OBJECTIVES: This study aims to analyze the biomechanics of three kinds of rigid internal fixation methods for condylar head fractures. METHODS: A three dimensional finite element model of the normal mandible was constructed. It was then used to prepare condylar head fracture finite element model and three kinds of rigid internal fixation finite element model (unilateral tension screw, bilateral tension screw, tension screw+titanium plate). The mechanical characteristics and changes of the mandible condyle under the same mechanical conditions were compared among the three different rigid internal fixation methods. RESULTS: The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of unilateral tension screw were 71.03 MPa and 4.72 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 78.45 MPa and 4.50 mm, respectively. The maximum stress of fracture suture was 3.27 MPa. The maximum equivalent stress and displacement of the non-free end of condyle under the rigid internal fixation method of bilateral tension screw were 70.52 MPa and 4.00 mm, respectively. The maximum equivalent stress and displacement of the free end of condyle were 72.49 MPa and 3.85 mm, respectively. The maximum stress of fracture suture was 2.33 MPa. The maximum equivalent stress and maximum displacement of the non-free end of condyle under the rigid internal fixation method of tension screw+titanium plate were 67.26 MPa and 2.66 mm, respectively. The maximum equivalent stress and maximum displacement of the free end of condyle were 69.66 MPa and 2.50 mm, respectively. The maximum stress of fracture suture was 2.18 MPa. CONCLUSIONS The tension screw+titanium plate rigid internal fixation method is the most conducive to biomechanical distribution for condylar head fractures.
Fracture Fixation, Internal/instrumentation* ; Mandibular Condyle/surgery* ; Biomechanical Phenomena ; Bone Screws ; Finite Element Analysis ; Humans ; Mandibular Fractures/surgery* ; Bone Plates ; Titanium ; Stress, Mechanical

OBJECTIVES: This retrospective study aimed to investigate factors influencing positional changes of the condyle and temporomandibular joint (TMJ) following mandibular defect reconstruction with bone flaps, and to evaluate the biomechanical impacts of flap reconstruction on condylar positioning, thereby providing evidence for optimizing surgical protocols and TMJ functional rehabilitation. METHODS: A retrospective study was conducted on 90 patients undergoing mandibular segmental resection with immediate bone flap reconstruction at Guizhou Medical University Affiliated Stomatological Hospital (June 2019 to May 2024). After strict screening, 50 cases with complete data were analyzed. Clinical parameters (defect size, location, reconstruction method) and craniofacial CT scans at four timepoints [preoperative (T0), 7-10 days (T1), 3 months (T2), and 6 months (T3) postoperatively] were collected. Mimics 20 software facilitated 3D reconstruction for measuring TMJ anterior/posterior/superior joint spaces (Kamelchuk method) and calculating condylar position via the Pullinger index [Ln (posterior/anterior space)]. Vitral and Krisjane methods quantified mandibular linear parameters (ramus length, condylar pole distances to the sagittal plane, angulation) and glenoid fossa morphology. Statistical analyses were performed using SPSS 21.0. RESULTS: Mandibular defect size and location were significant factors influencing postoperative condylar position changes (P<0.05). Compared to preoperative measurements, postoperative condylar anterior, posterior, and superior joint spaces were significantly increased (P<0.001). The most pronounced anterior condylar displacement occurred within 7-10 days postoperatively (P<0.05). In patients with condyle resection, postoperative joint space and angle changes were significant; in patients with condyle preservation, only superior and anterior joint space changes were statistically significant (P<0.05). Additionally, from T1 to T2, the changes in condylar medial-lateral distance, superior joint space, and anterior joint space were negatively correlated with the preoperative condylar position. Compared with preoperative,in the T0-T1 period, condylar medial-lateral distance, posterior joint space, and articular tubercle angle changes were significantly negatively correlated with time (P<0.05). Notably, the angle between the condylar long axis and the coronal axis showed a sustained negative trend from T1 to T3 (P<0.05). CONCLUSIONS Condylar position changes after mandibular defect repair with bone flap reconstruction are associated with the size and location of the defect. Additionally, adaptive remodeling of the temporomandibular joint (TMJ) joint space occurs postoperatively. The phenomenon of anterior displacement of the condyle in the early postoperative period (7-10 days) shows a trend of reduction with prolonged follow-up time, and further sample size research is needed.
Humans ; Retrospective Studies ; Temporomandibular Joint/surgery* ; Mandibular Condyle/surgery* ; Male ; Female ; Adult ; Middle Aged ; Mandibular Reconstruction/methods* ; Mandible/surgery* ; Surgical Flaps ; Tomography, X-Ray Computed ; Young Adult ; Biomechanical Phenomena ; Aged ; Adolescent ; Imaging, Three-Dimensional

OBJECTIVES: This study aimed to analyze the application value of a modified tragus edge incision and transmasseteric anteroparotid approach to condyle reconstruction. METHODS: Condyle reconstruction was performed in 16 patients (9 females and 7 males) with modified tragus edge incision and transmasseteric anteroparotid approach. After regular follow-up, the function of condyle reconstruction was evaluated by clinical indicators, such as parotid salivary fistula, facial nerve function, mouth opening, occlusal relationship, and facial scar. The morphology of rib graft rib cartilage was evaluated by imaging indicators, such as panoramic radiography, CT, and three-dimensional CT image reconstruction. RESULTS: At 6-36 months postoperative follow-up, all patients had good recovery of facial appearance, concealed incisional scar, no parotid salivary fistula, good mouth opening, and occlusion. One case had temporary facial paralysis and recovered after treatment. Radiographic evaluation further showed that costochondral graft survived in normal anatomic locations. CONCLUSIONS The modified tragus edge incision and transmasseteric anteroparotid approach can effectively reduce parotid salivary fistula and facial nerve injury in condylar reconstruction. The surgical field was clearly exposed, and the incision scar was concealed without increasing the incidence of other complications. Thus, this approach is worthy of clinical promotion.
Male ; Female ; Humans ; Mandibular Condyle/surgery* ; Cicatrix/surgery* ; Fracture Fixation, Internal/methods* ; Mandibular Fractures/surgery* ; Oral Surgical Procedures/methods* ; Treatment Outcome

Dentofacial deformities secondary to condylar hyperplasiais a kind of disease presenting facial asymmetry, malocclusion, temporomandibular joint dysfunction, and other symptoms caused by non-neoplastic hyperplasia of the condyle. The etiology is still unknown, and currently, pre- and post-operative orthodontics accompanied by orthognathic surgery, temporomandibular joint surgery and jawbone contouring surgery are the main treatment methods. A personalized treatment plan was developed, considering the active degree of condyle hyperplasia, the severity of the jaw deformity, and the patient's will, to correct deformity, obtain ideal occlusal relationship, and regain good temporomandibular joint function. Combined with the author's clinical experience, the etiology, clinical and imageological features, treatment aims, and surgical methods of condylar hyperplasia and secondary dentofacial deformities were discussed in this paper.
Humans ; Dentofacial Deformities/pathology* ; Hyperplasia/pathology* ; Mandibular Condyle/surgery* ; Orthognathic Surgical Procedures ; Temporomandibular Joint/surgery*

OBJECTIVES: This study aimed to use modified articular disc anchorage in treating old irreducible temporomandibular joint (TMJ) disc displacement with perforation and rupture, as well as to explore its efficacy. METHODS: A total of 31 patients (34 sides) with 47 TMJ disc perforations who underwent surgical treatment in the Affiliated Stomatolo-gical Hospital of Nanchang University from January 2018 to December 2021 were selected. According to the location of disc perforation, it has five types: posterior disc perforation (typeⅠ), anterior disc perforation (typeⅡ), lateral disc perforation (type Ⅲ), composite disc perforation, and destruction disc perforation. The modified methods of disc anchoring were divided into two types according to the location of the perforation. TypesⅠandⅢ disc perforation were trea-ted by posterior anchoring method. For posterior ancho-ring, a screw was implanted into the posterolateral side of the condylar neck, and the disc was fixed on the screw by horizontal mattress suture. TypeⅡdisc perforation and compo-site disc perforation combined typeⅡperforation were treated by anterior and posterior double-anchoring method. For anterior anchoring, anchor screws or holes were placed at the anterior edge of the condylar neck, and horizontal mattress suture was performed at the posterior edge of the anterior perforation with an anchor wire. The articular disc was then fixed on the anchor screws or holes. For the posterior anchoring method, it was the same as the previous one. Paired t test was used to analyze the visual analog scale (VAS), maximum interincisal opening (MIO), and TMJ disorder index (CMI) of the patient before surgery and 1, 3, and 6 months after surgery. Disk-condyle position relationship by magnetic resonance imaging and postoperative quality of life in postoperative were analyzed. RESULTS: The incidence of perforation was 41.2% (14/34) in typeⅠ, 11.8% (4/34) in typeⅡ, 8.8% (3/34) in typeⅢ, 29.4% (10/34) in composite type, and 8.8% (3/34) in destruction type. The VAS, MIO, and CMI at 3, 6 months after operation significantly improved compared with those before operation (P<0.05). The effective reduction rate of disc was 96.77% (30/31). The quality of life at 6 months after surgery was 47.22±2.13, and the rate of excellent evaluation was 96.4% (27/28). CONCLUSIONS Modified articular disc anchorage achieves a good curative effect for treating temporomandibular joint disc perforation and rupture. Nevertheless, its long-term effect requires further observation.
Humans ; Temporomandibular Joint Disc/surgery* ; Quality of Life ; Joint Dislocations/surgery* ; Temporomandibular Joint Disorders/surgery* ; Magnetic Resonance Imaging/methods* ; Temporomandibular Joint/pathology* ; Mandibular Condyle

PURPOSE: The main aim is to provide clinical reference for the application of mini suture anchor in the reduction and fixation of displaced temporomandibular joint (TMJ) disc with intracapsular condylar fracture. METHODS: From October 2018 to October 2019, 21 patients (31 sides) with intracapsular condylar fractures and articular disc displacement from West China Hospital of Stomatology, Sichuan University were included. The selection criteria were: (1) mandibular condylar fractures accompanied by displacement of the TMJ disc, confirmed by clinical examination, CT scan and other auxiliary examinations; (2) indication for surgical treatment; (3) no surgical contraindications; (4) no previous history of surgery in the operative area; (5) no facial nerve injury before the surgery; (6) informed consent to participate in the research program and (7) complete data. Patients without surgical treatment were excluded. The employed patients were followed up at 1, 3, 6 and 12 months after operation. Outcomes were assessed by success rate of operation, TMJ function and radiological examination results at 3 months after operation. Data were expressed as number and percent and analyzed using SPSS 19.0. RESULTS: All the surgical procedures were completed successfully and all the articular discs were firmly attached to the condyles. The articular disc sufficiently covered the condylar head after the fixation. The fixation remained stable when the mandible was moved in each direction by the surgeons. No complications occurred. The functions of the TMJ were well-recovered postoperatively in most cases. CT scan revealed that the screws were completely embedded in the bone without loosening or displacement. CONCLUSION Mini suture anchor can provide satisfactory stabilization for the reduced articular disc and also promote the recovery of TMJ functions.
Humans ; Joint Dislocations/surgery* ; Mandible ; Mandibular Condyle ; Mandibular Fractures/surgery* ; Suture Anchors ; Temporomandibular Joint Disc/surgery*

PURPOSE: The aim of this study is to evaluate the application value of virtual surgical planning in the management of mandibular condylar fractures and to provide a reliable reference. METHODS: This was a prospective randomized controlled study and recruited 50 patients requiring surgical treatment for their mandibular condylar fractures. The inclusion criteria were patients (1) diagnosed with a condylar fracture by two clinically experienced doctors and required surgical treatment; (2) have given consent for the surgical treatment; and (3) had no contraindications to the surgery. Patients were excluded from this study if: (1) they were diagnosed with a non-dislocated or only slightly dislocated condylar fracture; (2) the comminuted condylar fracture was too severe to be treated with internal reduction and fixation; or (3) patients could not complete follow-up for 3 months. There were 33 male and 17 female patients with 33 unilateral condylar fractures and 17 bilateral condylar fractures included. The 50 patients were randomly (random number) divided into control group (25 patients with 35 sides of condylar fractures) and experimental group (25 patients with 32 sides of condylar fractures). Virtual surgical planning was used in the experimental group, but only clinical experience was used in the control group. The patients were followed up for 1, 3, 6 and 12 months after operation. Variables including the rate of perfect reduction by radiological analysis, the average distance of deviation between preoperative and postoperative CT measurements using Geomagic software and postoperative clinical examinations (e.g., mouth opening, occlusion) were investigated for outcome measurement. SPSS 19 was adopted for data analysis. RESULTS: The average operation time was 180.60 min in the experimental group and 223.2 min in the control group. One week postoperatively, CT images showed that the anatomic reduction rate was 90.63% (29/32) in the experimental group and 68.57% (24/35) in the control group, revealing significant difference (X² = 4.919, p = 0.027). Geomagic comparative analysis revealed that the average distance of deviation was also much smaller in the experimental group than that in the control group (0.639 mm vs. 0.995 mm; t = 3.824, p < 0.001). CONCLUSION These findings suggest that virtual surgical planning can assist surgeons in surgical procedures, reduce operative time, and improve the anatomic reduction rate & accuracy, and thus of value in the diagnosis and treatment of condylar fractures.
Female ; Fracture Fixation, Internal/methods* ; Fractures, Comminuted ; Humans ; Male ; Mandibular Condyle/surgery* ; Mandibular Fractures/surgery* ; Prospective Studies ; Treatment Outcome

Treating dentofacial deformities secondary to condylar resorption is a remarkable clinical challenge. Combined orthodontic treatment and orthognathic surgery is currently the main treatment scheme and is often integrated with temporomandibular joint surgery or conservative treatment according to the severity of condylar resorption. This paper discussed the etiology, clinical features, imaging features, treatment options, and prophylaxis of condylar resorption.
Bone Resorption ; Dentofacial Deformities ; Humans ; Mandibular Condyle ; Orthognathic Surgery ; Orthognathic Surgical Procedures ; Temporomandibular Joint

OBJECTIVE: To investigate the effect of preoperative condylar condition for mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis on the stability of the jaw after orthognathic surgery and on the postoperative condylar volume changes. METHODS: In this retrospective study, from 2014 to 2019, 37 patients including 1 male and 36 female, aged between 21 to 34 years old with an average age of (28.03±6.52) years, were diagnosed with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis by Peking University School and Hospital of Stomatology and received orthognathic surgery, meeting the inclusion criteria were included. According to the preoperative condylar condition. There were divided into smooth group and non-smooth group, the lateral cephalometric films 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery were used to establish the coordinate system and cephalometric analysis to determine the stability of the jaw after operation. The three-dimensional model of the condyle was segmented by cone beam computed tomography (CBCT) 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery and the volume was obtained to evaluate the change of the condyle volume after surgery. CBCT image data was used to evaluate the changes of the condylar condition after surgery, and to clarify the correlation between the postoperative condylar condition and jaw stability. SPSS 20.0 statistical software was used for statistical analysis, Fisher's exact probability methods were used to compare whether there were statistically significant differences in the stability of the mandibular joint at stages T1, T2 and T3 with different preoperative condylar condition.Spearman correlation coefficient analysis and Mann-Whitney test were used to compare whether there were statistically significant differences in the volume changes at stages T1, T2 and T3 after surgery between the two groups. RESULTS: The recurrence rates of the mandible in the condylar smooth group were T1 36.85%, T2 47.37% and T3 42.11%, respectively. The recurrence rates in the non-smooth condylar group were T1 27.78%, T2 44.44% and T3 55.56%, respectively. There was no statistical difference in the recurrence rates between the two groups at different time points. There was no significant difference in the condylar volume change between smooth group and non-smooth group. CONCLUSION For patients with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis and no significant changes in the condyle observed for one year before surgery, there is no difference in the influence of the preoperative condylar condition on the stability of jaw after operation, and no definite influence on the volume of the condyle after operation. Condylar resorption 3 months after surgery can cause instability of the jaw after orthognathic surgery.
Adult ; Cone-Beam Computed Tomography ; Female ; Humans ; Male ; Mandible ; Mandibular Condyle ; Orthognathic Surgery ; Osteoarthritis/surgery* ; Retrospective Studies ; Temporomandibular Joint/surgery* ; Young Adult

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.
Cone-Beam Computed Tomography ; Facial Asymmetry ; Head ; Humans ; Malocclusion ; Mandibular Condyle ; Methods ; Orthognathic Surgery ; Osteotomy, Sagittal Split Ramus ; Prognathism