Double-jaw Surgery Research Articles

Effects of a Single-Dose of Pre-Emptive Pregabalin on Postoperative Pain and Opioid Consumption After Double-Jaw Surgery: A Randomized Controlled Trial

The effect of a single-dose of pre-emptive pregabalin is still unknown, although it is used as an adjuvant in controlling acute postoperative pain. The purpose of this study was to evaluate the effects of pre-emptive single-dose pregabalin on postoperative acute pain and 24-hour opioid consumption in patients who underwent double-jaw surgery. Forty patients (18 to 45 yr old; American Society of Anesthesiologists status I to II) for whom elective double-jaw surgery was planned under general anesthesia were included in this study, which had been planned as a prospective, randomized, and double-blinded study. Patients were randomly divided into 2 groups: the pregabalin group (n = 20) was given pregabalin 150 mg orally 1 hour before general anesthesia and the placebo group (n = 20) was given an oral placebo capsule. The groups were administered the routine general anesthesia protocol. Postoperative analgesia was performed intravenously in the 2 groups twice a day with dexketoprofen trometamol 50 mg and patient-controlled analgesia with fentanyl. Postoperative analgesia was evaluated using the visual analog scale (VAS). Fentanyl consumption, additional analgesia requirement, and side-effects were recorded during the first 24 hours after surgery. Descriptive and bivariate statistics were computed, and significance was set at a P value less than .05. Compared with placebo, the VAS score was statistically lower in the pregabalin group during the early postoperative period (P < .05). The 24-hour opioid consumption was significantly higher in the placebo group compared with the pregabalin group (509.40 ± 261.56 vs. 260.10 ± 246.53 μq, respectively; P = .004). In addition, the analgesia requirement was statistically lower in the pregabalin group (P < .05). Nausea or vomiting was observed more often in the placebo group, whereas other side-effects were similar for the 2 groups. A single 150-mg dose of pre-emptive pregabalin decreased postoperative opioid consumption in the first 24 hours after double-jaw surgery. Multimodal analgesia techniques that contain pre-emptive analgesia can be used successfully in preventing postoperative pain caused by orthognathic surgery.

Keyhole System: A Computer-Assisted Designed and Computer-Assisted Manufactured Maxillomandibular Complex Repositioner in Orthognathic Surgery

Currently, virtual orthognathic surgery using the CAD/CAM program and three-dimensional printing technology has provided a valuable tool supporting accurate surgical planning and precise surgery. However, despite the advancements in CAD/CAM virtual surgical planning, accurately reproducing surgical planning from a virtual surgery to the operating field is still challenging. Here, we report the Keyhole system as a method that has constantly provided us with consistent results during double-jaw surgery, especially during this age of ever increasing aesthetic demand from patients.

Soft Tissue Evaluation After Bimaxillary Orthognathic Surgery with 3D Cone Beam Computed Tomography Sumperimposition: Preliminary results

Facial soft tissues may change after skeletal movements in orthognathic surgery. The proportion between hard and soft tissues changes was constantly discussed, especially in two-dimensional analysis of the facial profile with lateral cephalograms superimposition. Recently, with the introduction of the cone beam computed tomography (CBCT), a new era of three-dimensional (3D) analysis has arised. However, these studies are frequently associated with a variety of different software’s which demands several file format conversions and computers with high processing capacity. The purpose of this study was to evaluate and compare the differences and correlation between hard and soft tissues after skeletal movements in skeletal Class III subjects who underwent double-jaw surgery. Preoperative (T0) and 6-months postoperative (T1) DICOM images of Cone Beam CT (CBCT) scans were superimposed using Ondemand3D (CyberMed, Seoul, Korea) and after assessed three dimensionally usingDolphin3D (Dolphin Imaging &Management Solutions, Chatsworth, Calif). These were CBCTs of a sample of 10 non-consecutive skeletal Class III subjects. Skeletal movements were recorded at Point A and Point B. Eight soft tissue points in the median sagittal plane and others 38 soft tissue points in parasagittal planes in the middle and lower thirds of the face were evaluated. Significance of differences between the time intervals and significance of correlation existing between these points were assessed. Proportions between hard and-soft tissues in the median sagittal plane were similar to those reported in twodimensional studies. This ratio decreased topoints further from the midline. Correlation between hard and soft tissues in the mandible was greater than in the maxilla. Similarly, correlations only between soft tissues, an aspect that has rarely been discussed in published articles, presented a greater correlation in the mandible. Results were similar to those found in studies on single-jaw surgery for both the maxilla and the mandible. The absence of the need to convert file formats between different computer programs allows surgeons to use the analysis presented to evaluate their cases in their clinical routine using userfriendly programs.

Maxillary Posterior Segmentation Using an Oscillating Saw in Le Fort I Posterior or Superior Movement Without Pterygomaxillary Separation

Any remaining tuberosity or pterygoid plate frequently interferes with posterior or superior movement of the maxilla, if no pterygomaxillary separation is performed in low-level Le Fort I osteotomy. The objective of this report is to describe a technique for maxillary posterior segmentation using an oscillating saw in Le Fort I posterior or superior movement without pterygomaxillary separation and to present the authors' preliminary multicenter experience with this technique. The authors retrospectively evaluated patients who underwent double-jaw surgery at 3 orthognathic surgery centers from May 2010 to December 2012. In all cases, the segmentation procedure was performed using an oscillating saw on a posterior or tuberosity area of the maxilla before downfracture obtained by leverage alone without pterygomaxillary separation, below or near the lower part of the pterygoid plate. In total, 1,231 patients (411 male and 820 female; mean age, 24.9 yr) were enrolled. Mean surgical time for the maxillary procedure was 55.9 minutes. None of the patients received a blood transfusion, and no significant soft or hard tissue complications clinically compromised the healing of the repositioned maxilla. Mean maxillary posterior and superior movements were 3.4 mm (range, 2.1 to 5.6 mm) and 4.0 mm (range, 1.3 to 5.6 mm), respectively. The preliminary results indicate that this maxillary posterior segmentation procedure using an oscillating saw in low-level stepped Le Fort I osteotomy can be completed safely and effectively for posterior or superior repositioning of the maxilla, with no need to disturb the integrity of the pterygoid plate.

Continuous Noninvasive Hemoglobin Measurement Is Useful in Patients Undergoing Double-Jaw Surgery

Continuous measurement of hemoglobin by pulse CO-oximetry (SpHb; Masimo Radical 7 device, Masimo Corp, Irvine, CA) may be helpful during double-jaw surgery when massive hemorrhage is anticipated. Given the possible influence of low blood pressure on the detection of hemoglobin levels, the agreement of the SpHb was evaluated in patients undergoing orthognathic surgery when using hypotensive anesthesia. Patients who underwent elective Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSO) were enrolled in this observational prospective cohort study. SpHb was compared with time-matched arterial total hemoglobin (tHb) before incision, at Le Fort I osteotomy, at BSSO, and at skin closure. The correlation between simultaneous SpHb and tHb measurement pairs was evaluated. Agreement was assessed by a comparison of SpHb with tHb using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. The average age of 51 patients was 23 ± 5 years and 32 patients were male. The correlations of SpHb and tHb measurements were 0.72, 0.85, 0.89, and 0.78 before incision, at Le Fort I osteotomy, at BSSO, and at closure, respectively. Bland-Altman analysis for SpHb and tHb showed respective bias values of 0.12, 0.07, -0.09, and -0.90 g/dL. ICC values between SpHb and tHb were 0.82, 0.90, 0.91, and 0.87, respectively. Continuous monitoring of hemoglobin may help to determine the appropriate time to perform an invasive measurement of hemoglobin in patients who undergo double-jaw surgery.

Accurate Movement of Jaw Segment in Virtual 3D Orthognathic Surgery

In traditional virtual 3D orthognathic surgery, after repositioning the maxillary segment to the desired position, surgeons usually roughly rotate or adjust the mandibular segment to obtain a relatively good relationship with maxillary dentition to calculate the virtual terminal occlusion splint. However, surgeons are not easy to avoid penetrability, overlap, or an overly large space existing between the maxillary and mandibular dentitions during this process. The present report offered a new method to obtain a suitable virtual terminal occlusal splint that could avoid penetrability, overlap, or an overly large space between the maxillary and mandibular dentitions, and simultaneously accurately moving the maxillary or mandibular segment to the desired position utilizing the planned terminal occlusion plaster models in virtual orthognathic surgery. For double jaw surgery, after aligning the planned plaster models to the 3D maxilla and mandible, we could simultaneously move the maxillary and mandibular segment as a whole that maintain the planned terminal occlusion to the desired position. This present method may enhance the accuracy of 3D virtual orthognathic surgery and save plenty of time spend on virtual surgery simulation, which also offers a useful educational method for training junior surgeons and students.

上下顎移動術における下顎近位骨片復位法の違いによる下顎頭の位置再現性の評価

Recently, double-jaw surgery is increasing in orthognathic surgery. In such double-jaw surgery, it is important to keep the condylar position at the preoperative position during surgery. Various condylar positioning devices (CPDs) have been reported to obtain stable skeletal and occlusal results. In this study, we investigated the availability of two methods (one step and two steps techniques) for condylar positioning. The subjects were 17 mandibular prognathic patients who underwent double-jaw surgery by a single operator. These 17 patients were divided into the one step technique group (n = 9) and the two steps technique group (n = 8) by the difference of methods for repositioning the mandibular proximal segment. In both groups, ramus inclination and ramus angulation were examined pre- and postoperatively using lateral and posteroanterior cephalograms. Pre- to postoperative changes of these angles were stable in both groups. Statistical analysis revealed no significant difference between the two groups. These results suggest that application of our two CPDs is useful in mandibular prognathic cases undergoing double-jaw surgery. In addition, our CPDs can standardize the procedure of orthognathic surgery without depending on the experience of surgeons.

Orthosurgical Management of a Severe Class III Malocclusion

Success in the management of a skeletal Class III malocclusion depends on proper diagnosis and treatment planning. In adults with a severe discrepancy, combined orthosurgical approach is the only way to achieve acceptable results. This case report describes the orthosurgical management of an adult male patient with a severe Class III malocclusion displaying a combination of maxillary deficiency and mandibular excess. The patient had a reverse overjet of 5 mm and an open bite of 7 mm. Incisal display both at rest as well as on smiling was decreased and he presented with a wide buccal corridor. A combination of Arnett’s clinical and cephalometric examination was used to diagnose and plan treatment for facial changes. Double jaw surgery including a 4 mm maxillary advancement and 4 mm rotation of the palatal plane downward anteriorly with a 6 mm mandibular setback was planned. The palatal plane was rotated downward to aid in closure of the open bite thereby taking care of the decreased incisal show. Ideal overjet, overbite, satisfactory facial balance and stomato gnathic function could be achieved because of a com­ bined orthosurgical approach.

Condylar Positional Changes Up to 12 Months After Bimaxillary Surgery for Skeletal Class III Malocclusions

Postsurgical changes in the condylar position are of great importance to surgical stability, especially in asymmetric double-jaw surgery. The aims of this study were to evaluate positional changes of the condyle up to 12 months after surgery in patients with Class III malocclusion and to identify the factors affecting postsurgical condylar position. The study included 33 adult patients diagnosed with skeletal Class III malocclusion who underwent bimaxillary surgery and had full cone-beam volumetric imaging (CBVI) records up to 1 year after surgery. The CBV images were obtained before surgery and 2 weeks, 3 months (T2), 6 months (T3), and 12 months after surgery. Condyles with deviated and nondeviated sides were examined separately regardless of the degree of asymmetry. Analyses of variance and multiple regression analysis were performed to identify factors that could affect the position of the mandibular condyles. The condyles exhibited anterior displacement at T2, which returned to a more distal position afterward in the axial view, and an inward rotation in the coronal view up to T3. From the sagittal view, the deviated and nondeviated condylar sides rotated forward and remained stable after T2. The degree of menton deviation affected the angle of condylar rotation (horizontal angle). The results of this study suggest that condyles tend to move in a certain direction, and this can influence postsurgical relapse up to 6 months after surgery. However, they remain relatively stable afterward.

Soft and hard tissue changes in skeletal Class III patients treated with double-jaw orthognathic surgery—maxillary advancement and mandibular setback

The soft tissues of the facial profile may change after skeletal movement in orthognathic surgery. The aim of this study was to evaluate and compare the differences and correlation between hard and soft tissues after double-jaw surgery in skeletal Class III subjects. Radiographs from the following time points were assessed using Dolphin Imaging software: preoperative (T0), 2–4 months postoperative (T1), and 6–12 months postoperative (T2). Eleven hard and soft tissue points of the facial profile were evaluated. The Student's t-test was used to assess the significance of differences between the time intervals; Pearson's correlation coefficient was used to assess the significance of correlation existing between these points; significance was set at P<0.05. In the sample of 58 subjects, the correlation between hard and soft tissues in the mandible was greater than in the maxilla. Similarly, the correlations only between hard tissues and only between soft tissues presented a greater correlation in the mandible. The results are similar to those found in studies on single-jaw surgery for both the maxilla and the mandible. The influence of movements in hard tissues was restricted to the soft tissues of the same jaw, although there were exceptions.

Treatment of anterior open bite and multiple missing teeth with lingual fixed appliances, double jaw surgery, and dental implants

The treatment of adult patients with severe anterior open bite frequently requires orthognathic surgery, especially when the chin is retruded severely. If a patient has multiple missing posterior teeth, it is difficult to control the occlusal plane because it is challenging to obtain anchorage during orthodontic treatment. We report on a 25-year-old woman who had a skeletal Class II malocclusion, severe anterior open bite, vertical maxillary asymmetry, and severe dental caries on her molars. There was no posterior occlusal contact between the maxillary and mandibular molars since 5 of her molars had to be extracted because of severe caries. Lingual fixed appliances and double jaw surgery were performed to treat her skeletal and dental problems, and dental implants helped restore her masticatory function. Pretreatment, posttreatment, and retention photographs demonstrate effective, esthetically pleasing, and stable treatment results.

Effect of setback Le Fort I osteotomy on midfacial soft-tissue changes as evaluated by cone-beam computed tomography superimposition for cases of skeletal Class III malocclusion

This study employed the cone-beam computed tomography (CBCT) superimposition method to evaluate postoperative midfacial soft-tissue changes in cases of skeletal Class III malocclusion after double-jaw surgery with setback and vertical reduction Le Fort I osteotomy. A retrospective study was carried out on 15 patients who had undergone maxillary setback Le Fort I osteotomy and mandibular setback sagittal split ramus osteotomy with alar cinch suturing and V-Y soft-tissue closure. Three dimensional CBCT volume scans were recorded preoperatively (T0) and 6 months postoperatively (T1) to measure soft-tissue changes of the upper lip and midface. Post-surgery, soft-tissue landmarks in the cheek and paranasal areas had moved forward; the soft-tissue thickness at the A-point had markedly increased (P<0.05); there was no significant change in the subnasale, and the midline of the soft-tissue of the upper-lip area had moved backward. The extent of the mean soft-tissue change at the labrale superius was greater than that at the other soft-tissue landmarks of the upper lip. The results suggest that maxillary setback movement of the maxilla by alar cinch suturing has a beneficial effect on paranasal soft-tissue and lip contours for patients with protrusive lip and acute nasolabial angle.

Surgical Orthodontic Treatment of Severe Skeletal Class II

This paper describes an adult Saudi male patient who presented with a severe skeletal class II deformity. The case was managed with a combination of presurgical orthodontic treatment followed by a double jaw orthognathic surgery and then another phase of orthodontic treatment for final occlusal detailing. Extraction of the four first premolars was done during the presurgical orthodontic phase of treatment to decompensate upper and lower incisors and to give room for surgical setback of the maxillary anterior segment. Double jaw surgery was performed: bilateral sagittal split ramus osteotomy for 8 mm mandibular advancement combined with three-piece Le Fort I maxillary osteotomy, 6 mm setback of the anterior segment, 8 mm impaction of the maxilla, and 5 mm advancement genioplasty. Although the anteroposterior discrepancy and the facial convexity were so severe, highly acceptable results were obtained, both esthetically as well as occlusally.

Influence of wrong determination of occlusal plane in maxillary advancement: a model surgery study

Aim: This study investigated whether an occlusal plane error of acquisition can influence on the treatment planning of maxillary advancement in double-jaw surgeries. Methods: Advancement of 8 and 4 mm were studied in different groups. For each group, 20 maxillary models were mounted by a 13-degree platform with superior articulator arm (control group) and other 20 models mounted with 7 degrees (study group). Intermediate splint was obtained by cast surgery performed in the control group. All the 40 maxillary models were remounted with this intermediate splint. Measurements in vertical and anteroposterior planes were accomplished pre- and postoperatively by digital caliper rule and Erickson’s platform. Results: Statistical analysis showed significant results in two planes. The alteration of occlusal plane from 13 degrees to 7 degrees modified the final result in vertical measurements: right molar from group of 4 mm advancement (p<0.0001) and left molar from two groups of advancement (p<0.0001); in anteroposterior measurements: maxillary incisor from 4 mm of advancement (p<0.005) and 8 mm of advancement (p<0.0001). Conclusions: Notwithstanding the importance of statistical findings, the result probably did not show clinical relevance in orthognathic surgery. Clinical studies addressing these concerns must be supplied in scientific literature.

Pharyngeal Airway Changes in Class III Patients Treated With Double Jaw Orthognathic Surgery—Maxillary Advancement and Mandibular Setback

The pharyngeal airway may change after skeletal movement in patients who have undergone orthognathic surgery. The aim of this study was to evaluate the skeletal and pharyngeal airway changes in subjects with a Class III facial pattern who underwent double-jaw surgery (maxillary advancement and mandibular setback). The present retrospective study assessed preoperative (T0), 2- to 4-month postoperative (T1), and 6- to 12-month postoperative (T2) radiographs of subjects with a Class III facial pattern treated at São Lucas Hospital (Porto Alegre, Brazil) using imaging software (Dolphin Imaging 3D 11.5). Five measurements of the pharyngeal airway space (nasopharynx; upper, middle, and lower oropharynges; hypopharynx) were evaluated and correlated with the skeletal movement of the jaws (lines perpendicular to the Frankfurt horizontal plane passing through the nasion point to points A and B). The Student t test for paired samples was used to assess the presence of significant differences between the intervals, and the Spearman correlation coefficient was used to assess the significant correlation existing between the skeletal movement and the pharyngeal airway changes. The results were considered at a maximum level of significance of 5% (P < .05). In the sample of 58 subjects (38 female and 20 male, 18 to 48 years old), measurements of the nasopharynx, upper oropharynx, and middle oropharynx increased, whereas measurements of the lower oropharynx and hypopharynx decreased during these periods (T0 to T1, T0 to T2). Decreases from T1 to T2 in the measurements of the nasopharynx and upper oropharynx were also identified. A correlation between the jaw movements and the change in airway measurement was found between the line perpendicular to the Frankfurt horizontal plane passing through the nasion point to point A and the nasopharynx and between the line perpendicular to the Frankfurt horizontal plane passing through the nasion point to point B and the lower oropharynx for T0 to T1 and T0 to T2. A correlation between skeletal movements and changes in the measurements of pharyngeal airway was found between maxillary advancement and the nasopharynx, with proportions of 102.8% and 85.5% in the short and medium terms, respectively, and between mandibular setback and the low oropharynx, with proportions of 44.8% and 43.5% in the short and medium terms. A correlation for pharyngeal airway measurements was found between those located anatomically near each other, showing the importance of the pharyngeal muscles in this relation.

Soft Tissue Changes After Orthodontic Surgical Correction of Jaws Asymmetry Evaluated by Three-Dimensional Surface Laser Scanner

Aesthetic improvement is an essential goal of treatment of facial asymmetry, and it is often difficult to achieve. Reliable three-dimensional measurements are required to support outcome studies. In this study, 15 white adult subjects, 9 females and 6 males, with maxillomandibular asymmetry and malocclusion were studied. The patients were treated with orthodontics and different surgical procedures in single or multiple steps. All patients received double-jaw surgery, except 1 patient who underwent only maxillary osteotomy. Nine of the 15 patients received additional procedures (genioplasty and rhinoplasty) to achieve better symmetry. Posterior-anterior and lateral cephalometry and three-dimensional facial surface data were obtained before (T0) and 1 year (T1) after surgery. Scan data at T0 and T1 were pooled by electronic surface averaging to obtain the mean pretreatment and posttreatment facial model. A symmetric model was constructed by averaging the actual T0 scans and their mirrored models to obtain the virtual optimal symmetric face. Different linear and angular measurements were then calculated for comparison of the mean T0 and T1 models. The normalization of facial proportion and a high increase in symmetry were evident. Residual defects were documented in the postoperative symmetry of the chin. Treatment of facial asymmetry, combined with dental occlusion problems, is still a challenge for maxillofacial surgeons. Orthognathic surgery provides an important improvement of symmetry, but further refinements of technique are still required. Three-dimensional evaluation results in an effective method to support outcome studies on the surgical correction of complex facial deformities.

A protocol used to manage maxillary hypoplasia in cleft lip and palate patients

Objectives: We report our experience and the protocol we used in managing maxillary hypoplasia in cleft lip and palate patients. Patients and methods: 14 adult cleft lip and palate patients with maxillary hypoplasia were evaluated clinically. Dental models and radiographs including (lateral cephalograms and orthopantographs) were obtained at the initial visit and upon completion of the presurgical orthodontic treatment. Patients with occlusal discrepancies larger than 6 mm and severe palatal scaring underwent Distraction osteogenesis (DO) to advance the maxilla. Patients with an occlusal discrepancy of 6 mm or less, underwent traditional orthognathic surgery including le fort I advancement and Bilateral sagittal split osteotomy (BSSO) to seat the mandible in occlusion. Results: Five patients underwent orthognathic surgery. Two of them underwent double jaw surgery. Three underwent single jaw conventional le fort l advancement. Four patients required bone grafting to repair the residual alveolar defect and to augment the midface deficiency. Nine patients with severe maxillary hypoplasia underwent maxillary advancement using distraction osteogenesis. Conclusion: Patients with a severe maxillary hypoplasia of 6 mm or more and excessive palatal scaring are successfully treated with DO. Conventional le fort I is reserved for patients with less severe maxillary hypoplasia. Both techniques gave promising results providing having followed the proper selection criteria.

Do Patients Treated With Bimaxillary Surgery Have More Stable Condylar Positions Than Those Who Have Undergone Single-Jaw Surgery?

Because condylar positioning after sagittal split ramus osteotomy of the mandible has been known to affect postoperative skeletal stability, accurate positional assessment of the temporomandibular joint after orthognathic surgery is vital to maximize stability of the surgery. The purpose of this study was to evaluate condylar changes after single-jaw and double-jaw surgeries in mandibular prognathism patients by comparing 3-dimensional angular and positional changes of the condylar heads in groups of patients receiving combined maxillary posterior impaction and mandibular setback and those undergoing only mandibular setback surgeries. We assessed condylar changes of patients who have been diagnosed with mandibular prognathism and underwent either bimaxillary surgery or isolated mandibular surgery at Kangdong Sacred Heart Hospital and SmileFuture Orthodontic Clinic, Seoul, South Korea, from August 2008 to February 2011. Condylar angulation, intercondylar distance, and amount of condylar displacement were examined based on the 3-dimensional reconstructed images. Preoperative and postoperative changes within each group were assessed by paired t test. Differences between the groups were determined by independent t test. A total of 43 skeletal Class III patients were included in this retrospective, multicenter study. After single-jaw surgery, condylar angulations in all dimensions did not change. In contrast, those who received double-jaw surgery showed forward rotation of 1.93° (P = .027) and medial rotation of 1.48° (P = .032) in the sagittal and axial planes, respectively. The mean distances of condylar displacements were 0.28 ± 0.44 mm in the single-jaw group and 0.31 ± 0.51 mm in the double-jaw group, but there was no statistically significant difference. Condylar angulations are more stable after sagittal split ramus osteotomy of the mandible as an isolated procedure than in combination with the posterior maxillary impaction in treatment of skeletal Class III malocclusion patients. Condylar displacements in both the single-jaw and double-jaw groups are clinically insignificant.

Soft Tissue Changes after Orthognathic Surgery: A Study

Aim and objective: The main aim and objectives of this study was to determine the changes in the facial soft tissue profile following orthognathic surgery, to evaluate eventual treatment effects on stability of facial aesthetics and degree of predictability of these changes.&#x0D; Materials and method: 15 numbers of patients underwent with le fort I, anterior maxillary osteotomy, genioplasty and bimaxillary surgery. The alar base cinch suture and the V-Y closure techniques were used in each maxillary procedure. The criteria applied included an average follow-up of 6 months post-operatively.&#x0D; Results: In this study preoperative and postoperative cephalometric tracing were compared to analyze the soft tissue profile changes in relation to hard tissue changes in both upper and lower lip and chin regions after double jaw surgery. Only horizontal changes were analyzed for which an X-Y coordinate system was used. The upper lip responded variably to the direction and amount of maxillary positioning. The predictability and the significance of changes of soft tissue in relation to hard tissue are variable as it reaches towards the nose.&#x0D; Conclusion: It is important for the clinician to realize that numerous factors of variability exist so that he can understand that the soft-tissue profile will sometimes deviate quite markedly from what is expected, in spite of careful planning.

Influence of single-jaw surgery vs bimaxillary surgery on the outcome and duration of combined orthodontic-surgical treatment

To analyze the effects of single-jaw surgery (mandible or maxilla only) vs bimaxillary surgery on final peer assessment rating (PAR) score outcome and overall treatment duration. Treatment records of 63 consecutively treated orthognathic patients were assessed; 41 underwent bimaxillary procedures, and the remainder single-jaw procedures. All treatment was undertaken at Kent and Canterbury Hospital in the United Kingdom. Demographic characteristics and clinical parameters, including treatment duration, number of visits required, initial and final PAR scores, and number of extractions undertaken, were recorded. The mean treatment time was 30.6 months; treatment time was shortest in the maxillary procedure only group. The mean reduction in percentage PAR score was 77%, with an average final score of 9. Linear regression analysis confirmed that procedure type had no influence on final PAR score (P = .62) or on overall treatment duration after adjustment for extractions and initial PAR score as confounders (P = .47). No significant difference was noted in treatment duration or in occlusal outcome between single- and double-jaw surgeries.