Prevalence of infection with the use of ß-tricalcium phosphate as a bone graft substitute during Le Fort I osteotomy.

While grafting with bone substitutes has been shown to provide greater stability in maxillary advancements, infection remains a concern with any material that is placed in close proximity to the maxillary sinus. The purpose of this study was to evaluate the prevalence of infection in maxillary advancements in which a bone graft substitute (ß-tricalcium phosphate; ß-TCP) was placed at the time of surgery. This was a retrospective study of all maxillary osteotomies. Patients were divided into two groups: group 1 included maxillary osteotomies in which ß-TCP was not used; group 2 included any maxillary osteotomy where ß-TCP was used. The prevalence of infection, slow healing, and need for second surgery due to infection or non union was noted. Fisher's exact test was used to compare differences between the groups. Records were adequate for 438 patients: group 1 included 297 patients, while group 2 included 141. No infections were noted in either group. In group 2, there was one patient who had delayed union/non-union requiring a second procedure. Statically, there was no significant difference between the two groups (P=0.3219). Based on the data obtained in this study, the use of ß-TCP does not increase the incidence of infection or complications when used in Le Fort I maxillary osteotomy.

Root contact with maxillomandibular fixation screws in orthognathic surgery: incidence and consequences.

The use of maxillomandibular fixation (MMF) screws in orthognathic surgery has become common in recent years. The risk of injury to adjacent roots with their placement in this population has not been studied extensively. The aim of this study was to review the incidence and consequences of root contact/injury in patients undergoing orthognathic surgery. A retrospective analysis of the treatment and radiographic records of patients who underwent orthognathic surgery between January 2013 and September 2014 at a university in Kentucky, USA was performed. The mean number of screws used was correlated to the mean number of roots affected using Spearman's test, set to a level of significance of 5%. Of 125 patients who underwent orthognathic surgery, 15 (12%) had evidence of root contact. Subsequent radiographs showed resolution of the bone defects. There was no clinical evidence of pulpal necrosis or pain during follow-up. The average number of screws used was 3.14±0.35 per patient, with an average of 0.17±0.52 root contacts per patient. There was no correlation between the number of screws used and the number of roots injured (P=0.279). Based on these results, MMF screws can safely be used to establish interim fixation during orthognathic surgery. Caution should be taken during placement to avoid direct injury to the roots of teeth.

Maintenance of soft tissue changes after rigid versus wire fixation for mandibular advancement, with and without genioplasty.

OBJECTIVE: This multisite prospective randomized clinical trial examined 2-year longitudinal soft tissue profile changes after bilateral sagittal split osteotomy for mandibular advancement by using rigid or wire fixation, with and without genioplasty. STUDY DESIGN: The study sample consisted of 127 subjects. The rigid-fixation group (n = 78) received 2-mm bicortical position screws, whereas the wire-fixation group (n = 49) received inferior border wires. In the rigid-fixation group, 35 subjects underwent genioplasty, whereas 24 subjects underwent genioplasty in the wire-fixation group. Soft tissue profile changes of labrale inferius, B-point, and pogonion were obtained from digitized cephalometric films taken immediately before surgery and up to 2 years after surgery. RESULTS: Regardless of fixation technique, subjects who had genioplasty in conjunction with the mandibular advancement had the largest surgical movement and the largest postsurgical change (P <.05). When all variables were constant, fixation technique was associated with maintenance of soft tissue change. Subjects who underwent rigid fixation maintained more soft tissue change than patients who underwent wire fixation. CONCLUSIONS: These findings suggest that subjects undergoing rigid fixation and genioplasty maintained the most soft tissue advancement.

Positional change of the hyoid bone after bilateral sagittal split osteotomy with rigid and wire fixation.

The purpose of this study was to compare positional changes of the hyoid bone and the amount of postsurgical compensation in mandibular position in patients who received either wire or rigid fixation after surgery. Data were analyzed from 97 patients (25 males and 72 females) who were randomized to receive wire (43) or rigid (54) fixation after mandibular advancement surgery as part of a multicenter clinical trial. Radiographs were digitized before surgery (T2), immediately after surgery (T3), and 8 weeks (T4), 6 months (T5), 1 year (T6), and 2 years (T7) after surgery. The wire group had greater sagittal relapse of the hyoid bone at T6 (P =.007), which persisted at T7 (P =.02). Both groups showed upward movement of the hyoid bone after surgery. There was no relationship between the vertical change in the the hyoid bone position and the vertical position of mandible (B point y coordinate, mandibular plane). However, there was a relationship between the horizontal hyoid bone position and B point during the postsurgical period (rigid, r = 0.450; wire, r = 0.517). The direct distance from the hyoid bone to basion increased (P <.001) in both groups at T3 and then recovered its original length after 8 weeks (P <.001). The rigid group showed no significant change in distance from the hyoid to the genial tubercles, but the wire group showed recovery of the muscle length at T6 (P <.05) and T7 (P <.05).

Mandibular range of motion after bilateral sagittal split ramus osteotomy with wire osteosynthesis or rigid fixation.

OBJECTIVES: An analysis was conducted to compare mandibular range of motion among Class II patients treated with wire osteosynthesis or rigid internal fixation after surgical mandibular advancement. STUDY DESIGN: Patients randomly received wire osteosynthesis and 8 weeks of maxillomandibular fixation (n = 49) or rigid internal fixation (n = 78). Mandibular range of motion was measured 2 weeks before surgery and 8 weeks, 6 months, and 1, 2, and 5 years after surgery. RESULTS: Both groups showed decreased mobility in all movement dimensions that progressively recovered to near presurgical levels over the 5-year follow-up period. The difference in range of motion between treatment groups was not statistically significant. Changes in proximal and distal segment position could not explain decreased mobility. CONCLUSIONS: Similar decreases in mandibular mobility occurred with wire and rigid fixation of a bilateral sagittal split ramus osteotomy after surgery. Long-term changes were statistically, but not clinically, significant.

Orthodontic and surgical camouflage for treatment of skeletal discrepancies.

Masking procedures can be used for a variety of situations and must be tailored to the patient's individual needs. Although they can result in esthetic changes for the patient, they do little for functional concerns. The most commonly used procedure is a bony augmentation genioplasty. It is most effective when a patient is genially deficient and has an overjet in the range of 3 to 5 mm.

Skeletal stability after mandibular advancement with rigid versus wire fixation.

PURPOSE: This study examined the stability of skeletal changes after mandibular advancement surgery with rigid or wire fixation up to 2 years postoperatively. PATIENTS AND METHODS: Subjects for this multisite, prospective, clinical trial received rigid (n = 78) or wire (n = 49) fixation. The rigid cases were fixed with three 2-mm bicortical position screws and 1 to 2 weeks of skeletal maxillomandibular fixation with elastics, and the wire fixation subjects were fixed with inferior border wires and had 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric radiographs were obtained before orthodontics, immediately before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Linear cephalometric changes were referenced to a cranial base coordinate system. RESULTS: Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior sagittal advancement of the mandibular symphysis was 4.92 +/3.01 mm in the rigid group and 5.11 +/- 3.09 mm in the wire group, and the inferior vertical displacement was 3.37 +/- 2.44 in the rigid group and 2.85 +/- 1.78 in the wire group. The vertical changes were similar in both groups. Two years postsurgery, the wire group had 30% sagittal relapse of the mandibular symphysis, whereas there was no change in the rigid group (P < .001). Both groups experienced changes in the orientation and configuration of the mandible. CONCLUSIONS: Rigid fixation is a more stable method than wire fixation for maintaining mandibular advancement after sagittal split ramus osteotomy.

Patients' own reasons and patient-perceived recommendations for orthognathic surgery.

In an attempt to learn more about patients' decision-making processes, an analysis was performed to examine patients' reasons for undergoing orthognathic surgery and their understanding of the reasons surgery was recommended. Before surgery, 105 females and 38 males completed an open-ended questionnaire in which they listed their reasons for choosing orthognathic surgery and their perceptions of their orthodontists' recommendations. Three raters classified the responses into 7 categories: esthetics, psychosocial, functional, TMJ/pain, authority, prevention, and other. Rater agreement ranged from a kappa of.55 to 1.00. Patients reported undergoing orthognathic surgery primarily for esthetic, functional, and TMJ improvements, 71%, 47%, and 28%, respectively. Females reported more TMJ-related reasons than males (P <.05). Patients reporting function (P <. 05), TMJ (P <.05), and prevention of future problems (P <.05) were older than patients not reporting these reasons. Mexican American patients indicated more psychosocial reasons (P <.05) than European Americans. Patients understood that orthognathic surgery was recommended primarily for esthetic, functional, and TMJ improvements, 52%, 44%, and 18%, respectively. Males reported receiving more preventative recommendations (23%) than females (10%). Mexican American patients reported receiving more psychosocial recommendations (P <.05) than European Americans. Agreement between each paired patient/patient-perceived reason was highest for TMJ problems (kappa = 0.588). In conclusion, patients underwent orthognathic surgery to improve esthetic, functional and TMJ problems and interpreted orthodontists' recommendations for similar reasons. On a case-to-case basis, agreement between patient and orthodontist-represented reasons was modest, suggesting differences between patients' own reasons and their perceptions of orthodontists' recommendations.

A comparative study of skeletal and dental stability between rigid and wire fixation for mandibular advancement.

This study examined the skeletal and dental stability after mandibular advancement surgery with rigid or wire fixation for up to 2 years after the surgery. Subjects for this multisite, prospective, randomized, clinical trial were assigned to receive rigid (n = 64) or wire (n = 63) fixation. The rigid cases received three 2-mm bicortical position screws bilaterally and elastics; the wire fixation subjects received inferior border wires and 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric films were obtained before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Skeletal and dental changes were analyzed using the Johnston's analysis. Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior advancement of the mandibular symphasis was 5.5 mm (SD, 3.2) in the rigid group and 5.6 mm (SD, 3.0) in the wire group. Two years after surgery, mandibular symphasis was unchanged in the rigid group, whereas the wire group had 26% of sagittal relapse. Dental compensation occurred to maintain the corrected occlusion, with the mandibular incisor moving forward in the wire group and posteriorly in the rigid group. However, at 2 years after surgery, when most subjects were without braces, the overjet and molar discrepancy had relapsed similarly in both groups.

Technical factors accounting for stability of a bilateral sagittal split osteotomy advancement: wire osteosynthesis versus rigid fixation.

OBJECTIVE: Relapse after bilateral sagittal split osteotomy has been attributed to various technical factors that are inherent in the surgical procedure. The purpose of this article was to analyze technical factors that predispose to relapse when wire or rigid fixation is used. STUDY DESIGN: Patients were randomized to either rigid or wire osteosynthesis. Cephalometric radiographs were obtained and digitized at multiple time periods before and after surgery. Data were analyzed through use of 2-sample t tests and stepwise regression analyses. RESULTS: Multivariate analysis indicated that the following factors correlated with relapse: initial advancement, change in ramus in inclination, change in the mandibular plane, and fixation type. CONCLUSIONS: Relapse increased with the amount of initial advancement and, to a lesser extent, with control of the proximal segment and change in the mandibular plane. These factors are similar for wire osteosynthesis and rigid fixation.

Bilateral sagittal split osteotomy and temporomandibular disorders: rigid fixation versus wire fixation.

OBJECTIVE: The effects of orthognathic surgery on temporomandibular disorders may be related to the surgical method that is used. Specifically, it has been suggested that the choice of stabilization technique may play a major role in the functional outcome of mandibular advancement surgery. The purpose of this study was to prospectively compare long-term (2 years) signs and symptoms of temporomandibular disorders after orthognathic surgery with bilateral sagittal split osteotomy in 127 patients randomized to receive rigid or wire fixation. STUDY DESIGN: Signs and symptoms of temporomandibular disorders were evaluated before and 2 years after surgery by means of the overall craniomandibular index (CMI), dysfunction index (DI), and muscle index (MI). Patients also reported subjective symptoms of temporomandibular disorders by marking areas of pain on a standard drawing of the head and rating the pain in each area on a scale ranging from 1 (very mild) to 7 (very extreme). Subjective pain was also assessed through use of the Oral Health Status Questionnaire and by a rating of the difficulty in opening the mouth because of pain. RESULTS: There were no statistically significant differences in the CMI, MI, or DI change scores between the wire and rigid fixation groups (mean CMI(wire) = 0.05, mean CMI(rigid) = 0.04; mean DI(wire) = 0.02, mean DI(rigid) = 0. 01; mean MI(wire) = 0.08, mean MI(rigid) = 0.08) 2 years after surgery. Temporomandibular joint sounds also demonstrated no significant differences between the two fixation methods. Subjective pain reports were consistent with the clinical examinations. On average, both wire and rigid scores decreased slightly, but the change scores were not significantly different between groups. CONCLUSIONS: These findings suggest that the long-term (2 years) effects of wire and rigid internal fixation methods on the signs and symptoms of temporomandibular disorders do not differ. Earlier concerns about increased risk for temporomandibular disorders with rigid fixation were not supported by these results.

Long-term effect of mandibular midline distraction osteogenesis on the status of the temporomandibular joint, teeth, periodontal structures, and neurosensory function.

PURPOSE: This study retrospectively evaluated the long-term effects of transverse symphyseal distraction osteogenesis (DO) on the temporomandibular joint (TMJ) symptoms, periodontal health, tooth vitality, and nerve injury after surgery. PATIENTS AND METHODS: Twenty-three patients were treated with symphyseal DO during a 4-year period. Fifteen patients were available for follow-up from 7 to 45 months postoperatively (ave, 24.5 months). The patients were clinically evaluated for TMJ symptoms, periodontal pocket formation, tooth vitality and mobility, crestal bone loss, and attached gingival tissue changes. Radiographs of the mandibular anterior teeth were used to evaluate for periodontal bone loss, periapical lesions, or widening of the periodontal ligament (PDL). RESULTS: Preoperatively, 47% of the patients had TMJ symptoms. No patient had symptom worsening or developed new symptoms postoperatively. Five patients' TMJ symptoms improved, and 3 experienced complete resolution of symptoms. No periodontal bone loss or soft tissue recession were evident. Tooth vitality was maintained in 13 patients. Two patients developed Class II mobility of 1 mandibular central incisor, 1 patient had tooth pain and a widened PDL adjacent to the osteotomy/corticotomy site, and 1 patient experienced mental nerve paresthesia. CONCLUSIONS: DO can be used to treat transverse discrepancies of the mandible with limited morbidity.

A 5-year comparison of hydroxyapatite-coated titanium plasma-sprayed and titanium plasma-sprayed cylinder dental implants.

OBJECTIVE: A preliminary report from this study showed that hydroxyapatite-coated (HA) titanium plasma-sprayed (TPS) cylinder implants had fewer failures than TPS cylinder implants before prosthetic loading. The purpose of this article is to report the long-term success associated with the 2 systems. In addition, local and systemic factors that may influence the success or failure of the implants were analyzed. STUDY DESIGN: Each of 65 subjects was randomized to either HA-coated TPS or TPS cylinder implants. Loss of an implant was considered a failure. Failures were analyzed in terms of the coating of the implant, age and gender of the patient, location and length of the implant, opposing dentition, and smoking status. Data were statistically analyzed through use of chi-square tests. RESULTS: Of 351 implants that were placed, 13 were lost before prosthetic loading and 17 were lost after prosthetic loading. The overall success rate was 92.8%. Three hundred thirty-eight implants were prosthetically loaded. The implant success rate after prosthetic loading was 95.3%. There was an overall nonsignificant higher failure rate for the TPS implants (8.0%). Patient age and patient gender were nonsignificant variables. Ten-mm implants had a significantly higher failure rate (17.4%; chi-square, 1.00; P = .39). Before prosthetic loading, more implants failed in the posterior mandible; after prosthetic loading, more implants failed in the anterior maxilla (chi-square, 8.97; P = .03). More implants failed when they were opposed by natural dentition or hybrids (chi-square, 7.36; P = .007). Smoking history was a significant factor (chi-square, 5.2; P = .002). CONCLUSIONS: Statistically, there is little difference between the 2 systems. Local and systemic factors appear to play a greater role in implant failure than does the surface of the implant.

Factors influencing condylar position after the bilateral sagittal split osteotomy fixed with bicortical screws.

PURPOSE: Multiple articles have discussed condylar position after bilateral sagittal split osteotomy (BSSO). However, previous studies have been limited to two-dimensional evaluation of condylar position. The purpose of this study was to evaluate change in condylar position after a BSSO fixed with bicortical screws using three-dimensional computed tomography to assess the factors that may influence the ultimate position of the condyle after surgery. PATIENTS AND METHODS: Seventeen patients underwent isolated mandibular advancement involving a BSSO with rigid fixation. Reformated axial computed tomography was done 1 week before and 8 weeks after surgery. Movements evaluated included 1) medial-lateral, 2) superior-inferior, 3) anterior-posterior, and 4) condylar angulation. Three separate factors were analyzed to study their effects on the four movements noted: 1) amount of mandibular advancement, 2) amount of proximal segment rotation, and 3) preoperative shape of the mandible. A linear regression analysis was used with statistical significance set at P<.05. RESULTS: Eight weeks after a BSSO and mandibular advancement, most cases showed displacement of the condyle medially, posteriorly, superiorly, and angled medially. The amount of mandibular advancement did not correlate with medial-lateral change of the condyle. The amount of advancement correlated with the condyle angulation and superior-inferior changes in condyle position. There was no correlation between amount of advancement and medial or anterior-posterior change in condyle position. There also was no correlation between any of the condylar movements and the degree of proximal segment rotation or the shape of the mandible. CONCLUSIONS: There are obvious changes in condyle position after a BSSO. These changes appear to be influenced mainly by factors other than amount of advancement, degree of proximal segment rotation, and shape of the mandible.

Psychological function in orthognathic surgical patients before and after bilateral sagittal split osteotomy with rigid and wire fixation.

A multisite randomized controlled trial was conducted to compare the psychological function of patients who undergo surgical correction of a Class II malrelation with bilateral sagittal split osteotomy with either wire or rigid fixation. Subjects were 31 male and 86 female patients referred by orthodontists. Psychopathological symptoms and psychological distress were measured with the Symptom Checklist-90 Revised at the following times: before placement of orthodontic appliances, 1 to 2 weeks presurgery, and 1 week, 8 weeks, 6 months, and 2 years postsurgery. Patients' satisfaction with their surgical outcome was measured with a 3-item questionnaire. Results showed no statistically significant differences in psychological function or satisfaction between patients treated with wire or rigid fixation. Psychological function was within normal limits immediately before surgery. Psychological parameters did not determine patient satisfaction, even among patients who met an operational definition of "psychopathological caseness." Psychological symptoms and general distress increased modestly immediately after surgery for both groups and then progressively declined over the succeeding 2 years, eventually reaching levels that were significantly lower than presurgical levels. It was concluded that (1) rigid and wire fixation do not differ in their effects on psychological function and satisfaction; (2) patients who seek orthognathic surgery for a Class II malocclusion are psychologically healthy, ie, comparable to normal populations, immediately before surgery; (3) presurgical psychological function does not determine satisfaction with surgical outcome; and (4) psychological function tends to improve during the 2 years after surgery.

Short-term changes of condylar position after sagittal split osteotomy for mandibular advancement.

OBJECTIVE: The goal of this study was to quantify condylar position changes after mandibular advancement surgery with rigid fixation (screws). Radiographic changes in condylar position were determined in all planes (X, Y, and Z). Computed tomography with image reconstruction was used. STUDY DESIGN: A consecutive population of patients who elected to have rigid fixation for surgical stabilization method were studied (n = 21). Computed tomography data were acquired in the axial plane through use of abutting 1.5-mm-thick slices. Data acquisition occurred 1 week preoperatively and 8 weeks postoperatively. Measurements were made from 2-dimensional reconstructions. RESULTS: The averages were as follows: lateral displacement from midline, 1.2 mm (55% of patients); medial displacement from midline, 1.5 mm (45% of patients; range, 3.2 mm); condyle angle increase from coronal plane, 3.5 degrees (60% of patients); condyle angle decrease from coronal, 4.3 degrees (40% of patients; range, 8.5 degrees); superior rotation of proximal segment, 3.2 degrees (39% of patients); inferior rotation of proximal segment, 8.6 degrees (61% of patients; range, 15.6 degrees); superior displacement, 1.2 mm (60% of patients); inferior displacement, 1.0 mm (40% of patients; range, 2.5 mm); anterior displacement, 1.6 mm (33% of patients); posterior displacement, 1.6 mm (67% of patients; range, 2.8 mm). CONCLUSIONS: Changes occurred in all planes, but the most common postoperative condyle position was more lateral; with increased angle, the coronoid process was higher and the condyle was more superior and posterior in the fossa.

Condylar position with rigid fixation versus wire osteosynthesis of a sagittal split advancement.

PURPOSE: In this randomized clinical study, two groups of patients who underwent a bilateral sagittal split osteotomy and either wire osteosynthesis or rigid fixation were compared. PATIENTS AND METHODS: Cephalometric radiographs obtained before surgery, immediately after surgery, and at 8 weeks, 6 months, and 1 and 2 years after surgery were available for 125 of these patients, 63 with wire fixation and 62 with rigid fixation. All were traced by an independent examiner, and vertical and horizontal changes in condylar position were recorded for each period. RESULTS: Condylar movement was slightly different with the two fixation techniques beyond 8 weeks postsurgery, but the ultimate position of the condyle was not different. The condyles in both groups moved posterior and superior. There initially was a correlation between the amount of advancement and the amount the condyle moved inferior in both groups, but this diminished with time. In addition, there was a weak but significant positive relationship between forward rotation of the proximal segment and superior condylar position immediately after surgery, which did not exist at later periods. CONCLUSIONS: Whether wire osteosynthesis or rigid fixation was used, the ultimate condylar position was posterior and superior after a bilateral sagittal split osteotomy to advance the mandible. No single factor could be identified to account for this change. It is suggested that change in mechanical load may have resulted in remodeling and adaptation of the condyles.

Effects of major Class II occlusal corrections on temporomandibular signs and symptoms.

This study explored the relationship between malocclusion and signs and symptoms of temporomandibular disorders (TMD) in 124 patients with severe Class II malocclusion, before and 2 years after bilateral sagittal split osteotomy (BSSO). Patients were evaluated with the Craniomandibular Index (CMI), the Peer Assessment Rating Index (PAR Index, to assess gross changes in the occlusion), and symptom questionnaires. The results showed a significant improvement in occlusion; PAR Index scores dropped from a mean of 18.1 before surgery to a mean of 6.1 at 2 years postsurgery (P < 0.001). The CMI and masticatory index (MI) for muscle pain indicated clinically small but statistically significant improvement (P = 0.0001) from before surgery (mean CMI = 0.14, mean MI = 0.15) to after surgery (mean CMI = 0.10, mean MI = 0.08). The number of patients with clicking upon opening decreased significantly from 33 (26.6%) to 13 (10.5%) (P = 0.001). However, the number of patients with fine crepitus increased from 5 (4.0%) before surgery to 16 (12.9%) at 2 years postsurgery (P = 0.005). Significant reductions in subjective pain and discomfort were also found 2 years after surgery. The magnitude of change in muscular pain was not related to the severity of the pretreatment malocclusion, a finding that suggests that factors other than malocclusion may be responsible for the change in TMD.