Background: Corticotomies have been described in order to accelerate orthodontic tooth movement, reduce adverse events and/or increase dental arch stability. Original approaches were invasive, with huge morbidity and significant patient discomfort. However, digital workflow has changed its approach. Computer-guided Piezocision™ has been sprawled as a safer minimally invasive procedure. Aims: To assess the accuracy and safety of computer-assisted PiezocisionTM comparing its deviation with freehand corticotomies, analyse the effect of location and position, and describe the manufacturing process planning. Materials and methods: An in-vitro study was made. Four resin mandible models and 52 corticotomies were performed. One investigator made the cuts using either the Computer-guided Piezocision™ system (guided group) or the conventional freehand method (freehand group). Accuracy assessment was measured by overlapping the virtual presurgical placement of the corticotomy in a Cone-Beam Computed Tomography (CBCT) and the real position in the postoperative CBCT. Descriptive and bivariate analysis of the data was made. Results: Computer-guided PiezocisionTM accuracy was higher than freehand group corticotomies in all precision variables except for depth discrepancy. However, both groups (freehand and guided) showed some degree of deviation from presurgical planning. Two incisions (7.69%) caused iatrogenic root damage, whereas in freehand 7 cuts were recorded (26.92%) (OR= 4.42; 95% CI: 0.82 to 23.8; p= 0.067). Except for guided angular discrepancy in anterior areas (MD: -6.38 mm; 95% CI: -9.95 to 2.61; p= 0.002), the outcomes were not influenced by position nor location. Conclusions: The accuracy of computer-assisted Piezocision™ is higher compared to conventional freehand technique. Thus, iatrogenic root damage is increased 4.42 times when PiezocisionTM is performed without a surgical guide. In accuracy parameters, only angular deviation was influenced by location and position. Technological improvements have led to precise surgical templates with a minimal deviation regarding virtual plan.

Treball Final de Grau d'Odontologia, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Curs: 2018-2019, Director: Octavi Camps Font