Evaluation of Postsurgical Stability And Condylar Morphology In Skeletal Class II Patients With Condylar Resorption Following Orthognathic Surgery

Background: To retrospectively evaluate postsurgical stability and condylar morphology for skeletal class II malocclusion patients with condylar resorption (CR) treated with orthognathic surgery.Methods: Thirty-five patients treated with combined orthodontic and orthognathic surgery between 2014 and 2018 were enrolled in this retrospective study. CT scans were acquired preoperatively (T0), 2–7 days after surgery (T1), and 1 year postoperatively (T2). The amount of mandibular advancement, postsurgical relapse, condylar morphology and joint spaces were analysed respectively. Statistical analysis was performed using R, version 3.4.3 (R Development Core Team 2010).Results: The average mandibular advancement and counter-clockwise rotation were 5.51 mm and -2.82 degrees respectively. The average relapse was 1.08 mm (19.6% of the advancement) and 1.13 degrees. The condylar volume showed a postoperative reduction of 161.86 mm3(13.7% of initial condylar volume). AJS increased after surgery and gradually returned to its original state, while SJS and PJS decreased and remained stable. Surgical advancement of B point was significantly correlated with skeletal relapse. The optimal cut-off values were as follows: MP-FH (40.75°); ramus height (51.125 mm); SJS (1.63 mm); surgical displacement (4.72 mm); CCR (-4.3°); AJSC (1.07 mm).Conclusions: Skeletal class II patients with CR have a high risk of postsurgical condylar resorption, which was most related to nonsurgical risk factors such as gender(female) and condylar angle. Condylar had moved posteriorly to the concentric position after surgery and remained quite stable through the 1-year follow-up. Preoperative skeletal patterns such as lower ramus height and surgical procedures such as larger advancement of the mandible were closely associated with sagittal relapse of the mandible.

MRI-based observation of the size and morphology of temporomandibular joint articular disc and condyle in young asymptomatic adults

Objective: To investigate the size and morphology of the temporomandibular joint (TMJ) articular disc and condyle in young asymptomatic adults by using magnetic resonance imaging (MRI) and to provide a reference for clinical diagnosis and scientific study of temporomandibular disorders (TMD). Methods: Overall, 93 undergraduate volunteers without TMD were enrolled from the freshmen pool at the Qingdao University. All participants underwent MRI of the oblique sagittal and oblique coronal TMJ planes. The articular disc and condyle were subsequently measured, and their morphology was evaluated. The obtained data were then grouped and analyzed statistically. Finally, intragroup correlation coefficient (ICC) was used to evaluate the interobserver measurement reliability. Results: We totally received 186 TMJ imaging samples. Based on our analysis, disc’s anterior band in young asymptomatic adult females were thicker than males of the same age (p = 0.024). Moreover, the media-lateral dimensions of the condylar head of adult females were shorter than males of equal age (P＜0.001). The bilateral articular disc morphology was the same in 72.4% of subjects while the condylar morphology was the same in 63.4% of participants. Finally, using measurement reliability assessment, we demonstrated that our conclusions are reliable (ICC ≥0.7). Conclusion: The thickness of the anterior band of the disc and the media-lateral dimensions of the condylar head were gender-related. Additionally, the morphology of the bilateral articular disc and condyle was different among the subset of young asymptomatic adults.

Temporomandibular joint morphology in Korean using cone-beam computed tomography: influence of age and gender

Objectives The purpose of this study was to investigate the condylar morphology and position of Koreans using cone-beam computed tomography (CBCT) images. Analyzing the mean values of this study with reference to left and right sides, gender, and age will help to understand the size of the condyle and glenoid fossa, condylar morphology, and temporomandibular joint (TMJ) symmetry for establishing the standard temporomandibular joint structures of Koreans and then design the standard temporomandibular joint prosthesis for Koreans. Results There was no significant result in the condyle size, condyle axis angle, joint space, fossa depth, and mandibular body size between the left and right sides (p > 0.05). On the other hand, the mediolateral width of the condyle and mandibular body size show significantly different with the gender (P < 0.05). Also, significant differences were found in condyle size, joint space, fossa depth, and mandibular body size according to age groups (p < 0.05). Conclusions Condylar position and morphology vary according to side, age, and gender. The results of this study are expected to help in customizing a treatment for the patients who need TMJ reconstruction by predicting the TMJ morphology according to age and gender and design the standard temporomandibular joint prosthesis for the Koreans.

Morphological Analysis of Bone Deformities of the Distal Femur in Toy Poodles with Medial Patellar Luxation

Objective The aim of this study was to evaluate the bone deformities of the distal femur of Toy Poodles with medial patellar luxation (MPL) using computed tomography. Methods Computed tomography data from 37 stifles of Toy Poodles (16 normal, 10 grade 2 MPL and 11 grade 4 MPL) were analysed. For trochlear morphology, sulcus angle, medial or lateral trochlear inclination and trochlear angle were compared. For condylar morphology, distance between the apex of the medial or lateral trochlear ridge and the most caudal point of the medial or lateral femoral condyle (MC or LC), the length of the cranial/middle (anterior) part (MC(a) or LC(a')) and caudal (posterior) part (MC(p) or LC(p')) of distal femur and medial or lateral condyle width (MCW or LCW) were measured, and the ratios of medial-to-lateral condyles and anterior–posterior parts were compared. Results Sulcus angle was significantly higher, and medial trochlear inclination was significantly lower in grade 4 MPL group than other groups. Lateral trochlear inclination was not significantly different among 3 groups. Trochlear angles at proximal trochlear groove were significantly lower in grade 4 MPL group than other groups. MC/LC, MC(a)/LC(a'), MC(a)/MC(p), and LC(a')/LC(p') were significantly lower in grade 4 MPL group than other groups; however, there were no significant differences in MC(p)/LC(p') and MCW/LCW among three groups. Conclusion Hypoplasia of the cranial and middle rather than caudal compartment of the distal femur was the primary morphological abnormality in Toy Poodles with grade 4 MPL.

Comprehensive 3D analysis of condylar morphology in adults with different skeletal patterns – a cross-sectional study

Background The correlation between individuals’ condylar morphology and their skeletal pattern is of great interest for treatment strategies ranging from orthodontic orthopaedics to orthognathic surgery. The objective of the present study was to investigate this relationship three-dimensionally. Methods A total of 111 adult patients (mean age = 27.0 ± 10.2 years) who underwent head computed tomography or cone beam computed tomography scans were included. Based on these data, 3D models of the skull and the condyles were calculated. The craniofacial skeleton was evaluated (1) transversally regarding skeletal symmetry (menton deviation), (2) sagittally regarding skeletal classes (Wits appraisal) and vertically regarding the inclination of the jaws (maxillomandibular plane angle). The condylar morphology was assessed (a) linearly by the condylar width, height and depth; (b) angularly by the antero-posterior and medio-lateral condylar inclination; and (c) volumetrically by the ratio of the condylar volume/mandibular volume (C/Mand). Results (1) Transversal: Asymmetric patients showed significantly higher discrepancies in the volumetric ratio C/Mand on the deviation and non-deviation side compared to symmetric patients. (2) Sagittal: Class III subjects demonstrated longer, more voluminous condyles with higher antero-posterior and medio-lateral inclination angles compared to Class II participants. (3) Vertical: Hyperdivergent subjects had smaller condyles with higher antero-posterior inclination angles than those of hypodivergent subjects. No interactions of skeletal class and vertical relationships regarding condylar morphology were observed. Conclusions This study demonstrates a clear correlation between pronounced skeletal patterns and condylar morphology in an adult population. The description of radiographic condyle characteristics in relation to the craniofacial morphology improves orthodontic treatment planning and could be helpful in the diagnosis of temporomandibular joint pathologies.