Rocuronium Induced Masseter Muscle Rigidity during Intubation in Patients with Dental Surgery / 계명의대학술지

Masseter muscle rigidity (MMR), known as the ‘jaw of steel’, sometimes makes laryngoscope unusable due to the stiffness of the jaw. MMR during general anesthesia was previously considered as an early episode of malignant hyperthermia (MH). Generally, MMR occurs in the pediatric patients after induction with succinylcholine and volatile agents. However, MMR following the administration of non-depolarizing muscle relaxants is uncommon, although described in some reports. We report a case of 62-year-old male patient which developed MMR following intravenous administration of rocuronium during induction of anesthesia. Our patient was not found to be vulnerable to MH. Although fiberoptic nasotracheal intubation had been successfully performed in our case, an unanticipated difficult airway due to MMR can be experienced at any time. Therefore, we should be aware that, although rare, MMR can occur after using non-depolarizing muscle relaxant. Additionally, in case of any incident of MMR, anesthesiologists need to recognize the management of a difficult airway and to maintain adequate oxygenation in a variety of methods according to a difficult airway algorithm.

Rocuronium Induced Masseter Muscle Rigidity during Intubation in Patients with Dental Surgery / 계명의대학술지

Masseter muscle rigidity (MMR), known as the ‘jaw of steel’, sometimes makes laryngoscope unusable due to the stiffness of the jaw. MMR during general anesthesia was previously considered as an early episode of malignant hyperthermia (MH). Generally, MMR occurs in the pediatric patients after induction with succinylcholine and volatile agents. However, MMR following the administration of non-depolarizing muscle relaxants is uncommon, although described in some reports. We report a case of 62-year-old male patient which developed MMR following intravenous administration of rocuronium during induction of anesthesia. Our patient was not found to be vulnerable to MH. Although fiberoptic nasotracheal intubation had been successfully performed in our case, an unanticipated difficult airway due to MMR can be experienced at any time. Therefore, we should be aware that, although rare, MMR can occur after using non-depolarizing muscle relaxant. Additionally, in case of any incident of MMR, anesthesiologists need to recognize the management of a difficult airway and to maintain adequate oxygenation in a variety of methods according to a difficult airway algorithm.

In vitro evaluation methods on adaptation of fixed dental prosthesis

Clinically, the fit of fixed prosthesis is an essential element for successful restoration. The fit of prosthesis is largely classified into marginal fit and internal fit, and various methods to assess these have been introduced including microscopic margin measurement, cross-sectional measurement, silicone replica technique, 3-dimensional scanning data superposition, weight technique and micro CT scanning. Thus, this study is aimed at proposing a more convenient and accurate measurement method of fits in a digital environment by comparatively analyzing the advantages and disadvantages of each known method based on existing literature.