ABSTRACT
The need for induced hypotension in orthognathic surgery was evaluated. Blood loss, duration of operation, quality of the surgical field, and surgical result were measured in 36 patients, assigned to either hypotension (mean arterial pressure, MAP, 50-64 mmHg) or normotension (MAP > or = 65 mmHg). Hypotension was achieved by increasing the amount of isoflurane given. The hypotensive group had significantly less bleeding over time (mean 0.9 ml/minute, 95% confidence interval (CI) of mean 0.6 to 1.2, compared with 1.8, 95% CI 1.3 to 2.4, p = 0.005). The corresponding difference in total blood loss did not differ significantly between the groups (mean 186 ml, 95% CI 98 to 275, compared with 304, 95% CI 210 to 399). No patient required transfusion of red cells. Neither the duration of surgery, nor the quality of the surgical field, nor the final result were significantly influenced by hypotension. The clinical relevance of induced hypotension in orthognathic surgery must be considered to be doubtful. A mean reduction of less than 150 ml will be of limited value at the low levels of blood loss reported.
Subject(s)
Blood Loss, Surgical/prevention & control , Hypotension, Controlled , Orthodontics, Corrective/methods , Adult , Female , Humans , Isoflurane/administration & dosage , MaleABSTRACT
The purpose of this investigation was to evaluate the possibility of correcting the appearance of a protruded or retruded chin through relocation of the anterior alveolar segment. Five patients with a protruded chin (group I) were treated by anterior repositioning of the alveolar segment, while five patients with a retruded chin (group II) were treated through posterior repositioning of the mandible. In the patients in group I, the convexity of the chin became less pronounced and the most anterior point of the soft tissue chin curvature (pogonion) moved superiorly. In the patients in group II, the convexity of the chin become more pronounced. The position of soft tissue pogonion was unchanged. The ratio of the segment-lip movement in both groups was close 1:1. The method is easy to perform and provides predictable results. For patients with a protruded chin, in whom reduction genioplasty often offers a poor result, the procedure described could be a method of choice.
