RESUMEN
Objective: To investigate the arthroscopic temporomandibular joint disc reduction on the outcome of orthodontic patients with anterior disc displacement without reduction. Methods: From January 2012 to December 2021, forty treated orthodontic patients with anterior disc displacement without reduction (unilateral/bilateral) and no obvious articular cartilage absorption were selected from Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The patients were (17.5±3.8) years old (12-25 years old), including 8 males and 32 females. Twenty patients who had completed arthroscopic temporomandibular joint disc reduction were included in the control group, and twenty patients with untreated temporomandibular joint disc were included in the experimental group. Model measurement (including overjet, etc.), cephalometric analysis (including ANB angle, which was formed by subspinale, nasion and supramental, etc.) and temporomandibular joint magnetic resonance imaging (including measurement of the condyle height of the displacement sides) were used to compare the difference of two groups. Objective grading system was used to evaluate the efficacy of orthodontic treatment. Results: The overjet of the experimental group and the control group after orthodontic treatment was (2.19±0.76) and (1.92±0.94) mm, respectively. Both two groups achieved ideal overjet with no statistical difference (t=1.02, P=0.314). The ANB angle difference before and after treatment in the control group (-1.97°±2.87°) was greater than that in the experimental group (0.09°±1.82°), and the difference was statistically significant (t=2.72, P=0.010). The variation of condyle height before and after treatment was (0.30±1.11) mm in the experimental group and (0.82±1.25) mm in the control group, with no statistical significance (t=1.80, P=0.076). The post-treatment objective grading system scores of the experimental group and the control group were 21.00 (16.00, 24.00) and 21.00 (17.00, 25.00), respectively, which had no statistical difference (U=0.24, P=0.808). Conclusions: In orthodontic patients with anterior disc displacement without reduction and no obvious articular cartilage absorption, whether displaced discs are repositioned after arthroscopic surgery has no significant effect on the orthodontic treatment outcome.
Asunto(s)
Luxaciones Articulares , Sobremordida , Trastornos de la Articulación Temporomandibular , Masculino , Femenino , Humanos , Adolescente , Adulto Joven , Adulto , Niño , Disco de la Articulación Temporomandibular/cirugía , Disco de la Articulación Temporomandibular/patología , Trastornos de la Articulación Temporomandibular/cirugía , Luxaciones Articulares/cirugía , China , Articulación Temporomandibular/patología , Imagen por Resonancia Magnética/métodos , Cóndilo MandibularRESUMEN
Objective: To investgate the effect of Herbst appliance on the growth and remodeling of the temporomandibular joint (TMJ) in class â ¡ patients with mandibular retrusion by using MRI. Methods: Between December 2010 and October 2014, 12 class â ¡ patients (11-16 years old) with mandibular retrusion were chosen. The patients were divided into two groups. The control group included 7 patients (14 joints) with normal disc condyle relationship and the anterior disc displacement (ADD) group included 5 patients (10 joints) with anterior disc displacement. The MRI images of TMJ were measured, including condylar height, joint space index and disc position ratio, before and after the treatment. Results: The condylar height of the patients in the control group was significantly increased (P<0.001) after treatment, and no significant difference in joint space index (P=0.821) and disc position ratio (P=0.146) was found. The joint space index of the patients ([-14.70±8.82]% and [4.90±11.35]%) in ADD group changed significantly (P<0.001) after treatment, and no significant difference in condylar height (P=0.294) and disc position ratio (P=0.120) was found. Conclusions: The normal disc condyle relationship was beneficial to the reconstruction of the condylar process, and the increase of the condylar height. The condyle moved forward in patients with anterior disc displacement after treatment.
Asunto(s)
Remodelación Ósea , Imagen por Resonancia Magnética , Maloclusión Clase II de Angle/terapia , Aparatos Ortodóncicos Funcionales , Retrognatismo/terapia , Disco de la Articulación Temporomandibular/lesiones , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Maloclusión Clase II de Angle/diagnóstico por imagen , Cóndilo Mandibular/diagnóstico por imagen , Retrognatismo/diagnóstico por imagen , Articulación Temporomandibular/diagnóstico por imagen , Disco de la Articulación Temporomandibular/crecimiento & desarrolloRESUMEN
The purpose of this study was to clarify the correlation between pre-treatment anterior disc displacement and mandibular stability after orthognathic and orthodontic treatment among patients with a skeletal class II malocclusion and without pre-treatment condylar resorption. Thirty-seven patients were included (7 male, 30 female). The mean length of follow-up was 6.76±3.06 years. Patients with condylar resorption before treatment were excluded. Magnetic resonance images and lateral cephalometric radiographs were taken before treatment (T0), after treatment (T1), and at follow-up (T2). Patients were classified according to the degree of disc displacement: -10-10° 'normal', 11-50° 'slight to mild', ≥51° 'moderate to severe'. Results showed the condyle moved posterosuperiorly after treatment, and then moved anteriorly to a more concentric location during the long follow-up period. Condylar movement was found not to correlate with disc displacement. The degree of disc displacement before treatment did not correlate with the post-surgical mandibular positional change in either the sagittal or vertical direction. To conclude, the mandibular bilateral sagittal split ramus osteotomy was stable in the long-term after orthognathic and orthodontic treatment. In the absence of pre-treatment condylar resorption, the degree of initial anterior disc displacement did not have a significant influence on the stability of mandibular advancement.