Condylar Changes Research Articles

Quantitative assessment of condyle positional changes before and after orthognathic surgery based on fused 3D images from cone beam computed tomography.

To establish one method that can be used to quantitatively evaluate the condyle positional changes with 3D images in postoperative mandibular prognathism patients. This is a retrospective observational study. Twenty-one patients who underwent bilateral sagittal split ramus osteotomy (BSSRO) were scanned with cone beam computed tomography (CBCT) for temporomandibular joints (TMJs) at 1 week preoperatively (T0), 1 to 2 weeks (T1), 3 months (T2), 6 months (T3), and 12 months (T4) postoperatively. The data were then grouped into T0T1, T1T2, T2T3, T3T4 and T0T1, T0T2, T0T3, and T0T4. Semi-automatic registration was conducted, and the condyle positional changes were measured in segmented 3D models. Inter- and intra-observer variability and the repeatability of registration were analyzed with paired t test; the repeated measurement analysis of variance was used for analyzing the repeatability of the marked points; the consistency of segmentation was analyzed with nonparametric test of multiple paired samples (Friedman test) and the independent-sample t test was applied to comparing changes between different periods of time. Differences were considered to be statistically significant when P < 0.05. In T0T1 and T1T2, the condylar position was changed greatly. In T2T3, the mean condylar translations were less than 0.2 mm in all directions, the mean rotational changes of condyle were less than 0.2 mm; in the period of T3T4, the mean condylar translations in all directions were less than 0.02 mm. For series 2, the condyle translational changes in axial, coronal, and sagittal views were within 0.10 mm, and the rotation direction of condyle in all three views was the same within 1 year after operation. Fused three-dimensional images can be used to qualitatively and quantitatively evaluate condyle positional changes. The condylar position might be stable at 3 months postoperatively. The condyles of most of patients did not fully return to their preoperative position within 1 year after the operation. One method for fusing images has been established to detect the condylar positional changes. This method may be applied to estimate the bony changes of condyle, even bony changes in other part of dentomaxillofacial region. Meanwhile, the data of condyle positional changes from asymptomatic patients after the surgery within 1 year can be used as a reference for further exploration of the relationship between orthognathic surgery and the occurrence of osteoarthritis postoperatively in the future. • By fused 3D images, the change of condylar position after bilateral sagittal split ramus osteotomy can be observed intuitively. • For the patients with mandibular prognathism, the condylar position would be stable at 3 months postoperatively. • The condyles of most mandibular prognathism patients did not fully return to their preoperative position within 1 year after operation.

Effects of Twin Inclined Plane Device on Adaptation and Ultrastructure Variations in Condyle of Growing Rats.

Objective This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. Materials and Methods Forty-eight male Wistar rats (six weeks old, body weight of approximately 190–210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). Results The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. Conclusion Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.

Effects of 17β-Estradiol Deficiency and Mechanical Overload on Osseous Changes in the Rat Temporomandibular Joint

To deduce the contributing factors to idiopathic condylar resorption in young female patients, we hypothesized that 17β-estradiol (E2) deficiency would cause arthritic changes in the mandibular condyle under mechanical overloading in a rat model. We also hypothesized that osseous changes in the microstructure by the combination of E2 deficiency and mechanical overloading would be different depending on the region of the condyle. The mandibular condyles of female Sprague-Dawley rats were mechanically overloaded (50g) 8weeks after an ovariectomy (OVX). Changes in the condyles were analyzed with micro-computed tomography and histochemical and immunohistochemical staining. The size of the mandibular condyle decreased significantly with OVX or mechanical loading. The incidence of arthritic changes, including osteophyte formation, bone erosion, and flattening, was significantly different between the sham and OVX groups. The posterior parts of the condyles showed poor bone quality before OVX, and their condition significantly worsened with reduced bone mineral density and bone volume/tissue volume, as well as a sparse trabecular pattern. E2 deficiency and mechanical overloading of the temporomandibular joint cause morphologic changes in the mandibular condyle and changes in the osseous microstructure, which are more apparent in areas of poor bone quality.

DIAGNOSTIC ULTRASOUND ASSESSMENT OF TEMPOROMANDIBULAR JOINTS: A SYSTEMATIC REVIEW

<h3>Background</h3> Diagnostic imaging is an essential part of the evaluation of temporomandibular disorder (TMD). Magnetic resonance imaging is accepted as the reference standard for imaging diagnosis of TMD and cone beam computed tomography (CBCT) has been the method of choice to evaluate the contours of the cortical bone and TMD osseous alterations. Although not in general clinical use, several studies have assessed ultrasound to evaluate TMJ alterations. This nonionizing imaging method is less expensive and transportable and can be easily used in a dental setting. <h3>Objective(s)</h3> The purpose of this systematic review was to determine the diagnostic capability of ultrasound to assess TMJ alterations as disk displacement, joint effusion, and condylar changes using 3-D imaging modalities as the reference standard. <h3>Study Design</h3> Studies of this systematic review were gathered by searching several electronic databases and partial gray literature up to January 8, 2018, without restrictions of language and time. The risk of bias was evaluated using the second version of Quality Assessment Tool for Diagnostic of Accuracy Studies-2 (QUADAS-2). The grading of Recommendation, Assessment, Development and Evaluation (GRADEpro system) instrument was applied to assess the level of evidence across the studies. <h3>Results</h3> After applying the eligibility criteria, 28 studies were identified and synthesized. All studies were methodologically acceptable, presenting low applicability concerns, although none of them fulfilled all QUADAS-2 criteria. The quantitative analysis included 22 studies reporting on 2829 joints in total. The quality of the evidence evaluated by GRADE system suggested moderate confidence in estimating the outcomes. <h3>Discussion/Conclusions</h3> This systematic review demonstrated that US has acceptable capability to screen for disk displacement and joint effusion in patients with TMD, but not to assess condylar changes. More advanced imaging, such as magnetic resonance imaging, can thereafter be used to confirm the diagnosis, if deemed necessary.

Evaluation of the Condylar Remodeling and Affecting Factors After Orthognathic Surgery

Many authors reported condylar change after orthognathic surgery including not only positional change but also bony change such as condylar apposition or condylar resorption. It is suggested that operation method can cause different condylar change. Vertical ramus osteotomy (VRO) is used widely to correct mandibular prognathism. Bell, et al. concluded that the condyle is positioned anteriorly and inferiorly and condylar mobility is associated with improved mandibular function in 1990. Ueki et al. reported VRO can improve disk dislocation and TMJ symptoms along with physiological movement of condylar position and angle in 2006. Newly formed bone layer in the posterior part of the condylar head was found in many reports. It is identified as a sign of bone remodeling of condyle.

Comparison of condylar morphology changes and position stability following unilateral and bilateral sagittal split mandibular ramus osteotomy in patients with mandibular prognathism

BackgroundUnilateral sagittal split ramus osteotomy (USSRO) is not widely used given the postoperative instability caused by the inevitable rotation of the mandibular segment during surgery. However, the influence of mandibular movement on the condylar morphology and position stability has not been completely explored. The aim of the study was to quantitatively evaluate the effect of USSRO on the condylar surface morphology changes and postoperative stability in patients with mandibular lateral prognathism and compare these findings with the classic bilateral sagittal split ramus osteotomy (BSSRO).Patients/methodsThis was a retrospective study involving 134 patients with mandibular lateral prognathism who received USSRO (n = 56) and BSSRO (n = 78) surgery. Here, cone beam computed tomography (CBCT) was performed before surgery (T0), immediately after surgery (T1), and 1 year postoperatively (T2). Differences of condylar sizes, condylar surface deviation, and mandibular positioning parameters (dental midline deviation, SNB, SN-MP) were calculated from T0 to T2. Comparisons were performed at the deviated side or nondeviated side of condyles between the USSRO and BSSRO groups. The relation between the dental midline deviation and condylar surface morphology changes from T0 to T2 were investigated.ResultsCondylar surface morphology changes at the deviated side of temporomandibular joint (TMJ) before and 1 year after the surgery were significantly different between the USSRO and BSSRO groups. The dental midline deviation was related to the changes of condylar volume, surface size and surface deviation at the deviated side of TMJ in patients following USSRO. No significant difference was noted between the USSRO and BSSRO groups for postoperative condylar surface morphology changes at the nondeviated side. In both groups, significant differences between T0 and T1 and no significant difference between T1 and T2 were noted for all of the mandibular positioning parameters.ConclusionsBoth BSSRO and USSRO exhibit favorable postoperative stability in the correction of mandibular prognathism. After USSRO surgery, condylar surface changes occurred at the deviated side of the TMJ, and the dental midline deviation was closely related to the changes of condylar surface morphology. USSRO represents a stable alternative for minor asymmetric mandibular prognathism correction with the advantages of reduced operating time and surgical trauma.

The Prevalence of Partial Changes in the Condylar Head in the Patients with Osteoarthritis: A Cone Beam Computed Tomography (CBCT) Study

Abstract Introduction: The present study aimed to review the condylar changes in the patients with osteoarthritis using cone beam computed tomography (CBCT) images. Methods: In this study, 80 CBCT images of the temporomandibular joint (TMJ) pertaining 20 patients with osteoarthritis and 20 healthy individuals were evaluated, as well as the CBCT images that were obtained for other reasons. The images were reviewed in the coronal and sagittal sections. Considering the higher prevalence of osteoarthritis in women and after eliminating gender-based interventions, all the female patients were enrolled in the study. Chi-square was used to evaluate the correlations between the changes in the condylar head by the grouping of the patients, and the significance level was considered at 0.05. Results: The correlation of condylar head flattening (P=0.051) and Ely’s cysts (P=0.544) was assessed in the control group and osteoarthritis patients, and no significant difference was observed between the two variables and patient classification. In addition, the association between erosion (P<0.001) and osteophyte (P=0.002) of the condylar head was evaluated in the control group and osteoarthritis patients, and the presence or absence of these conditions had a significant correlation with disease grouping. Conclusion: According to the results, the presence of osteophyte and erosion was more significant in the osteoarthritis group compared to the healthy subjects. The most prevalent bony changes in the condylar head were due to flattening, and the less prevalent changes were associated with Ely’s cysts. Moreover, osteophyte and erosion were more prevalent in the patients with osteoarthritis.

Condylar repair and regeneration in adolescents/young adults with early-stage degenerative temporomandibular joint disease: A randomised controlled study.

Anterior repositioning splint (ARS) can facilitate regenerative condylar remodelling. To determine the effect of ARS on osseous condylar changes in adolescents/young adults with early-stage degenerative joint disease (DJD). Sixty-nine patients with early-stage temporomandibular joint (TMJ) DJD based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and cone beam computed tomography (CBCT) imaging were recruited and randomly allocated to two treatment groups: (a) conservative therapy with ARS and (b) conservative therapy without ARS. Subjects with acute TMJ closed-lock had their displaced discs physically reduced by mandibular manipulation prior to ARS therapy. Clinical and CBCT data of 59 patients (86.4% females, mean age 17.95±4.53years, 67 joints) were attained pre- and at 6 or 12months post-treatment. Osseous changes after treatment were categorised into (a) progressed, (b) unchanged, (c) repaired (remodelled without new bone formation) and (d) regenerated (remodelled with new bone formation). Statistical analysis including chi-square test, independent samples t test or Mann-Whitney U test was conducted. About 85.5% of patients (59/69) completed the study, with 28 subjects (32 joints) in the splint group and 31 (35 joints) in the control group. The occurrence of condylar repair and regeneration was significantly higher with ARS (78.1%/[25/32] of joints) when compared to control group (48.6%/[17/35]) (P<0.05). Moreover, condylar regeneration was exclusively observed in 50%/(16/32) of joints with ARS. For the 14 joints in splint group that received physical TMJ closed-lock reduction, 85.7%/(12/14) exhibited condylar regeneration. The splint group (3.1%/[1/32]) also had significantly lower incidence of progressive TMJ degeneration than the control (37.1%/[13/35]) (P<0.001). Condylar repair and regeneration in early-stage TMJ DJD are possible, and ideal spatial disc-condyle relationship appears important. The possibility of restoring TMJ form/structure by ARS therapy presents an attractive area of new basic science and clinical research (Bone defect repair in early osteoarthrosis of temporomandibular joint by joint distraction therapy: A randomized controlled trial/ChiCTR-TRC-14005172).

Assessment of condylar changes after orthognathic surgery using computed tomography regional superimposition

Background: The impact of orthognathic surgery on the TMJ and diseases involving this joint has been widely discussed. One of the concerns is the resorption/remodeling process that takes place in mandibular condyles and could affect the stability and compromises the results of the orthognathic surgery.

Condylar positional changes after BSSRO in patients with mandibular retrusion and prognathism: a new condyle-fossa matching's concept

Condylar positional changes after BSSRO in patients with mandibular retrusion and prognathism: a new condyle-fossa matching's concept

Assessment of condylar changes after orthognathic surgery using computed tomography regional superimposition

This study aimed to investigate the effects of bimaxillary advancement orthognathic surgery on the condylar remodeling of the temporomandibular joint (TMJ) using voxel-based regional superimposition of cone-beam computed tomography (CBCT).In this retrospective study, the sample comprised 56 condyles from 28 healthy patients (aged from 16 to 50years) with mandibular retrognathism treated with bimaxillary advancement. CBCT scans were taken preoperatively and at 14.3±4.2months postoperatively. The scans at the two time points were superimposed using regional voxel-based registration to assess condylar changes in the follow-up period. The linear alterations were measured in six different areas of each condyle to determine the pattern of condylar remodeling.Although no significant correlation was observed between changes in condylar surfaces, bone resorption occurred predominantly in the posterior and superior regions, while bone formation was predominantly on the anterior surface. Medial and lateral surfaces presented fewer bone changes. The overall bone changes were smaller than 1mm bilaterally in 21 patients (75%) and, considering each condyle individually, were smaller than 1mm in 48 condyles (85.7%).The results suggested that mild condylar remodeling in healthy patients is a common finding after orthognathic surgery. Future studies may clarify the mechanisms involved in the remodeling and help to understand the reasons for the remodeling pattern.

CBCT evaluation of condylar changes in children with unilateral posterior crossbites and a functional shift

Posterior crossbite is one of the most frequently occurring malocclusions in adolescents with a prevalence of 7% to 23%. The most common form of posterior crossbite is a unilateral posterior crossbite with a functional side shift. It has been suggested that functional posterior crossbites (FUPXB) may result in right-to-left-side differences in the condyle fossa relationship, resulting in temporomandibular joint (TMJ) problems. The objective of this study was to determine if pathological position of the condyles can cause condylar signs or symptoms like degenerative joint disease (DJD) or juvenile condylar resorption (JCR), or if the position of the condyle is just an altered position within the TMJ. Sixty patients with an average age of 9.6years were randomly selected from the office of one of the investigators (T.S.). The study group consisted of 29 patients with a FUPXB and the control group had 31 patients with no posterior crossbite. All patients had multislice CT scans of the TMJ taken as part of the orthodontic records. Transverse widths were measured at the skeletal base and the dentoalveolar base. Molar inclinations, condylar angulations, condylar anterior joint space, superior joint space, and posterior joint space were measured. Independent sample t-tests were used to compare different measurements between groups and paired sample t-tests were used to compare differences within the same patient. Reliability of measurements were determined using pairwise correlation. For dentoalveolar measurements of transverse width, the maxillomandibular difference for the study group was -8.2 mm and for the control group was -4.0 mm. No significant differences were found between the molar inclinations, condylar width, angulation, or any joint space measurements between the two groups. A total of 61.3% of the subjects in the control group and 72.4% in the study group had a radiographic sign of joint disease. The lack of condylar positional differences between the control and crossbite groups suggests that TMJ signs and symptoms in the study group may be related to remodeling in the TMJ instead.

Three-dimensional analysis of condylar changes in surgical correction for open bite patients with skeletal class II and class III malocclusions

The aim of this study was to quantify three-dimensional condylar displacements as a result of two-jaw surgery for open bite correction in patients with skeletal class II and class III malocclusion. Pre-surgical (T1) and post-surgical (T2) cone beam computed tomography scans were taken for 16 patients with skeletal class II (mean age 22.3±9.47years) and 14 patients with skeletal class III (mean age 25.6±6.27years). T2 scans were registered to T1 scans at the cranial base. Translational and rotational condylar changes were calculated by x,y,z coordinates of corresponding landmarks. The directions and amounts of condylar displacement were assessed by intra- and inter-class Mann–Whitney U-test or t-test. Class II patients presented significantly greater amounts of lateral (P=0.002) and inferior (P=0.038) translation than class III patients. The magnitudes of condylar translational displacements were small for both groups. Skeletal class III patients had predominantly medial (P=0.024) and superior (P=0.047) condylar translation. Skeletal class II patients presented greater condylar counterclockwise pitch (P=0.007) than class III patients. Two-jaw surgery for the correction of open bite led to different directions and amounts of condylar rotational displacement in patients with skeletal class II compared to class III malocclusion, with greater rotational than translational displacements.

The investigation of the prevalence of condylar degenerative changes and its relationship with disc displacement in the magnetic resonance images of the patients with temporomandibular joint disorders

Aim: The purpose of this study is to investigate the relationship between TMJ disc displacement and chondylar degenerative changes.Material and Methods: The MRIs of 182 TMJs belonging to 91 patients with TMD were evaluated. TMJs were distributed into three groups according to the disc positions as normal disc position (Group 1, n=39), disc displacement with reduction (Group 2, n=49) and disc displacement without reduction (Group 3, n=94). Condylar degenerative change is diagnosed according to presence or absence of erosion, sclerosis, flattening and osteophyte encountered in MRI. When more than one type of degenerative change was observed, the joint was determined to have degenerative changes.Results: The results of MRI evaluation of 182 TMJs revealed Group 1, Group 2 and Group 3 in 39 (21.4%), 49 (26.9%) and 94 (51.6%) joints, respectively. No degenerative condyle was found in 107 (58.8%) joints whereas degenerative condylar changes were encountered in 75 (41.2%) of 182 TMJs by the MRI evaluation. Condyle degeneration was detected in 2 (5.1%) of the joints with normal disc position whereas 6 (12.2%) and 67 (71.3%) of the joints with reducing and non-reducing disc displacement revealed condyle degeneration, respectively.Conclusion: A statistically significantly higher rate of condyle degeneration was encountered in the joints with disc displacement without reduction than the joints with disc displacement with reduction and normal disc position. Advancing disc displacement causes condylar degenerative changes.Keywords: Temporomandibular joint disorders; magnetic resonance imaging; disc displacement; degenerative changes.

Osteoarthritis of the temporomandibular joint and increase of the horizontal condylar angle: a longitudinal study

Our previous study of patients with unilateral temporomandibular joint (TMJ) osteoarthritis (OA) showed that the affected joints had greater horizontal condylar angle (HCA) compared with the contralateral unaffected joints. However, it was unclear whether the HCA changes preceded or were the result of OA changes. The aim of this longitudinal study was to investigate the relationship between HCA and OA progression. In total, 127 patients (with or without TMJ disorders) completed baseline and follow-up examinations (average time to follow-up 7.9 years). Generalized estimating equation models were used to account for correlation of observations within the same patients. (1) HCA was greater in OA-affected joints than in unaffected joints (P = .04). (2) Increased HCA at follow-up was associated with change in joint status from no OA to OA. (P = .001). (3) Baseline HCA value alone did not predict future OA diagnosis. (4) All OA changes in fossa/articular eminence morphology, and some combinations of condylar changes, were associated with a greater HCA. (5) OA diagnosis was associated with pain during maximum opening (P = .005) and pain history (P = .002). (6) Aging alone was not correlated with increased HCA. Clinical progression of OA preceded increases in HCA. HCA alone did not predict OA development.

Diagnostic ultrasound assessment of temporomandibular joints: a systematic review and meta-analysis.

The purpose of this systematic review was to determine the diagnostic capability of ultrasound to assess TMJ alterations as disc displacement (DD), joint effusion (JE) and condylar changes (CC) using 3D imaging modalities as reference standard. Studies were gathered by searching several electronic databases and partial grey literature up to January eighth, 2018 without restrictions of language and time. The risk of bias was evaluated using the second version of Quality Assessment Tool for Diagnostic of Accuracy Studies-2 (QUADAS-2). The grading of Recommendation, Assessment, Development and Evaluation (GRADEpro system) instrument was applied to assess the level of evidence across the studies. After applying the eligibility criteria, 28 studies were identified and synthesized. All studies were methodologically acceptable presenting low applicability concerns, although none of them fulfilled all QUADAS-2 criteria. The quantitative analysis included 22 studies, 2829 joints in total. The quality of the evidence evaluated by GRADE system suggested moderate confidence in estimating the outcomes. This systematic review demonstrated the ultrasound has acceptable capability to screen for DD and JE in TMD patients. For screening of condylar changes, ultrasound needs further studies using CT or CBCT as reference standard to support its use. More advanced imaging such as MRI can thereafter be used to confirm the diagnosis if deemed necessary.

Three-dimensional volumetric analysis of mandibular condyle changes in growing subjects: A retrospective cross-sectional study

ABSTRACT Objective The purpose of this study is to analyze the mandibular condylar volumein a sample of subjects 11–26 years old. Methods CBCT condylescans from 94 patients (mean age 18.2 ± 4.5 y) acquired with areconstructed layer thickness of 0.5 mm and a 512×512 matrix were examined. Data on condylar volume were compared among three groups with different age ranges: 11–16 years, 17–21years, and 22–26 years. Condylar volumetric measurements were performed with Mimics™ software. Results A significant increase in condylar volume from puberty to young adulthood was detected (p < 0.01). Females showed a higher condylar volume in the 17–21 y group compared with the 11–16 y group. Males showed differences among all three groups. Conclusion The mandibular condyle growth seems to continue at least until 17–21 years in males but seems to stop before 17 years in females.

TMJ pathomorphology in patients with JIA-radiographic parameters for early diagnosis-

BackgroundJuvenile idiopathic arthritis (JIA) is often accompanied by pathomorphological changes to the temporomandibular joint (TMJ). By analyzing orthodontical orthopantomograms of JIA patients the aims of the study were a) classification of condyle changes, b) quantification of bony asymmetries of condylar destruction and c) detection of relationships between disease duration and TMJ-involvement.Patients/Methods46 caucasian JIA-patients (28 female; 18 male; < 16.0 years) were enrolled, each joint (n = 92) was morphologically assessed by means of orthopantomogram, quantitatively analysed and compared with duration of general disease. Condyle morphology was assessed using the Billiau scale for severity of destruction [1]. The quantitative analysis was based on ratios of condyle, ramus and mandible height.ResultsPatients were divided into groups (Group I – slightly affected, n = 36; Billiau severity 0–2; condyle findings: X-ray normal, condyle erosions, condylar flattening; Group II – severely affected, N = 10; Billiau severity 3–4; condyle findings: condylar flattenings and erosions, unilateral/bilateral complete loss of condyles), based on morphological analysis of condylar destruction. Duration of disease was significantly longer in Group II (8.9 ± 5.2 years) than in Group I (4.6 ± 4.7 years). Asymmetries of condyle, ramus and mandible height, quantitatively analysed by contralateral comparison, were significantly more marked in patients of Group II than of Group I.ConclusionsOrthopantomogram imaging can be used in orthodontics clinical routine to detect TMJ-pathologies and is an important reference for monitoring progression of JIA. Classification into severe and slightly affected TMJ is possible by analysis of condylar pathomorphology. An association between degree of destruction, extent of lower jaw asymmetry and disease duration is suggested by the results.

Condylar changes after orthognathic surgery for class III dentofacial deformity: a systematic review

After orthognathic surgery for class II dentofacial deformity, remodelling of the mandibular condyle will take place. In a number of cases, this may evolve towards a phenomenon of condylar resorption. Yet, studies on the occurrence of this complication after the correction of a class III deformity are scarce. A systematic review of the literature was performed with the aim of identifying reports on condylar resorption or remodelling after orthognathic surgery for class III dentofacial deformity. A search of the international databases yielded 12 eligible studies. Eight studies reported some degree of postoperative condylar remodelling, while symptoms of condylar resorption were only described in a limited group of patients. Thus, the literature may show evidence of condylar remodelling after orthognathic treatment of class III patients, and anecdotal reports of condylar resorption exist. The small sample sizes, heterogeneity in methods and outcomes, and use of two-dimensional radiographs indicate the need for updated long-term research. In the future, the use of cone beam computed tomography data for volumetric and morphological condylar analysis in combination with three-dimensional cephalometry may provide the opportunity to further elucidate this phenomenon and better characterize its aetiology.

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

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