RESUMEN
PURPOSE: The aim of the present study was to investigate the volumetric and 2-dimensional (2D) changes in the pharyngeal airway space (PAS) after bimaxillary orthognathic surgery (maxillary advancement and mandibular set back) in patients with skeletal Class III deformities. PATIENTS AND METHODS: In the present retrospective study, patients with skeletal Class III deformities were treated at Pusan National University Hospital (Busan, South Korea) and had undergone cone-beam computed tomography examination preoperatively, immediately postoperatively, 6.0 ± 0.6 months postoperatively, and 6.2 ± 1.3 years postoperatively. The anteroposterior length (APL), largest transverse width (LTW), and cross-sectional area (CSA) at 4 reference planes and the PAS volume were measured. Spearman's correlation analysis was used to assess the correlation between the PAS changes and skeletal movements. RESULTS: The subjects included 11 men and 12 women. Their mean age was 22.7 ± 4.7 years (range, 18 to 33 years). The APL and CSA on the PNS-Vp, CV1, and CV2 planes, the LTW on the CV1 plane, and the oropharyngeal and total volume had decreased at 6 months postoperatively. However, thereafter, no significant 2D or volumetric changes were observed until 6.2 years postoperatively. The long-term change of the LTW on the CV3 plane correlated negatively with mandibular relapse. CONCLUSIONS: The volume and morphology of the 6-month postoperative changes in PAS were stable at 6 years for patients who had undergone maxillary advancement and mandibular setback.
Asunto(s)
Maloclusión de Angle Clase III , Cirugía Ortognática , Procedimientos Quirúrgicos Ortognáticos , Adolescente , Adulto , Cefalometría , Tomografía Computarizada de Haz Cónico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/cirugía , Faringe/diagnóstico por imagen , República de Corea , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVES: To assess the root proximity and the insertion angles of miniscrews after miniscrew placement at a variety of maxillary and mandibular buccal sites using cone-beam computed tomography (CBCT) and to determine the differences in root proximity between CBCT and panoramic radiography (PR). MATERIALS AND METHODS: This retrospective study included 50 patients (mean age, 22.0 ± 4.5 years) who underwent postoperative CBCT and PR after miniscrew placements for intermaxillary fixation in orthognathic surgery. Twelve miniscrews were placed in the buccal bone of each patient: at sites between the central incisor and lateral incisor (SII), sites between the canine and first premolar (SCP), and sites between the second premolar and first molar (SPM) on the right and left sides of the mandible and maxilla. The insertion angles were measured on CBCT, and the root proximity was assessed on CBCT and PR. RESULTS: The mean vertical placement angles ranged from 84.27° to 95.12°, and the mean horizontal placement angles ranged from 90.93° to 101.1°. The rates of no contact between the root and the miniscrew were 68.0% in the SII, 50.5% in the SCP, and 57.8% in the SPM, which were significantly different (P = .000). The total concordance rate between PR and CBCT was 41.3%. CONCLUSIONS: Clinicians should use extreme caution during placement of miniscrews in the SCP. There are limitations on the use of PR for evaluating the root proximity of miniscrews.