Condylar and temporomandibular joint disc positions after mandibular osteotomy for prognathism

Changes in strain energy density in the temporomandibular joint disk after sagittal split ramus osteotomy using a computed tomography-based finite element model

PURPOSE

We evaluated the changes in the strain energy density (SED) in the temporomandibular joint (TMJ) disk after sagittal split ramus osteotomy (SSRO) at three time points. A finite element model (FEM) based on real patient-based computed tomography (CT) data was used to examine the effect of SSRO on the TMJ.

METHODS

Measurements of the condylar position and angulation in CT images and FEM analyses were performed for 17 patients scheduled to undergo SSROs at the following time points: before surgery, immediately after surgery, and 1 year after surgery. SED on the entire disk was calculated at each of the three time points using FEM. Furthermore, the relationship between individual SED values and the corresponding condylar position was also evaluated.

RESULTS

No significant change was observed in the condylar position at the three time points. The FEM analysis showed that SED was the highest and lowest immediately after and 1 year after surgery, respectively. A possible SED distribution imbalance between the left and right joints was improved 1 year after SSRO. Concerning the effect of fossa morphometry and condylar position, wide and deep glenoid fossae and a more posterior condylar position tended to show lower SED.

CONCLUSION

SED in the articular disk temporarily increased after surgery and significantly decreased 1 year after surgery compared with that before surgery. SSRO generally improved the imbalance between the left and right joints. Thus, SSRO, which improves maxillofacial morphology, may also improve components of temporomandibular disorders.

Feasibility of simultaneous TMJ arthroscopy in ADDwoR patients undergoing orthognathic surgery for jaw deformity

This study evaluated the feasibility of simultaneous temporomandibular joint (TMJ) arthroscopy and orthognathic surgery as a new treatment strategy for anterior disc displacement without reduction (ADDwoR) patients with severe jaw deformities. Twelve ADDwoR patients with facial deformities who underwent arthroscopy and orthognathic surgery between September 2015 and December 2019 were retrospectively evaluated. Pre- and postoperative maximum incisal opening (MIO) and joint pain were recorded. Computed tomography (CT) and three-dimensional cephalometric analysis were performed at 3 (T1) and ≥6 (T2) months postoperatively. Magnetic resonance imaging (MRI) of the TMJ was performed before, ≤7 days after and ≥6 months after surgery. The lateral profile radiological findings, the symmetry of the maxilla and mandible, and the MRI measurements were compared. Anterior disc displacement did not recur, and the maximum incisal opening (MIO) increased from 27.4 mm to 32.7 mm after surgery (p < 0.05). No significant differences were found in the lateral profile, symmetry indices or condylar height via MRI between T1 and T2. Joint morphology and the position of both the maxilla and mandible remained stable during postoperative follow-up, while joint symptoms were markedly relieved and facial appearance was noticeably improved. Combined arthroscopy and orthognathic surgery is effective and recommended for ADDwoR patients with jaw deformities.

Does Articular Disc Position Change Following Mandibular Setback Surgery?

BACKGROUND

Maintaining condyle position following bilateral sagittal split ramus osteotomy (BSSO) is crucial to minimizing postoperative relapse. However, the impact of BSSO on the articular disc position remains inconclusive.

PURPOSE

This study aimed to investigate the changes in articular disc position following setback BSSO surgery.

STUDY DESIGN, SETTING, AND SAMPLING

In this prospective cohort study, subjects with mandibular prognathism requiring setback BSSO were enrolled between August 2021 and June 2022 at the Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Chiang Mai University, Thailand. Patients with surgical complications, loss of follow-up, or significant artifacts in their MR images were excluded.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLES

The predictor variable was time. The articular disc position was assessed at 3 time points, preoperatively (T0), 3 months postsurgery (T1), and 6 months postsurgery (T2).

MAIN OUTCOME

The primary and secondary outcome variables were the changes in articular disc position between T0-T2 and T0-T1, respectively. Articular disc position was coded as normal, anterior disc displacement with reduction (ADDwR), anterior disc displacement without reduction (ADDwoR), and anterior disc displacement without reduction and degenerative joint disease (ADDwoR + DJD).

COVARIATES

Covariate variables collected included age (years), sex (male or female), asymmetry (present or absent), surgical procedure (single jaw (BSSO) or bimaxillary surgery), and setback distance (millimeters).

ANALYSES

Friedman's test with 80% power and a significance level of 0.05 was employed. Pairwise comparisons were performed using the Dunn-Bonferroni posthoc test to identify statistically significant differences.

RESULTS

The study included 16 subjects, 6 females and 10 males, with a total of 32 TMJs. Subjects had a mean age of 23.75 (4.57) years. The proportion of TMJs with normal disc position postoperatively increased from 3 (9.4%) to 19 (59.4%). Statistically significant differences were found in the changes in disc position over time (P < .001).

CONCLUSIONS

Following setback BSSO, the articular discs underwent changes, with a majority of ADDwR cases transitioning to a normal position. Cases with ADDwoR also demonstrated disc reduction capability after surgery. The combined orthodontic treatment and setback BSSO appear to have an effect on articular disc position in skeleton class III patients.

Biomechanical comparison of the effect of bilateral sagittal split ramus osteotomy with or without Le Fort I osteotomy on the temporomandibular joints of the patients with maxillofacial deformities under centric occlusion

Mandibular deformities negatively affect the daily activities of the patients and may cause temporomandibular disorders (TMD). Bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I osteotomy are effective treatments to correct the mandibular deformities. The aim of this study was to investigate and compare the effects of the BSSRO with or without Le Fort I on the stress distributions of the temporomandibular joints (TMJs) of the patients with mandibular deformities under centric occlusion based on finite element (FE) method. Preoperative and postoperative cone-beam computed tomography (CBCT) images of twenty-four patients diagnosed with mandibular prognathism, including ten patients with BSSRO and another 14 patients with bimaxillary osteotomy (BSSRO with Le Fort I), were used to construct maxillofacial models. Ten asymptomatic individuals were also performed CBCT scanning and defined as the control group. In addition, the muscle forces and boundary conditions corresponding to centric occlusions were applied on each model. For the preoperative groups with both the BSSRO and bimaxillary osteotomies, the average peak contact stresses of the TMJs were both greater than those of the control group. After the surgeries, the contact stresses of the discs and temporal bones of both groups considerably decreased. However, the contact stresses on the condyles slightly increased after BSSRO but decreased after bimaxillary osteotomy. The TMJs of the patients with maxillofacial deformities suffered abnormal tensile and compressive stresses compared with the asymptomatic subjects under centric occlusion. Both of the BSSRO and bimaxillary osteotomy could improve the risk stress distributions of the TMJs.

Global network mapping research findings on orthognathic surgery and temporomandibular disorder

OBJECTIVES

The objective of this work is to assess the relationship between orthognathic surgery and temporomandibular disorders literature through a bibliometric analysis.

METHODS

A bibliographic search in line with the STROBE guidelines and the concepts of the Leiden Manifesto was performed on the Web of Science using the terms orthognathic surgery AND temporomandibular. A citation analysis and establishment of the more cited articles were performed. A graphical representation of the keywords was created with VOSviewer.

RESULTS

A total of 810 articles were analyzed in this study. The research revealed a significant increase in publications on this topic, particularly in English language articles and a high H-index. The publications represented 55 nations, with the highest number of articles coming from the USA. The discussion of highly cited articles covered various aspects such as the relationship between orthognathic surgery and TMD, including condylar resorption or displacement, predisposing factors, dentoskeletal and occlusion patterns, anatomical factors, osteotomy techniques, condylar positioning techniques, and emerging technologies for improved TMJ stability.

CONCLUSION

The analysis reveals an increasing research interest in this field, with a significant number of publications in English and a high citation rate per article, indicating the impact of the research. Various factors associated with TMD in orthognathic surgery are explored, including condylar alterations, predisposing factors, occlusion patterns, and surgical techniques. The study underscores the importance of thorough assessment, treatment, and monitoring of TMD in orthognathic surgery patients, while acknowledging the need for further research and consensus in management strategies.

Effect of the magnitude of condylar head displacement on the TMJ function in skeletal class II patients undergoing different degrees of mandibular advancement: A retrospective comparative study

PURPOSE

This study aimed to compare the condylar head displacement (CHD) after bilateral sagittal split ramus osteotomy (BSSO) between different degrees of mandibular advancement in skeletal class II patients and to evaluate whether the temporomandibular joint (TMJ) function would be affected.

PATIENTS AND METHODS

Fifty-nine patients (118 condyles) were included in this retrospective study and were divided into three groups based on the distance of mandibular advancement. The CHD in three directions, x (sagittal direction), y (coronal direction), and z (axial direction), was measured before operation (T0), immediately after operation (T1), and at least 6 months after operation (T2), and the TMJ function of patients was followed up and scored using the Helkimo index system. All the abovementioned data were statistically analyzed, and p < 0.05 was considered the statistical difference standard.

RESULT

During the BSSO surgery, the condyle was predominantly displaced in a lateral, posterior, and superior direction whenever in T1 and T2, even though the degree of CHD was different. Regarding the amount of CHD, the large advancement group was higher than the other two groups in T1 and T2 (p＜0.01). The Helkimo index scores of the three groups were evaluated, and there was no significant statistical difference between the Ai and Di index of the three groups.

CONCLUSION

In our center, CHD occurred in lateral, posterior, and superior directions following mandibular advancement in skeletal class II patients, with a positive correlation between the CHD and the mandibular advancement; however, the TMJ function of the three groups did not show significant differences.

Condylar positional changes and remodeling following bimaxillary anterior segment osteotomy with and without Le Fort I osteotomy: a three-dimensional comparative analysis

OBJECTIVE

To evaluate 3D condylar displacement and long-term remodeling following the correction of bimaxillary protrusion by anterior segment osteotomy (ASO) with and without Le Fort I surgery.

MATERIALS AND METHOD

This retrospective study included 32 adults with bimaxillary protrusion who underwent ASO alone (group 1) or with concomitant Le Fort I osteotomy (group 2). Subject's computed tomography scans at basic (T0), immediate postoperatively (T1), and at 1 year or more follow-up (T2) were collected. The condyle displacement was measured at superior-inferior, lateromedially, and anteroposterior surfaces, while condyle remodeling was measured at the superior, lateral, anterior, medial, and posterior surfaces. All 3D analyses were performed using 3D Slicer software (4.11.2).

RESULTS

At T1, 52.7%, 86.7%, and 94.4% of condyles in group 1 were displaced inferiorly, laterally, and posteriorly, respectively, as well as 75%, 89.2%, and 53.5% of condyles in group 2, which had not fully returned to the original preoperative positions at T2. Condylar remodeling was observed in both groups at T2, and no significant difference was found in the overall condylar volume between T1 and T2 in both groups. Patients in group 2 exhibited significant bone resorption at both lateral and anterior surfaces compared to group 1 (P = 0.000 and 0.01, respectively).

CONCLUSION

This study's results demonstrated that ASO is associated with a degree of condylar changes even if the posterior mandible is not osteomized. The positional changes vary between bimaxillary ASO alone and those with simultaneous Le Fort I osteotomy. However, both groups' condyle volume remained stable at the long-term follow-up.

Descriptions of the dynamic joint space of the temporomandibular joint

BACKGROUND

Clinical diagnosis and treatment depended heavily on the motion analysis of the human joints. Although the dynamic joint space (DJS) of other organs was widely used in academic investigations, they were not universally used in the temporomandibular joint (TMJ) field, which was also important for the motion evaluation of the TMJ. The objectives of this study are to introduce the DJS of the TMJ and characterize the DJS regulars of mandibular movements.

METHODS

Ten asymptomatic subjects were selected to instruct this application. The mouth opening and closing, mandibular protrusion, and left and right protrusions, were tracked by the optical motion tracking system. According to trajectories of markers and reconstructed models from computed tomography, the motions of the mandibles could be obtained. The DJSes, which were described as the minimum Euclidian distances, were subsequently calculated based on the geometrical surfaces between the condyle and fossa during the motions. Then, the DJS map could be drawn based on the calculated values.

RESULTS

The DJS map manifested a decreasing trend when the condyle crossed the glenoid fossa, while it generally increased after the condyle crossed the fossa during the mouth opening. The results showed that the average maximum and minimum anterior joint spaces were 5.39 mm and 2.07 mm during mouth opening respectively with a great discrepancy existing among the subjects. The average maximum and minimum anterior joint spaces were 4.74 mm and 2.19 mm during mandibular protrusion. As for left and right protrusions, the DJS of the contralateral side was greater than that of the ipsilateral side.

CONCLUSION

In comparison to morphological analyses or only mandibular motions, the DJS provides more dynamic and interactive information about the TMJ. The research and methodology may help us comprehend TMJ motions and temporomandibular disorders.

Vertical Ramus Osteotomy, Is It Still a Valid Tool in Orthognathic Surgery?

The purpose of this study is to evaluate mandibular osteotomy procedures during orthognathic surgery, with an emphasis on the complications of the two leading procedures: intraoral vertical ramus osteotomy (IVRO) and sagittal split osteotomy (SSO). We conducted a retrospective cohort study by extracting the records of patients who underwent either IVRO or SSO procedures during orthognathic surgery in a single center between January 2010 and December 2019. A total of 144 patients were included (median age of 20.5 years, 52 males). The IVRO:SSO ratio was 118:26 procedures. When referring to all surgeries performed, IVRO procedures were associated with shorter hospitalization than the SSO procedures, while the overall durations of surgery and follow-up periods were comparable. In contrast, when referring only to bimaxillary procedures, the duration of the IVRO bimaxillary procedures was significantly shorter than the SSO bimaxillary procedures. There were 53 complications altogether. Postoperative complications consisting of skeletal relapse, temporomandibular joint dysfunction, sensory impairment, and surgical-site infection were significantly fewer in the IVRO group. Both types of osteotomies have acceptable rates of complications. IVRO appears to be a safer, simpler, though less acceptable procedure in terms of patient compliance.

The Anatomical Basis for Plate Fixation in BSSO to Minimize Condylar Torquing: A Comparative CT Study of Mandibular Advancement and Setback

Introduction

Condylar displacement after bilateral sagittal-split osteotomy (BSSO) occur in the sagittal plane as clockwise/counter-clockwise rotation of the ramus, in the coronal plane as medial/lateral inclination, or in the axial plane as medial/lateral condylar torquing. The purpose of this prospective CT study was to evaluate the role of plate fixation in minimizing condylar torquing or rotational changes in the axial plane.

Materials and Methods

This prospective study was carried out on 26 patients, 13 of whom underwent advancement BSSO and 13 setback BSSO, without maxillary LeFort I osteotomies. All mandibular movements were symmetrical. Fixation of the osteotomized segments was achieved with a single 4-hole plate and monocortical screws. In case of mandibular setbacks, a straight plate was used, whereas an inset-bent plate was used for advancements. Computed tomography scans were obtained preoperatively and postoperatively to measure condylar rotation or torqueing in the axial plane. An increase in condylar angle on axial slices was considered as lateral condylar torquing, whereas a decrease was considered as medial condylar torquing.

Results

A mean medial condylar torquing of 0.2° was noted postoperatively in case of setbacks (p > 0.05 not significant). This suggested minimal condylar torquing, indicating that the proximal and distal segments maintained contact at the anterior vertical osteotomy fixed with a straight plate. In case of advancements, a mean lateral condylar torquing of 2.2° was noted postoperatively (p < 0.005, highly significant). This suggested that the proximal segment flare at the anterior vertical osteotomy site was maintained by inset-bent plate fixation.

Conclusion

The gaps between the proximal and distal segments created by mandibular advancement and setback should be maintained. An attempt to close these gaps, especially in mandibular advancement, will result in an unfavourable axial condylar torque. Consequently, the areas of bony contact between the proximal and distal osteotomy sites created by mandibular advancement and setback should be maintained as well.

Correction of Condylar Displacement of the Mandible Using Early Screw Removal following Patient-Customized Orthognathic Surgery

OBJECTIVE

Orthognathic surgery (OGS) is a surgical intervention that corrects dentofacial deformities through the movement of maxillary and mandibular segments to achieve adequate masticatory function, joint health, and facial harmony. However, some patients present with occlusal discrepancies, condylar sag, and/or temporomandibular disorders after OGS. Various methods have been employed to solve these problems after surgery. This study aimed to evaluate the effectiveness of early screw removal in patients with occlusal discrepancies after OGS using three-dimensional cone-beam computed tomography (CBCT).

METHODS

In 44 patients with dentofacial deformities, patient-customized OGSs with customized plates were performed to correct facial deformities using customized guides with computer-aided surgical simulation. Of the 44 patients, eight patients complained of occlusal discrepancies and temporomandibular disorders after OGS. These eight patients underwent screw removal under local anesthesia around four weeks. The temporomandibular joint spaces at three time points (pre-surgical, post-surgical, and after screw removal) in the sagittal and coronal planes were compared using CBCT.

RESULTS

Eight patients showed an increase in joint space on CBCT images immediately after surgery (T1), but after early screw removal (T2), these spaces almost returned to their pre-surgical state, and the temporomandibular joint problem disappeared.

CONCLUSIONS

The removal of screws located in the distal segment under local anesthesia between three and four weeks post-surgically may be a treatment option for patients with post-OGS occlusal discrepancies, condylar sag, and/or temporomandibular disorder.

Mandibular condyle displacements after orthognathic surgery-an overview of quantitative studies

The repositioning of bone segments during orthognathic surgeries often results in mandibular condyle positional changes and can also affect jaw muscles, soft tissues and the temporomandibular joint (TMJ). Condylar displacements are considered as one of the factors of bone remodeling and further skeletal relapse. The quantitative approach is commonly used in comparative analyses and evaluations of the relationships between examined factors. The aim of this study is the overview of the current literature including quantitative analysis in the research of mandibular condyle positional changes as a consequence of orthognathic surgeries. Thirty articles were included in the overview. Most of the articles present a comparative and evaluative analysis of treatment results concerning different surgical approaches, fixation methods or types of skeletal defects. The correlation between condylar displacements and bone remodeling, skeletal relapse and TMJ dysfunctions were considered. The most frequently repeated study variables were: short-term changes, Class III malocclusion, yaw rotation, 3D cephalometry measurements. Quantitative data might be useful in the evaluation of patterns and range of condylar displacements for specific treatment conditions. Available literature concerning the analysed topic is characterized by great heterogeneity with regards to the purpose and methodologies of the studies. More systematic approaches and long-term considerations are needed in future research.

Analysis of Sagittal Position Changes of the Condyle After Mandibular Setback Surgery Across the Four Different Types of Plating Systems

The authors analyzed the three-dimensional postoperative condylar position change across the plating systems. This retrospective study was conducted with the patients who underwent bilateral sagittal split ramus osteotomy with setback surgery. The condylar change was analyzed from preoperative cone-beam computed tomography to postoperative 1 month (T1) and postoperative 6 months (T2) using superimposition software, automatically merging based on the anterior cranial base. The condylar changes during T1 and T2 were analyzed across the four types of plates (4-hole sliding, heart-shaped, 3-hole sliding, and 4-hole conventional) Mean intraclass correlation coefficient values were consistently high for each measurement (>0.850). During T1, the conventional plate had a decreased condylar anterior distance when compared with the 3-hole sliding plate (P = 0.032). During T2, the conventional plate had an increased condylar posterior distance when compared with the 3-hole sliding plate (P = 0.031). Superimposition software based on the anterior cranial base could be available for measurement of condylar position with highly reproducible results. After bilateral sagittal split ramus osteotomy, the 3-hole sliding plate could effectively compensate for the anterior displacement of the condyle compared to other plates.

Differences of condylar changes after orthognathic surgery among Class II and Class III patients

BACKGROUND/PURPOSE

The nature of susceptibility to condylar resorption after orthognathic surgery can be different between skeletal Class II and Class III populations, which was addressed by few in the past. The aim of the present study was to use cone-beam computed tomographic (CBCT) images to investigate the displacement and morphological changes of temporomandibular joints (TMJs) in patients received orthodontic treatment combined with orthognathic surgery.

METHODS

Both Class III (n = 34) and Class II (n = 17) patients were compared through overall and regional superimpositions of the initial and posttreatment CBCTs. Two-sample t-test was used to identify significance between group differences. Pearson's correlation coefficient was used to address changes of TMJ and the amount of setback or advancement.

RESULTS

The axial ramal angle increased significantly in Class III group and decreased in Class II groups after orthognathic surgery (p < FDR_p). For condylar dimensions, significant widths and lengths reductions were noted only in Class II group. However, no significant difference was found after comparing subgroup differences according to one-jaw and two-jaw options, nor any significant correlation found between the condylar changes and the amount of surgical movements.

CONCLUSION

The nature of condylar susceptibility could result more from different skeletal patterns than the amount of surgical movements. However, the direction of mandibular surgery may contribute to different changes of condylar angle in axial section.

The three-dimensional evaluation of positional change in mandibular condyle after intraoral vertical ramus osteotomy

OBJECTIVES

The purpose of this study was to compare the changes of the condylar axis, the anteroposterior condylar position relative to the glenoid fossa, after intraoral vertical ramus osteotomy (IVRO).

STUDY DESIGN

21 patients diagnosed as skeletal class III malocclusion underwent IVRO and were followed according to the authors' postoperative management regimen. The three-dimensional positions of the condyles were evaluated by cone-beam computerized tomography (CBCT) at pre-op, post-op, and at follow-up. CBCT images were referenced to assess the condylar axis change and the anteroposterior condylar position in the glenoid fossa. A repeated-measures analysis of variance (P<0.05) also was performed.

RESULTS

After surgery, both the axial condylar angles and the anteroposterior condylar position were significantly different (P<0.05). The coronal condylar axis rotated outwardly. The anteroposterior condylar position in the glenoid fossa had moved from the concentric to the anterior position. But the condyle changes between post-op and follow-up (P>0.05) were insignificant.

CONCLUSIONS

With postoperative intermaxillary elastic traction, the condyles changed their positions physiologically for newly established jaw movement after IVRO.

Biomechanical effect of asymmetric mandibular prognathism treated with BSSRO and USSRO on temporomandibular joints: a three-dimensional finite element analysis

Asymmetric mandibular prognathism is a clinically common skeletal dentomaxillofacial deformity. Unilateral sagittal split ramus osteotomy (USSRO) is an effective alternative procedure to bilateral sagittal split ramus osteotomy (BSSRO) for some patients. However, the biomechanical effect of temporomandibular joint (TMJ) of USSRO has not been fully studied. This study aims to evaluate the stress distribution changes in the TMJ of asymmetric mandibular prognathism treated with BSSRO/USSRO, to validate the clinical feasibility of USSRO. Nineteen patients with mandibular prognathism patients who were treated with BSSRO (n=12) and USSRO (n=7) had preoperative and postoperative computed tomographic scanning. Preoperative and postoperative 3-dimensional finite element analysis (FEA) of functional TMJ movements were made on one BSSRO patient and one USSRO patient. In all patients, the ANB angle and mandibular deviation were significantly improved postoperatively. There was no significant difference in the postoperative ANB angle and mandibular deviation between the BSSRO group and the USSRO group. In two preoperative FEA models, the maximum stresses of non-deviation side TMJ structures were greater than the deviation side during functional movements. The unbalanced stress distribution was corrected postoperatively in both BSSRO/USSRO FE models. Both BSSRO/USSRO can improve the ANB angle and mandibular deviation. The bilateral TMJ structure in patients with asymmetric mandibular prognathism had unbalanced stress, which could be significantly improved with the USSRO as effectively as BSSRO.

Evaluation of temporomandibular joint function after orthognathic surgery using a jaw tracker

OBJECTIVE

It has been reported that temporomandibular joint (TMJ) function after orthognathic surgery differs from normal patients. Dysfunction of the joints occurs often even in the general public, with an incidence in the range of 20%-25%. Population-based studies among adults report that approximately 10%-15% have symptoms of pain and 5% of them had a perceived need for treatment. To date, no studies have reported on the evaluation of TMJ function after orthognathic surgery through the use of four-dimensional jaw tracking.

DESIGN AND SETTING

This study evaluated TMJ function using such a device and information from a TMJ questionnaire. Sixteen orthognathic surgery patients and 17 controls were included in this study. Four-dimensional jaw tracking information was obtained using the SiCAT JMT device. Clinical signs and jaw function were evaluated.

RESULTS

Within the limitations of the study, the following results were seen using the SICAT JMT+ jaw tracking device: (1) no significant differences were found in any of the millimetric measurements between the surgery patients and controls; (2) no significant difference was found in subjective reported symptoms of pain, clicking, crepitation, locking, stiffness, headaches and migraines between the groups; and (3)there was a significant difference in the popping of the joints for surgery and non-surgery groups.

CONCLUSION

Jaw tracking did not detect significant differences in jaw function, but some clinical symptoms were present.

Cone-beam CT evaluation of temporomandibular joint in permanent dentition according to Angle's classification

OBJECTIVES

To compare characteristics of temporomandibular joint (TMJ) and related structures according to Angle class I, II¹, II², and III.

METHODS

123 Chinese patients (13-36 years old, 60 males, and 63 females) were classified in four groups according to Angle's classification: skeletal class I (31 patients), skeletal class II division 1 (30 patients), skeletal class II division 2 (30 patients), and skeletal class III (32 patients). Left and right TMJs of each subject were evaluated independently with cone-beam computed tomography (CBCT). The position of condyle in the joint fossa was analyzed according to Pullinger.

RESULTS

There were significant differences between class III subjects and class I, II¹, II² in the superior joint space (p < 0.05). Compared with class II¹, II², and III subjects, the height and diameter of condyle in class I was significantly larger (p < 0.05). The width of joint fossa was significantly larger in Angle class III than in Angle class I, II¹, and II², while the depth was significantly smaller. The condyle position in class III subjects was more anteriorly displaced compared with that in class I subjects. In class II² patients, the condyle position was mainly concentric and posterior.

CONCLUSIONS

There are significant differences in condylar morphology, joint space, joint fossa morphology, and condylar position between different Angle classifications.

Three-Dimensional Analysis of Perioperative Condylar Displacement After Mandibular Setback Surgery With Intended Manual Condylar Positioning

PURPOSE

The purpose of this study is to investigate the effect of orthognathic surgery with intended manual condylar positioning on condyle by examining a change in its position.

METHOD

About 18 patients with mandibular prognathism who underwent orthognathic surgery with intentional manual condyle positioning were included. Condyle displacement was analyzed through 3D cone-beam computed tomography before and after operation. The patients were categorized into 2 experimental groups: group A (1-jaw) and group B (2-jaw). The experimental groups were examined before surgery (T0), 3 days (T1), and 6 months (T2) after surgery. Condylar displacement direction was investigated in terms of bodily shift and rotational movement.

RESULTS

Downward bodily shift of condyle after surgery was significantly apparent from all of the patients. Condylar bodily shift in other directions was statistically insignificant. Gross bodily shift of condyle right after surgery was anterolateral-inferior direction. In perspective of rotational movement, condyle rotated in infero-medial direction right after operation, but no significant change was presented afterwards. In addition, no significant difference in the amounts of condylar shift and pattern existed between groups A and B.

CONCLUSION

Intended manual condylar positioning may minimize postoperative displacement of condyle while accomplishing skeletal stability.

Condylar response to large mandibular advancement combined with maxillary impaction and counterclockwise rotation: A computed tomographic study

Background

This study aims to analyze the effectiveness of cone-beam computed tomography (CBCT) in the evaluation of the condylar position, angulation and intercondylar distance and assess the changes in these parameters before and after bimaxillary surgery, preformed with the critical movments of Le Fort I osteotomy (for impaction of the maxilla and conterclockwise rotation of the upper occlusal plane) and Bilateral Sagittal Split Osteotomy (BSSO) for mandibular advancement (> 8mm).

Material and Methods

Twenty class II patients successfully treated with BSSO of the mandible, in conjunction with Le Fort I osteotomy, were studied to evaluate the condylar changes before and after surgery. The position of the condyle was classified according to the Pullinger & Hollender’s formula in both phases. A MANOVA analysis followed by post-hoc tests were conducted to ascertain if there were statistically significant differences between pre and post surgical variables under study. The agreement of the condylar position’s classification was evaluated resorting to the Kappa statistics.

Results

There were no statistically significant differences between the values of the position and angulation of the condyles and intercondylar distance before and after surgery. There was an increase of the axial angle of the left condyle and the frontal angle of both condyles, while there was a decrease of the axial angle of the right condyle, the sagittal angle of both condyles and intercondylar distance.

Conclusions

The CBCT is a useful method for assessing variations of condylar position in detail. It was verified that the critical movements of maxillary impaction associated with the mandibular advancement do not produce significant alterations in the mandibular condyles, however, these tend to perform a posterior and inferior movement.

Key words:Cone-Beam computed tomography, orthognathic surgery, mandibular condyle, osteotomy, le fort, temporomandibular joint.

Pain Complaints in Patients Undergoing Orthognathic Surgery

The aim of this retrospective study was to assess the frequency of orofacial (nonodontogenic, neuropathic, or atypical) and temporomandibular joint (TMJ) and/or masticatory muscle pain in orthognathic patients in a tertiary institution. A total of 286 consecutive patients undergoing sagittal split osteotomy from 2014 to 2016 were included. Thirty-nine (13.6%) patients presented with TMJ pain and 10 (3.5%) with orofacial nonodontogenic pain before orthognathic surgery; 79.6% (39/49) of these patients had no pain 1 year after surgery. Twenty-nine patients (12.2%) with no preoperative orofacial pain and 22 (9.3%) without preoperative TMJ pain presented with pain 1 year after surgery. Fifty-one (17.8%) of the 286 patients treated for orthognathic cases at our center over the 3-year period presented with pain 1 year after surgery. Most patients were managed conservatively with nonsurgical therapeutic modalities including counseling, physical therapy, warmth application, and bilateral chewing and splint therapy. In patients with TMJ pain refractory to conservative treatment, arthroscopic surgery was advised and successful in all patients for both pain reduction and improvement of the maximal interincisal opening. TMJ symptoms do develop after orthognathic surgery in patients with and without a previous history of TMJ complaints. Most patients can be managed with nonsurgical therapeutic modalities.

Positional change in mandibular condyle in facial asymmetric patients after orthognathic surgery: cone-beam computed tomography study

Background

We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry.

Methods

Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively.

Results

On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A.

Conclusions

There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

Orthognathic Surgery as a Treatment for Temporomandibular Disorders

Well-controlled clinical trials supporting orthognathic surgery as the primary management for temporomandibular disorders (TMDs) are lacking. Most published studies lack an adequate experimental design to minimize biases. Studies that did minimize some biases do support an overall reduction in the frequency of TMD signs and symptoms in some Class III and Class II patients who had orthognathic surgery. However, Class II correction with counter-clockwise rotation of the mandible increased TMD. Individual variability precludes the ability to predict TMD outcome after surgery. Irreversible therapies such as orthognathic surgery should not be primary treatments in the management or prevention of TMDs.

Cone-beam computed tomography evaluation on the changes in condylar long axis according to asymmetric setback in sagittal split ramus osteotomy patients

OBJECTIVE

To determine whether the condylar rotation is affected by asymmetric setback in patients undergoing sagittal split ramus osteotomy.

MATERIALS AND METHODS

Thirty patients who underwent bilateral sagittal split ramus osteotomy setback surgery were divided into the two groups, symmetric setback and asymmetric setback, according to the right/left difference of setback amount (<2.0, ≥2.0 mm). Condylar long axis changes were evaluated using the three-dimensional superimposition of before and immediately after surgery cone-beam computed tomography volume images. Evaluations were performed separately in lesser setback and greater setback side in patients undergoing asymmetric setback, whereas both side condyles were evaluated together in patients undergoing symmetric setback. Condylar axis changes on axial view were correlated with setback amount or right/left setback difference using Pearson correlation analysis.

RESULTS

In general, the condylar axis change occurred in a pattern of inward rotation. The condyles in patients undergoing symmetric setback showed 3.4° rotation in average. In case of asymmetric setback, the lesser setback side showed larger value (4.3°) than the greater setback side (2.3°) with a statistical significance. In the correlation analysis, setback amount showed no significant correlation with the condylar axis changes in both groups. However, correlation with right/left setback difference showed a positive correlation in lesser setback side of patients undergoing asymmetric setback.

CONCLUSION

The findings of this study indicate that large amount of setback alone does not contribute to the change in condylar long axis, but asymmetric setback might cause a change in condylar long axis, particularly on the lesser setback side.

A Comparative Review of Mandibular Orthognathic Surgeries with a Focus on Intraoral Vertico-sagittal Ramus Osteotomy

Severe dentofacial deformities require both orthodontics and surgical management to repair. Modern mandibular orthognathic surgery commonly uses sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) methods to treat patients. However, complications like neurosensory disturbances and temporomandibular joint disorders are common following both procedures. In 1992, Choung introduced the intraoral vertico-sagittal ramus osteotomy (IVSRO) which led to a decrease in postoperative complications. The 'straight' IVSRO or Choung’s type II osteotomy has a 'condylotomy' effect that reduces iatrogenic temporomandibular joint symptoms and treats preoperative temporomandibular joint symptoms. This osteotomy type is especially applicable for prognathism with excessive flaring of the ramus and with temporomandibular joint dysfunction. The 'L-shaped' IVSRO or Choung’s type I osteotomy is indicated for patients with condylar hyperplasia and high condylar process fractures.

Complications associated with orthognathic surgery

While most patients undergo orthognathic surgery for aesthetic purposes, aesthetic improvements are most often followed by postoperative functional complications. Therefore, patients must carefully decide whether their purpose of undergoing orthognathic surgery lies on the aesthetic side or the functional side. There is a wide variety of complications associated with orthognathic surgery. There should be a clear distinction between malpractice and complications. Complications can be resolved without any serious problems if the cause is detected early and adequate treatment provided. Oral and maxillofacial surgeons must have a full understanding of the types, causes, and treatment of complications, and should deliver this information to patients who develop these complications.

Clinical predictive factors for temporomandibular disorders following combined orthodontic and orthognathic surgical treatment in patients with Class III malocclusion

OBJECTIVE

The aim of this study was to identify clinical factors predisposing to the development or worsening of temporomandibular disorders (TMDs) following orthodontic surgical treatment for Class III malocclusion.

METHODS

A retrospective cohort study was performed on 88 patients with Class III malocclusion having undergone a combined orthodontic and orthognathic surgical treatment. Temporomandibular joint and masticatory muscle examinations were available prior to treatment and one year post-operatively. Multivariate logistic regression was used to predict the development of post-operative TMDs, and linear regression was used to predict the worsening of TMDs using Helkimo indices.

RESULTS

Patients with Class III malocclusion presenting with pre-treatment anamnestic TMJ clicking (OR = 5.8; p = 0.03) and undergoing bimaxillary osteotomy procedures (OR = 18.6; p = 0.04) were more at risk for the development of TMDs.

DISCUSSION

TMDs must be evaluated, monitored, and managed with caution in patients with Class III malocclusion presenting with pre-treatment joint clicking and who are planned for bimaxillary osteotomies.

Sequential changes of postoperative condylar position in patients with facial asymmetry

OBJECTIVE

To evaluate sequential images of the condylar position in relation to the glenoid fossa after orthognathic surgery in patients with facial asymmetry using cone beam computed tomography.

MATERIALS AND METHODS

A total of 20 adult patients (11 men and 9 women; mean age, 22.1 ± 4.02 years) with facial asymmetry who underwent sagittal split ramus osteotomy with rigid fixation were involved. Cone beam computed tomography scans were obtained before treatment (T0), 1 month before the surgery (T1), and 1 day (T2), 3 months (T3), 6 months (T4), and 12 months (T5) after the surgery. The condyle position was evaluated.

RESULTS

At 1 day after surgery (T2), the condylar position on both sides significantly changed posteriorly, inferiorly, and laterally, but no significant difference was observed between the nonaffected and affected sides. The condyle on the nonaffected side had a tendency to recover its preoperative position at 3 months after surgery (T3) and inclined slightly laterally up to 1 year after the surgery (T5). The condyle on the affected side returned more closely to the glenoid fossa than to its pretreatment position at 3 months after surgery (T3). Thereafter, it showed a more backward and downward position (T5).

CONCLUSIONS

The overall condylar position after an orthognathic surgery in patients with facial asymmetry was relatively stable at 1 year after surgery. However, the condyle on the affected side during the first 3 months after surgery should be carefully monitored for surgical stability.

Comparison of Orthodontics-First and Surgery-First Approach in Positional Changes of the Condyle After Mandibular Setback Surgery Using Three-Dimensional Analysis

PURPOSE

To examine and compare the 3-dimensional (3D) postoperative changes of the condylar position after mandibular setback surgery using the orthodontics-first approach (OFA) and surgery-first approach (SFA).

MATERIALS AND METHODS

This retrospective cohort study included patients who had undergone bilateral sagittal split ramus osteotomy for mandibular prognathism using OFA or SFA. Computed tomography images were obtained and analyzed preoperatively (T0), postoperatively (T1), and at the 6-month follow-up visit (T2). The bodily shift of the condylar center and rotational movement of the condylar head were measured using the 3D coordinate system between each time point and compared between the OFA and SFA groups. Repeated measures analysis of variance with a Bonferroni post hoc test was used to compare the time course changes of the condylar position for the 2 surgical-orthodontic approaches.

RESULTS

A total of 55 patients (mean age 21.9 years; 31 males, 24 females) were evaluated. Of the 55 patients, 29 had undergone OFA and 26, SFA. In both groups, the condyle showed perioperative lateral and inferior displacement with inward rotation, followed by returning to its preoperative position during the 6 months postoperatively. No significant difference was found between the 2 groups in the time course change of the condylar position.

CONCLUSIONS

Regardless of the timing of the operation (OFA vs SFA), the perioperative and postoperative changes of the condylar position after mandibular setback surgery are equivalent.

Are condylar morphologic changes associated with temporomandibular disorders in patients with orthognathia?

OBJECTIVE

To determine the association between morphologic condylar changes and temporomandibular disorders (TMDs) in patients with orthognathia.

STUDY DESIGN

Data from 89 patients were analyzed. TMDs were classified according to the Research Diagnostic Criteria for TMDs. TMD severity was scored according to the Helkimo indices. Calculation of the condylar area, perimeter, and height was performed by using a specific computational method including panoramic radiography.

RESULTS

Sixty-five (73%) patients presented with morphologic condylar changes. Decreases in condylar perimeter and area were found to be predictors of postoperative TMDs (P = .009; odds ratio [OR] = 3.66) and disk displacement (P = .008; OR = 4.43), respectively. Condylar area and height decreases were associated with worsening of TMDs (P = .03 and 0.04).

CONCLUSIONS

This study demonstrated that in orthognathic patients, postoperative condylar changes are associated with postoperative TMDs as well as with the degree of TMD severity and that preoperative TMDs are associated with such condylar changes.

MRI changes in the temporomandibular joint following mandibular setback surgery using sagittal split ramus osteotomy with rigid fixation

OBJECTIVES

This study examined the changes in temporomandibular joint dysfunction (TMD) symptoms and investigated the variations in the disc position, disc and condylar morphology following sagittal split ramus osteotomy (SSRO) with rigid fixation in patients with mandibular prognathism. Furthermore, the authors examined the correlation between mandibular setback and TMD symptoms.

METHODS

The study included 24 Japanese patients with jaw deformities who were treated using bilateral SSRO and Le Fort I osteotomy. The clinical and magnetic resonance imaging findings in the temporomandibular joint were evaluated preoperatively and at three and six months postoperatively.

RESULTS

The preoperative TMD symptoms were significantly associated with the prevalence of TMD symptoms at six months postoperatively. Anterior disc displacement improved in four joints with slight displacement and with no morphological change. There were no postoperative changes in condylar morphology. There was no significant correlation between mandibular setback and the postoperative TMD symptoms.

CONCLUSION

Postoperative TMD symptoms may be influenced mainly by preoperative TMD symptoms rather than mandibular setback using SSRO with rigid fixation. Therefore, patients with TMD symptoms require physical examination and MRI for appropriate diagnosis preoperatively.

Orthognathic surgery and temporomandibular joint symptoms

The aim of this article is to review temporomandibular joint symptoms as well as the effects of orthognathic surgery(OGS) on temporomandibular joint(TMJ). The causes of temporomandibular joint disease(TMD) are multifactorial, and the symptoms of TMD manifest as a limited range of motion of mandible, pain in masticatory muscles and TMJ, Joint noise (clicking, popping, or crepitus), myofascial pain, and other functional limitations. Treatment must be started based on the proper diagnosis, and almost symptoms could be subsided by reversible options. Minimally invasive options and open arthroplasty are also available following reversible treatment when indicated.

TMD manifesting in a variety of symptoms, also can apply abnormal stress to mandibular condyles and affect its growth pattern of mandible. Thus, adaptive developmental changes on mandibular condyles and post-developmental degenerative changes of mandibular condyles can create alteration on facial skeleton and occlusion. The changes of facial skeleton in DFD patients following OGS have an impact on TMJ, masticatory musculature, and surrounding soft tissues, and the changes of TMJ symptoms. Maxillofacial surgeons must remind that any surgical procedures involving mandibular osteotomy can directly affect TMJ symptoms, thus pre-existing TMJ symptoms and diagnoses should be considered prior to treatment planning and OGS.

Clinical changes of TMD and condyle stability after two jaw surgery with and without preceding TMD treatments in class III patients

Background

This study are to identify the symptomatic changes and condylar stability after 2 jaw surgery without preceding treatments for Temporomandibular joints(TMJ) in class III patients with the TMJ symptoms; and to assess therapeutic effect of 2 jaw surgery and the necessity of preceding treatment for alleviation of TMJ symptoms.

Methods

30 prognathic patients with preexisting TMJ symptoms were divided into 2 groups according to presence or absence of preceding treatments before the surgery. We evaluated symptomatic changes on both TMJ by questionnaires and clinical examinations. And we reconstructed 3D cone beam computed tomography images before 2 jaw surgery, immediately after the surgery, and 6 months or more after the surgery with SimPlant software, and analyzed the stability of condylar position on 3D reconstruction model. Significances were assessed by the Wilcoxon signed rank test on SPSS ver. 20.0.

Results

Both groups had favorable changes of TMJ symptoms after orthognathic surgery. And postoperative position of condyle had good stability during follow-up period.

Conclusion

2 jaw surgery without preceding treatments for TMD can have therapeutic effect for TMD patients with class III malocclusion.

Positional change of the condyle after orthodontic-orthognathic surgical treatment: is there a relationship to skeletal relapse?

Objectives

The purpose of this study was to evaluate the condylar position in relation to the glenoid fossa before and after orthodontic-orthognathic surgical treatment and to investigate the relationship with skeletal relapse.

Materials and Methods

Lateral cephalograms and temporomandibular joint tomograms from 19 patients with mandibular prognathism who received orthodontic-orthognathic surgery were included in this study. Samples were divided into two groups based on skeletal change during the retention period. The relapse group consisted of 7 patients (3 females and 4 males; mean age, 21.9 years) whose pogonion or menton displaced more than 1 mm during the retention period and the stable group consisted of 12 patients (5 females and 7 males; mean age, 21.7 years). Anterior joint space, posterior joint space, superior joint space, and anteroposterior index were measured on tomograms at pretreatment and posttreatment timepoints. Condyle position and frequency of the positional change were compared between both groups.

Results

In the relapse group and stable group, 42.9% and 45.8% of the condyles, respectively, showed forward or backward displacement at posttreatment. However, the changes were small and the mean anterior, posterior, superior joint spaces and frequencies of the positional changes did not differ statistically between both groups.

Conclusion

Our results suggest that small positional changes of the condyle, which may occur after orthodontic-orthognathic surgery treatment, may not be related to skeletal relapse after removal of the orthodontic appliances.

A CBCT study on positional change in mandibular condyle according to metallic anchorage methods in skeletal class III patients after orthognatic surgery

PURPOSE

This study was to evaluate the postoperative stability of the mandibular condyle according to the number of screws in the proximal segment using cone beam computed tomography (CBCT).

PATIENTS AND METHODS

Thirty patients diagnosed with skeletal class III malocclusion and underwent sagittal split ramus osteotomy (SSRO) were enrolled in this study. In Group A, 4 screws and a 4-hole miniplate were used for the internal fixation of an osteotomy and 3 screws, only 1 screw in the proximal segment, and a 4-hole miniplate were used in Group B. We digitally measured anteroposterior, supero-inferior, and mediolateral positions and angles of the long axis of the mediolateral poles in CBCT scans pre-operatively, within 1 week postoperatively and 3, 6 months after surgery.

RESULTS

The condylar head angle in the axial plane showed consistent and significant changes. The condylar head angle in the coronal plane decreased in both groups, which shows that condylar heads bent inward. In the axial plane, Group A showed statistically significant differences while Group B did not in early stage (T0-T1-T2). The change in distance between condylar heads shows that these have moved outward in both groups.

CONCLUSION

The results show that a fixation method using 3 screws with a 4-hole miniplate did seemed preferable and may give some flexibility for condylar heads to be positioned in physiologic position during postoperative phase.

Cone-beam computed tomographic evaluation of the condylar remodeling occurring after mandibular set-back by bilateral sagittal split ramus osteotomy and rigid fixation

Objective

To evaluate condylar head remodeling after mandibular set-back sagittal split ramus osteotomy (SSRO) with rigid fixation in skeletal class III deformities. The correlation between condylar head remodeling and condylar axis changes was determined using cone-beam computed tomography (CBCT) superimposition.

Methods

The CBCT data of 22 subjects (9 men and 13 women) who had undergone mandibular set-back SSRO with rigid fixation were analyzed. Changes in the condylar head measurements and the distribution of the signs of condylar head remodeling were evaluated by CBCT superimposition.

Results

The subjects showed inward rotation of the axial condylar angle; reduced condylar heights on the sagittal and coronal planes; and resorptive remodeling in the anterior and superior areas on the sagittal plane, superior and lateral areas on the coronal plane, and anterior-middle and anterior-lateral areas on the axial plane (p < 0.05).

Conclusions

The CBCT superimposition method showed condylar head remodeling after mandibular set-back SSRO with rigid fixation. In skeletal class III patients, SSRO with rigid fixation resulted in rotation, diminution, and remodeling of the condylar head. However, these changes did not produce clinical signs or symptoms of temporomandibular disorders.

[Relations between orthognathic surgery and temporomandibular disorders: a systematic review]

A painful and dysfunctional temporomandibular joint can be associated with a musculoskeletal anomaly. The multifactorial character of the etiology is now recognized. Among the etiologies, the role of orthognathic surgery is still debated. The analysis of the literature from 2000 to 2011 reveals for most authors a decrease in the frequency and intensity of signs and symptoms after surgery, especially pain and clicking. Risk factors may influence post-surgical results. Studies on patient risk factors such as age, sex, type of dysmorphia are inconclusive. Surgical techniques and the procedure used may have an influence on the development of post-surgical clinical signs and symptoms of temporomandibular disorders.

Temporomandibular disorders after orthognathic surgery in patients with mandibular prognathism with depression as a risk factor

OBJECTIVE

To examine the prevalence of temporomandibular disorders (TMD) after orthodontic-surgical treatment in patients with mandibular prognathism and analyze psychosocial variables related to TMD.

MATERIALS AND METHODS

The case-control study comprised 40 patients with mandibular prognathism who underwent combined orthodontic-surgical treatment (orthognathic surgery group). Forty-two patients with untreated mandibular prognathism served as a control group. Research diagnostic criteria for temporomandibular disorders was used in order to assess the clinical diagnosis of TMD (Axis I) and to estimate depression, somatization and patient's disability related to chronic pain (Axis II).

RESULTS

The overall prevalence of TMD was not significantly different between the groups. Myofascial pain was significantly higher, while arthralgia, arthritis and arthrosis was significantly lower in the orthognathic group compared with the controls (90.5% vs 50.0%, 0.0% vs 27.8%, respectively) (p < 0.05). Females in orthognathic surgery group showed higher prevalence of TMD (p < 0.05) and myofascial pain (p < 0.01) and increased level of chronic pain (p < 0.05) in comparison with post-operative males. No significant difference in chronic pain, somatization and depression scores was found between investigated groups. With respect to presence of TMD within the groups depression was higher in untreated subjects with dysfunction (p < 0.05).

CONCLUSION

Prevalence of TMD immediately after completion of orthodontic-surgical treatment for mandibular prognathism is similar to frequency of dysfunction in untreated subjects, is significantly higher in females and is most commonly myogenic. Furthermore, females show an increased level of chronic pain post-operatively. Somatization and depression levels do not differ between patients with corrected prognathism and untreated prognathic patients.