Locoregional Anesthesia of the V3 and Limited Mouth Opening

Trismus is an involuntary contracture of the masticatory muscles, blocking the opening of the jaw, first intermittent then permanent and irreducible. Trismus is the result of pain or spasm or even muscle fibrosis, due to infectious, inflammatory or tumoral involvement of the masticatory muscles.

During any anesthesia, control of the patient's upper airways is a major issue. Orotracheal intubation is the gold standard. Trismus will therefore complicate this management of the airways. This trismus can prevent the realization of a classic intubation, by the inability to use a laryngoscope or video laryngoscope, in favor of awake fiberoptic intubation, a technique that causes discomfort during the procedure, then a state of post-traumatic stress.

Mandibular block is increasingly used in the analgesia of mandibular surgeries thanks to the simplicity of the technique and its good efficiency. It has been described that the mandibular locoregional anesthesia made it possible to remove the trismus due to a dental infection, allowing the realization of a surgical gesture under good conditions. In addition, authors have described V3 block as a technique that could improve the safety of anesthesia in patients with acute trismus, by avoiding the need for awake nasofibroscopy intubation. One study showed that performing locoregional anesthesia of the mandibular nerve improved the mouth opening in patients with mandibular fracture. The investigators wondered if this locoregional anesthesia could also work on other types of trismus such as infectious, tumoral and osteoradionecrosis trismus.

During preoperative consultation, anesthesists usually measure the mouth opening. In our study, anesthesists will also measure the mouth opening after performing locoregional anesthesia of the V3 nerve (mandibular block). In addition to the measurement made before the start of the anesthetic treatment, research provides for three other measurements of the mouth opening using a rule (millimeters), taken at different times : after sedation, after performing locoregional anesthesia and after curarization. The investigators will also collect the cause of the limited mouth opening, the duration of development. The investigators will study pain at rest and when opening the mouth, under sedation, when performing the block, then when opening the mouth after performing the block. The presence of edema next to the area of locoregional anesthesia, the type of product used for sedation and locoregional anesthesia, the intubation technique performed, as well as the difficulty experienced by the operator will be collected