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Submitted by Maria Helena Ribeiro (helena.ribeiro@lisboa.ucp.pt) on 2021-09-22T15:29:01Z No. of bitstreams: 1 Catarina Carvalho.pdf: 1000995 bytes, checksum: 7a752bd3f8e4a4fc0baf2e26b8bdb8b8 (MD5) Made available in DSpace on 2021-09-22T15:29:01Z (GMT). No. of bitstreams: 1 Catarina Carvalho.pdf: 1000995 bytes, checksum: 7a752bd3f8e4a4fc0baf2e26b8bdb8b8 (MD5) Previous issue date: 2021-07-29

Relevance of the problem and aim of the work. Orthodontic developments, especially during the last years, have been accompanied by a significant increase in the esthetic demands of the patients. However, patients often don’t want to wear fixed appliances, which are seen while smiling or talking, has a negative effect on the periodontal health and discomfort so clear aligners are the best alternative for those patients. Unfortunately, this is a new tooth straightening technique so more and more clinical studies show signs of various degree of apical root resorption. The aim of this work is to evaluate root resorption following orthodontic treatment with aligners. Material and the methods. Articles search was carried out in two databases – Pubmed and Science Direct and also the references of the related literature were searched manually. Scientific article selection included full text publications from 2008 through 2018 in English. Systemic review protocol was executed by PRISMA requirements. The related literature was screened in 3 stages according to the inclusion criteria and exclusion criteria. Finally, 6 articles were included into meta-analysis. Results. 6 clinical studies showed that orthodontically-induced apical root resorption following treatment with aligners is statistically significant. The group of studies consisted of 453 adult healthy patients treated with aligners, all patients had a minimum of one tooth affected with a reduction of the root length. Incisors showed a consistent average apical root resorption, more than other analyzed tooth, followed by mandibular first molars. Severe root resorption occurred mostly in lower lateral incisors, about 6,86%. Conclusions. Orthodontic treatment with clear aligners leads to apical root resorption. Considering the severity of root resorption, most teeth were affected of minimal root resorption, up to 10% root length. Generally, incisors and first molars develop apical root resorption more often and more severely than other teeth.

The relevance of the problem and the aim of the work: Invisalign aligners – it is a modern orthodontic treatment system which was the first to use digital 3D teeth position modeling and manufacturing methods. Despite clear aligners system advantages it‘s a rather new technology and because of that it is uncertain if the system is capable of teeth straigthtening and occlusal correction function. The aim of this work – evaluation of clear aligners treatment effectiveness on class I orthodontic abnormalities through a systematic review. Material and methods: From a total of 5977 articles there was only 13 which complied with selection criteria - 4 prospective, 9 retrospective. 5 articles evaluated thermoplastic aligners treatment effectiveness in teeth crowding, 2 - in teeth distalization, only 1 - in treatment of deep bite, 2 – in treatment of open bite. 3 - articles evaluated predictability of orthodontic movement, 2 – evaluated orthodontic tooth movement effectiveness using clear aligners. Results: There was found one article with strong evidence, others only mediocre. When teeth crowding is 4-6mm and above treatment with Invisalign system causes slight increase of dental arch width and incisors proclination even when using IPR. When staging aligners to distalize teeth for 0,25mm per two weeks the biggest effectiveness (87%) is achieved moving upper molars. When deep bite is ≥4mm, it decreases 1,6mm on average. Treatment result morphological basis – mandibular incisors proclination and upper incisors intrusion. In treatment of moderate open bite cases, vertical incisors overlap increases by 3,3mm because of both jaws incisors extrusion and molars intrusion. The predicted result precision by ClinCheck in the mandibular: vestibulolingual tipping of canines 0,66%, canines rotation 0,54%, incisors rotation 0,67%, in maxilla mesiodistal tipping of caines, premolars, molars and molars rotation is close to 100% of predicted treatment result. Conclusion: If teeth crowding is 4mm and above non-extraction treatment with clear aligners increases incisors vestibulolingual tipping and deantl arch width even using IPR. Invisalign clear aligners efectiveness in upper molars distalization is 86,9%. Average second molar distalization distance is 2,52mm, first molar – 2,25mm. Invisalign clear aligners are effective in treatment mild and moderate deep bite cases but it causes an increase in buccolingual incisors proclination for lower jaw. Aligners are also effective in mild and moderate open bite treatment by using both jaws incisors extrusion and molars intrusion. Clinchek modelated end result treatment view will not match the final clinical treatment result.

Threatment with thermoplastic aligners is relatively new in the history of orthodontic treatment, that is why many doctors evaluate this treatment method controversially. The aim of this study is to evaluate and better understand the treatment with thermoplastic aligners method effectiveness, for this purpose the systemic review was made. The total sample of 10 scientific articles was chosen for the review, 2 of them tested thermoplastic aligners generated forces during treatment, 4 articles evaluated teeth shift during the treatment with aligners, 2 articles evaluated the accuracy of computer programs used with aligners, 2 articles compared aligners with braces. In this systemic review was found that forces generated during the treatment with clear aligners often exceed recommended orthodontic forces, during the 2-week treatment period teeth shift 0.39 - 0.74mm for overbite and 0.69 - 1.33mm for overjet. The accuracy of computer programs created post- treatment image is from 40 to 100%. Treatment with braces is more effective and lasts less than treatment with clear thermoplastic aligners.