compared to longer intubation times.     

Short-term periodontal and microbiological changes following orthognathic surgery

ObjectiveAim of the present study was to evaluate the influence of orthognathic surgery on the development of periodontal and microbiological changes.Materials and methodsFifteen consecutively treated patients with a mean age of 24.9 ± 7.7 years receiving orthognathic surgery were included in the present study. Plaque index (PI) and concentrations of 11 periodonto-pathogenic bacteria were recorded one day prior to surgery (t₀) and one week (t₁) and six weeks (t₂) post-surgery. In addition, a complete periodontal examination including pocket probing depth (PPD), gingival recession (GR), clinical attachment level (CAL), bleeding on probing (BOP) and width of keratinized gingiva (WKG) was conducted at t₀ and t₂. For statistical analysis, general linear model and paired t-test were applied.ResultsA significant increase of PI (t₀–t₁, p = 0.037) was followed by a significant decrease (t₁–t₂, p = 0.017). Apart from Eikenella corrodens (p = 0.036), no significant microbiological changes were recorded. PPD significantly increased on oral sites (p = 0.045) and GR especially on buccal sites (p = 0.001). In the incision area the development of GR was significantly higher on the test (buccal) than on the control sites (oral). Both gingival biotypes were affected by GR.ConclusionsOrthognathic surgery causes statistically significant changes of periodontal parameters, but these changes do not necessarily impair the aesthetic appearance of the gingival margin.     

Facial soft tissue profile following bimaxillary orthognathic surgery

OBJECTIVE: To determine the changes in the position and area of nasal and labial soft tissues in adult skeletal Class III patients who underwent bimaxillary orthognathic surgery. MATERIALS AND METHODS: Pretreatment (T1), preoperative (T2), and posttreatment (T3) cephalometric variables and upper-lower lip areas were measured on lateral cephalometric radiographs for 20 individuals (9 male, 11 female; mean age 21.3 years at T1, 22.4 years at T2, and 23.4 years at T3) who had maxillary advancement and mandibular setback. Analysis of variance (ANOVA) and Duncan tests were used to compare the cephalometric and area measurements at the beginning of treatment, and at presurgery and postsurgery, respectively. Paired t-tests were also performed to analyze changes within the periods. RESULTS: The tip of the nose was affected less with the movement of the underlying skeletal structure (0.25%), while the soft tissue B point (B') moved equally with the skeletal B point. As the maxilla related variables increased due to the forward movement, the upper labial areas decreased. With the backward movement of the mandible, the middle and inferior lower labial areas increased, while the superior lower labial area decreased. CONCLUSIONS: The results of our study suggest that the dramatic improvement in the facial profiles of the bimaxillary surgery patients is primarily related to the backward movement of the mandible and the significant reduction in the superior lower lip area.     

Fibroscopic findings in patients following maxillary osteotomies in orthognathic surgery

Objective

To evaluate the intranasal complications in patients submitted to maxillary Le Fort osteotomy within the orthognathic evaluation through flexible fibroscope, method which is safety, reliable and minimally invasive.

Materials and methods

A prospective, systematic non-randomized study is presented with a series of 47 patients who underwent a Le Fort I maxillary osteotomy due to dentofacial deformity between January 2008 and December 2008. The patients who were included underwent an evaluation of nasal respiratory function using a questionnaire designed for this objective, after which a fibroscopic examination was carried out.

Results

With regards to the results of the NOSE questionnaire, 4/47 patients had Grade 2 nasal obstruction before the surgery. After the intervention, three improved to a 0–1 grade. 3/47 patients reported snoring during sleep without OSAS that was not modified as a result of the surgery. 2/47 patients presented with sequelae regarding the deviation of the septum, and 1/47 had a luxation of the anterior nasal spine that had not been recorded before the orthognathic surgery. The presence of synechiae was observed in 3/47 cases. A septal perforated mucosa was found in the IV area of the nasal septum. Hypertrophy of the lower turbinate was observed in 4/47 cases.

Conclusion

The fibroscope procedure is minimally invasive and it does not require local anesthesia or sedation, and it allows the surgeon to carry out an immediate and exhaustive evaluation, on an outpatient basis, of possible septal and nasal sequelae in patients undergoing orthognathic surgery.     

Carotid-cavernous sinus fistula following maxillofacial trauma and orthognathic surgery

The presence of a carotid-cavernous sinus fistula after maxillofacial trauma or orthognathic surgery is uncommon. 2 patients are described who developed a carotid-cavernous sinus fistula. Early diagnosis is important, since delay in treatment may cause irreversible neurological and/or ophthalmological damage. The etiology of the carotid-cavernous sinus fistulas is discussed, in the cases described.     

Recovery following orthognathic surgery and autologous blood transfusion.

Patients undergoing maxillary surgery, with or without mandibular surgery, were divided into two groups. One surgeon's patients served as controls and did not receive blood unless hemodynamically indicated. The remaining surgeons' patients were transfused regardless of their hemoglobin levels following surgery. An attempt was made to identify benefits or complications associated with the reinfusion of autologous blood, particularly in patients with "low blood loss." Patients were asked to record when they returned to their presurgical level of activity. Of the 46 patients in the study 14 (12 nontransfused, two transfused) were not back to full activity 6 weeks after surgery. Of the 32 patients that reported a return to full activity within the study period, transfused patients reported a significantly quicker return to full activity at 2 weeks, 3 weeks, and 4 weeks postoperatively than did their nontransfused counterparts, even when blood loss at surgery was minimal. No complications have occurred with this practice.     

Visualizing three-dimensional facial soft tissue changes following orthognathic surgery

Laser scanning can be used to visualize the face in three dimensions. These scans can then be processed to enable assessment of facial changes. The aim of this single-centre, prospective, longitudinal, cohort study was to investigate whether four different visualization methods correctly represented facial changes occurring as a result of orthognathic surgery. Twenty-six consecutive orthognathic patients (13 female mandibular advancement and 13 male bimaxillary Class III) were included as well as a control group of 12 non-growing adults (6 males and 6 females). Pre- and post-operative facial laser scans were superimposed and four different visualization methods applied: correspondences with sensitivity to movement, normals, radial, and closest point. A group of 10 'blinded' observers determined the surgical procedure (if any) that had been performed by applying a specific colour scale to each facial image. The sensitivities and specificities for each visualization method applied to each subject group were determined. The intraobserver repeatability was investigated using Cohen's kappa (k). The radial method was found to be superior for identifying mandibular advancement patients (sensitivity/specificity 58.5/92.4 per cent), the normals method for visualization of bimaxillary Class III cases (26.2/99.6 per cent), while the control group was best represented using the closest point (60.0/80.8 per cent). Overall, intraobserver repeatability was good (k = 0.61). A good level of repeatability was demonstrated in the separate subject groups (mandibular advancement 0.70, bimaxillary Class III 0.70, and controls 0.62). There was no significant difference in the abilities of the four visualization methods to represent facial changes. Each method allowed correct identification of different proportions of the subject groups.