Maxillary Sinus Volume and Its Effect on Treated Impacted Canines.

The goal of study was to explore the role of 3D CBCT (cone beam computer tomography) in detecting impacted canines and their movement to evaluate the influence of orthodontic therapy parameters on treatment options, and to monitor quality of healing process based on shape and size of sinus maxillae volume. It is known that the volume of maxillary sinus plays an important role in patients with impacted teeth. The prospective study consisted of 26 individuals. For each individual, pre-treatment and post-treatment CBCT data were acquired. Changes of size, and position of impacted canine in 3D CBCT image before and after therapy were prepared using 3D reconstruction. Volumetric measurements of the maxillary sinuses were performed before and after orthodontic therapy of impacted canines, using InVivo6 software. The main effects MANOVA performed on linear measurements showed metric differences between pre-op and post-op images. A paired t-test showed no statistically significant differences between pre-op and post-op values of the sinus volume. Changes of size and position of impacted canine in 3D image before and after therapy were precise and reproducible, using 3D reconstruction in three planes - horizontal, midsagittal, and coronal. The linear measurements showed metric differences between pre-op and post-op images.

Improving lip aesthetics in the face profile after treatment of class II, division 2 malocclusion.

AIM: The aims of our research were as follows: 1) Description of changes in the position of the upper and lower lips, as a result of the change in the position of upper and lower incisors after orthodontic treatment of malocclusion of Class II, division 2 type. 2) Determination of correlation between changes in the position of lips and incisors in the profile of the face after orthodontic treatment of malocclusion of Class II, division 2 type.MATERIALS AND METHODS: Our study analyses the documentation of 115 patients with malocclusion of Class II, division 2 type treated with a fixed orthodontic appliance in the upper and lower dental arches at the Orthodontic Department of the Clinic of Dentistry in Olomouc from January 1, 1996 to December 31, 2017. There were 78 women and 37 men aged 11 to 36 years included in the database. Cephalometric images of patients from the group taken before and after the treatment were used for the purpose of cephalometric analysis according to Kamínek (1) and Burstone's analysis (2) of soft tissues. Subsequently, all output data were processed statistically. RESULTS: While the protrusion of the incisors after treatment of malocclusion of Class II, division 2 type was 3 mm, the facial profile showed statistically significant changes in soft tissues in the ventral direction by 1 mm on average just in the area of the upper and lower lips, which means a shift corresponding to one third of teeth movement. CONCLUSION: A statistically significant change in the position of incisors, soft tissues as well as correlation between changes in hard and soft tissues in the face profile after orthodontic treatment of malocclusion of Class II, division 2 type were demonstrated. The more the incisors were inclined, the more the lips moved forward, and the patient's profile turned out to be aesthetically improved (Tab. 2, Fig. 3, Ref. 39).

A tensomeric and planimetric evaluation of the durability of the bond between an orthodontic bracket and enamel.

The development of orthodontics has improved thanks to the introduction of adhesives which are physically and chemically akin to tooth enamel and brackets. These materials often fall short of the required durability standards. The objective was to evaluate the real strength of the adhesives and to introduce a proprietary device, generating multiple vectors of strength between dental brackets and the surface of enamel. 11 types of adhesive materials have been studied. 990 applications have been made using removed teeth, followed by a randomised creation of 11 groups containing 90 samples each. The threshold values of the strength needed to break the brackets off were determined in torsional, shear and tension strength tests. A comparison between tensometric and planimetric methods was made by means based on ARI index. Resistance was highest for torsional stress, weaker for shear stress and the weakest for tension stress. A correlation was found between tensometric results. The study attempted to systematise the methodology of direct tests.

Effectiveness of treatment of adult patients with the straightwire technique and the lingual two-dimensional appliance.

The aim of this prospective study was to compare the outcome of orthodontic therapy using two different therapeutic strategies: the labial straightwire (SW) technique and the lingual two-dimensional (2D) technique on the lower dental arch. The sample included 50 subjects (39 females and 11 males) with a complete dentition and an Angle Class I malocclusion with crowding who were treated non-extraction. The subjects were divided into two groups: group A, consisted of 25 patients (19 females and 6 males), who were treated with the lingual 2D technique, and group B, 25 patients (20 females and 5 males) treated using the labial SW appliance (Roth system). Changes in the position of the lower incisors to the A-Po and mandibular lines were measured on cephalograms and those in the transverse and sagittal planes on individual sectors of the dental arch from 2D images of model casts obtained before and after the active phase of orthodontic treatment. Standard statistical methods were used for evaluation. Both methods (when used with appropriate indications) showed comparable results. The lingual 2D technique also represents an aesthetically favourable solution for adult patients.