Effects of patient- and operation-related factors on postoperative pain after orthognathic surgery.

PURPOSE: This study aimed to assess the association between patient- and operation-related factors and postoperative pain in patients undergoing intraoral vertical ramus osteotomy (IVRO) or IVRO + genioplasty (GeP) for the treatment of mandibular prognathism. MATERIALS AND METHODS: A visual analog scale (VAS) was used to evaluate postoperative pain for 2 days in 63 patients who underwent orthognathic surgery (42 IVRO and 21 IVRO + GeP). Correlations between VAS and patient age, sex, blood loss, operation time, and intraoperative reduction in blood parameters were assessed and compared between IVRO and IVRO + GeP procedures. RESULTS: Mean operation time and blood loss were 252.02 minutes and 99.64 mL in the IVRO group and 317.62 minutes and 187.86 mL in the IVRO + GeP group, respectively. Operation time, blood loss, and postoperative reduction in blood parameters were significantly greater in the IVRO + GeP group than in the IVRO group. Mean VAS scores on the first and second postoperative days were 3.02 and 1.33 in the IVRO group and 2.95 and 1.14 in the IVRO + GeP group. However, postoperative pain did not differ significantly between the IVRO and IVRO + GeP groups on the first or second postoperative day. CONCLUSIONS: Postoperative pain associated with orthognathic surgery was acceptable, controllable, and not different between IVRO and IVRO + GeP procedures.

Assessment of the related factors of blood loss and blood ingredients among patients under hypotensive anesthesia in orthognathic surgery.

OBJECTIVE: The objective of the study was to understand the factors associated with presurgical and postsurgical blood loss and blood ingredients among patients in the treatment of mandibular prognathism by intraoral vertical ramus osteotomy combined genioplasty. METHODS: Preoperative and postoperative values of blood loss and blood ingredients were collected from 30 mandibular prognathic patients who underwent orthognathic surgery. The linear regression models and correlation coefficients were used to identify factors with respect to patients' blood loss level and 3 types of blood ingredients (ie, red blood cells, hemoglobin, and hematocrit). RESULTS: The mean blood loss and operation time were 179.2 mL and 311.7 minutes, respectively. No blood transfusion was received by our patients. After adjusting for potential factors, the regression models showed that no significant factor was found to be associated with blood loss and reduce blood ingredients. Moreover, female patients were found to be more likely to have a low level of presurgical blood ingredients (ß = -0.293 to -3.551; P < 0.05), whereas female sex (ß = -1.606 to -4.008; P < 0.001), a high blood loss level (ß = -0.003 to -0.009; P < 0.05), and long operation time (ß = -0.005 to -0.018; P < 0.05) were associated with a low level of postsurgical blood ingredients (ie, hemoglobin and hematocrit). CONCLUSIONS: No significant factor was associated with blood loss and reduced blood ingredients among patients in orthognathic surgery with hypotenstive anesthesia. Improvements in anesthesia provided surgeons with more time to promote hemostasis during surgery. Hypotensive anesthesia was a well-accepted method to reduce blood loss during orthognathic surgery.

Changes in the transverse dimensions by vertical ramus osteotomy after mandibular prognathism correction.

OBJECTIVE: A harmonious face displays not only a good lateral profile but also a pleasant frontal appearance. The purpose of the current study was to evaluate the changes in the transverse dimensions by vertical ramus osteotomy (VRO) in the treatment of mandibular prognathism correction. METHODS: Twenty patients who underwent mandibular prognathism correction by VRO were included. Lateral and frontal cephalometric radiographs were obtained at the following stages: preoperative (T1), immediately after the surgery (T2), and completion of orthodontic treatment (T3). Three linear measurements (menton, intercondylion, and intergonial distances) and the ramus angle were compared from T1 to T3. RESULTS: A final mean menton setback of 12.2 mm and upward movement of 0.3 mm were noted. The intercondylion and intergonial distances significantly increased by 5.1 and 7.1 mm, respectively. Without significant difference, ramus angles decreased 1.7 degrees in the right side and 0.1 degrees in the left side. CONCLUSION: The surgical correction of mandibular prognathism using VRO led to an increase in the transverse dimensions.

Correlation between the change of gonial region and skeletal relapse after intraoral vertical ramus osteotomy for correction of mandibular prognathism.

BACKGROUND: The gonial region is coincided with harmonious face and masticatory function. The aims of the present study were to assess changes in the gonial region in patients who had mandibular setback surgery by intraoral vertical ramus osteotomy (IVRO) and to investigate the contributing factors in relation to skeletal relapse. METHODS: Twenty-one patients with mandibular prognathism were corrected by IVRO. Three cephalometric radiographs were collected from preoperative orthodontic treatment (T1), immediately after surgery (T2), and at 2-year postoperative follow-up (T3). Relapse was defined as forward movement of menton (Me) after the 2-year follow-up. Three angular (SN-Go angle, mandibular plane angle, and gonial angle) and 2 linear (horizontal-Me and vertical-Me) measurements were compared after immediate operation and at the 2-year follow-up. Spearman rank correlation and Student t tests were used for statistical analysis. RESULTS: The mean setback of the Me was 12.7 mm, and the mean relapse was 1.5 mm. The magnitude of setback was not significant for relapse. There were weak correlations between relapse and factors concerned with the gonial region (SN-Go angle, mandibular plane angle, and gonial angle). CONCLUSIONS: Surgical correction of mandibular prognathism using IVRO can lead to an increase in the angle changes of gonial region but not correlate to skeletal relapse in long-term follow-up.

The stability of intraoral vertical ramus osteotomy and factors related to skeletal relapse.

BACKGROUND: Intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO) have been advocated as two major procedures for the correction of mandibular prognathism. However, only a few reports with at least a 2-year follow-up period describe the long-term stability especially of the IVRO method. This study aimed to identify factors contributing to skeletal relapse after a 2-year postoperative follow-up period. METHODS: A set of three standardized lateral cephalograms were obtained from each subject, taken preoperatively (T1), immediately postoperatively (T2), and 2 years postoperatively (T3). Relapse was defined as forward movement of the menton (Me) after a 2-year follow-up period. Two angular measurements (SNB and SN-occlusal plane angle) and five linear measurements (horizontal Me, vertical Me, overbite, anterior facial height, and mandibular length) were compared immediately after the operation and at the 2-year follow-up visit. RESULTS: The mean setback of the menton was 12.8 mm, and the mean relapse was 1.3 mm (10.2% = 1.3/12.8). The magnitude of the setback was not significantly accounted for in the relapse. There were weak correlations between the relapse and the concerned factors, namely, overbite, anterior facial height, mandibular length SNB, and SN-occlusal plane angle). CONCLUSION: The current study confirmed the stability of IVRO in the treatment of mandibular prognathism.

Skeletal changes after modified intraoral vertical ramus osteotomy for correction of mandibular prognathism.

BACKGROUND: Orthognathic surgery is widely used to correct congenital and acquired dentofacial discrepancies. Various surgical procedures have been advocated for correction of mandibular prognathism. In this study, a modified intraoral vertical ramus osteotomy has been developed for surgical correction of mandibular prognathism. The aim of this study is to identify contributing factors to skeletal change by analysing cephalometric changes after modified intraoral vertical ramus osteotomy. METHODS: Forty-one patients, treated for absolute mandibular prognathism by bilateral modified intraoral vertical ramus osteotomy, were evaluated cephalometrically with reference to the menton point. A set of four standardised lateral cephalograms were obtained from each subject preoperatively (T1) and immediately postoperatively (T2), prior to removal of maxillomandibular fixation (T3), and at 1-year postoperatively (T4). The mean setback of the menton was 12.4 mm in the horizontal direction. Relapse was defined as forward movement of the menton during the 1-year follow-up. RESULTS: The highly significant backward movements in a horizontal direction were observed during the maxillomandibular fixation period (T3-T2). Moreover, highly significant forward movement was observed following the maxillomandibular fixation period (T4-T3). After 1-year follow-up (T4-T2), the mean changes of the menton were 0.1 mm backward in the horizontal direction. CONCLUSIONS: In this series, the mean skeletal change compared with the amount of setback was less than 1% (0.1/12.4 mm) in backward movement. The results suggest that the modified intraoral vertical ramus osteotomy technique is useful and the more stable approach for correction of severe mandibular prognathism.