Unit:
Κατεύθυνση Ορθοδοντική (Κλινικές Ειδικεύσεις)Βιβλιοθήκη Οδοντιατρικής
Author:
Sampaziotis Dimitrios
Supervisors info:
Απόστολος Τσολάκης, Αναπληρωτής Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Κωνσταντίνος Τσιχλάκης, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας,ΕΚΠΑ
Βασιλική Μπενέτου,Αναπληρώτρια Καθηγήτρια, Τμήμα Ιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Original Title:
Σύγκριση κεφαλομετρικών γραμμικών μετρήσεων στην κάτω γνάθο επίμυων μέσω δισδιάστατης και τρισδιάστατης απεικόνισης. Αξιολόγηση αξιοπιστίας μεταξύ των τεχνικών
Translated title:
Comparison of mandibular linear measurements between 2 D and 3 D imaging techniques on rats. Evaluation of reliability for every technique.
Summary:
Introduction
Cephalometric analysis is an important part of orthodontic diagnosis. The way that the analysis is performed traditionally has some disadvantages such as the superimposition of three dimensional structures, differential magnification between right and left side (Chadwick και συν. 2009) and geometric distortion (Pittayapat και συν. 2014). These problems can be solved with the application of Cone Beam Computed Tomography (CBCT). The reduced dosage of irradiation comparing with the classic axial tomography has also contributed to the everyday usage of CBCT in clinical orthodontic practice (Pauwels et al. 2012). Via computer software there is the opportunity for three dimensional imaging of the craniofacial complex. Many clinical and ex vivo studies on human skulls evaluate the accuracy and the reliability of linear cephalometric measurements on the two dimensional and three dimensional cephalometric analysis. The term accuracy refers to the correspondence of the linear cephalometric measurement to the real anatomic distance and the term reliability is the tendency for the repeated measurements to concur (Houston 1983). Studies in the past have shown that the cephalometric analysis on the three dimensional model is more accurate than the traditional analysis in two dimensions (Pittayapat et al. 2013, 2014, Cavalcanti et al. 2004, Gribel et al. 2011, Li et al. 2016, Οlmez et al. 2011, Varghese et al. 2010, Ηilgers et al. 2005). The gold standard in all these studies is the craniometric distance on the human skull. The results for the reliability do not coincide among studies. Some studies find better reliability for the three dimensional model (Pittayapat et al. (2014), Varghese et al. (2009), some other studies for the 2D analysis (Damstra et al. 2011 , Van Vlijmen et al. 2010) while one study does not find any difference between the two cephalometric methods regarding the reliability (Gribel et al. 2011).
Experimental studies on animals have been performed in order to evaluate the skeletal changes on the craniofacial complex during natural growth or after growth modification. Rats are possibly the most common animals for these experiments. The evaluation of changes is usually done with the cephalometric analysis in two dimensions (Tsolakis et al. 1997, Watanabe et al. 2008 ,Αbbassy et al. 2008, Ρadzys et al. 2012, da Silva et al. 2009). However, there is not any animal study to use Cone Beam Computed Tomography for the evaluation of skeletal changes. In addition, there is not any study to evaluate the accuracy of the cephalometric measurements and their reliability in comparison with another cephalompetric method. As the traditional cehalometric analysis has the disadvantages that mentioned above, a study that compares the most common 2D cephalometric measurements with the corresponding 3 D measurements from CBCT will be of prominent interest, because the 3D measurements are closer to the anatomic measurements, as mentioned above. In addition the evaluation of difference regarding the reliability between the two methods is also important. In rats, the identification of the cephalometric point of condyle is very difficult as the bone on this area is very thin and there is superimposition of hard and soft tissues.
The purpose of this study is to compare six common linear cephalometric measurements on mandible of rats on the 3 D model constructed from CBCT and on the 2D model from the lateral cephalometric xray. To compare the reliability between methods as well.
Main subject category:
Health Sciences
Keywords:
Cephalometrics, CBCT, Rats
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