China
Africa
Explore chapters and articles related to this topic
Orally Induced Tolerance to Nickel: The Role of Oral Exposure (Orthodontic Devices) in Preventing Sensitization
Published in Jurij J. Hostýnek, Howard I. Maibach, Nickel and the Skin, 2019
Jurij J. Hostýnek, Katherine E. Reagan, Howard I. Maibach
Release of nickel from different types of simulated orthodontic appliances was determined in vitro by immersion in a simulated oral medium under both static and dynamic conditions by Kerosuo et al. (1995). Five identical samples, each consisting of a fixed appliance, a headgear, and a quad-helix equivalent to one half of a dental appliance were immersed in 0.9% sodium chloride for 2 h, 24 h, and 7 days. A control appliance was subjected to dynamic test conditions in a specially built “oral simulator” under similar test conditions. A significant release of nickel was detected from the quad-helix during the first 2 h in static conditions, whereas during the following two periods significantly less nickel was released from the quad helix than from the other appliances. The fixed appliance with simulated function showed a significantly higher cumulative release of nickel than the similar appliance in static conditions, 44.2 versus 17.1 μg. The results indicate certain differences in the amount and pattern of nickel release from different stainless-steel orthodontic appliances in vivo. The release rate of nickel from fixed appliances under dynamic conditions was found to be accelerated compared with nickel released under static conditions.
Removable appliances to correct anterior crossbites in the mixed dentition: a systematic review
Published in Acta Odontologica Scandinavica, 2020
When comparing the removable with the fixed appliance in the correction of an anterior crossbite with a functional shift the average duration of treatment time in the fixed appliance group was 5.5 months compared to 6.9 months in the removable appliance group. Thus, the fixed appliance saved 20% of the total treatment time. The longer treatment time in the removable appliance group may be due to the lack of patient’s compliance with the appliance wear [25], which is an essential element in the treatment protocol with a removable appliance. However, it can be argued that a difference of 1.4 months, which equates to 6 weeks period in treatment duration, between the two appliances is not clinically significant as it will add only a one to two follow-up visits by the patient. In addition, it was found that a fixed appliance was more cost-effective than a removable appliance in the correction of a crossbite when both direct and indirect costs where compared. This may be attributed to the longer treatment time in the removable appliance group which in turn requires one or 2 more appointments and to the laboratory cost of constructing the removable appliance. These findings are in accordance with a previous study which analyzed the cost-effectiveness between a quad-helix appliance and an expansion plate in the treatment of a unilateral posterior crossbite in the mixed dentition [26].
Early orthodontic treatment in a Finnish public health centre: a retrospective cross-sectional study
Published in Acta Odontologica Scandinavica, 2023
Annika Arpalahti, Anni Saarnio-Syrjäläinen, Sirkku Laaksonen, Heidi Arponen
In this retrospective cross-sectional study, we found 26.4% of children in mixed dentition phase to have undergone orthodontic treatment and an additional 4.4% were waiting for the treatment to commence. The most frequently used appliances were quad-helix and prefabricated eruption guidance appliance.
Malocclusions in primary and early mixed dentition in very preterm children
Published in Acta Odontologica Scandinavica, 2020
Elina Maaniitty, Tero Vahlberg, Petra Lüthje, Päivi Rautava, Anna-Liisa Svedström-Oristo
In primary dentition, one case child and two control children had been treated with an expanding quad helix appliance because of a posterior crossbite. In addition, one of the control children had been treated in a private dental office; information regarding this treatment was not available.