Friction is an intensely studied feature in orthodontics, as the sliding mechanics approach remains one of the most utilized techniques in current practice, and the question of whether self-ligating brackets produce less friction than conventional brackets still stands. The objective of this study was to compare a self-ligating system with different closing mechanisms and a conventional system with different ligating mechanisms regarding their frictional properties. Laboratory measurements were performed using an advanced materials testing machine generating tensile strength and load at maximum Load values, which were statistically analyzed and compared. These two parameters have been associated with the frictional resistance generated at the archwire–bracket slot interface. Statistically significant results were obtained when comparing the active self-ligating brackets with the passive self-ligating (tensile strength mean 1.953, SD 0.4231; load at maximum moad mean 6.000, SD 1.3000) and conventional brackets (tensile strength mean 1.953, SD 0.4231; load at maximum load mean 6.000, SD 1.3000), as well as when comparing the passive self-ligating brackets with the conventional brackets (tensile strength mean 1.708, SD 0.8628; load at maximum load mean 5.254, SD 2.645). The active self-ligating brackets tended to produce more friction when compared to the passive self-ligating brackets but were similar to conventional brackets with stainless steel ligatures.

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Adhesion remains a key element in dentistry, whether approached in prosthetics, odontology, or orthodontics. It is a continuously researched aspect, as improved materials and adhesive methods keep emerging in the market. No orthodontic treatment can be effective without the proper adhesion strength of the bonded elements on the teeth. The objective of this research, in the broad context of self-ligating versus conventional brackets, was to compare active and passive self-ligating systems with a conventional one by conducting an in vitro study on human-extracted premolars. Shear bond strength tests were executed by means of an advanced materials-testing machine that generated maximum load and tensile strength values. The data obtained underwent statistical analysis with a statistical threshold of p < 0.05. The results regarding the statistical significance were acquired when comparing the passive self-ligating system with the active self-ligating and conventional systems (load-at-maximum-load mean 204.9, SD 91.09, and p < 0.05). In this study, the passive self-ligating bracket system appears to present increased shear bond strength.

Objective: The purpose of this study was to assess any existing correlations between the phonatory function obviously affected in deaf-mute patients and dento-maxillary and/or facial anomalies. Material and Methods: The study comprised 55 deaf-mute patients (28 males and 27 females) aged between 23 and 76 from 2 cities of Romania, belonging to the Hearing Deficiency Persons' Association. 13 were edentulous. Each patient was clinically and radiographically assessed. We applied computer assisted interpretetation of the profile teleradiographies using AudaxCeph and Scanora Lite 3.2.6 software for the following parameters: SNA, SNB, ANB, SN/ML, FH/ML, NL/ML, NL/+1 and ML/-1 angles, Ls-ELine, Li-ELine, UP and LP distances.The data was compared to normal values as referred to in the mentioned computer programs by using Student's t-tests and the Bland Altman plot. Results: The following characteristics were identified as being statistically different from the normal values: SN/ML with a mean of -5,5°, FH/ML by 6,2°, NL/ML with -5,2°, Ls-ELine by -4,2 mm and Li-ELine with a mean of -3,7 mm. Conclusions: Deaf-mute patients tend to present hypodivergent vertical skeletal patterns, anterior mandibular growth/rotation and skeletal deep bite and also protruded lips, aspects which must be taken into consideration when commencing an orthodontic treatment.

Objective: The purpose of this study was to establish a statistics on the contemporary use of classical mobile orthodontic appliances, anchorage means and certain procedures (functional exercises) among orthodontic specialists. Material and Methods: The present study was based on a questionary comprising 15 questions addressed to 55 postgraduate, specialist and senior orthodontists concernig the use of classical orthodontic methods. The questionary was delivered online by means of Google Forms and intermediated by the National Dentists‘ Association of Tirgu Mures, Romania. The sole inclusion criteria was the specialty of orthodontics. Results: 92,7% of the orthodontists use removable appliances (palatal plate with expansion screw), 90,9 % recommend functional exercises (correct palatal tongue placement), 89,1% exploit space maintainers, 87,3% provide lingual cribs for functional reeducation, 80% apply functional devices and the Goshgarian arch as an anchorage method, 72,2% use the Delaire mask and 69,8% the headgear and 58,2 apply the Hawley plate as a contention mean. Conclusions: A very high percentage of resident, specialist and senior doctors utilize classical removable and functional appliances and methods.