Summary Introduction In everyday clinical practice, we often encounter a lack of space for placing all the teeth present into dental arch; therefore it is often recommended to extract teeth within orthodontic treatment. In clinical practice, the most commonly used methods of closing space after are elastic chains and NiTi closed spiral springs. The aim of this paper was to compare postextraction space closure speed using two different sliding mechanisms, NiTi closed coil springs and elastic chains within treatment with fixed orthodontic appliances. Material and Method The total sample in this study consisted of 46 postexstraction spaces in 23 patients indicated for the extraction of first premolars using treatment with fixed orthodontic appliances. Two sliding mechanisms, NiTi closed coil spring and elastic chains were applied to postextraction space closure. Postextraction spaces were monitored for 4 months with appointments every 4 weeks. During appointments mechanisms were activated and digital caliper was used to measure the width of the postextraction space. Results The results showed that NiTi closed coil springs method achieved greater reduction in postexstraction space (3.94 mm) while with elastic chain method the closure of 3.10 mm was achieved. The total difference between these two methods in the observed period was 0.84mm and no statistically significant difference was found (p> 0.05). The lowest value for NiTi closed springs was 2.19 mm, while for the elastic chain it was 1.29 mm. The best postextraction space closure was 5.70 mm and it was completed using NiTi closed springs while for elastic chain the best value was 4.80 mm. Conclusion: NiTi closed coil springs lead to faster closure of postextraction spaces in relation to elastic chain. Since this difference is minimal, in practice, both methods can be used equally.

Summary Introduction Lundstrom segmental analysis is often used analysis in orthodontic diagnosis. It includes measurements of available and needed space in the arch in order to determine whether there is a lack or excess of space for proper teeth alignment. Measurements are traditionally performed on plaster study models, but with recent developments of computer-based systems, there is an increase in use of digital models in measuring process. The aim of this study was to present a photogrammetry based measurement approach that requires no specialized and expensive hardware and compare results with ones obtained on 3D scanned models. Material and method On 50 plaster study models measurements of 24 teeth, widths of 12 segments and Lundstrom segmental analysis were performed. 3D scanned study models were analyzed in the photogrammetry software Ortho-Photo4D on the set of four photographs of the study model in custom made measurement apparatus. The software corrects for finite distance of the camera and corrects errors due to perspective distortion. Results Statistical analysis performed on obtained measurements provided Bland-Altman plots that strongly suggested high degree of correspondence between the two measurements methods. Discrepancies for maxilla for individual segments were under 0.25 mm with standard deviation of up to 0.16 mm, and less than 1 mm and deviation of up to 0.4 mm for complete arch. For mandible the differences were up to 0.27 mm for segments with 0.15 mm deviation and 0.6 mm for complete arch with up to 0.24 mm deviation. Correlation coefficient was over 0.985 in all cases. Conclusions Both analyzed methods can be equally used in clinical practice.

Introduction/Objective Rapid developments in information technologies lead to the wider use of digital representations of dental study models in orthodontics. Most popular way of digitizing the models is to use a 3D scanner and then perform measurements on 3D models, which requires additional and expensive hardware and software resources. In this paper we present an alternative approach based on the use of photogrammetry in the newly developed OrthoPhoto4D software that calculates and corrects perspective distortion errors. Methods We measured individual tooth width for 24 teeth, 12 two-teeth segments as well as inter-molar and inter-canine distances on 50 models. Measurements are performed in OrthoPhoto4D software that uses four photographs of each model for measurements, uses QR codes for automation, calculates the camera position and corrects perspective distortion-caused errors in measurements. Obtained measurements are compared to ones obtained from models generated by structured light 3D scanner. Results Statistical analysis strongly indicates that there is no significant difference between the two methods. The recorded differences also have no clinical impact as they have mean values of 0.2 mm for individual tooth widths, approximately 0.2 mm for two teeth segments, and under 0.3 mm for both intercanine and inter-molar distances. All recorded differences fall within the expected measurement error. Conclusion We concluded that the described photogrammetry measurements performed in OrthoPho-to4D can be used in diagnosis and therapy planning.

Summary Introduction After the completion of treatment with fixed orthodontic appliances, it is necessary to remove the brackets and bands from teeth using an appropriate method. The aim of this study was to determine the most common way of bond failure between teeth and metal brackets, as well as to compare bond failure between the brackets and upper and lower premolars. Material and Method Metal brackets were bonded with Aspire composite material on 154 human premolars, extracted for orthodontic purposes. After debonding, the surface of remaining adhesive on the teeth and brackets was measured. Adhesive Remnant Index (ARI) was used to estimate bond failure between teeth and metal brackets. Results The average size of remaining adhesive surface after removing brackets from the upper premolars was 12.06 mm2, while it was 9.32 mm2 on the lower premolars. The average size of the remaining adhesive surface area on the brackets removed from the upper premolars was 0.37 mm2, while it was 2.08 mm2 on the brackets removed from lower premolars. A statistically significant difference was found between these values. The most common score of ARIteeth was 3 (85.71%) and the most frequent score of ARIbrackets was 0 (85.71%). Conclusion The most common way of bond failure between teeth and metal brackets was between the bracket base and adhesive surface. A statistically significant difference was found between the values of the size of residual adhesive surface on the upper and lower premolars as well as on the brackets debonded from them.

Univerzitet u Banjoj Luci, Medicinski fakultet, Studijski program stomatologija SažetakCilj ovog istraživanja je bio da se utvrdi koji su tipovi lica najčešće zastupljeni kod populacije Republike Srpske kao i kolike su prosečne vrednosti za razvijenost zubnih lukova, s obzirom na veliki značaj ovih podataka za postavljanje pravilne i precizne ortodontske dijagnoze. Takođe, ovim istraživanjem željelo se doći do odgovora postoje li i kolike su razlike u sagitalnoj i transverzalnoj razvijenosti zubnih lukova kao i tipu lica između pripadnika muškog i ženskog pola. Primjena antropometrije u stomatologiji pruža mogućnost boljeg upoznavanja i određivanja morfoloških karakteristika kraniofacijalnog sistema. Podaci dobijeni merenjem navedenih parametara su od velikog značaja za postizanje pravilne ortodontske dijagnoze. Kod 300 ispitanika sa I klasom dentoalveolarnih odnosa je određen tip lica, te su nakon uzimanja otisaka gornje i donje vilice izliveni studijski modeli na kojima su ispitivani osnovni parametri koji pokazuju sagitalnu i transverzalnu razvijenost zubnih lukova. Najčešće zastupljen tip lica je bio uski (50,33%), zatim srednji tip lica (30,67%), a najmanje je bio zastupljen široki tip lica (19%). Prosečna prednja širina gornjeg zubnog luka je iznosila 36,75 mm a donjeg 35,93 mm. Prosečna zadnja širina gornjeg zubnog luka je iznosila 46,53 mm a donjeg 46,52 mm. Za visinu gornjeg zubnog luka je utvrđena prosečna vrednost od 24,22 mm, dok je kod donjeg ona iznosila 19,32 mm. Razlike u vrednostima navedenih parametara kod ispitanika muškog i ženskog pola su se pokazale statistički značajnim.Ključne reči: antropometrija, tip lica, razvijenost zubnih lukova.