A new type of modified Essix Retainer for anterior open bite retention.

The most problematic malocclusion type to retain is anterior open bite although many classical retention appliances are known. The difficulty of maintaining the occlusion arises from the lack of control over the tongue behavior and posture in open bite cases. In the current article, a 2 year follow-up of 2 open-bite patients who were retained with a new type of retention appliance, successfully, were presented.

Roles of intrinsic and extrinsic tongue muscles in feeding: electromyographic study in pigs.

The performance of tongue muscles in various feeding behaviours is not well defined. This study was undertaken to examine the role of the intrinsic and extrinsic tongue muscles during natural drinking, food ingestion and chewing. Ten 12-week-old Yucatan miniature pigs (5 in each gender) were used.

Tongue deformation, jaw movement and muscle activity during mastication in pigs.

This study was undertaken to address the lack of information about tongue functional deformation in relation to jaw movement and muscle activity. Dimensional changes in tongue anterior and base widths, body length and base thickness were measured using six ultrasonic crystals implanted into the tongue in eight Yucatan minipigs. Jaw movements were captured on videotape and digitized, and electromyography (EMG) of tongue intrinsic (verticalis/transversus [V/T], superior and inferior longitudinalis [SL, IL]), extrinsic (genioglossus and styloglossus [GG, SG) and jaw (masseter and digastricus [MA, DI]) muscles were recorded.

Temperature rise during orthodontic bonding with various light-curing units--an in vitro study.

The purpose of this in vitro study was to investigate the temperature changes in the pulp chamber during bracket bonding using three different light sources. Bracket bonding was performed on one lower first premolar and one lower central incisor at two different distances (surface and 10 mm). The measurements were taken with a J-type thermocouple wire, placed in the pulp chamber and connected to a data logger.

Tooth-size ratio for patients requiring 4 first premolar extractions.

Introduction: The relationship between total mesiodistal widths of the maxillary and mandibular teeth is an important factor in orthodontic treatment planning. The purposes of this article are to report a mathematical tooth-size ratio specifically designed for patients needing the extraction of 4 first premolars and to compare the anterior "6" and overall "12" ratio values reported by Bolton with the calculated anterior "6" and overall "10" ratio values obtained from data in this study.

Methods: This study was conducted in 3 phases.

Asymmetric maxillary expansion (AMEX) appliance for treatment of true unilateral posterior crossbite.

The aim of this study was to evaluate the effects of an asymmetrical maxillary expansion (AMEX) appliance. Patients with true unilateral posterior crossbites were included in the study. The treatment group consisted of 18 patients who had a mean age of 14 +/- 2.