Reza Movahed

Twenty-Year Follow-up Study on a Patient-Fitted Temporomandibular Joint Prosthesis: The Techmedica/TMJ Concepts Device

PURPOSE To evaluate subjective and objective outcomes of patients receiving Techmedica (currently TMJ Concepts) patient-fitted temporomandibular joint (TMJ) total joint replacement (TJR) devices after 19 to 24 years of service. PATIENTS AND METHODS This prospective cohort study evaluated 111 patients operated on by 2 surgeons using Techmedica (Camarillo, CA) patient-fitted TMJ TJR devices from November 1989 to July 1993. Patients were evaluated before surgery and at least 19 years after surgery. Subjective evaluations used standard forms and questions with a Likert scale for 1) TMJ pain (0, no pain; 10, worst pain imaginable), 2) jaw function (0, normal function; 10, no movement), 3) diet (0, no restriction; 10, liquid only), and 4) quality of life (QoL; improved, the same, or worse). Objective assessment measured maximum incisal opening (MIO). Comparison analysis of presurgical and longest follow-up data used nonparametric Mann-Whitney and Wilcoxon signed rank tests. Spearman correlations evaluated the number of prior surgeries in relation to objective and subjective variables. RESULTS Of the 111 patients, 56 (50.5%) could be contacted and had adequate records for inclusion in the study. Median follow-up was 21 years (interquartile range [IQR], 20 to 22 yr). Mean age at surgery was 38.6 years (standard deviation, 10 yr). Median number of previous TMJ surgeries was 3 (IQR, 4). Presurgical and longest follow-up data comparison showed statistically significant improvement (P < .001) for MIO, TMJ pain, jaw function, and diet. At longest follow-up, 48 patients reported improved QoL, 6 patients reported the same QoL, and 2 patients reported worse QoL. Spearman correlations showed that an increased number of previous surgeries resulted in lower levels of improvement for TMJ pain and MIO. CONCLUSIONS At a median of 21 years after surgery, the Techmedica/TMJ Concepts TJR continued to function well. More previous TMJ surgeries indicated a lesser degree of improvement. No devices were removed owing to material wear.

Low Condylectomy and Orthognathic Surgery to Treat Mandibular Condylar Osteochondroma: A Retrospective Review of 37 Cases

PURPOSE To evaluate the outcomes from surgical treatment of mandibular condylar osteochondroma (condylar hyperplasia [CH] type 2) using a specific surgical protocol. CH type 2 is a unilateral benign pathologic condition, with progressive proliferation of osseous and cartilaginous tissues in the condylar head. This causes condylar enlargement, often with exophytic growth, resulting in significant facial deformity, pain, and masticatory and occlusal dysfunction. PATIENTS AND METHODS This was a retrospective cohort study of 37 patients (28 females and 9 males), with an average age of 26.3 years (range 13 to 48), with CH type 2, and associated dentofacial deformity. The condylar pathologic features were confirmed by histologic analysis. All patients were treated with low condylectomy, recontouring of the condylar neck to form a new condyle, repositioning of the articular disc over the condylar stump and repositioning of the contralateral disc, if displaced, and any indicated orthognathic surgical procedures. Postoperative follow-up averaged 48 months (range 12 to 288). Patients were assessed preoperatively and at the longest follow-up point for incisal opening, lateral excursions, pain, jaw function, diet, disability, and occlusal and skeletal stability. The pre- and postoperative assessments were compared using paired t test. RESULTS At the longest follow-up point, a nonsignificant decrease (2.3 mm) was seen in the maximum incisal opening; however, the excursive movements had decreased significantly an average of 2.5 mm on the right and 2.2 mm on the left. A statistically significant improvement was seen in pain, jaw function, diet, and disability. A stable Class I skeletal and occlusal relationship was maintained in 34 of the 37 patients (92%). Two patients developed relatively minor postoperative malocclusions that were managed with orthodontics. In 1 patient, a high condylectomy was performed, and the tumor continued to grow, causing malocclusion and jaw deformity to recur. A low condylectomy and sagittal split were performed 14 months later, with a stable result at 4 years after surgery. CONCLUSIONS The results of the present study have demonstrated that a low condylectomy procedure with recontouring of the condylar neck to function as a condyle and repositioning of the articular discs, combined with orthognathic surgery, is a viable option for the treatment of osteochondroma of the mandibular condyle and associated jaw deformity.

Protocol for concomitant temporomandibular joint custom-fitted total joint reconstruction and orthognathic surgery utilizing computer-assisted surgical simulation.

Clinicians who address temporomandibular joint (TMJ) pathology and dentofacial deformities surgically can perform the surgery in 1 stage or 2 separate stages. The 2-stage approach requires the patient to undergo 2 separate operations and anesthesia, significantly prolonging the overall treatment. However, performing concomitant TMJ and orthognathic surgery (CTOS) in these cases requires careful treatment planning and surgical proficiency in the 2 surgical areas. This article presents a new treatment protocol for the application of computer-assisted surgical simulation in CTOS cases requiring reconstruction with patient-fitted total joint prostheses. The traditional and new CTOS protocols are described and compared. The new CTOS protocol helps decrease the preoperative workup time and increase the accuracy of model surgery.

Management of temporomandibular joint ankylosis.

Temporomandibular joint (TMJ) ankylosis is a pathologic condition where the mandible is fused to the fossa by bony or fibrotic tissues. This interferes with mastication, speech, oral hygiene, and normal life activities, and can be potentially life threatening when struggling to acquire an airway in an emergency. Trauma is the most common cause of TMJ ankylosis, followed by infection. Diagnosis of TMJ ankylosis is usually made by clinical examination and imaging studies. The management goal in TMJ ankylosis is to increase the patients mandibular function, correct associated facial deformity, decrease pain, and prevent reankylosis.

Protocol for Concomitant Temporomandibular Joint Custom-fitted Total Joint Reconstruction and Orthognathic Surgery Using Computer-assisted Surgical Simulation

Combined orthognathic and total joint reconstruction cases can be predictably performed in 1 stage. Use of virtual surgical planning can eliminate a significant time requirement in preparation of concomitant orthognathic and temporomandibular joint (TMJ) prostheses cases. The concomitant TMJ and orthognathic surgery-computer-assisted surgical simulation technique increases the accuracy of combined cases. In order to have flexibility in positioning of the total joint prosthesis, recontouring of the lateral aspect of the rami is advantageous.

Application of cranial bone grafts for reconstruction of maxillofacial deformities

This retrospective study evaluated outcomes with the use of calvarial bone grafts (CBGs) in maxillofacial reconstruction as well as donor and recipient site complications. The records of 50 consecutive patients from a private practice were reviewed; there were 34 women and 16 men, with an average age of 32.4 years (range 16 to 66 years). Among the 50 patients, CBGs were placed in 63 sites: the ramus (10), nasal dorsum (14), maxilla/alveolar ridge (12), glenoid fossa/temporal bone (14), mandibular body/symphysis (3), and orbitozygomatic complex (10). The longest follow-up averaged 22.4 months (range 12 to 48 months). An outer-table CBG harvest technique was utilized. All subjects were evaluated for infection, dehiscence, loss of graft, and any other complications. Three complications occurred (5%) at the recipient sites. Two grafts became infected requiring removal, and one nasal dorsal graft was mobile but remained in position. At 50 donor sites, 2 complications (4%) occurred, resulting in dural tears in two patients that were immediately repaired with no untoward consequence. In conclusion, CBGs are an effective bone source for maxillofacial reconstruction with low donor and recipient site complications.

Outcome assessment of 603 cases of concomitant inferior turbinectomy and Le Fort I osteotomy

This retrospective study assessed the outcome of 603 patients undergoing partial inferior turbinectomies (PIT) in association with Lefort I osteotomy. The study included 1234 patients from a single private practice; these patients had dentofacial deformities and underwent Lefort I osteotomy procedures. For the full patient group, 888 patients (72%) were women; in the turbinectomy group, 403 (67%) were women. The anteroposterior, transverse, and vertical dimensions of the mandible, maxilla, and occlusal plane of each subject were assessed, in addition to cephalometric analysis and determination of the presence or absence of temporomandibular joint disorders. PIT, when indicated, was performed after downfracture of the maxilla, providing access to the turbinates where approximately two thirds of the total turbinate volume was removed and septoplasty was completed if indicated. Hypertrophied turbinates causing significant nasal airway obstruction were present in 603 (49%) of the 1234 patients undergoing Le Fort I osteotomy. The results of this study showed that PIT performed simultaneously with Le Fort I osteotomy is a safe method of managing nasal airway obstruction related to hypertrophied turbinates with minimal complications.

Computational fluid dynamics for the assessment of upper airway changes in skeletal Class III patients treated with mandibular setback surgery

OBJECTIVE To analyze and compare pharyngeal airflow characteristics pre- and post-mandibular setback surgery in patients with Class III skeletal dysplasia using cone beam computed tomography (CBCT) and computational fluid dynamics (CFD). MATERIALS AND METHODS Records of 29 patients who had received orthodontic treatment along with mandibular setback surgery were obtained. CBCT scans were obtained at three time points: T1 (before surgery), T2 (average of 6 months after surgery), and T3 (average of 1 year after surgery). Digitized pharyngeal airway models were generated from these scans. CFD was used to simulate and characterize pharyngeal airflow. RESULTS Mean airway volume was significantly reduced from 35,490.324 mm3 at T1 to 24,387.369 mm3 at T2 and 25,069.459 mm3 at T3. Significant increase in mean negative pressure was noted from 3.110 Pa at T1 to 6.116 Pa at T2 and 6.295 Pa at T3. There was a statistically significant negative correlation between the change in airway volume and the change in pressure drop at both the T2 and T3 time points. There was a statistically significant negative correlation between the amount of mandibular setback and change in pressure drop at the T2 time point. CONCLUSIONS Following mandibular setback surgery, pharyngeal airway volume was decreased and relative mean negative pressure was increased, implying an increased effort required from a patient for maintaining constant pharyngeal airflow. Thus, high-risk patients undergoing a large amount of mandibular setback surgery should be evaluated for obstructive sleep apnea and the proposed treatment plan be revised based on the risk for potential airway compromise.

Pharyngeal airway evaluation after isolated mandibular setback surgery using cone-beam computed tomography

Introduction: In this study, we investigated volumetric and dimensional changes to the pharyngeal airway space after isolated mandibular setback surgery for patients with Class III skeletal dysplasia. Methods: Records of 28 patients who had undergone combined orthodontic and mandibular setback surgery were obtained. The sample comprised 17 men and 11 women. Their mean age was 23.88 ± 6.57 years (range, 18‐52 years). Cone‐beam computed tomography scans were obtained at 3 time points: before surgery, average of 6 months after surgery, and average of 1 year after surgery. Oropharyngeal, hypopharyngeal, and total volumes were calculated. The lateral surface and anteroposterior dimensions at the minimal axial areas for oropharyngeal and hypopharyngeal volumes and mean mandibular setback were determined. Results: The mean mandibular setback was 9.93 ± 5.26 mm. Repeated measures analysis of variance determined an overall significant decrease between the means for 6 months and up to 1 year after surgery for oropharyngeal and hypopharyngeal volumes, anteroposterior at oropharyngeal, lateral surface at oropharyngeal, and anteroposterior at hypopharyngeal. No strong correlation between mandibular setback surgery and pharyngeal airway volumes or dimensions was determined. Conclusions: After mandibular setback surgery, pharyngeal airway volume, and transverse and anteroposterior dimensions were decreased. Patients undergoing mandibular setback surgery should be evaluated for obstructive sleep apnea and the proposed treatment plan modified according to the risk for potential airway compromise. HighlightsPharyngeal airway volume is decreased after isolated mandibular setback surgery.Lateral and anteroposterior oropharyngeal dimensions also decrease significantly.Anteroposterior hypopharyngeal dimension decreases.Amounts of mandibular setback and pharyngeal airway change are not strongly correlated.Amount of mandibular setback surgery could not predict pharyngeal airway changes.

Fluid structure interaction simulations of the upper airway in obstructive sleep apnea patients before and after maxillomandibular advancement surgery

Introduction The purpose of this study was to analyze pharyngeal airflow using both computational fluid dynamics (CFD) and fluid structure interactions (FSI) in obstructive sleep apnea patients before and after maxillomandibular advancement (MMA) surgery. The airflow characteristics before and after surgery were compared with both CFD and FSI. In addition, the presurgery and postsurgery deformations of the airway were evaluated using FSI. Methods Digitized pharyngeal airway models of 2 obstructive sleep apnea patients were generated from cone‐beam computed tomography scans before and after MMA surgery. CFD and FSI were used to evaluate the pharyngeal airflow at a maximum inspiration rate of 166 ml per second. Standard steady‐state numeric formulations were used for airflow simulations. Results Airway volume increased, pressure drop decreased, maximum airflow velocity decreased, and airway resistance dropped for both patients after the MMA surgery. These findings occurred in both the CFD and FSI simulations. The FSI simulations showed an area of marked airway deformation in both patients before surgery, but this deformation was negligible after surgery for both patients. Conclusions Both CFD and FSI simulations produced airflow results that indicated less effort was needed to breathe after MMA surgery. The FSI simulations demonstrated a substantial decrease in airway deformation after surgery. These beneficial changes positively correlated with the large improvements in polysomnography outcomes after MMA surgery. HighlightsBoth CFD and FSI simulations indicated less effort was required to breathe after MMA surgery.FSI simulations showed a large decrease in airway deformation postsurgery.Airway simulation changes correlated positively with polysomnography improvements.