Orthodontic correction of acquired open bite with TMJ degeneration: A retrospective study of outcomes and stability.

BACKGROUND/PURPOSE: Newly developed temporary anchorage devices (TADs) serve a strong orthodontic anchorage to intrude molars for correction of anterior open bite (AOB). We measured cephalometric changes in skeletal open bite patients which developed subsequently to temporomandibular joint disorders with bilateral point contacts at terminal molars. METHODS: We retrospectively recruited 32 patients who had been treated their TMD before orthodontic correction (overbite: -3.14 ± 1.86 mm). Partial orthodontic appliances were used to intrude posterior teeth using TADs until positive OB obtained (T1). Full fixed appliances were then used to achieve proper overjet and overbite (T2). We collected lateral cephalograms before (T0), during (T1) and after (T2) treatment, and at follow-ups (T3). Using ANOVA, we analyzed the differences among these time points to determine treatment changes and stability of orthodontic results. RESULTS: In this group predominantly comprising young adult women, orthodontic treatment with TADs significantly reduced upper posterior dental heights (T2-T0:-1.84 ± 0.66 mm) and facilitated the retraction and uprighting upper incisors (T2-T0: -9.92 ± 1.72°), to achieve appropriate OJ (T2-T0: -3.21 ± 0.49 mm) and OB (T2-T0: 4.10 ± 0.28 mm) with p < 0.05. Except upper posterior dental height, most of cephalometric changes including OJ, OB, and upper incisal axis remained significant at follow-ups with retention time of 3.7 ± 2.6 years. Only three out of 30 patients experienced small amount of open bite at T3. CONCLUSION: Orthodontic correction of OJ remained relatively stable among 90 % of patients with TMJ degeneration by intrusion via TADs. This modern but conservative orthodontic approach can improve occlusal functions in skeletal open bites.

An unusual extraction pattern for retreatment in a patient with dental protrusion and a deficient soft-tissue chin.

A patient with dental protrusion and deficient soft-tissue chin, previously treated with maxillary first premolar extraction, sought retreatment to improve his facial profile. Orthognathic surgery was proposed as the ideal treatment option, but the patient declined. Therefore, other orthodontic options were considered. The combined intrusion and retraction force systems supported with skeletal anchorage on both arches and a midpalatal miniscrew successfully reduced the protrusion and rotated the mandible counterclockwise to improve the facial profile and chin projection. Sagittal correction enhanced by active vertical control with skeletal anchorage and de-wedging with posterior extraction was illustrated. In addition, advancement genioplasty was performed after orthodontic treatment to improve the chin projection further. The mechanics and results of this retreatment case were discussed.

Torque control of maxillary anterior teeth with the double J retractor and palatal miniscrews during en masse retraction.

A double J retractor (DJR) and palatal miniscrews were used to retract maxillary anterior teeth after failure of buccal posterior miniscrews. The line of action passing through the center of resistance of the maxillary anterior teeth and the moment generated by the palatal miniscrews via torquing springs successfully controlled the overbite and incisor torque during space closure. The DJR and palatal miniscrews work well with labial fixed appliances to address bimaxillary protrusion.

An interdisciplinary approach to orthodontic treatment of a mutilated Class III malocclusion with mini-implants, dental implants, and an autotransplant.

This case report demonstrates the interdisciplinary treatment of a 24-year-old female. Her skeletal discrepancy, anterior crossbite, mutilated dentition, and midline deviation made it challenging to achieve satisfactory treatment results, especially without major orthognathic surgery. This article thoroughly discusses the decision-making process associated with various treatment alternatives, the biomechanical considerations with temporary skeletal anchorage devices, and the detailed operational process of dental implant restoration and autotransplantation. CLINICAL SIGNIFICANCE: Orthodontic treatment aims to obtain better facial and dental esthetics, achieve functional occlusion, and improve oral health. Treatment of patients with a mutilated dentition requires interdisciplinary teamwork from a group of professionals with various types of expertise. Orthodontists should be the navigator that generates the tooth movement and space redistribution, thus facilitating the subsequent functional rehabilitation under a well-organized occlusal architecture. Autotransplantation offers an economical and biologically-friendly opportunity to replace a missing tooth.

Telmisartan Loaded Nanofibers Enhance Re-Endothelialization and Inhibit Neointimal Hyperplasia.

Stent implantation impairs local endothelial function and may be associated with subsequent adverse cardiovascular events. Telmisartan, an angiotensin II receptor blocker that has unique peroxisome proliferator-activated-receptor-gamma-mediated effects on cardiovascular disease, has been shown to enhance endothelial function and limit neointimal hyperplasia. This study utilized hybrid biodegradable/stent nanofibers to facilitate sustained and local delivery of telmisartan to injured arterial vessels. Telmisartan and poly(d,l)-lactide-co-glycolide (PLGA) (75:25) were dissolved in hexafluoroisopropyl alcohol and electrospun into biodegradable nanofibrous tubes which were coated onto metal stents. By releasing 20% of the loaded telmisartan in 30 days, these hybrid biodegradable/stent telmisartan-loaded nanofibers increased the migration of endothelial progenitor cells in vitro, promoted endothelialization, and reduced intimal hyperplasia. As such, this work provides insights into the use of PLGA nanofibers for treating patients with an increased risk of stent restenosis.

Interdisciplinary rehabilitation for mutilated dentition with mini-implants, autotransplants, and a dental implant.

A patient with mutilated dentition was treated to an acceptable result with the help of mini-implants for anchorage, autotransplantation of 2 teeth, one dental implant, and multiple prostheses. The major problems for this mutilated dentition were multiple missing teeth, bite collapse with posterior crossbites, deepbite with a canted gummy smile, and severe skeletal discrepancy of maxillary protrusion and mandibular retrusion. Mini-implant anchorage was applied to retract and intrude the maxillary arch to reduce the protrusion and rotate the mandible counterclockwise to improve the chin projection. Two autotransplantations, one dental implant, and multiple prostheses were used to accomplish a satisfactory full mouth rehabilitation with an interdisciplinary approach, including orthodontics, periodontics, endodontics, prosthodontics, and implantology. The understanding of biological principles, improvement in surgical protocol makes it possible to preserve the periodontal ligament (PDL) cells with atraumatic extraction after loosening the donor with orthodontic force and reduce the extraoral time with the 3-dimensional print-out replica segmented from cone-beam computed tomography for trying fitness. Soft wire splinting to gain initial stabilization and root canal treatment to avoid endotoxin further reduce the risk of root resorption, loss of attachment, and ankylosis. Autotransplantation could be considered as a part of full mouth rehabilitation. Orthodontic space management is also an important procedure to confirm the site of dental implant installation in the interdisciplinary collaboration.

Airway increase after open bite closure with temporary anchorage devices for intrusion of the upper posteriors: Evidence from 2D cephalometric measurements and 3D magnetic resonance imaging.

OBJECTIVE: The aim of this study was to analyse morphological changes in the upper airways in patients with anterior open bite treated with temporary anchorage devices for intrusion of upper posterior teeth. MATERIALS AND METHODS: Twelve nonobese (body mass index: <25) anterior open bite patients between the ages of 19 and 44 years (mean age: 22.83 ± 8.19 years) were recruited for this study. Cephalometric radiographs and magnetic resonance imaging (MRI) scans before and after anterior bite closure without bracketing on anterior teeth were used to measure the upper airway, which was divided into retropalatal and retroglossal regions. RESULTS: The mandibular plane angle and lower facial height were significantly reduced by intrusion of the upper posteriors and autorotation of the mandible. The retroglossal airway width (AW2) and retroglossal area (RG area) measured on cephalometric radiographs both increased significantly after treatment. Retroglossal volume increased and the retroglossal width/length ratio decreased significantly in MRI analysis. All other measurements were not significantly changed. However, no statistically significant correlations were observed between all measurements in 2D and 3D images, with the exception of the AW2 linear measurement in 2D images correlating with the AP length in MRI axial view images (r = 0.56, P = 0.0430). CONCLUSION: Counterclockwise rotation of the mandible after anterior open bite closed using orthodontic treatment changed the airway morphology. Retroglossal volume significantly increased and the airway shape became less elliptical after bite closure.