background and aims. the manufacturing process of rotary ni-ti file can influence its resistance to fracture. the rotary profile (dentsply-maillefer, baillagues, switzerland) is manufactured by grinding mechanism whereas twisted file (sybron endo, usa) is manufactured with a twisting method. the purpose of this study was to comparatively evaluate the effect of manufacturing process on distortio...

Unilateral posterior arch fractures of the atlas are discussed with two clinical examples and an experimental study of their mechanism. Laboratory fracturing of posterior arches of atlas specimens with a specially adapted universal testing machine produced nonsimultaneous fractures of the two sides in four of six specimens. In three of these specimens, a complete fracture on one side was tempor...

IMPORTANCE Classically, pterygoid plate fractures have been associated with fractures of the mid-face and skull base. When isolated pterygoid plate fractures are identified on imaging that only extends to the level of the skull base, other related facial fractures may be missed. We sought to evaluate isolated lateral pterygoid plate fractures on computed tomography (CT) scans in conjunction wit...

OBJECTIVE The mixed levator and frontalis muscles lack the interior muscle spindles normally required to induce involuntary contraction of their slow-twitch fibers. To involuntarily move the eyelid and eyebrow, voluntary contraction of the levator nonskeletal fast-twitch muscle fibers stretches the mechanoreceptors in Müller's muscle to evoke trigeminal proprioception, which then induces reflex...

Scapula fractures following low-velocity injuries are extremely rare but can be a missed associated fracture of other upper limb injuries. We describe the case of a patient who sustained a fracture of the scapula through an unusual and hitherto unreported indirect mechanism. The injury was associated with a radial head fracture and initially missed on presentation. This case highlights the need...

Patellar fracture after total knee replacement (TKR) is one of the challenging problems in periprosthetic fracture. Open reduction with internal fixation (ORIF), as tension band wiring (TBW), usually required in cases with extensor mechanism disruption. However, many studies reported a high failure rate after using this technique. In this report, we presented an interesting case of periprosthet...

Introduction: The fracture mechanisms of bone tissue have been described as a damage accumulation process, which starts with the initiation and propagation of microcracks. Knowledge of crack initiation and propagation at tissue level (tissue fracture toughness) is critical to understand and prevent bone fractures. Tissue fracture toughness could provide valuable information for defining bone qu...