Modelling of initiation of bone remodelling due to orthodontic treatment

doctoral thesis

• Title (croatian): Modeliranje iniciranja koštane pregradnje kod ortodontske terapije
• Author: Jasna Leder Horina
• Mentor: Tanja Jurčević-Lulić (mentor)
• Mentor: Bert van Rietbergen https://orcid.org/0000-0002-2278-2934 (komentor)
• Committee member: Ivica Smojver (predsjednik povjerenstva)
• Committee member: Tanja Jurčević-Lulić (član povjerenstva)
• Committee member: Bert van Rietbergen https://orcid.org/0000-0002-2278-2934 (član povjerenstva)
• Committee member: Janoš Kodvanj (član povjerenstva)
• Committee member: Tomislav Lauc (član povjerenstva)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2015-04-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; General Mechanical Engineering (Construction)
• Universal decimal classification (UDC): 51 - Mathematics ; 611 - Anatomy ; 616.31 - Stomatology

Abstract

Goal of research is whether orthodontic bone remodelling can be predicted using load adaptive bone remodelling theories developed in orthopaedic biomechanics where strain energy density, SED, is a mechanical stimulus for the bone and it is associated with bone density changes. The hypothesis is that the tooth is “hanging” in the fibrous PDL and orthodontic loading would reduce the loading in the fibres on the side to which the tooth is pushed and increase the loading in the fibres on the other side. In the process the alveolar bone and the periodontal ligament react mechanically and biologically to the loading. The focus in research was on the mechanics and the phenomenological aspect of biology described with Finite Element Method. Chewing force represents daily loading in the mouth and referent value of stimulus. 3D model was developed from CT scans from a patient to whom orthodontic treatment was recommended and it was made in the software Mimics, which reads bone density from CT images. 3D model was imported in Marc Mentat where different orthodontic loading were analysed. Last step is the implementation of bone remodelling algorithm made in the programming language Fortran into Marc Mentat by special user subroutine. The proposed description of bone remodelling initiation is able to indicate underloading and overloading condition, which leads to bone resorption and formation mimicking biological response. The main contribution is the development of a numerical model of bone remodelling initiation which includes influence of chewing force, fibrous periodontal ligament, patient-specific geometry and putting SED as mechanical stimulus.

Abstract (croatian)

Cilj istraživanja doktorskoga rada bio je može li se ortodontska koštana pregradnja predvidjeti koristeći teorije koštane pregradnje koje se temelje na prilagodbi kosti opterećenju razvijene u ortopedskoj biomehanici, gdje je gustoća energije deformiranja mehanički stimulus za kost i povezana je s gustoćom kosti. Hipoteza je da zub "visi" u vlaknastom PDL-u te da će ortodontsko opterećenje smanjiti opterećenje u vlaknima na gurnutoj strani i povećati na suprotnoj strani. U procesu, alveolna kost i parodontni ligament reagiraju na opterećenje mehanički i biološki. Fokus istraživanja bio je na mehanici i fenomenološkim aspektima biologije opisanima pomoću metode konačnih elemenata. Žvačna sila predstavlja dnevno opterećenje u ustima te referentnu vrijednost stimulusa. 3D model razvijen je iz CT snimki pacijenta kojemu je preporučena ortodontska terapija te je napravljen u softveru Mimics, koji omogućuje očitanje gustoće kosti s CT snimaka. 3D numerička analiza napravljena je u Marc Mentatu, gdje su različita ortodontska opterećenja analizirana. Zadnji korak bila je implementacija algoritma koštane pregradnje napisanog u programskom jeziku Fortran u Marc Mentat pomoću specijalnih rutina. Predloženi opis inicijacije koštane pregradnje može predvidjeti podopterećene i preopterećene uvjete koji vode ka koštanoj resorpciji i formiranju oponašajući biološki proces. Glavni je doprinos dokorskoga rada razvoj numeričkoga modela inicijacije koštane pregradnje, koji uključuje utjecaj žvačne sile, vlaknastoga parodontnoga ligamenta, personaliziranu geometriju te postavljanje gustoće energije deformiranja kao mehaničkoga stimulusa.

• Keywords: tooth; orthodontic treatment; bone remodelling; numerical model
• Keywords (english): zubi; ortodontska terapija; koštana pregradnja; numerički model
• Language: english
• URN:NBN: urn:nbn:hr:235:367089
• Study programme: Title: Mechanical Engineering and Naval Architecture; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-04-21 07:29:14