Unilateral Condylar Hyperplasia: Is Reactivation After a Long Latency Period of Inactivity Plausible?

Unilateral condylar hyperplasia (UCH) is characterized by an overgrowth of the mandibular condyle responsible for a facial and dental asymmetry associated with temporomandibular joint function and maxillary growth consequences. The diagnosis is based on a body of clinical, radiological and histological arguments. A 38 years old woman with a reactivation of UCH after a latency period of 16 years following an orthognathic surgery performed for facial asymmetry normalization is presented. She was addressed to our department for a facial progressive asymmetry relapse and dental prosthetic consequences.The radiological images and the planar scintigraphy combined with single-photon emission computed tomography scans showed an active left unilateral condylar hyperplasia. A left proportional condylectomy was performed.The case presented highlights the possibility for the UCH to be reactivated after a long period of latency, leading to a relapse of the occlusal and facial disorders and so advocates the need for first condylectomy or at least a long-term follow-up if condylectomy is not performed as a first-line treatment.

Release and toxicity of bisphenol-A (BPA) contained in orthodontic adhesives: A systematic review.

OBJECTIVE: The objectives of this systematic review of the literature are to search for BPA release from biomaterials used in orthodontics and to highlight their possible impact on human health. MATERIALS AND METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model, digital and manual searches were conducted in February 2020 in the database of CENTRAL, MEDLINE and EMBASE. Thirteen parameters relating to the release and biological effects of BPA were identified and analysed. RESULTS: Thirty-one non-randomized clinical trials were included. In general, the level of evidence was low, and the risk of bias ranged from moderate to high. Furthermore, although at different concentrations, most of in vitro and in vivo studies found BPA release from orthodontic adhesives. The lack of standardized protocols and the clinical and methodological heterogeneity of the studies prevented a valid interpretation of the actual results. Concerning the possible toxicity of BPA, no conclusive scientific evidence could be drawn, but it seems that orthodontic biomaterials containing BPA have potential adverse biological effects in humans. DISCUSSION AND CONCLUSION: Until we have solid evidence from clinical trials, clinicians should consider that orthodontic adhesives containing BPA have potential short- and long-term adverse biological effects in humans. Careful consideration should therefore be given to bonding, polymerization and debonding protocols in orthodontics.

Determination of irritant threshold concentrations to weeds, trees and grasses through serial dilutions in intradermal testing on healthy clinically nonallergic dogs.

Irritant threshold concentration (ITC) for intradermal testing (IDT) was determined in 31 healthy, clinically nonallergic dogs. Twenty-three allergens were tested at five variable concentrations ranging from 1000 to 8000 PNU/mL. To distinguish irritant reactions from subclinical IgE-mediated hypersensitivities, serum allergy testing was performed. ITCs were determined by evaluating the lowest concentration to which no dogs (0% cut-off) and to which at least 10% of dogs (> or = 10% cut-off) reacted. ITCs at the 0% cut-off were: 1000 PNU/mL (Johnson grass), 2000 PNU/mL (Ash, Lamb's Quarter and Bermuda), 3000 PNU/mL (Bahia, Rye, Pig Weed and Virginia Oak), 4000 PNU/mL (Marsh Elder and Maple), 5000 PNU/mL (Sorrel sheep) and 7000 PNU/mL (Cocklebur and Black Willow). ITC for Dog Fennel, Box Elder and Red Cedar was <1000 PNU/mL. ITCs at the > or = 10% cut-off were: 2500 PNU/mL (Johnson), 3000 PNU/mL (Box Elder), 5000 PNU/mL (Bahia), 6000 PNU/mL (Pigweed and Marsh Elder) and 8000 PNU/mL (Virginia Oak and Black Willow). For all other allergens, the ITC was >8000 PNU/mL and could not be determined. No significant agreement between positive values was found for the same allergen on IDT and serum allergy testing for each dog suggesting reactions caused by the determined ITCs are less likely subclinical IgE-mediated reactions. These results suggest that ITCs may vary, also they may be very high for the allergens tested and that higher test concentrations may be used for IDT for the tested allergens without inducing an irritant reaction. Further studies are needed to evaluate the benefit of higher IDT concentrations in atopic dogs.

Implementation of orthodontic extraction for pre-implant soft tissue management: A systematic review.

OBJECTIVE: This systematic review aims to define the recommendations allowing an optimized clinical implementation for orthodontic extraction as a pre-implant soft tissue management procedure. MATERIALS AND METHODS: A digital search was performed in the Cochrane Library, PubMed, Scopus, and DOSS databases; a pre-screening was conducted according to the title and summary of the articles. After a complete reading, only the articles meeting all of our inclusion criteria were selected, and a second search, this time manual, was performed within their references. The selected articles were then analysed according to twelve parameters. RESULTS: Thirty-nine articles were included. Despite low statistical evidence in the available literature, some principal guidelines, which seem generally accepted by the scientific community, could be highlighted based on this analysis. However, no ideal clinical protocol could be established. CONCLUSIONS: Orthodontic extraction is an efficient procedure for pre-implant soft tissue management, however, further studies are needed to establish full clinical recommendations and optimize its clinical implementation.