Digital Dynamic 3D Monitoring of Lower Incisors Intrusion in Lingual Orthodontics
Elia Kodjo Chardey1, Rosamaria Fastuca2, *, Matteo Beretta1, Alberto Di Blasio3, Nicolò Vercellini1, Alberto Caprioglio4, Piero Antonio Zecca5, Aldo Macchi1
1 Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy
2 Department of Biomedical Sciences, Dentistry and Morphological and Functional Imaging, University of Messina, Messina, Italy
3 Department of Biotechnological, Biomedical and Translational Sciences, Section of Orthodontics, University of Parma, Parma, Italy
4 Department of Medicine and Surgery, University of Insubria, Varese, Italy
5 Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
The aim of the present study is to propose a 3-dimensional evaluation of lower intrusion obtained with lingual orthodontics considering not only the crowns but also dental roots.
9 adult patients underwent fixed lingual orthodontic treatment with i-TTя lingual brackets system for the correction of crowding in the lower arch associated with a deep overbite. Initial records, consisting of photos, CBCTs and intraoral scans were collected. Threshold segmentation of the CBCT was performed to generate a three-dimensional virtual model of each the teeth of the lower arch, superimposed with the crown of the same teeth obtained by intraoral scan models to generate a complete set of digital composite lower arch The same procedure was performed to monitor one key step of the i-TTЯ technique consisting in lower incisors intrusion (T2). T1-T2 three-dimensional superimposition and color displacement maps were generated to measure and evaluate the movements obtained at the lower arch.
The root displacement of the incisors during their intrusion in the early stage was totally “bone-safe” in the 88.9% (8 of 9) of the cases observed. No significant extrusion of the premolars used as anchorage unit was measured.
This method has proved to be an accurate and reliable approach to dynamically visualize the 3-dimensional positions of the teeth, including their roots, with no additional radiation for in-progress treatment monitoring. The 3-dimensional evaluation showed that the employed lingual appliance allowed to obtain significant lower incisors intrusion with negligible undesired extrusion of premolars employed as anchorage teeth.
Keywords: Lower intrusion, Root position, Lingual orthodontics, Digital setup, 3D imaging, Deepbite, Anterior crowding.
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* Address correspondence to this author at Department of Biomedical Sciences, Dentistry and Morphological and Functional Imaging, University of Messina, via G. Piatti 10, 21100, Varese, Italy, Tel: +39 380 3546218; E-mail: email@example.com