A FEA-Based Methodology to Predict the Osteotome Wear Status during Nasal Bone Surgical Operations

Abstract

A FEA-based methodology was developed in order to predict the wear status of an osteotome (surgical instrument) during its use in a lateral nasal bone osteotomy considering its fatigue strength. The latter parameter was determined by appropriate FEM-evaluation of the perpendicular impact test results. For the simulation of the surgical procedure, two scenarios were examined: (i) when utilizing a brand new osteotome and (ii) when utilizing an already used osteotome characterized by decreased fatigue strength. The actual nasal bone geometry used in the FEA model was obtained from a high-resolution, maxillofacial, computed tomography (CT) scan of a single patient. In both cases examined, depiction of fracture patterns for the osteotome and the nasal bone were obtained. The wear of a new osteotome and an already used osteotome was also calculated and compared. The developed von Mises stresses in both the osteotome and nasal bone were depicted. The proposed methodology allowed an accurate prediction of the critical number of impacts that the osteotome can receive during the lateral nasal osteotomy which is followed in all rhinoplasties. Based on the developed methodology, a preventive replacement of the osteotome before its extensive fracture can be determined, thereby minimizing the risk of postoperative complications.

Effect of the crystallinity of NCD and MLD diamond coatings characterized by same level of residual stresses after annealing on their fatigue strength and wear behavior in milling

“…The fatigue strength of the NCD and MLD coated cemented-carbide inserts was investigated by conducting inclined impact tests at temperatures of 25 o C and 300 o C [4]. The impact tester device was designed and manufactured by the Laboratory for Machine Tools and Manufacturing Engineering of the Aristotle University of Thessaloniki in conjunction with the company Impact-BZ (see figure 1a) (London, UK) [9,10]. The Raman spectroscopy on the untreated as well as treated diamond coatings was carried out using a LabRAM HR spectrometer.…”

Fatigue Strength and Wear Behavior of NCD and MLD Diamond Coatings Characterized by Different Level of Residual Stresses after Annealing

“…The impact tester device was designed and manufactured by the company Impact-BZ (London, UK) in conjunction with the Laboratory for Machine Tools and Manufacturing Engineering of the Aristotle University of Thessaloniki (see Fig. 1a) [10,11]. The milling investigations were conducted employing a three-axis numericallycontrolled milling center using aluminum foam as workpiece material.…”