Three-dimensional soft tissue changes after reduction malarplasty in female patients.

The aim of this study was to determine the three-dimensional soft tissue changes after reduction malarplasty. Soft tissue changes relative to the amount of movement of the zygomatic bone were studied. Pre- and postoperative cone beam computed tomography images of 21 female patients were superimposed. The anterior-most point of the body osteotomy (point A), arch osteotomy site (point D), and points dividing line A-D into thirds (points B and C) were marked on lateral view images. The vertical distances from the midsagittal line to the centre of the zygomatic bone and the outer prominence of the soft tissue were measured on the coronal view of each image. The proportion of the change in soft tissue to that of the bone before and after surgery was calculated for each point. The relationship between body mass index and the soft tissue change ratio, and the differences in soft tissue changes at each point were analysed. Mean soft tissue changes for points A, B, C, and D were 53.43%, 66.66%, 63.67%, and 57.23%, respectively. The amount of soft tissue change at point B was greater than that at points A and D, which were osteotomy sites. There was no statistical correlation between body mass index and the soft tissue change ratio at each point.

A three-dimensional planned osteotomy on the zygomatic arch for reduction malarplasty.

During a reduction malarplasty, precise sectioning of the zygomatic arch according to the plan formulated in the diagnostic stage is very important, because differences in the locations of the osteotomies in the left and right zygomatic arch will result in facial asymmetry, and arch osteotomies that are placed at locations other than those specified during planning elicit unwanted results. A method for the precise planning and sectioning of the zygomatic arch involving the use of computed tomography (CT) and a viewer program is presented herein. Furthermore, a case in which this method was applied during reduction malarplasty via a combined intraoral and external incision is described.

Prevalence and risk factors of tooth discolouration after orthognathic surgery: a retrospective study of 1455 patients.

This study was conducted to evaluate the prevalence of tooth discolouration and to examine the factors that may pose a higher risk for tooth discolouration after orthognathic surgery. This was a retrospective study of 1455 orthognathic surgeries. The following data were collected for analysis: presence of discoloured teeth, sex, age at operation, the extent of the surgical displacement of the maxilla, and whether patients had undergone genioplasty, zygomaplasty, or descending palatine artery (DPA) ligation. Out of 1339 patients who underwent double-jaw surgery, 49 received root canal treatment due to tooth discolouration. No tooth discolouration was found in the 116 patients undergoing single-jaw surgery. DPA ligation, genioplasty, and mandibular sub-apical osteotomy were associated with a significant risk of tooth discolouration. Patients should be informed preoperatively of the possibility of tooth discolouration. Additionally, the DPA should be preserved during Le Fort I osteotomy to reduce the risk of tooth discolouration.

Emergence agitation after orthognathic surgery: a randomised controlled comparison between sevoflurane and desflurane.

BACKGROUND: This study aimed to compare emergence agitation following sevoflurane and desflurane anaesthesia in adults undergoing orthognathic surgery. The hypothesis was that there might be a difference in the incidence of emergence agitation following sevoflurane and desflurane anaesthesia considering the difference in blood solubility and speed of recovery between the two. METHODS: In this prospective randomised double-blind study, 144 adults undergoing orthognathic surgery were randomly allocated to either sevoflurane or desflurane anaesthesia. The incidence of emergence agitation and possible causative factors were then compared between the groups. RESULTS: The incidence of emergence agitation was lower in the desflurane group than in the sevoflurane group (24% vs. 71%, P < 0.001). In addition, the time intervals between the discontinuation of anaesthetics and the first response, extubation, and discharge from post-anaesthesia care unit were significantly shorter in the desflurane group (P = 0.002, P < 0.001 and P = 0.003, respectively). The other variables were similar in the two groups. CONCLUSIONS: In adults undergoing orthognathic surgery, desflurane anaesthesia was associated with less emergence agitation than was sevoflurane anaesthesia.