Resorbable PLLA-PGA screw fixation of mandibular sagittal split osteotomies.

The purpose of this study was to evaluate the intraoperative placement and clinical effectiveness of resorbable copolymeric screws for mandibular sagittal split ramus osteotomies. Thirty-seven patients who underwent bilateral sagittal split osteotomies of the mandible were fixated with three 2.5-mm copolymeric poly-L-lactic-polyglycolic (PLLA-PGA) screws on each side. No postoperative maxillomandibular fixation was applied. Twenty-five patients experienced mandibular advancement and 12 patients had setbacks. The average advancement was 6.5 mm (range, 3-17 mm) and the average set-back was 5.2 mm (range, 3-8 mm). Intraoperative placement was uncomplicated and no screws were stripped during placement. No problems in immediate postoperative stability were encountered and relapse was not evident in any patient. Follow-up ranged from 3 to 17 months. The screw holes remained evident radiographically after 1 year. Two and one-half-millimeter copolymeric PLLA-PGA resorbable screws for mandibular ramus osteotomies appear to offer clinical results comparable with metallic screw fixation.     

Fixation of bimaxillary osteotomies with resorbable plates and screws: experience in 20 consecutive cases.

PURPOSE: This study evaluated the potential effectiveness of resorbable plate and screw fixation for skeletal stabilization of simultaneously performed maxillary and mandibular osteotomies. PATIENTS AND METHODS: Twenty consecutive patients underwent simultaneous maxillary and mandibular osteotomies that were fixed using copolymeric poly L-lactic acid/polyglycolic acid (PLLA/PGA) plates and screws. Prefabricated acrylic intermediate and final splints were used as guides and then removed at completion of the surgery. Guidance elastics were applied at 2 weeks postoperatively. RESULTS: The LeFort I osteotomies included segmentalizations with and without bone grafts (7/20), impactions (4/20), advancements (8/20), and unilateral downgrafting with a bone graft (2/20)- one of which was segmental. The mandibular sagittal split osteotomies involved advancements (11/20), setbacks (5/20), and asymmetric rotation (4/20). Three patients had simultaneous genioplasties, which were also stabilized with resorbable fixation. All maxillae were fixed with four 2.0-mm L-shaped plates and screws. The mandibular rami were maintained with three 2.5-mm bicortical screws per side. The mandibular symphyseal segments were held in position with two or three 2.5 mm bicortical screws. All surgeries were accomplished uneventfully, and no problems in the immediate postoperative stability of the occlusion were encountered. Follow-up ranged from 12 to 25 months. CONCLUSIONS: The initial clinical findings suggest that this form of bone fixation is a viable alternative to standard metallic fixation techniques for certain maxillomandibular deformities in which excessive bony movements are not performed. Differences exist in both intraoperative application and postoperative management of masticatory function. This is partially a US government work. There are no restrictions on its use.     

Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism

IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism.Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS^®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22 months (mean 17.8 months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6 months postoperatively.ResultsThe average setback was 6.9 mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6 months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance.ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.     

Assessment of material- and technique-related complications following sagittal split osteotomies stabilized by biodegradable polylactide screws

OBJECTIVE: The aim of this retrospective clinical study was to determine whether there are any material-related problems and increased occurrence of postoperative mandibular nerve and temporomandibular joint dysfunctions in connection with the use of biodegradable self-reinforced poly-L-lactide (SR-PLLA) screws for bone fixation after bilateral sagittal split osteotomies (BSSO). STUDY DESIGN: Forty consecutive patients who underwent BSSO and mandibular advancement that included fragment fixation using SR-PLLA screws were monitored for an average of 2.2 years postoperatively. RESULTS: The osteotomy sites healed uneventfully with no adverse reactions. The incidence of postoperative sensory disturbances of the inferior alveolar nerve was 27%. Symptoms of temporomandibular joint disorders (TMJD) observed preoperatively in 73% of patients were reduced to 48% after surgery. CONCLUSION: The occurrence of postoperative sensory disturbances and TMJD symptoms in this study did not deviate strikingly from that of other studies using conventional osteosynthesis. No specific complications related to the screw material were observed.     

A comparative analysis of the efficacy of cortical screws as lag screws and miniplates for internal fixation of mandibular symphyseal region fractures: a randomized prospective study

The management of facial trauma is one of the most rewarding and demanding aspects of oral and maxillofacial surgery. Being the most prominent mobile bone of the facial skeleton, mandible fracture occurs more frequently than any other fracture. In this study, open reduction and internal fixation was performed for isolated mandibular symphyseal region fractures using cortical screws (as lag screws) in 40 patients and using miniplates in 40 patients. Clinical and radiological evaluations were made at 6 months postoperatively. Primary stability of fracture segments, postoperative swelling, restricted lip mobility, infection, wound dehiscence, implant removal, and mal-union or non-union of fracture segments was evaluated. Primary stability was achieved in 100% of cases treated with cortical screws, whereas for patients treated with miniplates, 97.5% attained primary stability, while one case (2.5%) showed persistent clinical mobility. Postoperative complications were noted in 13 (16.25%) of the total 80 patients. The duration of postoperative swelling was less in patients treated with cortical screws compared to patients treated with miniplates. It is concluded that cortical screw fixation is an effective procedure for the treatment of symphyseal region fractures, but the procedure is somewhat technically sensitive.     

Resorbable fixation techniques for genioplasty.

PURPOSE: This study evaluated the capability and effectiveness of resorbable bone fixation devices in genioplasty surgery. MATERIALS AND METHODS: Twenty patients underwent different genial movements that were stabilized with either 2.5-mm polylactic-polyglycolic acid lag screws or 2.0-mm polylactic-polyglycolic acid plates and screws. RESULTS: Twenty-one anterior mandibular osteotomies were performed in 20 patients. Sixteen patients had advancement (80%), 2 had horizontal setback (10%), and 2 had vertical reduction (10%). The average advancement was 7.6 mm (range, 4 to 14 mm), the average horizontal setback was 6.0 mm (range, 4 to 8 mm), and the average vertical reduction was 7.0 mm (range, 5 to 9 mm). Fixation was done using the lag screw technique in 13 patients (65%) and plate and screw fixation in 7 patients. (35%) Intraoperative stability was satisfactory in all cases. There were no postoperative infections or segmental instability up to 6 months after surgery. CONCLUSION: Resorbable polylactic-polyglycolic acid lag screw and plate and screw fixation is a viable alternative for fixation of anterior horizontal osteotomies of the mandible.     

Early secondary closure of alveolar clefts with mandibular symphyseal bone grafts and β-tri calcium phosphate (β-TCP)

Alveolar reconstruction of bony defects in cleft lip and palate patients is a widely accepted treatment regimen for which multiple donor sites can be used. For 25 years, autogeneous bicortical mandibular symphyseal bone grafts have been used at the authors’ centre. In cases in which the alveolar defect was too large to match the volume of the mandibular symphyseal bone transplant, β-TCP granules were packed against the bone transplant to fill the defect completely. In a retrospective study, 18 patients, who were treated with mandibular symphyseal bone wrapped in β-TCP granules, were compared with 29 patients, who were treated with mandibular symphyseal bone only. To assess alveolar height, occlusal radiographs were taken directly postoperatively and 1 year later. Mean alveolar bone loss was calculated and compared between groups using Student's t-test and linear regression analysis. No statistically significant difference in alveolar height was found between the two groups. It was concluded that mandibular symphyseal bone grafts enriched with β-TCP granules can be used successfully in cases in which the alveolar cleft is too large to be grafted with mandibular symphyseal bone alone.     

Complications with intermaxillary fixation screws in the management of fractured mandibles

A dedicated bicortical bone screw for temporary intraoperative intermaxillary fixation (IMF) during open reduction and fixation of mandibular fractures offers many benefits to surgeons and patients. We have used this system for 2 years and confirm the benefits over traditional methods of intermaxillary fixation. However, complications can arise. One hundred and twenty-two patients with mandibular fractures had IMF screws of which five (4%) developed complications intraoperatively and postoperatively. Complications included fracture of the screws on insertion, iatrogenic damage to teeth causing loss and bony sequestra around the area of screw placement.     

LactoSorb内固定系统治疗颌面部骨折的临床观察

目的 观察LactoSorb内固定系统应用于颌面部骨折的临床效果。方法 对23例颌面部骨折的患者用LactoSorb内固定系统术后6、9、12、18、24个月时复查伤口愈合、骨段固定、咬合关系，并行三维CT和（或）全景片检查。结果 23例患者局部伤口、骨段愈合均良好，咬合关系正常。术后2年螺钉的空洞完全被正常的骨小梁代替。结论 LactoSorb系统具有良好的内固定作用，植入人体后18～24个月完全降解，基本满足临床治疗的需要。     

Postsurgical maxillary movement: a comparison study of bone plate and screw versus wire osseous fixation

This study was designed to examine amounts of postoperative maxillary movement in patients who received Lefort I osteotomies, comparing bone plate and screw fixation with conventional transosseous wire fixation. Cephalograms of 17 patients whose maxillae were fixated with wire osseous fixation and 13 patients whose maxillae were fixed with bone plates and screws were compared at four different time periods throughout the first postoperative year. Millimeters of movement of five maxillary assessment points were assessed in the horizontal and vertical planes of space by use of a line constructed 7 degrees to sella-nasion at nasion as the horizontal reference. Results indicate that the amount of maxillary movement was similar for the two groups during the two time periods subsequent to the surgical procedure. However, it appears that the maxillae fixated with bone plates and screws were more stable than those with wire osteosynthesis during the last postoperative period (6 months to 1 year) and during the overall postoperative time interval (2 days to 1 year).     

Stability of simultaneous maxillary intrusion and mandibular advancement: A comparison of rigid and nonrigid fixation techniques

This study examines the short-term stability of bimaxillary surgery following Le Fort I impaction with simultaneous bilateral sagittal split osteotomies and mandibular advancement using two standard techniques of postsurgical fixation. Fifteen adults had skeletal plus dental maxillomandibular fixation, and fifteen adults had rigid internal fixation using bone plates in the maxilla and bicortical bone screws between the proximal and distal segments in the mandible. The group with rigid internal fixation did not undergo maxillomandibular fixation. Radiographic cephalograms were analyzed during the postsurgical period to evaluate skeletal and dental stability. There was no statistical difference in postsurgical stability with rigid internal fixation or skeletal plus dental maxillomandibular fixation other than the vertical position of the maxillary molar; the skeletal plus dental maxillomandibular fixation group had a significant amount of postsurgical intrusion of the maxillary molar when compared with the rigid internal fixation group. Although the other measures showed no statistically significant difference between the experimental groups, the amount of variability in postsurgical stability in the group with skeletal plus dental maxillomandibular fixation was greater than that found in the group with rigid internal fixation.     

Open bite: stability after bimaxillary surgery--2-year treatment outcomes in 58 patients

Stability after bimaxillary surgery to correct open bite malocclusion and mandibular retrognathism was evaluated on lateral cephalograms before surgery, 8 weeks post-operatively, and after 2 years. The 58 consecutive patients were treated to a normal occlusion and good facial aesthetics. Treatment included the orthodontic alignment of teeth by maxillary and mandibular fixed appliances, Le Fort I osteotomy, and bilateral sagittal split ramus osteotomy. Twenty-six patients also had a genioplasty. Intra-osseous wires or bicortical screws were used for fixation. Twenty-three patients had maxillo-mandibular fixation (MMF) for 8 weeks or more, six for 4-7 weeks, 14 for 1-3 weeks, and 15 had no fixation. At follow-up 2 years later, the maxilla remained unchanged and the mandible had rotated on average 1.4 degrees posteriorly. Seventeen patients had an open bite. Among them, eight patients had undergone segmental osteotomies. The relapse was mainly due to incisor proclination. The most stabile overbite was found in the group with no MMF after surgery.     

Use positional screws for Le Fort I osteotomy fixation: technical note

In recent years, several studies related to fixation systems have been published, but few suggest any variations of the Le Fort I osteotomy technique, and the use of plates and screws placed along the canine and zygomatic pillar are common. The 20-year-old patient with Crouzon syndrome presented with severe hypoplasia of the maxillary, mandibular prognathism, and class III facial pattern. The patient underwent orthognathic surgery and high Le Fort I osteotomy with the fixation of eight positional screws. The aim of this paper is to describe a different technique for the fixation in high maxillary osteotomies, which can be used in specific cases.     

Stability of skeletal Class III malocclusion after combined maxillary and mandibular procedures: titanium versus resorbable plates and screws for maxillary fixation.

PURPOSE: The aim of this study was to evaluate skeletal stability after double jaw surgery for correction of skeletal Class III malocclusion to assess if there were any differences between resorbable plate and screws and titanium rigid fixation of the maxilla. PATIENTS AND METHODS: Twenty-two Class III patients had bilateral sagittal split osteotomy for mandibular setback stabilized with rigid internal fixation. Low level Le Fort I osteotomy for maxillary advancement was stabilized with conventional titanium plate and screws in 12 patients (group 1) and with resorbable plate and screws in 10 patients (group 2). Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively. RESULTS: Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary stability was excellent in both groups. In group 1 no significant correlations were found between maxillary advancement and relapse. In group 2, significant correlations were found between maxillary advancement and relapse at A point and posterior nasal spine. No significant differences in postoperative skeletal and dental stability between groups were observed. CONCLUSION: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure for maxillary advancements up to 5 mm independently from the type of fixation used to stabilize the maxilla. Resorbable devices should be used with caution for bony movements of greater magnitude until their usefulness is evaluated in studies with large maxillary advancements.     

A new material (single crystal sapphire screw) for internal fixation of the mandibular ramus

A new single crystal sapphire bone screw which has favourable properties such as chemical stability, mechanical strength and biocompatibility, was applied for rigid internal fixation of the sagittal split osteotomies in 86 cases since 1982. Radiographic findings supported the excellent biocompatibility of the material; there was no noticeable bone loss around the screw and the excellent bone adaptation to the threaded portion was observed. The screws can mechanically support the split mandibular rami until bone union occurs. Complications due to the screw were not encountered in follow-up periods of 0.5-3.5 years.     

The use of self-reinforced biodegradable bone plates and screws in orthognathic surgery.

PURPOSE: This report describes the authors' experience with self-reinforced biodegradable bone plates and screws to stabilize maxillary and mandibular osteotomies. Patient acceptance, demographics, types of osteotomy, means of stabilization, etiology of the deformity, complications, and patient disposition are reviewed. PATIENTS AND METHODS: Seventy patients underwent 194 osteotomies of the maxilla and/or mandible. Stabilization of each osteotomy was achieved using self-reinforced polylactite bone plates and/or screws of similar size and configuration to that of titanium systems. Placement of the devices was accomplished transorally and transfacially, consistent with the osteotomy approach. Maxillomandibular elastics were used to control the position of the jaws in each patient. RESULTS: There was good patient acceptance of the material (70/74). Stabilization was accomplished as planned in all patients. Three patients experienced problems that resulted in immediate loosening of the bone screws. The remaining 67 experienced no short-term problems (6 to 24 months), and healing progressed uneventfully. In each case, acceptable occlusion and favorable aesthetic changes were noted. CONCLUSIONS: The experience with self-reinforced polylactite bone plates and screws to stabilize maxillary and mandibular osteotomies has been favorable on short-term observation.     

Resorbable poly-L-lactide plates and screws for the treatment of mandibular condylar process fractures: a clinical and radiologic follow-up study.

PURPOSE: The purpose of this study was to determine whether a resorbable poly-l-lactide (PLLA) miniplate system could be used to treat mandibular condylar process fracture. PATIENTS AND METHODS: Fourteen patients (12 males, 2 females, aged 23.1 +/- 5.7 years) who had mandibular condylar process fractures treated with PLLA implants were recalled for follow-up clinical and radiologic examinations at 3 years. RESULTS: Mouth opening recovered to more than 35 mm and occlusion was stable in all patients. There was no facial asymmetry 3 months postoperatively. Two patients had mild chronic postoperative tenderness at the implantation site; however, there was no wound infection. All fractured mandibular condyles showed anatomic good reduction and long-term stability with the use of resorbable miniplates and screws. Bone healing was satisfactory in all patients, and there was no evidence of abnormal resorption of the condylar process. The screw holes remained evident after 3 years. Screw holes in 2 patients showed enlargement on radiographic examination. CONCLUSION: The PLLA miniplate system provides reliable stability when used for the fixation of mandibular condylar process fractures.     

Stability of skeletal Class III malocclusion after combined maxillary and mandibular procedures

The aim of this study was to evaluate the skeletal stability and time course of postoperative changes after surgical correction of skeletal Class III malocclusion. Combined maxillary and mandibular procedures were performed in 40 consecutive patients. Bilateral sagittal split osteotomy stabilized with wire osteosynthesis for mandibular setback and low-level Le Fort I osteotomy stabilized with plates and screws for maxillary advancement were performed. Maxillomandibular fixation (MMF) was in place for 6 weeks. Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively. Patients were divided into 2 groups according to vertical maxillary movement at surgery: a maxilla-up group with upward movement of the posterior nasal spine of 2 mm or more (group 1, n = 22), and a minimal vertical change group with less than 2 mm of vertical repositioning (group 2, n = 18). The results indicate that surgical correction of Class III malocclusion with combined maxillary and mandibular osteotomies appears to be fairly stable. One year postsurgery, maxillary stability was excellent, with a mean horizontal relapse at point A that represented 10.7% of maxillary advancement in group 1 and 13.4% in group 2. In the vertical plane, maxillary stability was also excellent, with a mean of 0.18 mm of superior repositioning at point A for group 1 and 1.19 mm for group 2. The mandible relapsed a mean of 2.97 mm horizontally at pogonion in group 1 (62% of mandibular setback) and 3.41 mm (49.7% of setback) in group 2. Bilateral sagittal split osteotomy with wire osteosynthesis and MMF was not as stable as maxillary advancement and accounted for most of the total horizontal relapse (almost 85%) observed. A trend to relapse was observed for maxillary advancement greater than 6 mm, while the single variable accounting for mandibular relapse in group 1 was the amount of surgical setback. Clockwise rotation of the ascending ramus at surgery was not correlated with mandibular relapse in relation to the type of fixation performed and therefore does not seem to be responsible for relapse.     

The management of unstable oblique infected mandibular fractures with a 2.3 mm mandibular osteosynthesis reconstruction bone plate

This study is aimed to evaluate the efficacy of 2.3 mm reconstruction bone plates in the treatment of unstable infected mandibular fractures.

Material

The study included 32 patients with unstable oblique infected mandibular fractures (23 males and 9 females), with a mean age of 33 years. The patients were divided into two groups. Group 1 were treated with an osteosynthesis plate (with at least 3 screws on each side of fracture sites) applied to the mandibular fracture site, while in group 2 the bone plate was applied (2 screws on each side of fracture sites) with maxillomandibular fixation (MMF). Clinical and radiographic examinations were carefully assessed preoperatively and postoperatively at follow-up intervals of 1, 2, 6, 12 months. Postoperative complications in terms of dysocclusion, wound dehiscence and neurosensory disturbances were examined.

Result

Postoperative clinical and radiographic results showed that group 1 had quicker bone generation and more precise anatomical alignment of fracture sites than with those in group 2. All patients showed no evidence of infection, plate fracture or exposure, malunion, osteomyelitis, neurosensory disturbances, or dental injury.

Conclusion

The 2.3 mm reconstruction bone plates provide excellent stability and healing of the unstable infected mandibular fractures provided that the fracture site is fixed by at least 3 screws on each side of the fracture sites.     

Alterations in osseous crestal height following interdental osteotomies.

A study was performed to evaluate the osseous crestal changes following maxillary and mandibular segmental osteotomies. Ten patients with 22 osteotomy sites were evaluated prior to surgery and 6 months postsurgery. Periodontal sounding measurements along with plaque and gingival indices were used as parameters. Except for two patients whose osteotomies were carried out between closely approximated teeth, no patients experienced significant osseous crestal level changes during the investigation period. This leads the authors to believe that segmental osteotomies may be performed without significantly modifying the height of interproximal bone.