João Roberto Gonçalves

Maxillo-mandibular counter-clockwise rotation and mandibular advancement with TMJ Concepts® total joint prostheses: Part III – Pain and dysfunction outcomes

47 end-stage TMJ patients with high occlusal plane angulation, treated with TMJ custom-fitted total joint prostheses and simultaneous maxillo-mandibular counter-clockwise rotation were evaluated for pain and dysfunction presurgery (T1) and at the longest follow-up (T2). Patients subjectively rated their facial pain/headache, TMJ pain, jaw function, diet and disability. Objective functional changes were determined by measuring maximum interincisal opening (MIO) and laterotrusive movements. Patients were divided according to the number of previous failed TMJ surgeries: Group 1 (0-1), Group 2 (2 or more). Significant subjective pain and dysfunction improvements (37-52%) were observed (<or= 0.001). MIO increased 14% but lateral excursion decreased 60%. The groups presented similar absolute changes, but Group 2 showed more dysfunction at T1 and T2. For patients who did not receive fat grafts around the prostheses and had previous failure of proplast/teflon and or silastic TMJ implants, more than half required surgery for TMJ debridement and removal of foreign body giant cell reaction and heterotopic bone formation. End-stage TMJ patients can be treated in one operation with TMJ custom-made total joint prostheses and maxillo-mandibular counter-clockwise rotation, for correction of dentofacial deformity and improvement in pain and TMJ dysfunction; Group 1 patients had better results than Group 2 patients.

Midpalatal suture maturation: classification method for individual assessment before rapid maxillary expansion.

INTRODUCTION In this study, we present a novel classification method for individual assessment of midpalatal suture morphology. METHODS Cone-beam computed tomography images from 140 subjects (ages, 5.6-58.4 years) were examined to define the radiographic stages of midpalatal suture maturation. Five stages of maturation of the midpalatal suture were identified and defined: stage A, straight high-density sutural line, with no or little interdigitation; stage B, scalloped appearance of the high-density sutural line; stage C, 2 parallel, scalloped, high-density lines that were close to each other, separated in some areas by small low-density spaces; stage D, fusion completed in the palatine bone, with no evidence of a suture; and stage E, fusion anteriorly in the maxilla. Intraexaminer and interexaminer agreements were evaluated by weighted kappa tests. RESULTS Stages A and B typically were observed up to 13 years of age, whereas stage C was noted primarily from 11 to 17 years but occasionally in younger and older age groups. Fusion of the palatine (stage D) and maxillary (stage E) regions of the midpalatal suture was completed after 11 years only in girls. From 14 to 17 years, 3 of 13 (23%) boys showed fusion only in the palatine bone (stage D). CONCLUSIONS This new classification method has the potential to avoid the side effects of rapid maxillary expansion failure or unnecessary surgically assisted rapid maxillary expansion for late adolescents and young adults.

Condylar Resorption of the Temporomandibular Joint: How Do We Treat It?

Condylar resorption (CR) is a common sequela of some temporomandibular joint (TMJ) abnormalities. CR can result in jaw deformities and dysfunction, malocclusion, pain, headaches, and airway obstruction. Most cases can be classified into 1 of 4 categories based on cause: (1) adolescent internal CR; (2) reactive (inflammatory) arthritis; (3) autoimmune and connective tissue diseases; and (4) other end-stage TMJ pathologic abnormality. MRI is helpful in differentiating the cause and defining treatment options. This article presents the nature and progression of the different TMJ CR pathologic abnormalities, clinical and imaging characteristics, and treatment options to produce predictable and stable outcomes.

3D osteoarthritic changes in TMJ condylar morphology correlates with specific systemic and local biomarkers of disease

OBJECTIVE To assess 3D morphological variations and local and systemic biomarker profiles in subjects with a diagnosis of temporomandibular joint osteoarthritis (TMJ OA). DESIGN Twenty-eight patients with long-term TMJ OA (39.9 ± 16 years), 12 patients at initial diagnosis of OA (47.4 ± 16.1 years), and 12 healthy controls (41.8 ± 12.2 years) were recruited. All patients were female and had cone beam CT scans taken. TMJ arthrocentesis and venipuncture were performed on 12 OA and 12 age-matched healthy controls. Serum and synovial fluid levels of 50 biomarkers of arthritic inflammation were quantified by protein microarrays. Shape Analysis MANCOVA tested statistical correlations between biomarker levels and variations in condylar morphology. RESULTS Compared with healthy controls, the OA average condyle was significantly smaller in all dimensions except its anterior surface, with areas indicative of bone resorption along the articular surface, particularly in the lateral pole. Synovial fluid levels of ANG, GDF15, TIMP-1, CXCL16, MMP-3 and MMP-7 were significantly correlated with bone apposition of the condylar anterior surface. Serum levels of ENA-78, MMP-3, PAI-1, VE-Cadherin, VEGF, GM-CSF, TGFβb1, IFNγg, TNFαa, IL-1αa, and IL-6 were significantly correlated with flattening of the lateral pole. Expression levels of ANG were significantly correlated with the articular morphology in healthy controls. CONCLUSIONS Bone resorption at the articular surface, particularly at the lateral pole was statistically significant at initial diagnosis of TMJ OA. Synovial fluid levels of ANG, GDF15, TIMP-1, CXCL16, MMP-3 and MMP-7 were correlated with bone apposition. Serum levels of ENA-78, MMP-3, PAI-1, VE-Cadherin, VEGF, GM-CSF, TGFβ1, IFNγ, TNFα, IL-1α, and IL-6 were correlated with bone resorption.

Regional 3D superimposition to assess temporomandibular joint condylar morphology

OBJECTIVES To investigate the reliability of regional three-dimensional registration and superimposition methods for assessment of temporomandibular joint condylar morphology across subjects and longitudinally. METHODS The sample consisted of cone beam CT scans of 36 patients. The across-subject comparisons included 12 controls, mean age 41.3 ± 12.0 years, and 12 patients with temporomandibular joint osteoarthritis, mean age 41.3 ± 14.7 years. The individual longitudinal assessments included 12 patients with temporomandibular joint osteoarthritis, mean age 37.8 ± 16.7 years, followed up at pre-operative jaw surgery, immediately after and one-year post-operative. Surface models of all condyles were constructed from the cone beam CT scans. Two previously calibrated observers independently performed all registration methods. A landmark-based approach was used for the registration of across-subject condylar models, and temporomandibular joint osteoarthritis vs control group differences were computed with shape analysis. A voxel-based approach was used for registration of longitudinal scans calculated x, y, z degrees of freedom for translation and rotation. Two-way random intraclass correlation coefficients tested the interobserver reliability. RESULTS Statistically significant differences between the control group and the osteoarthritis group were consistently located on the lateral and medial poles for both observers. The interobserver differences were ≤0.2 mm. For individual longitudinal comparisons, the mean interobserver differences were ≤0.6 mm in translation errors and 1.2° in rotation errors, with excellent reliability (intraclass correlation coefficient >0.75). CONCLUSIONS Condylar registration for across-subjects and longitudinal assessments is reliable and can be used to quantify subtle bony differences in the three-dimensional condylar morphology.

Orthognathic Surgery in the Young Cleft Patient: Preliminary Study on Subsequent Facial Growth

PURPOSE This study evaluated the long-term effects of orthognathic surgery on subsequent growth of the maxillomandibular complex in the young cleft patient. PATIENTS AND METHODS We evaluated 12 young cleft patients (9 male and 3 female patients), with a mean age of 12 years 6 months (range, 9 years 8 months to 15 years 4 months), who underwent Le Fort I osteotomies, with maxillary advancement, expansion, and/or downgrafting, by use of autogenous bone or hydroxyapatite grafts, when indicated, for maxillary stabilization. Five patients had concomitant osteotomies of the mandibular ramus. All patients had presurgical and postsurgical orthodontic treatment to control the occlusion. Radiographs taken at initial evaluation (T1) and presurgery (T2) were compared to establish the facial growth vector before surgery, whereas radiographs taken immediately postsurgery (T3) and at longest follow-up (T4) were used to determine postsurgical growth. Each patients lateral cephalograms were traced, and 16 landmarks were identified and used to compute 11 measurements describing presurgical and postsurgical growth. RESULTS Before surgery, all patients had relatively normal growth. After surgery, cephalograms showed statistically significant growth changes from T3 to T4, with the maxillary depth decreasing by -3.3 degrees +/- 1.8 degrees , Sella-nasion-point A by -3.3 degrees +/- 1.8 degrees, and point A-nasion-point B by -3.6 degrees +/- 2.8 degrees. The angulation of the maxillary incisors increased by 9.2 degrees +/- 11.7 degrees. Of 12 patients, 11 showed disproportionate postsurgical jaw growth. Maxillary growth occurred predominantly in a vertical vector with no anteroposterior growth, even though most patients had shown anteroposterior growth before surgery. The distance increased in the linear measurement from nasion to gnathion by 10.3 +/- 7.9 mm. Four of 5 patients operated on during the mixed dentition phase had teeth that erupted through the cleft area. A variable impairment of postoperative growth was seen with the 2 types of grafting material used. No significant difference was noted in the effect on growth in patients with unilateral clefts versus those with bilateral clefts. The presence of a pharyngeal flap was noted to adversely affect growth, whereas simultaneous mandibular surgery did not. After surgery, 11 of 12 patients tended toward a Class III end-on occlusal relation. CONCLUSIONS Orthognathic surgery may be performed on growing cleft patients when mandated by psychological and/or functional concerns. The surgeon must be cognizant of the adverse postsurgical growth outcomes when performing orthognathic surgery on growing cleft patients with the possibility for further surgery requirements. Performing maxillary osteotomies on cleft patients would be more predictable after completion of facial growth.

Temporomandibular Joint Condylar Changes Following Maxillomandibular Advancement and Articular Disc Repositioning

PURPOSE To evaluate condylar changes 1 year after bimaxillary surgical advancement with or without articular disc repositioning using longitudinal quantitative measurements in 3-dimensional (3D) temporomandibular joint (TMJ) models. METHODS Twenty-seven patients treated with maxillomandibular advancement (MMA) underwent cone-beam computed tomography before surgery, immediately after surgery, and at 1-year follow-up. All patients underwent magnetic resonance imaging before surgery to assess disc displacements. Ten patients without disc displacement received MMA only. Seventeen patients with articular disc displacement received MMA with simultaneous TMJ disc repositioning (MMA-Drep). Pre- and postsurgical 3D models were superimposed using a voxel-based registration on the cranial base. RESULTS The location, direction, and magnitude of condylar changes were displayed and quantified by graphic semitransparent overlays and 3D color-coded surface distance maps. Rotational condylar displacements were similar in the 2 groups. Immediately after surgery, condylar translational displacements of at least 1.5 mm occurred in a posterior, superior, or mediolateral direction in patients treated with MMA, whereas patients treated with MMA-Drep presented more marked anterior, inferior, and mediolateral condylar displacements. One year after surgery, more than half the patients in the 2 groups presented condylar resorptive changes of at least 1.5 mm. Patients treated with MMA-Drep presented condylar bone apposition of at least 1.5 mm at the superior surface in 26.4%, the anterior surface in 23.4%, the posterior surface in 29.4%, the medial surface in 5.9%, or the lateral surface in 38.2%, whereas bone apposition was not observed in patients treated with MMA. CONCLUSIONS One year after surgery, condylar resorptive changes greater than 1.5 mm were observed in the 2 groups. Articular disc repositioning facilitated bone apposition in localized condylar regions in patients treated with MMA-Drep.

Disc Repositioning: does it really work?

Although limited, there is evidence to support the assumption that temporomandibular joint (TMJ) articular disc repositioning indeed works; to date, there is no evidence that TMJ articular disc repositioning does not work. Despite the controversy among professionals in private practice and academia, TMJ articular disc repositioning is a procedure based on (still limited) evidence; the opposition is based solely on clinical preference and influenced by the ability to perform it or not.

Airway space changes after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts® total joint prostheses: three-dimensional assessment

This study focused on three-dimensional (3D) airway space changes and stability following simultaneous maxillomandibular counterclockwise rotation, mandibular advancement, and temporomandibular joint (TMJ) reconstruction with custom-made total joint prostheses (TMJ Concepts(®)). Cone beam computed tomography (CBCT) scans of 30 consecutive female patients with irreversibly compromised TMJs were obtained at the following intervals: T1, presurgery; T2, immediately after surgery; and T3, at least 6 months after surgery. The CBCT volumetric datasets were analysed with Dolphin Imaging(®) software to evaluate surgical and postsurgical changes to oropharyngeal airway parameters. The average changes in airway surface area (SA), volume (VOL), and minimum axial area (MAA) were, 179.50 mm(2), 6302.60 mm(3), and 92.23 mm(2), respectively, at the longest follow-up (T3-T1) (P≤0.001). Significant correlations between the amount of mandibular advancement and counterclockwise rotation of the occlusal plane and 3D airway changes were also found (P≤0.01). The results of this investigation showed a significant immediate 3D airway space increase after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts total joint prostheses, which remained stable over the follow-up period.

3D superimposition and understanding temporomandibular joint arthritis

OBJECTIVES To investigate the 3D morphological variations in 169 temporomandibular ioint (TMJ) condyles, using novel imaging statistical modeling approaches. SETTING AND SAMPLE POPULATION The Department of Orthodontics and Pediatric Dentistry at the University of Michigan. Cone beam CT scans were acquired from 69 subjects with long-term TMJ osteoarthritis (OA, mean age 39.1±15.7 years), 15 subjects at initial consult diagnosis of OA (mean age 44.9±14.8 years), and seven healthy controls (mean age 43±12.4 years). MATERIALS AND METHODS 3D surface models of the condyles were constructed, and homologous correspondent points on each model were established. The statistical framework included Direction-Projection-Permutation (DiProPerm) for testing statistical significance of the differences between healthy controls and the OA groups determined by clinical and radiographic diagnoses. RESULTS Condylar morphology in OA and healthy subjects varied widely with categorization from mild to severe bone degeneration or overgrowth. DiProPerm statistics supported a significant difference between the healthy control group and the initial diagnosis of OA group (t=6.6, empirical p-value=0.006) and between healthy and long-term diagnosis of OA group (t=7.2, empirical p-value=0). Compared with healthy controls, the average condyle in OA subjects was significantly smaller in all dimensions, except its anterior surface, even in subjects with initial diagnosis of OA. CONCLUSION This new statistical modeling of condylar morphology allows the development of more targeted classifications of this condition than previously possible.