Effect of Botox injection in the anterior belly of digastric on skeletal relapse following mandibular advancement surgery. Randomized controlled trial

The aim of this study was to determine the vertical and anteroposterior alterations in the soft, the dental and the skeletal tissues associated with the facial profile after Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement performed in patients with a high angle Class II skeletal deformity.The study population consists of 21 patients (11 females and 10 males, mean age 24.5±1.6 years) who underwent Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement. Lateral cephalograms were obtained prior to the surgery and 1.3±0.2 years postoperatively. Wilcoxon test was performed to compare the pre- and postsurgical cephalometric measurements. Pearson correlation test was carried out to determine the relative changes in skeletal, dental and the facial soft tissues.The insignificant decrease in the nasolabial angle was correlated with the significant decrease in the vertical position of the nose due to the nasal protraction noticed after bimaxillary surgery. The retraction of both the upper lip and the upper incisors was correlated with the insignificant decrease in the columella-lobular angle. The insignificant decrease in both the vertical height of the mandibular B point and the lower incisors was correlated with the insignificant decrease in vertical height of the soft tissue pogonion, attributable to the resulting superior movement of the soft tissues of the chin and the counter clockwise rotation of the mandible after maxillary impaction and bilateral sagittal split osteotomy, respectively.Le Fort I maxillary impaction in conjunction with mandibular sagittal split osteotomy for mandibular advancement significantly affected the vertical and anteroposterior positions of the maxilla and the mandible, respectively. When performed in combination, these surgical techniques may efficiently alter the position of upper incisor and the nasal position in both vertical and anteroposterior directions. Bimaxillary orthognathic surgery seems to be an efficient method for obtaining satisfactory results in the appearance of the soft, the dental and the skeletal tissues associated with the facial profile in patients with high angle Class II skeletal deformity.

Causes, location, and timing of relapse following rigid fixation after mandibular advancement

Introduction: This study aims to assess the postoperative changes in the pharyngeal airway space and the positions of the hyoid bone, soft palate, and tongue after mandibular advancement, mandibular setback, and bimaxillary surgeries. It also aims to compare the effects of mandibular setback and bimaxillary surgeries in the treatment of skeletal Class III patients. Materials and method: Lateral cephalograms of the patients were taken preoperatively and in a period of 3 months postoperatively on 21 subjects (3 groups, 7 patients each) who underwent mandibular setback surgery, bimaxillary surgery for Class III correction, and mandibular advancement surgery, respectively. Pre- and postoperative evaluation of skeletal and soft tissue landmarks were conducted to study the dimensions of the pharyngeal airway space and the position of the hyoid bone, soft palate, and tongue. Results: A significant increase in the oropharyngeal airway was observed after mandibular advancement surgeries, with an uprighting of the soft palate and anterior positioning of the tongue. In the mandibular setback group, the nasopharyngeal airway dimension increased significantly, and the hyoid bone was repositioned posteroinferiorly with posterior movement of the tongue. After bimaxillary surgery in Class III subjects, the nasopharyngeal airway space increased significantly associated with postural changes in the soft palate. Conclusion: Mandibular advancement surgeries can provide conditions for increased airway patency. With regard to the PAS, in Class III patients, maxillary advancement should be preferred to mandibular setback. When mandibular setback is indispensable, the association of movements in bimaxillary surgery can neutralize or minimize the effects of the setback.

Introduction: The aim of this study was to evaluate the changes of the pharyngeal airway obtained using mono-and bimaxillary orthognathic surgery in patients with skeletal malocclusion. Material and Methods: The analysis was conducted on cone-beam computed tomography images taken preoperatively and postoperatively of patients undergoing mono-or bimaxillary orthognathic surgery. The pharyngeal airway was divided into four airway volume segments and measured by planimetry. Results: The bimaxillary surgery group showed an increase in nasopharynx and velopharynx volumes and a decrease in glossopharynx and hypopharynx volumes (P < 0.05). The mandibular setback surgery group showed decreases in glossopharynx, hypopharynx, oropharynx, and pharynx volumes (P < 0.05). The mandibular advancement surgery group showed increases in glossopharynx, hypopharynx, oropharynx, and pharynx volumes (P < 0.05). The maxillary advancement surgery group showed increases in nasopharynx, velopharynx, and pharynx volumes (P < 0.05). Discussion and Conclusion: Mandibular setback surgery had a narrowing effect on the pharyngeal airway volume. Maxillary advancement surgery compensated for the constrictive effect of mandibular setback surgery on both the oropharynx and pharynx volumes. Although maxillary and mandibular advancement surgery affected different sites, these were the operations that contributed most to the increase in pharyngeal volume.

High-angle skeletal Class II malocclusion is one of the most challenging dentofacial deviations to treat and, in adults, a combination of orthodontic treatment and bimaxillary orthognathic surgery is often indicated. This study examines the rate of clinically significant relapse and whether a genioplasty affects the treatment outcome of high-angle Class II malocclusions. Cephalometric tracings of 36 consecutively treated high-angle Class II patients were evaluated from pre-surgery to 3 years post-surgery. All patients had undergone bimaxillary surgery (Le Fort I and BSSO), 13 of them had in addition a genioplasty. The maxilla remained stable, whereas relapse (greater than or equal to 2 mm) of the mandibular advancement was seen in 40 per cent of the patients. Advancement greater than 10 mm increased the risk for horizontal relapse. The overjet was normalized and remained stable despite mandibular relapse. Half of the patients had an anterior open bite 3 years post-surgery. A supplemental genioplasty did not affect the relapse rate. Overjet was normalized and remained stable long term; there was an open bite in half of the patients. Combined orthodontic and bimaxillary surgical treatment of high-angle Class II patients showed skeletal relapse (greater than or equal to 2 mm) of the mandible in 40 per cent of patients. Mandibular advancement greater than 10 mm increased the risk for relapse. There was no increased risk for dental or skeletal instability associated with a genioplasty in combination with maxillary and mandibular surgery in the treatment of high-angle skeletal Class II malocclusion.

Evaluation of mandibular positional changes after orthognathic surgery in skeletal class II and class III surgery-first approach patients

Class II treatment options broaden

Purpose of the Study:To predict the changes and evaluate the stability that occurs in the soft tissues following the skeletal movement subsequent to surgical advancement of the mandible through bilateral sagittal split osteotomy and to provide the patient reliable information with regard to esthetic changes that can be expected following the treatment.Materials and Methods:Twenty adult patients diagnosed with skeletal class II malocclusion and underwent bilateral sagittal split osteotomy for mandibular advancement by a mean of 8 mm using rigid fixation were included in the study. Soft tissue changes brought about by the surgical procedure and their stability over a period of time were evaluated prospectively using 12 linear (4 vertical and 8 horizontal) and 4 angular measurements on profile cephalograms which were taken preoperatively after the pre-surgical orthodontics (T1) and postoperatively with duration of 1 month (T2) and 6 months (T3) respectively.Results:It was observed that compared to the linear measurements, the angular measurements showed significant changes. The improvement in the esthetic outcome is a direct reflection of the angular changes whereas the linear changes played a contributing role. Following mandibular advancement surgery the profiles of the patients was perceived to have improved with reduction in the facial convexity, an increase in the lower facial height, decrease in the depth of the mentolabial sulcus and improvement in the lip competency with lengthening, straightening and thinning of the lower lip.Conclusion:The soft tissue response and its stability depends on the stability of the surgical procedure itself, postsurgical growth and remodeling of the hard tissues and soft tissue changes as a result of maturation and aging.

Satisfaction with Facial Appearance following Bimaxillary Orthognathic Surgery

PurposeThe aim of this study is to analyze mandibular condyle position changes after bilateral sagittal split osteotomy (BSSO) and bimaxillary orthognathic surgery in patients operated at a single department by two surgeons in 2013–2022. Compared were groups of mandibular advancement vs setback and bimaxillary vs BSSO.MethodsNinety-nine subjects were included. Inclusion criteria were patients who underwent one of the BSSO or bimaxillary surgery and had CT scans performed before and after surgery. Preoperative CT scans were performed 1 day before surgery and postoperative CT scans 6–12 months afterwards. Changes in mandibular condyle position were measured in axial and sagittal planes.ResultsCT condylar position measurements indicated significant postoperative changes in AB angle bilaterally (p = < 0.001). In mandibular advancement and setback comparison, values were significantly lower in ABL angle values in the setback group (p = 0.011326) and significantly higher in FDR in the advancement group (p = 0.005795). There were no statistically significant changes found in BSSO and bimaxillary group comparison.ConclusionWithin the limitations of this study, it can be concluded that orthognathic surgery does have a moderate effect on position of the condyles, especially condylar rotation in transversal axis.

This study tested the hypothesis that a layperson's social perceptions of a dentofacial deformity (DFD) patient with primary mandibular deficiency (PMD) are more positive after bimaxillary orthognathic surgery.A survey was implemented comparing layperson's social perceptions of emotional expressions and personality traits before and >6 months after orthognathic surgery when viewing standardized facial photographs. The study sample comprised 20 patients selected randomly from a larger primary mandibular deficiency database, treated by 1 surgeon after orthognathic surgery. The outcome variable was change in 6 perceived emotional expressions and 6 personality traits studied. Descriptive and bivariate statistics were computed (P < .05).Five hundred respondents (raters) completed the survey. The respondents were 52% male with 44% aging from 25 to 34. After bimaxillary and chin orthognathic surgery, primary mandibular deficiency patients were perceived to be significantly more dominant, trustworthy, friendly, intelligent, attractive, and less threatening (P < .05). They were also perceived as happier and less angry, surprised, sad, afraid, or disgusted than before surgery (P < .05).Laypeople consistently report improved social traits in primary mandibular deficiency patient's perceived emotional expressions and perceived personality traits after bimaxillary and chin orthognathic surgery.

Change of Lip Cant After Bimaxillary Orthognathic Surgery

Accuracy of Virtual Surgical Planning with Mandible-first Surgery and Factors that may Affect It

Treatment of hyperhidrosis

Simple SummaryIn individuals with severe malocclusions, orthognathic surgery seeks to rebalance the relationships between the jaws by providing a stable occlusion, a healthy muscle balance, and the functioning of the temporomandibular joint. Cone beam computed tomography may be used to determine the position of the mandibular condyle in the glenoid fossa. This study aimed to assess how the position of the mandibular condyle varies in class II and III malocclusions before and after bimaxillary orthognathic surgery. Before and after orthognathic surgery, 56 TMJs from 28 patients were studied. Following surgery, both class II and class III patients experienced changes in the anterior joint space, posterior joint space, condyle position, and condyle angle. The preliminary findings are promising for determining changes in condyle position and joint spaces that might guide oral and maxillofacial surgeons to address a debilitating clinical affliction.This study aimed at evaluating the mandibular condyle position changes before and after bimaxillary orthognathic surgery in class II and III malocclusion patients. CBCT scans from patients who underwent bimaxillary orthognathic surgery were analyzed: Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO). Both condyles were independently assessed for their largest anterior and posterior joint spaces, smallest medial joint spaces, and condyle angles concerning the transverse line. In the sagittal plane, the minimum size of the anterior and posterior joint spaces was measured. In the coronal plane, the smallest medial joint space was measured. The position of the condyle within the glenoid fossa was determined before and after surgery. A total of 56 TMJs from 28 patients were studied. Following orthognathic surgery, the anterior and posterior space in class II increased. Postoperatively, the anterior joint space in class III decreased. In 42.85% of malocclusion class II patients and 57.14% of malocclusion class III patients, the pre-and post-surgical position of the condyle changed, the condyle was anteriorly positioned (42.85%) in class II patients and centrically positioned (71.4%) in class III patients. Significant changes in the joint space, condylar position, and condyle angle were found in the class II and class III subjects.