Effect Of Orthognathic Surgery Research Articles

Effect of Orthognathic Surgery On Pulp Blood Flow and Pulp Sensibility: A Prospective Control Trial

IntroductionOrthognathic surgery has the potential to compromise the vitality of the teeth. This paper aims to assess changes in pulp blood flow (PBF) and pulp sensibility (PS) of the anterior dentition following orthognathic surgery and to assess the influence of the proximity of the surgical osteotomy on the PBF and/or PS. MethodsTwenty-six patients undergoing orthognathic surgery (Le Fort I or bilateral sagittal split osteotomy [BSSO]) were compared to sixteen control patients treated by fixed appliances only using Laser Doppler flowmeter (LDF) and thermal testing (CO2 snow). Surgery patients were tested at T1 (presurgery), T2 (4-5 weeks postsurgery), T3 (3 months postsurgery), and T4 (6 months postsurgery). Control patients were tested at T1 (pretreatment), T2 (6 months posttreatment), T3 (12 months posttreatment), and T4 (18 months posttreatment). Differences between the maxilla and mandible were assessed. ResultsNo differences in PBF or PS were recorded in the control group. In the surgery group, both jaws followed the same pattern after surgery, an initial decrease at T2 followed by a gradual recovery to pretreatment PBF levels with no significant difference between T1 versus T4 in both jaws. No difference in PBF was observed between the maxilla and mandible at any testing time interval. Conclusions and Clinical ImplicationsPBF and PS of the anterior dentition was severely affected immediately postsurgery, followed by a gradual increase to full recovery. This pattern of recovery was exhibited in both jaws. A negative sensibility response or discoloration should not be seen as an indication of irreversible ischemic pulp changes. Monitoring for at least 6 months or using LDF as a confirmatory test is required before any irreversible endodontic treatment is to be considered.

Effect of Orthognathic Surgery on Pre-existing Temporomandibular Disorders.

The management of patients with pre-existing temporomandibular disorders (TMDs) undergoing orthognathic surgery remains a subject of ongoing debate. This study aimed to profile these individuals and evaluate the correlation between orthognathic surgery and alterations in TMD indicators and symptoms. We conducted a retrospective cohort investigation involving patients with skeletal malocclusion and established TMDs. Variables of interest encompassed the performance of orthognathic surgery, documented TMDs (including temporomandibular joint (TMJ) sounds, TMJ pain, muscle discomfort, and jaw locking), and patients' self-assessments of TMJ and muscle pain using a visual analog scale (VAS). The primary outcome measures focused on changes in TMD indicators and symptoms. Among the study cohort, 73.4% exhibited skeletal class III malocclusion, while 26.6% presented with skeletal class II malocclusion. Notably, patients classified as skeletal class III were significantly younger than their skeletal class II counterparts (mean age: 23.06±5.37 vs. 26.71±7.33; P=0.034). The most prevalent pre-existing TMD complaint was TMJ sounds (65.5%), followed by TMJ pain (39.1%), muscle discomfort (23.4%), and jaw locking (12.5%). Skeletal class II patients were more likely to experience TMJ sounds compared to skeletal class III patients (88.2% vs. 57.4%; P=0.022). Statistically significant improvements were observed in the VAS assessments among class III patients following surgery. A majority of patients with pre-existing TMDs seeking orthognathic surgery exhibited skeletal class III malocclusion and were younger than those with skeletal class II malocclusion. Importantly, orthognathic surgery was associated with positive changes in TMD indicators and symptoms in these patients.

Effect of Orthognathic Surgery on the Quality of Life

Dentofacial deformities have an effect on the quality of life (QoL) by affecting numerous elements of an individual's life and oral health. Orthognathic surgery is generally performed to correct facial abnormalities related to the maxilla and/or mandible. Several observational studies have looked at how orthognathic surgery and other factors affect the QoL of adults. The reported overall satisfaction in observational studies is high, ranging from 70% to 87%. Satisfaction in terms of aesthetic outcome is higher compared to functional improvement, especially in female patients. Additionally, orthodontic surgery resulted in remarkable improvements in social adjustment, social functioning, self-esteem, selfconfidence, and facial appearance changes, as well as positive life improvement. Finally, it has been determined that orthognathic surgery results in physical and psychosocial quality of life improvements after surgery and is connected with high patient satisfaction ratings. Psychological variables and aesthetics exerted a considerable influence on the patient's QoL and were more influential in determining large changes than functional considerations.

Effect of Orthognathic Surgery on Movement of the Cheilion.

The cheilion (Ch), corner of the mouth, is the soft-tissue landmark where the upper and lower lips intersect. Orthognathic surgery can modify Ch position, which can affect facial esthetics. The aims were to evaluate Ch movements resulting from Le Fort I maxillary advancement with maxillary impaction or downgrafting, and with mandibular advancement or setback, and to investigate relationships between surgical movements and Ch movements. The 45 patients had undergone bilateral sagittal split ramus osteotomy with Le Fort I advancement surgery. They were divided into 4 groups according to surgical movement direction. Preoperative and postoperative photographs were calibrated. Standardized methods were used to identify and measure preoperative and postoperative Ch positions. Significant correlations were detected between extent of maxillary downgrafting and inferior movement of the Ch in group 1 ( r =0.988, P =0.001) and group 3 ( r =0.915, P =0.001). Also, significant correlations were detected between extent of mandibular advancement and anterior movement of the Ch in group 3 ( r =0.561, P =0.046) and group 4 ( r =0.661, P =0.005). The findings indicate that, in patients who undergo bilateral sagittal split ramus osteotomy/Le Fort I surgeries, mandibular advancement moves Ch anteriorly and maxillary downgrafting moves Ch inferiorly.

Effects of the Orthognathic Surgery on the Voice Characteristics of Skeletal Class III Patients.

To analyze the effects of the bimaxillary orthognathic surgery on the voice characteristics of skeletal Class III cases, and to evaluate correlations between acoustic and skeletal changes. Skeletal Class III adult patients (7 male, 18 female) were asked to pronounce the sounds "[a], [ɛ], [ɯ], [i], [ɔ], [œ], [u], [y]" for 3 seconds. Voice records and lateral cephalometric x-rays were taken before the surgery (T0) and 6 months after (T1). Voice records were taken for the control group with 6 months of interval (n=20). The formant frequencies (F0, F1, F2, and F3), Shimmer, Jitter and Noise to Harmonic Ratio (NHR) parameters were considered with Praat version 6.0.43. In the surgery group, significant differences were observed in the F1 of [e], F2 and Shimmer of [ɯ] and F1 and F2 of [œ] and F1 of [y] sound, the post-surgery values were lower. F3 of [u] sound was higher. In comparison with the control group, ΔF3 of the [ɔ], ΔF3 of the [u] and ΔF1 of the [y] sound, ΔShimmer of [ɛ], [ɯ], [i], [ɔ], [u] and [y], and the ΔNHR of [ɔ] sound significantly changed. The Pearson correlation analysis proved some correlations; ΔF2 between ΔSNA for [ɯ] and [œ] sounds, ΔF1 between ΔHBV for [y] sound. Bimaxillary orthognathic surgery changed some voice parameters in skeletal Class III patients. Some correlations were found between skeletal and acoustic parameters. We advise clinicians to consider these findings and inform their patients.

Effects of orthognathic surgery with maxillary impaction plus septoplasty and total turbinectomy on breathing

Complete removal of hypertrophied inferior nasal turbinates may favour the occurrence of the empty nose syndrome (ENS). Some surgeons recommend partial turbinectomy in order to minimize the occurrence of ENS. However, little is known about whether total removal of the inferior nasal turbinate is associated with ENS. The aim of the present study was to evaluate the effects of total turbinectomy and septoplasty on the breathing of individuals undergoing orthognathic surgery with maxillary impaction. A total of 20 individuals participated in this cross-sectional study, in which the relationship between exposure (maxillary orthognathic surgery) and outcome (nasal respiratory function) was investigated. The Empty Nose Syndrome 6-Item questionnaire and Nasal Obstruction Symptom evaluation scale were applied to investigate the ENS. A three-dimensional assessment of the piriform opening was performed pre- and postoperatively by computed tomography in order to measure the volume of the nasal cavities using the Dolphin Imaging software. ENS was detected in 35% of patients, while 13 reported improved breathing. Symptoms of ENS such as dryness, suffocation, nose feels too open and nasal crusting were mentioned. The mean nasal cavity volume was 7477.15 mm³ greater in the initial evaluation (p<0.05). In summary, the occurrence of ENS does not constitute an absolute contraindication of total turbinectomy, a procedure that contributed to the improvement of airway permeability.

Three-dimensional morphological and biomechanical analysis of temporomandibular joint in mandibular and bi-maxillary osteotomies

Orthognathic surgery is a typical approach for treating maxillofacial deformities. However, orthognathic surgery results in positional changes in the condyles. In a previous review, the effects of orthognathic surgery on temporomandibular joints (TMJs) are not provided. Hence, in this study, we investigate the morphological changes in TMJs after mandibular and bi-maxillary osteotomies. The relationship between the morphological parameters of TMJs and symptoms of temporomandibular disorders (TMDs) is discussed. Finite element contact stress analysis is performed, and the results show that the two abovementioned surgeries can improve maxillofacial deformities, although the positions of the condyles are changed. Moreover, preoperative stress asymmetry of the left and right TMJs is observed, which remain after the surgeries. TMD patient-specific analysis shows that three joint spaces (medial joint space, lateral joint space, superior joint space) are significantly correlated with TMD symptoms.

The effect of orthognathic surgery on temporomandibular disorder

This study aimed to evaluate the difference in prevalence of temporomandibular disorder (TMD) before and after orthognathic surgery (OGS), particularly in patients with mandibular asymmetry.A prospective cohort study of patients undergoing corrective orthognathic surgery was conducted. Pre-operative and post-operative (3 months, 6 months and 1 year) TMD assessment were performed according to the Diagnostic Criteria for TMD (DC/TMD) protocol.64 patients were included in the study. Overall, there was a significant reduction of 26.5% in TMD prevalence from 60.9% pre-operatively to 34.4% 1-year post-operatively (p = 0.003). In all, 37.5% of patients had their TMD condition treated, 50% had no change in their symptoms while 12.5% experienced a worsening of their symptoms. No significant difference in terms of change in TMJ status was observed among the different ramus procedures, the type and magnitude of mandibular movement, skeletal class, and presence of mandibular asymmetry.In conclusion, it appears that corrective orthognathic surgery for dentofacial deformities might provide a secondary benefit of treating TMD. However, surgeons have to be aware that a small percentage of patients might experience a deterioration of their TMD condition, and that those who were previously asymptomatic may develop TMD symptoms after surgery.

The Effect of Orthognathic Surgery on Changes in Masticatory Muscle Volume in Patients With Facial Asymmetry.

The masseter muscle changes remarkably with orthognathic surgery and has a marked influence on the contours of the lower face. If the postoperative volume change of masticatory muscles, including the masseter muscles, can be predicted, it will facilitate preoperative planning and outcome prediction. This study investigated the association of masticatory muscle volume according to the presence or absence of facial asymmetry, and evaluated whether the volume of masticatory muscles, including that of the masseter muscle, changes after orthognathic surgery in facial asymmetry patients.Twenty patients who underwent LeFort I osteotomy and bilateral sagittal segmentation ramus osteotomy (BSSRO) with facial asymmetry between 2011 and 2017 were assigned to the asymmetric group. Additionally, 207 patients with a simple nasal fracture between 2016 and 2019 were included as the common group. Threedimensional computed tomography images were retrospectively analyzed and compared between the asymmetric group and common group.The volume of both temporal and masseter muscles differed according to facial asymmetry, with the asymmetry in the muscle volume increasing in proportion to the degree of facial asymmetry. The difference in masseter volume on the shortened and lengthened sides was significantly reduced after orthognathic surgery, but a difference of about 1 cm 3 remained. Additionally, the masticatory muscle volume on the lengthened side tended to be decreased more than that on the shortened side.Consideration of the postoperative change in the volume of the masticatory muscles may be helpful in planning orthognathic surgery in facial asymmetry patients.

The Effect of Orthognathic Surgery on the Hyoid Bone Position in Skeletal Class III Patients: An Evaluation Using Cephalometric Analysis.

BACKGROUNDThis study aimed to investigate the positional changes of the hyoid bone following orthognathic surgery in skeletal class III patients.METHODSThis double-blinded quasi-experimental study was carried out in Mashhad University of Medical Sciences, Iran, from Apr 2019 to Jun 2020. All skeletal Class III patients who were candidates for orthogenetic surgery were included. They underwent mandibular setback surgery using bilateral sagittal split osteotomy. Cephalometric assessments in relation to hyoid bone position and posterior airway space (PAS) were conducted one day preoperatively (T0), as well as one week (T1), six months (T2) and one year (T3) postoperatively, determining the parameters like the Long axis of the hyoid bone (LAH), Retrognation (RGn), Hyoidale (H), Palatal plane (PP), Mandibular plane (MP) and C3 Vertebrae (C3). All cephalograms were examined using AudaxCeph, Planmeca software. The data analysis was performed via SPSS-19 (P<0.05)RESULTS25 class III patients, including 18 females (72%) and 7 males (28%) with a mean age of 24.32±5.87, were studied. The cephalometric analysis demonstrated significant decreases in variable angles during the follow-up periods, except for LAH-MP angle (P<0.001). The hyoid bone moved downward and backward relative to its original position following the mandibular setback surgery. However, the bone gradually returned to the preoperative location between 6 to 12 months postoperatively. CONCLUSIONThe findings revealed the downward and backward movement of the hyoid bone following the mandibular setback surgery, returned near to its preoperative position after 1 year, postoperatively.

The effects of orthognathic surgery on auditory function

BackgroundOrthognathic surgery is widely used in treating functional and skeletal problems. Any surgical procedure could cause side effects.ObjectivesThis study aimed to evaluate the potential changes in orthognathic surgery on the hearing function of patients.Materials and methodsThirty-one orthognathic surgery candidates were recruited in this study. Patients underwent either single or double jaw surgery. Pure tone audiometry (PTA), tympanometry, and Eustachian Tube Dysfunction Test (ETFT) were performed postoperatively at 24 h, 6 weeks, and 6 months after surgery. Patients were tabulated based on the type of maxilla and mandibular surgical movements (vertical and horizontal).ResultsPTA evaluation, based on horizontal or vertical movements, did not show significant differences, although vertical movements resulted in less change in hearing threshold. In other words, no significant changes occurred in patients’ hearing threshold after surgery. No significant difference was also observed between horizontal and vertical movements in the results of tympanometry. Negative changes were found in the results of ETFT in vertical movements, which returned to pre-surgery values in the final test.ConclusionsThe risk of minor changes in hearing function is probable during the first week after orthognathic surgery, but these negative changes will either totally fade or remain negligible. Patients gave informed consent preoperatively, and reassurance postoperatively is prudent.

The Effect of Orthognathic Surgery on the Hyoid Bone Position in Skeletal Class III Patients: An Evaluation Using Cephalometric Analysis

The Effect of Orthognathic Surgery on the Hyoid Bone Position in Skeletal Class III Patients: An Evaluation Using Cephalometric Analysis

The Effect of Orthognathic Surgery on Temporomandibular Joint Function and Symptoms: What are the Risk Factors? A Longitudinal Analysis of 375 Patients

The effects of orthognathic surgery (OGS) on the temporomandibular joint (TMJ) are still controversial. Based on a high-volume uniform collective, the function and clinical symptoms of the TMJ and the dysfunction index (Di) by Helkimo were evaluated prior and up to 2years after OGS. A longitudinal cohort study was performed between 2006 and 2016. A comprehensive examination focusing on TMJ function, temporomandibular disorder (TMD) symptoms, and the Di had been performed preopertaively (T0) and postoperatively at 6weeks (T1), 6months (T2), 1 year (T3), and 2years (T4). The predictor variables used were sex, age, skeletal class, type of surgery, and amount of dysfunction or number of TMD complaints before treatment. The outcome of this study was TMD symptoms and the Di. Descriptive and bivariate statistics were computed, and the significance level was set at P<.05. The sample consisted of 375 patients (247 women, 128 men, mean age 28.1±9.4years), 269 with skeletal Class II (71.7%) and 106 with skeletal Class III (28.3%) treated with sagittal split osteotomy bilateral sagittal split osteotomy (n=173) or Le Fort I and bilateral sagittal split osteotomy (n=202). Severe signs of dysfunction (Di 2/3) were seen in 5.9% of the patients before OGS and in 2.1% of the patients 2years after OGS. The difference in Di (Di0/1 and Di2/3) between T0 and T1/T2 was statistically significant (P=.028; P=.011, respectively). TMD symptoms were significantly reduced 2years after OGS (P=.028). Female gender (P=.013), skeletal Class II (P<.001), and counterclockwise rotation (P<.001) were the only risk factors significantly associated with the occurrence of TMD at T1. The results of this study suggest that in most cases TMD symptoms can be significantly reduced and only a few can be induced with OGS. No risk factors were found for long-term effects on the TMJ.

Effects of Orthognathic Surgery on Voice Characteristics

Orthognathic surgery not only corrects dentofacial deformities but also affects some vital structures involving voice production. The primary aim of this study was to analyze the effects of bimaxillary orthognathic surgery on voice characteristics of patients with class II and III skeletal deformities; the second aim was to evaluate possible associations among acoustic parameters, pharyngeal airway, and skeletal changes after surgery. Using a prospective cohort study design, we enrolled a sample of patients who underwent bimaxillary orthognathic surgery in the university hospital between January 2018 and January 2019. Voice records and cone-beam computed tomography (CBCT) scans of the patients were acquired before surgery and 6months after surgery. Pharyngeal airway volume, minimum cross-sectional area, hyoid bone position, and skeletal movements of the maxilla and mandible were assessed with Dolphin Imaging software using CBCT data as predictor variables. Acoustic analysis of voice samples (vowel/a/) were performed with Praat software as outcome variables. The within-group and between-group differences in data were analyzed using paired-sample and independent-sample t tests. The degree of relationship between voice and CBCT parameters was assessed using Pearson correlation and multiple regression analysis. The study sample comprised 33 patients; 14 patients had class II skeletal deformity and 19 patients had class III skeletal deformity. Orthognathic surgery in both patients with class II and III skeletal deformities resulted in significant changes in all the voice parameters (All P<.05). Only patients with class II skeletal deformity showed significant changes in airway parameters (increase; all P<.001) and hyoid bone positions (anterosuperior movement; P=.001 and P=.008, respectively). Multiple regression analysis showed that some specific structural changes significantly affected some specific acoustic parameters. Bimaxillary orthognathic surgery significantly changed the acoustic parameters of voice in patients with class II and III skeletal deformities. Some of the structural changes were significantly associated with some of the acoustic parameters.

Effects of orthognathic surgery on quality of life compared with nonsurgical controls in an American population

To determine the psychosocial effects of a facial skeletal mal-relationship with its subsequent surgical correction in a group of patients treated using surgical orthodontics compared with a matched group of nontreated controls. This study was approved by The Ohio State University Institutional Review Board. Subjects were patients presenting with facial skeletal mal-relationships whose proposed treatment plans included orthognathic surgery. This study used valid and reliable questionnaires: Orthognathic Quality of Life Questionnaire (OQLQ), Beck Depression Inventory II (Children's Depression Inventory - 2), Satisfaction with Life Scale, and State Trait Anxiety Inventory (State Trait Anxiety Inventory for Children), administered at 3 different stages of treatment (time 1=initial pretreatment, time 2=before oral surgery, and time 3=at completion of treatment). Matched controls recruited at each time point completed the same questionnaires. A total of 267 subjects were recruited to participate in this study. There were no significant differences between treatment and control groups in age, sex, education level, or employment status at any of the 3 time points. The randomization test was used to compare values for all outcome variables between groups at the 3 stages of treatment. For the pretreatment period, T1, there were significant differences between patients and controls in domains 1 (P=0.0126), 2 (P=0.0000), and 3 (P=0.0000) of the OQLQ (social aspects, facial esthetics, and oral function, respectively) as well as total OQLQ (P=0.0000). For the presurgery period, T2, there were significant differences between patients and controls in domains 2 (P=0.0136) and 3 (P=0.0001) of the OQLQ (facial esthetics and oral function) as well as total OQLQ (P=0.0291). Finally, for the posttreatment period, T3, there was a significant difference between patients and controls only in domain 3 (P=0.0196) of the OQLQ (oral function). The psychosocial profile of patients with a facial skeletal mal-relationship does not differ from the general population in depression, anxiety, and overall satisfaction with life. However, these patients do report a reduced quality of life based on condition-specific measures in social aspects, facial esthetics, and oral function. Concerns about oral function remain even up to 2years after treatment is completed.

The effect of orthognathic surgery on facial recognition algorithm analysis

The purpose of this study was to evaluate the ability of a publicly available facial recognition application program interface to calculate similarity scores for presurgical and postsurgical photographs of patients who underwent orthognathic surgeries. Our primary objective was to identify which surgical procedure(s) had the greatest effect(s) on the similarity score. Existing photographs for 25 orthodontic-orthognathic patients were analyzed using the application program interface to calculate similarity scores between the presurgical and postsurgical photographs. Photographs from 2 presurgical timepoints were compared as controls. Both relaxed and smiling photographs were included to assess the added impact of a facial pose. Patient characteristics and surgery types were recorded for statistical analysis. Nonparametric Kruskal-Wallis rank-sum tests were performed to analyze the relationship between patient characteristics and similarity scores. Multiple comparisons Wilcoxon rank-sum tests were performed on the statistically significant characteristics. Recognition scores were significantly lower after orthognathic surgery at rest (P=0.009) and smiling (P<0.001). Patients receiving both LeFort I and bilateral sagittal split osteotomy (BSSO) surgeries had a lower median similarity score compared with those that received only BSSO (P=0.009) when comparing relaxed photographs before and after surgery. Similarly, for the score comparing presurgical relaxed photographs to postsurgical smiling photographs, patients that received both surgeries were found to have lower similarity scores compared with those receiving only BSSO (P=0.036). Two-jaw surgeries were associated with a statistically significant decrease in similarity score when compared with 1-jaw procedure. Pose was also found to be a factor influencing similarity scores, especially when comparing presurgical relaxed photographs to postsurgical smiling photographs.

Orthognathic surgery for obstructive sleep apnea

As the importance in the management of obstructive sleep apnea and other obstructive upper airway disease continues to increase, the effect of orthognathic surgery on the upper airway in correction of both dentofacial deformities and obstructive sleep apnea has become a prominent component of treatment planning in recent decades. Applied correctly, orthognathic surgery can have a dramatic and life-changing effect on decreasing nocturnal obstructions through expansion of the upper airway. Large advancements of the maxillomandibular complex allows for three-dimensional upper airway expansion to nocturnal obstruction that diminish the deleterious effects of obstructive sleep apnea. This paper will discuss the orthognathic surgical techniques that are essential in the treatment planning to achieve the desired results of relief of nocturnal upper airway obstructions.

Changes of Transverse Mandibular Width in Set-Back Mandibular Surgery: Sagittal Split versus Intraoral Verticosagittal Osteotomy

Aim: This study was performed to evaluate the movement of the proximal segment following different methods of ramus osteotomy that is one of the side effects of orthognathic surgery. Theoretically, with intraoral verticosagittal ramus osteotomy, it can minimize the movement of the proximal segment. The changes in the intergonal distance of mandible and the angle of the ramus flaring in two methods of osteotomy have been compared in this study. Materials and Methods: In this randomized clinical trial, included 60 patients (32 males) with mandibular prognathism and without any asymmetry were selected and divided into two groups (n = 30). One group underwent bilateral sagittal split ramus osteotomy technique to achieve mandibular setback and the other by the intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner-ramal angle in the transverse plane were measured on radiographs preoperatively and 1 and 12 weeks postoperatively. Data were analyzed using covariance test with the significance level set at P 0.1). Conclusion: Considering our findings, there was no significant difference between two ramus osteotomy techniques regarding changes in mandibular width and inter-ramal flaring angle.

No evidence about the effects of orthognathic surgery in psychosocial functioning owing to limitations in the systematic review

Broers DLM, van der Heijden GJMG, Rozema FR, de Jongh A. Do patients benefit from orthognathic surgery? A systematic review on the effects of elective orthognathic surgery on psychosocial functioning and patient satisfaction [published online ahead of print September 11, 2017]. Eur J Oral Sci. .

Effects of Orthognathic Surgery on TMJ Function and Dysfunction

Effects of Orthognathic Surgery on TMJ Function and Dysfunction