Effect of post–orthognathic surgery condylar axis changes on condylar morphology as determined by 3-dimensional surface reconstruction

ABSTRACT Objective: To evaluate the effect of postoperative condylar axis changes on mandibular condylar remodeling by comparing the condylar head in three-dimensional (3D) surface reconstructions before and after surgery in skeletal Class III deformities (one-jaw [mandibular setback] or two-jaw surgery), and also to determine the relationship between condylar inward rotation and condylar surface remodeling after orthognathic surgery. Materials and Methods: A retrospective analysis was conducted of 30 patients with skeletal Class III deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 ± 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 ± 2.2 years). Sixty condyles were reconstructed and superimposed pre- and postoperatively to compare the changes of condylar surfaces. The relation between the condylar axis change and the surface change using the Pearson correlation were investigated from the 3D image software. Results: Condylar surface changes before and after the surgery were significant. The postoperative inward rotation of the condyles was correlated with the average absolute deviation of the condyles, regardless of the surgery type (one- or 2-jaw surgery; r = .70, P < .05). Conclusion: After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface.

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Postsurgical Stability of Temporomandibular Joint of Skeletal Class III Patients Treated with 2-Jaw Orthognathic Surgery via Computer-Aided Three-Dimensional Simulation and Navigation in Orthognathic Surgery (CASNOS)

BioMed Research International ◽

10.1155/2021/1563551 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Ling-Chun Wang ◽

Yi-Hao Lee ◽

Chi-Yu Tsai ◽

Te-Ju Wu ◽

Ya-Ying Teng ◽

...

Keyword(s):

Orthognathic Surgery ◽

Three Dimensional ◽

Class Iii ◽

Skeletal Class ◽

Computer Aided ◽

Before And After ◽

Bimaxillary Orthognathic Surgery ◽

The Mean ◽

Dimensional Simulation ◽

The Right

Objective. The aim of this study is to clarify the postsurgical stability of temporomandibular joints in skeletal class III patients treated with 2-jaw orthognathic surgery which was performed utilizing computer-aided three-dimensional simulation and navigation in orthognathic surgery (CASNOS) protocol. Materials and Methods. 23 consecutive nongrowing skeletal class III patients with mandibular prognathism associated with maxillary retrognathism treated with 2-jaw orthognathic surgery between 2018 and 2019 were enrolled in this study. The surgery was planned according to the standardized protocol of CASNOS (computer-aided three-dimensional simulation and navigation in orthognathic surgery). Computed tomography (CT) scans were performed in all patients 3 weeks presurgically and 6 months postsurgically. ITKSNAP and 3D Slicer software were used to reconstruct three-dimensional facial skeletal images, to carry out image segmentation, and to superimpose and quantify the TMJ position changes before and after surgery. Amount of displacement of the most medial and lateral points of the condyles and the change of intercondylar angles were measured to evaluate the postsurgical stability of TMJ. Results. A total amount of 23 skeletal class III patients female : male = 12 : 11 with age ranged from 20.3 to 33.5 years (mean: 24.39 ± 4.8 years old ) underwent Le Fort I maxillary advancement and BSSO setback of the mandible. The surgical outcome revealed the satisfactory correction of their skeletal deformities. The mean displacement of the right most lateral condylar point (RL-RL ′ ) was 1.04 ± 0.42 mm and the mean displacement of the left most lateral condylar point (LL-LL ′ ) was 1.19 ± 0.41 mm . The mean displacement of the right most medial condylar point (RM-RM ′ ) was 1.03 ± 0.39 mm and the left most medial condylar point (LM-LM ′ ) was 0.96 ± 0.39 mm . The mean intercondylar angle was 161.61 ± 5.08 ° presurgically and 159.28 ± 4.92 ° postsurgically. Conclusion. The postsurgical position of TM joint condyles in our study only presented a mild change with all the landmark displacement within a range of 1.2 mm. This indicates the bimaxillary orthognathic surgery via 3D CASNOS protocol can achieve a desired and stable result of TMJ position in treating skeletal class III adult patients with retrognathic maxilla and prognathic mandible.

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Three-dimensional analysis of lip soft tissue changes and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry

Journal of X-Ray Science and Technology ◽

10.3233/xst-210903 ◽

2021 ◽

pp. 1-14

Author(s):

Wenjie Xu ◽

Hao Tan ◽

Xuehuan Meng ◽

Ye Ming ◽

Tao Wang ◽

...

Keyword(s):

Soft Tissue ◽

Orthognathic Surgery ◽

Three Dimensional ◽

Facial Asymmetry ◽

Class Iii ◽

Class Iii Malocclusion ◽

Skeletal Class ◽

Tissue Changes ◽

Soft Tissue Changes ◽

Jaw Surgery

OBJECTIVE: To investigate three-dimensional soft tissue changes of lips and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry using cone-beam computerized tomography (CBCT). METHOD: This study included 46 CBCT scans of patients with aforementioned character before (T1) and 6–12 months after orthognathic surgery (T2). Subjects were divided into 2 groups according to two types of orthognathic surgery namely, the one-jaw surgery group who underwent bilateral sagittal splint ramus osteotomy (BSSRO) and the two-jaw surgery group who underwent Le Fort I osteotomy and BSSRO. Mimics 19.0 software are used for model reconstruction, landmark location and three-dimensional cephalometric analysis. Descriptive statistics and correlation analyses are used to investigate jaw hard tissue and lip soft tissue changes. RESULTS: In one-jaw group, the mandible shows changes in contour and position (p < 0.05), and the surgery causes changes of lip structure on the deviated side. While in two-jaw group, jaws only show changes in spatial position, and surgery changes contour of bilateral lips and nasolabial angle (p < 0.05). At the same time, lip symmetry increases significantly in both groups postoperatively. CONCLUSIONS: Orthognathic surgery can improve lip aesthetics in patients with skeletal class III malocclusion and facial asymmetry. However, changes induced by two surgical approaches are different. Surgeons should have a clear acquaintance with this difference to deal with different situations.

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Evaluation of Condylar Positional, Structural, and Volumetric Status in Class III Orthognathic Surgery Patients

Medicina ◽

10.3390/medicina56120672 ◽

2020 ◽

Vol 56 (12) ◽

pp. 672

Author(s):

Jevgenija Podčernina ◽

Ilga Urtāne ◽

Pertti Pirttiniemi ◽

Ģirts Šalms ◽

Oskars Radziņš ◽

...

Keyword(s):

Orthognathic Surgery ◽

Three Dimensional ◽

Study Groups ◽

Class Iii ◽

Skeletal Class ◽

Condylar Position ◽

Bimaxillary Surgery ◽

One Year ◽

Jaw Surgery

Background and objectives: The need to evaluate the condylar remodeling after orthognathic surgery, using three-dimensional (3D) images and volume rendering techniques in skeletal Class III patients has been emphasized. The study examined condylar positional, structural, and volumetric changes after bimaxillary or single-jaw maxillary orthognathic surgeries in skeletal Class III patients using the cone-beam computed tomography. Materials and Methods: Presurgical, postsurgical, and one-year post-surgical full field of view (FOV) cone-beam computed tomography (CBCT) images of 44 patients with skeletal Class III deformities were obtained. Group 1 underwent a bimaxillary surgery (28 patients: 24 females and 4 males), with mean age at the time of surgery being 23.8 ± 6.0 years, and Group 2 underwent maxillary single-jaw surgery (16 patients: 8 females and 8 males), with mean age at the time of surgery being 23.7 ± 5.1 years. After the orthognathic surgery, the CBCT images of 88 condyles were evaluated to assess their displacement and radiological signs of bone degeneration. Three-dimensional (3D) condylar models were constructed and superimposed pre- and postoperatively to compare changes in condylar volume. Results: Condylar position was found to be immediately altered after surgery in the maxillary single-jaw surgery group, but at the one-year follow-up, the condyles returned to their pre-surgical position. There was no significant difference in condylar position when comparing between pre-surgery and one-year follow-up in any of the study groups. Condylar rotations in the axial and coronal planes were significant in the bimaxillary surgery group. No radiological signs of condylar bone degeneration were detected one year after the surgery. Changes in condylar volume after surgery were found to be insignificant in both study groups. Conclusions: At one year after orthognathic surgery, there were no significant changes in positional, structural, or volumetric statuses of condyles.

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Diagnosis and evaluation of skeletal Class III patients with facial asymmetry for orthognathic surgery using three-dimensional computed tomography

Seminars in Orthodontics ◽

10.1053/j.sodo.2015.07.004 ◽

2015 ◽

Vol 21 (4) ◽

pp. 274-282 ◽

Cited By ~ 5

Author(s):

Sung-Jin Kim ◽

Hyoung-Seon Baik ◽

Chung-Ju Hwang ◽

Hyung-Seog Yu

Keyword(s):

Computed Tomography ◽

Orthognathic Surgery ◽

Three Dimensional ◽

Facial Asymmetry ◽

Class Iii ◽

Skeletal Class

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Computer-Aided Planning in Orthognathic Surgery: A Comparative Study with the Establishment of Burstone Analysis-Derived 3D Norms

Journal of Clinical Medicine ◽

10.3390/jcm8122106 ◽

2019 ◽

Vol 8 (12) ◽

pp. 2106 ◽

Cited By ~ 1

Author(s):

Cheng-Ting Ho ◽

Rafael Denadai ◽

Hsin-Chih Lai ◽

Lun-Jou Lo ◽

Hsiu-Hsia Lin

Keyword(s):

Orthognathic Surgery ◽

Three Dimensional ◽

Computer Assisted ◽

Class Iii ◽

Facial Soft Tissue ◽

Skeletal Class ◽

Nasolabial Angle ◽

Normal Occlusion ◽

Computer Aided ◽

Cephalometric Measurements

Three-dimensional (3D) computer-aided simulation has revolutionized orthognathic surgery treatment, but scarce 3D cephalometric norms have been defined to date. The purposes of this study were to (1) establish a normative database of 3D Burstone cephalometric measurements for adult male and female Chinese in Taiwan, (2) compare this 3D norm dataset with the two-dimensional (2D) Burstone norms from Caucasian and Singaporean Chinese populations, and (3) apply these 3D norms to assess the outcome of a computer-aided simulation of orthognathic surgery. Three-dimensional Burstone cephalometric analysis was performed on 3D digital craniofacial image models generated from cone-beam computed tomography datasets of 60 adult Taiwanese Chinese individuals with normal occlusion and balanced facial profile. Three-dimensional Burstone analysis was performed on 3D image datasets from patients with skeletal Class III pattern (n = 30) with prior computer-aided simulation. Three-dimensional Burstone cephalometric measurements showed that Taiwanese Chinese males had significantly (p < 0.05) larger anterior and posterior facial heights, maxillary length, and mandibular ramus height than females, with no significant (p > 0.05) difference for facial soft-tissue parameters. The 3D norm dataset revealed Taiwanese Chinese-specific facial characteristics, with Taiwanese presenting (p < 0.05) a more convex profile, protrusive maxillary apical bases, protruding mandible, protruding upper and lower lips, and a shorter maxillary length and lower facial height than Caucasians. Taiwanese had significantly (p < 0.05) larger maxillary projection, vertical height ratio, lower face throat angle, nasolabial angle, and upper lip protrusion than Singaporean Chinese. No significant (p > 0.05) difference was observed between 3D norms and computer-aided simulation-derived 3D patient images for horizontal skeletal, vertical skeletal, and dental measurements, with the exception of two dental parameters (p < 0.05). This study contributes to literature by providing gender- and ethnic-specific 3D Burstone cephalometric norms, which can assist in the multidisciplinary-based delivery of orthodontic surgical care for Taiwanese Chinese individuals worldwide, including orthodontic management, computer-assisted simulation, and outcome assessment.

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