Predictability of maxillary repositioning during bimaxillary surgery: accuracy of a new technique

The purpose of this retrospective study was to evaluate the predictability of maxillary repositioning following Le Fort I osteotomy during bimaxillary surgery using a new technique with splints to reposition the maxilla in the three planes of space. In order to assess the accuracy of horizontal and vertical maxillary movements of the maxilla, 32 consecutive patients who underwent bimaxillary surgery had their predictive tracings and model surgery measures compared to postoperative cephalograms taken 1 week after surgery. There was a strong positive correlation between model surgery and postoperative result: 53% of horizontal movements and 41% of vertical movements showed less than 0.2 mm variation. When predictive tracings were compared to postoperative results 44% of horizontal and 50% of vertical movements showed less than 0.2 mm variation. There was no significant difference (P>0.05) between the planned and actual maxillary positions in the sample evaluated. This technique for maxillary repositioning during two-jaw surgery proved to be effective and predictable, with strong agreement between predictive tracings, model surgery and postoperative results.

Biomechanical comparison of plating techniques for fractures of the mandibular condyle

We compared the biomechanical behaviour of various rigid internal fixation techniques for treatment of fractures of the mandibular condylar process. Fifteen sheep hemimandibles were used to evaluate three bicortical plating techniques. A custom-made 3-point biomechanical test model was used for the samples. Each group was tested with compression forces by an Instron Lloyd LRX machine. The resistance to forces (N) that caused displacements of 1.75 and 3.50mm were compared using the Instron software programme and displacement graphics. There were no significant differences among the three groups for displacements of 1.75 and 3.50mm. Our study showed that the titanium miniadaptation plates, minicompression plates, and the absorbable miniplates did not differ significantly in their biomechanical behaviour.

[Surgical treatment of temporomandibular joint: apropos of 94 cases]

INTRODUCTION

The temporomandibular joint (TMJ) is a complex entity subjected to repeated stress with several symptoms. About one-third of people have at least one of those symptoms but only few (3 to 7%) need treatment. The aim of this retrospective study was to evaluate the results of temporomandibular joint surgery in 94 patients.

PATIENTS AND METHODS

Several data were used for decision-making and the surgical technique was adapted to the etiology. The type of postoperative physiotherapy performed depended on the type of pathology.

RESULTS

Most patients who underwent surgery between 1989 and 2004 were women (83%). The mean age was 30 years. We performed 179 surgical procedures and among them 151 Dautrey procedures. In 28 cases miniplates were used to avoid recurrences. In 57 cases postoperative physiotherapy was performed. The mean postoperative mouth opening increase was 4.7 mm (+ 23%). There was no infection or lost of plate. The mean of follow-up was about 14 months.

DISCUSSION

With a long follow-up and an acceptable number of patients and operations, this retrospective study demonstrated the effectiveness of the Dautrey procedure in TMJ subluxations.

Using composite bonding in oral and maxillofacial surgical office practice

OBJECTIVE

Composite bonding plays a significant role in all phases of dental practice from orthodontics to restorative dentistry and even endodontics, yet, at the present time has had limited use by the oral and maxillofacial surgeon. The purpose of this article is 3-fold: to recommend a material for bonding and the method of application for composites; to describe the requirements of the orthodontist when referring a patient for the uncovering of teeth because this is usually the surgeon's primary, if not only, experience with bonding; and to describe situations that may present in the office that will benefit with the use of composite bonding.

PATIENTS AND METHODS

Patients with various problems requiring the stabilization of teeth are presented and in a number of cases the effectiveness of the wired bar and the bonded bar is compared. These cases include the management of dentoalveolar fractures, avulsed or displaced teeth, its application to porcelain restorations without ill effects, and other situations that may arise in the office where fixation and stabilization of teeth is mandatory for success.

RESULTS

Composite bonding provides the most effective method of stabilizing and immobilizing teeth with successful results in almost all cases. On the other hand, the wired arch bar and other wire combinations, which at the present time is the primary, if not the only treatment for these cases, are second to it from all aspects.

CONCLUSION

The successful results with composite bonding along with its case of placement without pain or bleeding or psychological stress on the patient or operator warrants consideration by the oral and maxillofacial surgeon for greater utilization of this material in his office.

Skeletal Stability After Simultaneous Mandibular Angle Resection and Sagittal Split Ramus Osteotomy for Correction of Mandible Prognathism

PURPOSE

Simultaneous mandibular angle resection with bilateral sagittal split ramus osteotomy (BSSRO) is a useful modification of conventional BSSRO in patients with prominent mandibular angles. The purpose of this study is to prove whether simultaneous mandibular angle resection and BSSRO can influence the tendency of postoperative skeletal instability by means of shortening the pterygomasseteric sling.

PATIENTS AND METHODS

This study was based on 26 cases of mandible prognathism. The experimental group consisted of 12 patients (average age, 24.6 +/- 3.9) who underwent BSSRO and mandibular angle resection simultaneously. Fourteen patients (average age, 21.4 +/- 3.4) served as a control group where only BSSRO was carried out. In lateral cephalometric tracings, horizontal and vertical changes of B point, pogonion, and menton were measured to determine the amount of postoperative instability. The amount of skeletal instability was compared between 2 groups.

RESULTS

In the experimental group, point B and pogonion moved posteriorly 1.86 mm and 1.21 mm, respectively. In the control group they moved anteriorly 1.04 mm and 0.96 mm, respectively.

CONCLUSIONS

Simultaneous mandibular angle resection and BSSRO proved to be a useful modification of the conventional BSSRO to reduce the tension in the pterygomasseteric muscle sling and to obtain more esthetic results clinically.

Extensive ameloblastoma of the jaws: surgical management and immediate reconstruction using microvascular flaps

OBJECTIVE

Ameloblastoma is a rare histological benign but locally aggressive tumor with a marked tendency for recurrence. Especially larger, aggressive lesions require a more radical surgical approach resulting in large jaw defects. The purpose of this study is to analyze the long-term functional and esthetic results after immediate reconstruction of large jaw defects using microvascular flaps.

STUDY DESIGN

A review of 7 cases of giant ameloblastoma (2 in the maxillary and 5 in the mandibular region) is presented. The lesions were between 4 and 8 cm in diameter. All patients were treated by a radical surgical protocol. All cases were immediately reconstructed using microvascular grafts from either the scapula or the iliac crest bone. Dental implants were inserted in all patients after removal of the osteosynthesis material.

RESULTS

All patients were prosthetically rehabilitated. All implants survived throughout the observation time. The esthetic and functional outcomes were satisfying in all patients. No case of recurrence of the tumor could be observed so far.

CONCLUSION

According to our opinion, immediate reconstruction is the treatment of choice after radical surgical excision of ameloblastoma. This 1-step procedure decreases the number of surgeries and allows earlier prosthetic rehabilitation.

Open reduction and rigid internal fixation of mandibular condylar fractures by an intraoral approach: a long-term follow-up study of 15 patients

PURPOSE

To evaluate the long-term results obtained with open reduction and rigid internal fixation of mandibular condylar fractures by an intraoral approach.

PATIENTS AND METHODS

Fifteen patients with 24 mandibular condylar fractures were retrospectively examined with an average follow-up of 23 months (range, 6-63 months). Clinical and radiographic examination was conducted according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), including an evaluation of maximum voluntary bite force measurements and facial nerve function. Statistical analysis was performed on maximum voluntary bite force measurements and maximum pressure pain threshold.

RESULTS

Two patients fulfilled the criteria for a RDC/TMD diagnosis. Myofacial pain (group I) and bilateral arthralgia (group III), combined with a moderate nonspecific physical symptom score, was diagnosed in 1 patient and 1 patient received a diagnosis of disc displacement with reduction (group II). Satisfying radiographic fracture healing was seen in 12 joints. However, miniplate fracture occurred in 3 patients and severe bone resorption of the condylar head was seen in one patient. Minor adjustment of the postoperative occlusion was necessary in 6 patients. No significant difference between maximum voluntary isometric bite force measurements or maximum pressure pain threshold was found between the fracture side and the opposite side in unilateral cases or between the operated and nonoperated side in bilateral cases. None of the patients showed facial nerve injury or visible facial scars.

CONCLUSION

Within the limitations of a retrospective study, the present study emphasized that optimal management of dislocated bilateral condylar injuries combined with other fractures of the facial skeleton constitute a challenging issue in maxillofacial trauma. Moreover, open reduction and rigid internal fixation of mandibular condylar fractures by an intraoral approach is a technically demanding surgical procedure associated with a high risk of postoperative complications in these injuries.

Mandibular corpus ostectomy for the correction of mandibular prognathism: a case report

AIM

To present the dentofacial changes produced by mandibular body ostectomy in a female patient, 19 years of age, and the patient's 2-year follow-up records.

SUBJECT AND TREATMENT

An increased lower facial height and a prominent chin, Angle Class III molar relationship, edentulous gaps in the first premolar regions of the mandible, with overjet and overbite values of -1 mm were observed. Radiographic evaluations revealed impaction of the maxillary right canine. The treatment plan included leveling and coordination of the arches, extraction of the maxillary left first premolar and the impacted canine, and a "rectangular" body ostectomy of 5 mm.

RESULTS

Treatment lasted for 24 months. An increase of ANB was observed. Normal overjet and overbite were established. The posterior movement of the lower lip and soft and hard tissue points B and Pg were observed. No major changes were observed for the dentofacial structures at the 2-year follow-up visit. However, slight spacing at the ostectomy sites was present.

CONCLUSION

The rectangular mandibular body ostectomy might be considered an alternative effective method for the correction of mandibular prognathism, particularly when the posterior occlusion is to remain unchanged and when edentulous gaps in the anterior region of the mandible are present.

Complicated late mandibular fracture following third molar removal

Mandibular fractures are a rare complication after third molar removal. Symptoms show a wide variance. Treatment options range from prescription of a soft diet to surgical treatment by open reduction and internal fixation. This article describes a patient who presented a late mandibular fracture following third molar removal. The fracture was not detectable in radiographs at the time of fracture. Six weeks after the reported cracking noise, the patient presented a mandibular fracture with associated osteomyelitis. Treatment by open reduction and internal fixation and autologous iliac crest graft was performed via a submandibular approach. The delayed diagnosis of this pathologic fracture demonstrates the necessity of repeated radiologic controls to prevent osteomyelitis when a fracture is suspected.

Masticatory function and neurosensory disturbance after mandibular correction by bilateral sagittal split ramus osteotomy: a comparison between miniplate and bicortical screw rigid internal fixation

Bilateral sagittal split osteotomy is commonly used to treat mandibular prognathism. Several fixation methods for bony segments have been described. The present study compared masticatory function and neurosensory recovery patterns after mandibular correction between two methods of rigid fixation, bicortical screw (n = 38) and monocortical miniplate (n = 32). Patients who had undergone bilateral sagittal split osteotomy for Class III malocclusion were reviewed, and masticatory function and neurosensory recovery were studied with the appropriate indicators at 1, 3, 6 and 12 months postoperatively. Minimal differences were seen between groups at 1-year postoperatively, and although patients treated with miniplate fixation tended to recover faster, with regard to masticatory function and neurosensory disturbance, than those treated with screw fixation, no significant differences were identified. As the two methods seem to provide equal comfort and reliability, the choice should be made by the individual surgeon.

The Functional Long-Term Results After Bilateral Sagittal Split Osteotomy (BSSO) With and Without a Condylar Positioning Device

PURPOSE

The goal of this retrospective study was to examine whether utilization of condylar positioning devices in bilateral sagittal split osteotomy leads to long-term benefits for temporomandibular joint function as compared with the manual positioning technique.

PATIENTS AND METHODS

The joint function of 49 patients (98 joints) who underwent bilateral sagittal split osteotomy or bimaxillary osteotomy at the University Hospital of Aachen between 1993 and 2003 was analyzed by recording joint movements with axiography supported by clinical examination of the temporomandibular joint. In 10 patients out of 28 with mandibular advancement and in 10 out of 21 with mandibular setback the Luhr positioning device was used intraoperatively to reproduce the condylar position. The joints of the remaining patients were positioned manually. The received data were statistically evaluated by using unrelated t test at P = .05.

RESULTS

In mandibular advancement the manually positioned group showed significantly less signs of temporomandibular disorders, while there were slight advantages in axiographically measured joint track lengths for the patients who were operated with positioning devices. After mandibular setback surgery clinical analysis as well as axiography presented comparable results in both groups.

CONCLUSION

The use of a positioning device did not provide a better functional outcome long term in either mandibular advancement or setback surgery. With the manual positioning technique, an at least equally good temporomandibular joint function was attained.

The Stability of Maxillary Osteotomies Fixated With Biodegradable Mesh in Orthognathic Surgery

PURPOSE

This study measures the stability of maxillary osteotomies fixated with 1-mm biodegradable mesh and screws.

MATERIALS AND METHODS

This prospective study involved 27 patients who underwent maxillary osteotomies. All cases had fixation with biodegradable mesh and screws (70% l-lactide and 30% D,l-lactide polymers). Lateral cephalometric radiographs were taken preoperatively within 2 months (T1), immediately postsurgically within 1 week (T2), postsurgically between 6 and 12 weeks (T3), and long-term postoperatively between 6 months and 1 year (T4). All cephalometric radiographs were digitized with Dolphin Imaging (Dolphin software version 9.0.0018, Chatsworth, CA). Vertical and horizontal measurements were made to several skeletal landmarks including Sella (S), A point (APT), posterior nasal spine (PNS), and upper incisor (UPI).

RESULTS

Twenty patients were completed. Seven patients were not included because lateral cephalometric radiographs were not obtained in the specific time period. It appears that the postsurgical vertical change was not statistically significant, but the horizontal change was significant (P < .01). Relapse was significant in the horizontal dimension.

CONCLUSION

There was more relapse in the anteroposterior (horizontal) direction than the superoinferior (vertical) direction in biodegradable mesh and screws. Biodegradable fixation was more stable in vertical surgical change than horizontal surgical change.

Biomechanical evaluation of different types of rigid internal fixation techniques for subcondylar fractures

PURPOSE

The aim of this study was to evaluate the biomechanical stability of various internal fixation systems for subcondylar fractures.

MATERIALS AND METHODS

Eighteen identical synthetic mandibles were used. Left condylar processes were cut to mimic perpendicular subcondylar fracture and right sides were mimicked oblique subcondylar fracture. The fixation systems used included single 4-hole mini adaptation plate, double fixation with the same plates, single 4-hole mini dynamic compression plate (DCP), Eckelt lag screw system, Wurzburg lag screw plate system and double 4-hole biodegradable miniplates made of poly L-lactide (PLLA). In oblique fractures, one of the screws fixing plates was used bicortically through bone fragments. The loading vector simulated physiologic forces to the condyle on biting with servohydraulic testing machine until failure was reached. Load-displacement curve, maximum load for failure, and stiffness were measured.

RESULTS

In perpendicular fracture, double adaptation plate showed the highest level of tolerance load followed by Eckelt lag and double PLLA plate. In stiffness, double adaptation plate and Eckelt lag screw showed higher level of stiffness, whereas double PLLA was almost at the same level of single DCP. In oblique fracture, double adaptation plate showed the highest strength.

CONCLUSIONS

In this laboratory setting, double adaptation plates fixation proved to have superior biomechanical stability in both fracture conditions. Eckelt lag screw showed good stability in the perpendicular fracture, however, it was weak in the oblique fracture.

Comparison of torsional stability of 2 types of split crimpable surgical hooks with soldered brass surgical hooks

INTRODUCTION

The purpose of this in-vitro study was to compare the torsional stability of split crimpable surgical hooks and soldered brass surgical hooks on a rectangular stabilizing archwire.

METHODS

Coated split crimpable hooks (Never-Slip Grip, TP Orthodontics, LaPorte, Ind), ribbed crimpable hooks (TP Orthodontics), and .032-in brass soldered hooks/notched electrodes (Ormco/Sybron Dental Specialties, Orange, Calif) were attached to a 0.019 x 0.025-in stainless steel archwire. The archwire/hook attachment assembly was secured into a dual contact jig and statically mounted to the base of a universal testing machine. The hooks were engaged by a wire loop attached to the upper load cell of the machine, which pulled the wire until the hook was torsionally displaced from the archwire.

RESULTS

The mean forces, measured in newtons (N), required to dislodge the hooks were as follows: soldered brass surgical hooks (51.3 +/- 5.2 N), coated split crimpable hooks (49.9 +/- 6.6 N), and ribbed split crimpable hooks (31.3 +/- 5.4 N). Data were analyzed with 1-way ANOVA and Tukey HSD post-hoc tests at alpha = .05. Ribbed split crimpable hooks provided significantly less resistance to torsional displacement than the other types of hooks (P <001). There was no difference between coated split crimpable hooks and soldered brass surgical hooks (P >05).

CONCLUSIONS

Under the conditions of this study, the results suggest that soldered brass surgical hooks and coated split crimpable hook attachments provide more stability to torsional dislodgement from a rectangular stabilizing archwire than ribbed split crimpable hooks.

Treatment outcome of short- and long-term appliance therapy in patients with TMD of myogenous origin and tension-type headache

The aim was to compare the short- and long-term effect of a stabilization appliance with a control appliance in myofascial pain patients suffering from episodic or chronic tension-type headache. Sixty patients (mean age 29 +/- 12 years) with temporomandibular disorders (TMD) of myogenous origin and headache were studied in this prospective controlled study. Seventy-seven per cent of the patients reported episodic and 23% chronic tension-type headache at the start of the study. The 60 patients were randomly assigned to a treatment group (stabilization appliance) or to a control group (control appliance). The patients were interviewed regarding symptoms of headache and myofascial pain and clinically examined for masticatory muscle tenderness. At the 10-week and the 6- and 12-month evaluations of appliance therapy, the treatment outcome of tension-type headache was studied. At the 10-week evaluation, 17 patients dropped-out from the control group by requesting another appliance and receiving a stabilization appliance. Another patient in the control group dropped out later during the trial. In an intent-to-treat analysis, significant differences in improvement of headache between treatment and control groups were found at the follow-ups. A 30% reduction of muscles tender to palpation correlated significantly to improvement of headache at all follow-ups. The stabilization appliance seems to have a positive effect on tension-type headache, both in a short- and in a long-term perspective in patients with TMD with pain of myogenous origin.

Evaluation of osteotomy fixation changing the number, the extension and the location of the plates

We used a two-dimensional model that simulated a fractured human mandible to study the extent of load resistance of different plates. We studied 49 bovine ribs in seven groups using varying number (1 or 2), lengths of plates (4 or 6-holes), and location (near the lower or upper border). The number and location of plates had a greater effect on resistance to load than length of plates. The best mean resistance values were achieved by a combination of two parallel plates secured near the lower and upper borders, followed by single plates secured near the upper border. The lowest values were with single plates secured close to the lower border.

One-year postoperative stability of LeFort I osteotomies with biodegradable fixation: A retrospective analysis of skeletal relapse

INTRODUCTION

The purpose of this retrospective analysis was to determine the magnitude of postoperative skeletal relapse of a maxillary LeFort I osteotomy procedure performed with fixation plates and screws composed of a biodegradable copolymer (poly-L lactic and poly-L glycolic acid).

METHODS

Twenty-three consecutively treated subjects, aged 19 to 39, were diagnosed with excess vertical maxillary height or anteroposterior maxillary deficiency and treated with LeFort I impaction or advancement osteotomies. Lateral cephalometric radiographs were measured and compared for the absolute magnitude of skeletal relapse from pretreatment to immediately postoperative to 1 year after surgery.

RESULTS

Correlation analysis determined that a positive relationship existed between the magnitude of the surgical movement and the magnitude of postoperative relapse. The greatest relapse for any subject in any direction was 0.940 mm (anterior nasal spine to nasion-perpendicular). The greatest average relapses were 0.249 mm horizontally (anterior nasal spine to Frankfort horizontal) and 0.141 mm vertically (M-point Frankfort horizontal).

CONCLUSIONS

The most significant contribution of this study to surgical stability literature is reporting the absolute magnitudes of postoperative relapse over a 1-year period of observation. Consistent with previously published reports on postoperative stability, greater magnitudes of relapse were noted for larger surgical movements, yet the absolute values of postoperative relapse with biodegradable copolymers was clinically negligible. Biodegradable copolymers can provide excellent postoperative stability for superior and anterior maxillary surgical repositioning that appears to rival published stability measurements for rigid internal metallic fixation.

Oromandibular Reconstruction Using a Fibula Osteocutaneous Free Flap: Four Different ???Preplating??? Techniques

BACKGROUND

The aim of oromandibular reconstruction following a partially or fully extended resection is to recreate the normal morphology with a mandibular profile as similar as possible to the original and to restore oral function. Oromandibular reconstruction can be performed with fibula osteocutaneous free flaps combined with the preplating technique. The authors report their experience using the preplating technique for oromandibular reconstruction.

METHODS

Four different methods can be used to mold the titanium plate that will be used in reconstruction against the existing mandible before resection. The preplating technique was used in 18 patients between 1998 and 2003. In eight patients, the external cortical bone of the mandible was spared by the tumor and the vestibular preplating technique was used. In one patient, the internal cortical bone was unaffected and the lingual preplating technique was used. When the tumor affected both the internal and external cortical bones, the double preplating technique was adopted in eight cases and Luhr's approach was used in one case.

RESULTS

A good cosmetic appearance was obtained through the accurate reconstruction of the inferior mandibular border. Mandible continuity was restored, and the masticatory and oral muscles were anchored to the titanium plate, resulting in good occlusal and functional rehabilitation.

CONCLUSION

The preplating technique combined with a fibula microvascular free flap is a useful, predictable method for oromandibular reconstruction.