Oral appliance–generated malocclusion traits during the long-term management of obstructive sleep apnea in adults:

ABSTRACT Objectives To identify malocclusion characteristics generated after using oral appliances (OAs) for at least 5 years for the management of snoring and obstructive sleep apnea (OSA) in adults. Materials and Methods PubMed, MEDLINE (Ovid), Scopus, CINAHL, and Informit were searched without language restrictions through January 20, 2021. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and the Pro-Quest Dissertation Abstracts and Thesis database. Authors were contacted when necessary, and reference lists of the included studies were screened. Risk of bias was assessed through the revised Cochrane Risk of Bias tool for randomized controlled trials (RoB2) and Non-Randomized Studies of Interventions for non-RCTs and uncontrolled before–after studies (ROBINS-I). A random-effects meta-analysis was conducted only on studies that used the same OAs to exclude biomechanical differences. Risk of bias across studies was assessed with the Grading of Recommendations, Assessment, Development and Evaluation tool. Results A total of 12 studies were included in the final qualitative synthesis. Eight included studies had high, one had moderate, and three had low risks of bias. Significant progressive decreases of overjet (OJ; −1.43 mm; 95% confidence interval [CI], −1.66 to −1.20) and overbite (OB; −1.94 mm; 95% CI, −2.14 to −1.74) associated with maxillary incisor retroclination and mandibular incisor proclination were reported long term. Although most studies showed no sagittal skeletal changes, some degree of vertical skeletal changes were noted. Conclusions Based on a very low evidence level, inevitable anterior teeth positional changes seem to be a common long-term adverse effect of OAs. The magnitude of those changes could be considered clinically irrelevant for most pretreatment occlusions, but in occlusions with limited OJ and OB, it may be worth clinical consideration.

Changes in Hard and Soft Tissue During the First 6 Months After Immediate Implant Placement and Provisionalization of a Single Anterior Maxillary Incisor: A Prospective Cohort Study

Background: To evaluate changes in hard and soft tissue during the first 6 months after immediate implant placement and provisionalization (IIPP) of a single maxillary incisor.Methods: Failed maxillary incisors were replaced with IIP implants in 34 patients. Intraoral scans and cone beam computed tomography (CBCT) were performed before and 6 months after IIPP. Changes in soft tissue thickness, soft tissue contour, and hard tissue contour were measured by a three-dimensional superimposition method. The correlations of hard and soft tissue contour changes were assessed.Results: A total of 31 patients completed the study. Soft tissue contour tended to collapse after 6 months. Soft tissue was significantly thickened 1–3 mm below the gingival margin. Correlation analysis showed strong correlations between the hard and soft tissue contour changes at 0–5 mm apical to the implant platform. The mid-facial recession at 6 months was −0.46 ± 0.55 mm.Conclusions: Soft tissue contour collapsed after tooth extraction, regardless of IIPP. Both soft and hard tissue change affected the soft tissue contour change.

Difference in the Alveolar Bone Remodeling Between the Adolescents and Adults During Upper Incisor Retraction: a Retrospective Study

Background: The purpose of this study was to compare the difference of alveolar bone remodeling between the adolescents and adults in the maxillary incisor area during retraction. Methods: This retrospective study included 72 female patients who needed moderate anchorage to correct the bimaxillary protrusion. Subjects were further divided into the minor group (n=36, 11-16 years old) and adult group (n=36, 18-35 years old). Digital lateral cephalography and cone beam CT scanning were taken in each patient before (T0) and after treatment (T1). Cephalometry was conducted to assess incisor retraction, while alveolar bone thickness (ABT), alveolar bone distance (ABD, and alveolar bone area (ABA) were detected to assess changes in the alveolar bone. Results: No difference in the inclination of upper incisors was observed at both T0 and T1. Changes in the alveolar bone showed a similar tendency with bone apposition on the labial side and resorption on the palatal side. Less increase in the labial ABT (T1-T0) and more decrease in the palatal ABT (T1-T0) was found in the adult group, leading to less total ABT in the adult group. Higher reduction inn ABD (T1-T0) was found in the adult group. Moreover, more decrease in the ABA (T1-T0) was found in the adult group. Conclusion: When compared adolescents, adult patients have less alveolar bone support after orthodontic treatment, showing a through-the-bone remodeling pattern. Orthodontic should take the age into consideration to reduce the potential periodontal risks during treatment planning.

Evaluation of the Effect of Various Antioxidants on the Shear Bond Strength of the Composite Resin to the Bleached Enamel: An In Vitro study

Objective Various intrinsic and extrinsic stains cause discolored teeth, which is of great concern to patients, which can be treated by bleaching, enamel microabrasion, veneers, and crowns. However, bleaching leads to reduced bond strength if adhesive restorations are performed immediately.Thus, the application of antioxidant agents after bleaching has been recommended, which are proved to act as free radical scavengers, improving the bond strength. Materials and Methods A total of 120 extracted human maxillary incisor teeth were taken. Using a slow-speed diamond saw and a water coolant spray, the roots of all the teeth were removed approximately 2 mm below the cementoenamel junction. With the labial surface facing upward, each sectioned sample was embedded in the acrylic resin. Then, the central portion of the embedded tooth was ground flattened with 600-grit silicon carbide paper such that the labial enamel surface becomes smooth and evenly flat.All 120 samples were divided into two control groups (n = 20), i.e., positive control group (n = 10) and negative control group (n = 10) and five experimental groups (n = 100), such that each experimental group had 20 samples.The enamel surface in both the control groups and groups treated with antioxidants was thoroughly rinsed off with distilled water for 30 seconds and subjected to bonding procedure. Result Significant differences were observed among the experimental groups (p < 0.05). The samples that were treated with 10% sodium ascorbate (group III) demonstrated significantly higher mean shear bond strength than the other experimental groups (p < 0.05).

The Expression of MMP-2 on the Pressure Side During Tooth Movement

Objectives: To explore the effects of matrix metalloproteinase-2 (MMP-2) on the development of orthodontic root resorption in rats and to provide a theoretical basis for prevention and treatment of root resorption in clinical diagnosis.Methods: Thirty-five 6-8-week-old male SD rats were randomly divided into 7 groups, each with 5 rats weighing approximately 200 g±20 g. An orthodontic traction device was applied between the right first molar and the maxillary incisor in the experimental rats, and a mesial tractive force of 60 g was applied. Five rats were used for the control group without orthodontic applications. After 0, 1, 3, 5, 7, 14, and 21 days, the maxillae were abducted, and immunohistochemical analysis was performed. We used hematoxylin eosin staining to observe root resorption. The expression of MMP-2 was also assessed by immunohistochemical staining. SPSS17.0 statistical software was used to process the data.Results: Forcing 3 d was observed in the formation of bone resorption lacunae, which were confined to the cementum. After that, it becomes more serious. The most serious damage in 7 days. In 14 d, root absorption was relieved, and osteogenic cells aggregated at the root absorption site. Root resorption lacuna visible dentin repair phenomenon. With the extension of the force application time, the expression of MMP-2 was raised gradually, reached the peak at 7 d, and then gradually declined, 21d tends to be stable, but still stronger than controls.Conclusion: MMP-2 is involved in the metabolism of extracellular matrix in the process of root absorption.

ANTERIOR MAXILLARY IMMEDIATE IMPLANT AFTER EXTRACTION WITH CLOSE LOADING TEMPORARY CROWN

Immediate implant placement after extraction is a dental implant treatment procedure reported in several case studies with satisfactory results for patients and less crestal bone loss around the implant. This case report describes the method of immediate implant placement after extraction. It directs temporary crown placement in a female patient with failed post-endodontic treatment restoration on the maxillary incisor. The procedure was performed under local anesthesia, preceded by tooth extraction and socket cleaning post-extraction, followed by the implant and bone grafting procedure, then finalized by provisionalization. The immediate implant procedure is a simple and time-saving technique. No second surgery is required, such as delayed implant procedure, but the operator's good analytical, diagnostic, and planning skills in its implementation.