Masticatory function after bite-raising with light-cured orthodontic band cement in healthy adults

Objectives:To evaluate the effects of bite-raising with light-cured orthodontic band cement, a method commonly used in contemporary orthodontic treatment, on masticatory function, as assessed by objective and subjective methods.Materials and Methods:The objective evaluation of masticatory performance and subjective evaluation of masticatory ability were performed on 30 healthy volunteers (19 females and 11 males, 22.3 ± 1.56 years) with a normal occlusion. Assessment was performed before and immediately after bite-raising. The bite-raising was done by adding light-cured orthodontic band cement (3 × 5 × 2-mm width × length × height) on the palatal cusps of the upper first molars. The masticatory performance index (MPI) was calculated from chewed test food particles using a sieving method. For the subjective evaluation, the participants performed the food intake ability (FIA) test using a questionnaire with six types of food. The correlation between the evaluation methods was determined.Results:The MPI and FIA scores of the participants were significantly reduced after bite-raising (P < .001). The MPI and FIA score reduction was not significantly different between females and males. No significant correlations were found between the changes in MPI and FIA scores.Conclusions:Masticatory function after bite-raising with light-cured orthodontic band cement was immediately reduced, both objectively and subjectively. However, because there was no significant correlation between the objective and subjective results, an individual may not perceive his/her decreased masticatory ability to the same degree as masticatory performance was reduced. Further study is required to evaluate the long-term adaptation to this bite-raising method.     

Stability of anterior open bite in permanent dentition treated using extraction or non-extraction methods: A systematic review and meta-analysis of each method

Purpose

To evaluate the literature on the stability of open bite treatment using extraction or non-extraction methods.

Differences in maturation of the jaw‐opening reflex between rats that received early‐and late‐masticatory stimulation

The jaw‐opening reflex (JOR) plays an important role in the regulation of jaw movement during mastication. Previous study showed that altered masticatory function during growth impedes JOR maturation and thus may affect masticatory performance in adults. However, no studies have compared the benefit of early and delayed correction in terms of functional development. Therefore, this study tested the hypothesis that early‐stimulation of masticatory function during growth can promote JOR maturation better than late‐stimulation during adulthood. Soon after weaning, 120 female Wistar rats were divided into two groups and fed either solid (control group) or liquid (experimental group) diets. The experimental group was further divided into early‐, late‐, and non‐stimulation subgroups. Early‐ and late‐stimulation groups were fed a solid diet instead of a liquid diet at 5‐ and 11‐week‐old, respectively, whereas non‐stimulation group was fed only a liquid diet until the end of the experiment. At 3, 5, 7, 9, 11 and 13 weeks, JOR recordings were conducted in anaesthetised rats of all groups. Latency and peak‐to‐peak amplitude of the JOR were compared between the groups. From 7 to 13 weeks, early‐stimulation group showed a JOR with short latency and high amplitude similar to that of control group. In contrast, late‐ and non‐stimulation groups showed significantly longer latency and smaller amplitude of the JOR than in control group. We demonstrated that early masticatory stimulation within the critical period for programming mastication may have greater potential to restore JOR maturation to values close to those in normal adults.