Change in taste sensation after orthognathic surgery.

OBJECTIVE: The objective of this study was to evaluate the effect of orthognathic surgery on taste sensation. MATERIALS AND METHODS: Thirty-five patients scheduled to undergo Le Fort I osteotomy (LFIO), sagittal split ramus osteotomy (SSRO), and bimaxillary surgery (BMS) were evaluated by administering localized and whole-mouth taste tests preoperatively and postoperatively at months 1, 3, and 6. The patients were asked to identify the quality of four basic tastes applied to six locations on the palate and tongue and to rate the taste intensities they perceived. Taste recognition thresholds and taste intesity scores were evaluted according to operation groups and follow-ups. RESULTS: There were significant decreases in the quinine HCl recognition thresholds at the postoperative follow-ups compared to the preoperative in LFIO patients (p = 0.043). There were significant decreases in sucrose taste intensity scores in the right posterolateral part of the tongue at months 3 and 6 compared to preoperative in SSRO patients (p = 0.046), and significant increases in quinine HCL taste intensity scores in the right and left anterior parts of the tongue at month 6 compared to preoperative in LFIO patients (p < 0.05). CONCLUSION: Taste perception is affected due to potential damage to the chemosensory nerves during orthognathic surgical procedures. Generally, non-significant alterations have been observed in taste perception after orthognathic surgery, except for significant alterations in bitter and sweet taste perceptions. CLINICAL RELEVANCE: Maxillofacial surgeons should be aware of taste perception change after orthognathic surgery procedures and patients should be informed accordingly. THE TRIAL REGISTRATION NUMBER (TRN): NCT06103422/Date of registration: 10.17.2023 (retrospectively registered).

Can different osteotomies have an influence on surgically assisted rapid maxillary expansion? A systematic review.

The purpose of this study was to systematically review the randomized and non-randomized clinical trials (RCT; nRCT) concerning the different available osteotomies for surgically assisted rapid maxillary expansion (SARME): pterygomaxillary disjunction (SARME + PD vs SARME-PD) and segmental Le Fort I osteotomy (2-piece vs 3-piece). Outcomes focused on skeletal, dental, upper airway changes, complications, and relapse. Two authors investigated five databases (PubMed, Cochrane Library, Google Scholar, Scopus, Web of Science) until August 2023. The Cochrane Collaboration Tool and the Newcastle-Ottawa scale were used for the quality assessment of the included RCTs and nRCTs, respectively. A total of 554 articles were retrieved and after duplicates removing and full-text reading, 40 studies were included. Two RCTs showed a low risk of bias, one an unclear risk and one a high risk. Among the non-RCTs, 15 studies showed a good quality, while 21 exhibited a fair quality score. SARME + PD resulted in more homogeneous posterior bone expansion, with minimal dental effects. No difference between 2-piece and 3-piece in asymmetric expansion was observed, although 3SO showed 1-2 mm of more transverse increase. The oropharynx minimum cross-sectional area, the nasopharynx and the oropharynx volume were greater in SARME + PD. Both dental and bone relapse can occur but no differences between the groups were observed. All osteotomies guaranteed a correction of transverse maxillary deficiency. Lower side effects were described in SARME + PD. Two-piece and 3-piece segmental Le Fort I osteotomies did not show any differences in the symmetry and amount of expansion.

Comprehensive analysis of lateral nasal wall anatomy to optimize the osteotomy in different skeletal patterns.

PURPOSE: Variations in nasal wall anatomy are crucial in patients with dentofacial deformities undergoing Le Fort I osteotomy. These structural variations heighten the potential for complications during surgical procedures. Hence, the study focused on evaluating the differences in the lateral nasal wall anatomy across different skeletal Classes. METHODS: This study evaluated 86 patients aged 18-43 years with different skeletal Classes. In the axial images acquired from coronal sections, two angulations and the linear distances of the lateral nasal wall were measured in Class I, II, and III patients. The measurement between the piriform opening and the most anterior point of the greater palatine foramen was evaluated in three parts regarding the osteotomy line. Differences between the skeletal patterns were analyzed using an independent sample t-test and Mann-Whitney U test with a significance level of 0.05. The intra-class correlation coefficient was calculated for inter-observer and intra-observer agreement. RESULTS: There was a statistically significant difference between Class I and Class II subjects regarding the anterior lateral nasal wall (p = 0.011) and anterior nasal thickness (a) (0.004). There was a significant difference between Class I and Class III patients regarding anterior nasal thickness (a) (p < 0.001) and total lateral nasal wall length (p < 0.001). CONCLUSION: For instance, the measurements of Class III and Class II patients were relatively different from those of the Class I patients. Therefore, preoperative Cone-Beam Computed Tomographic analysis should be performed for each patient prior to Le Fort I osteotomy to ensure that the procedure is performed safely.

Validation of a fully automatic three-dimensional assessment of orthognathic surgery.

The aim of the present study was to propose and validate FAST3D: a fully automatic three-dimensional (3D) assessment of the surgical accuracy and the long-term skeletal stability of orthognathic surgery. To validate FAST3D, the agreement between FAST3D and a validated state-of-the-art semi-automatic method was calculated by intra-class correlation coefficients (ICC) at a 95 % confidence interval. A one-sided hypothesis test was performed to evaluate whether the absolute discrepancy between the measurements produced by the two methods was statistically significantly below a clinically relevant error margin of 0.5 mm. Ten subjects (six male, four female; mean age 24.4 years), class II and III, who underwent a combined three-piece Le Fort I osteotomy, bilateral sagittal split osteotomy and genioplasty, were included in the validation study. The agreement between the two methods was excellent for all measurements, ICC range (0.85-1.00), and fair for the rotational stability of the chin, ICC = 0.54. The absolute discrepancy for all measurements was statistically significantly lower than the clinical relevant error margin (p < 0.008). Within the limitations of the present validation study, FAST3D demonstrated to be reliable and may be adopted whenever appropriate in order to reduce the work load of the medical staff.

Influencing factors for the development of obstructive sleep apnea after orthognathic surgery in skeletal class III patients: A systematic review.

This systematic review aimed to investigate the factors that may contribute to the development of OSA after orthognathic surgery in patients with skeletal class III. Electronic searches of PubMed, Embase, Web of Science, and Cochrane databases were conducted up to December 10, 2022. In total, 277 studies were retrieved and screened according to the inclusion and exclusion criteria, and 14 were finally selected. All studies were of medium quality (moderate risk of bias). The occurrence of OSA after orthognathic surgery in patients with class III skeletal relationships depends on surgical factors and patient self-factors. Surgical factors include surgery type, amount of maxillary and mandibular movement, and the patient's postoperative swelling. Patient self-factors include weight, age, gender, and hypertrophy of the soft palate, tonsils, and tongue. According to information in the 14 selected articles, the incidences of OSA after Le Fort I impaction and BSSO setback, BSSO setback, and Le Fort I advancement and BSSO setback were 19.2%, 8.57%, and 0.7%, respectively, mostly accompanied with greater amounts of mandibular recession. However, no clear evidence exists to confirm that orthognathic surgery is a causative factor for postoperative sleep breathing disorders in patients with mandibular prognathism. The wider upper airway in patients with class III skeletal might be the reason for the rare occurrence of OSA after surgery. In addition, obesity and advanced age may lead to sleep apnea after orthognathic surgery. Obese patients should be advised to lose weight preoperatively.

Simultaneous standard total joint prosthesis reconstruction with SSRO and Le Fort I osteotomy in the treatment of unilateral temporomandibular joint ankylosis with jaw deformity: a case cohort study.

OBJECTIVE: Unilateral temporomandibular joint ankylosis with jaw deformity (UTMJAJD) may require simultaneous total joint prosthesis (TJP) reconstruction, sagittal split ramus (SSRO), and Le Fort I osteotomies. The purpose of this study was to evaluate outcomes in patients treated with these procedures. METHODS: Patients diagnosed UTMJAJD between 2016 and 2018 were selected for the study. Mandible-first procedure was performed after ankylosis release with TJP on the ankylosed side and SSRO on the contralateral side. Le Fort I osteotomy with and without genioplasty was lastly performed. Maximal incisor opening (MIO), facial symmetry, and jaw and condyle stability were compared before, after operation, and during follow-ups. RESULTS: Seven patients were included in the study. Their average chin deviation was 9.5 ± 4.2 mm, and maxillary cant was 5.1 ± 3.0°. After operation, jaw deformity significantly improved, with chin deviation corrected 7.6 ± 4.1 mm (p = 0.015) and advanced 5.9 ± 2.5 mm (p = 0.006). After an average follow-up of 26.6 ± 17.1 months, MIO significantly increased from 11.4 ± 9.3 to 35.7 ± 2.6 mm (p = 0.000). The occlusion was stable with no significant positional or rotational changes of the jaw (p > 0.05). There was no obvious condylar resorption during follow-ups. CONCLUSION: Simultaneous TJP reconstruction, SSRO, and Le Fort I osteotomy are reliable and effective methods for the treatment of UTMJAJD.

[Comparison of the virtual surgical planning position of maxilla and condyle with the postoperative real position in patients with mandibular protrusion].

OBJECTIVE: To compare the difference between virtual surgical planning (VSP) position and postoperative real position of maxilla and condyle, and to explore the degree of intraoperative realization of VSP after orthognathic surgery. METHODS: In this study, 36 patients with mandibular protrusion deformity from January 2022 to December 2022 were included. All the patients had been done bilateral sagittal split ramus osteotomy (SSRO) combined with Le Fort Ⅰ osteotomy under guidance of VSP. The VSP data (T0) and 1-week postoperative CT (T1) were collected, the 3D model of postoperative CT was established and segmented into upper and lower jaws in CCMF Plan software. At the same time, accor-ding to the morphology of palatal folds, the virtual design was registered with the postoperative model, and the unclear maxillary dentition in the postoperative model was replaced. Then the postoperative model was matched with VSP model by registration of upper skull anatomy that was not affected by the operation. The three-dimensional reference plane and coordinate system were established. Selecting anatomical landmarks and their connections of condyle and maxilla for the measurement, we compared the coordinate changes of marker points in three directions, and the angle changes between the line connecting the marker points and the reference plane to analyze the positional deviation and the angle deviation of the postoperative condyle and maxilla compared to VSP. RESULTS: The postoperative real position of the maxilla deviates from the VSP by nearly 1 mm in the horizontal and vertical directions, and the anteroposterior deviation was about 1.5 mm. In addition, most patients had a certain degree of counterclockwise rotation of the maxilla after surgery. Most of the bilateral condyle moved forward, outward and downward (the average distance deviation was 0.15 mm, 1.54 mm, 2.19 mm, respectively), and rotated forward, outward and upward (the average degree deviation was 4.32°, 1.02°, 0.86°, respectively) compared with the VSP. CONCLUSION: VSP can be mostly achieved by assistance of 3D printed occlusal plates, but there are certain deviations in the postoperative real position of maxilla and condyle compared with VSP, which may be related to the rotation axis of the mandible in the VSP. It is necessary to use patient personalized condylar rotation axis for VSP, and apply condylar positioning device to further improve surgical accuracy.

Comparative Analysis of Temperature-Responsive Hydrogel (PF 72) for Postoperative Pain After Bimaxillary Surgery: A Retro-spective Study.

Bimaxillary surgery is a painful invasive procedure in plastic surgery. Pain control is typically achieved using intravenous analgesics. We aimed to investigate the efficacy of a novel temperature-responsive hydrogel, PF72, mixed with ropivacaine, as a local pain management solution when applied directly to the surgical site following orthognathic surgery. The study was conducted from October 2022 to July 2023 and included a cohort of 40 candidates for orthognathic surgery, encompassing LeFort I maxillary ostectomy and sagittal split ramus osteotomy. The participants were divided into an Injection group (n = 20), where PF72 was administered at the surgical site before the orthognathic surgery, and a Control group (n = 20), which relied solely on intravenous analgesics. Pain was evaluated at 3, 6, 24, 48, and 72 h after surgery using a numerical rating scale (NRS). The mean NRS scores at 24 h were 6.35 and 4 for the Control and Injection groups, respectively. The mean NRS scores at 72 h were 3.4 and 2.55 for the Control and Injection groups, respectively. Patients who received PF72 experienced less pain than those who received intravenous analgesics. These findings underscore the potential of PF72 as an effective alternative for enhancing pain management in patients undergoing orthognathic surgery.Level of Evidence III Therapeutic study. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Three-dimensional positioning of the maxilla using novel intermediate splints in maxilla-first orthognathic surgery for correction of skeletal class III deformity.

OBJECTIVES: Successful orthognathic surgery requires accurate transfer of the intraoperative surgical plan. This study aimed to (1) evaluate the surgical error of a novel intermediate splint in positioning the maxilla during maxilla-first orthognathic surgery and (2) determine factors influencing surgical error. MATERIALS AND METHODS: This prospective study examined 83 patients who consecutively underwent Le Fort I osteotomy for correction of skeletal class III deformity using a novel intermediate splint and a bilateral sagittal split osteotomy. Surgical error was the outcome variable, measured as the difference in postoperative translational and rotational maxillary position from the virtual plan. Measures included asymmetry, need and amount for mandibular opening during fabrication of intermediate splints, and planned and achieved skeletal movement. RESULTS: Mean errors in translation for vertical, sagittal, and transversal dimensions were 1.0 ± 0.7 mm, 1.0 ± 0.6 mm, and 0.7 ± 0.6 mm, respectively; degrees in rotation for yaw, roll, and pitch were 0.8 ± 0.6, 0.6 ± 0.4, and 1.6 ± 1.1, respectively. The transverse error was smaller than sagittal and vertical errors; error for pitch was larger than roll and yaw (both p < 0.001). Error for sagittal, transverse, and roll positioning was affected by the achieved skeletal movement (roll, p < 0.05; pitch and yaw, p < 0.001). Surgical error of pitch positioning was affected by planned and achieved skeletal movement (both p < 0.001). CONCLUSIONS: Using the novel intermediate splint when performing Le Fort I osteotomy allowed for accurate positioning of the maxilla. CLINICAL RELEVANCE: The novel intermediate splint for maxillary positioning can be reliably used in clinical routines.

Le fort I osteotomy with or without concomitant removal of upper third molars: A prospective cohort study of intraoperative findings, related complications, and level of pterygomaxillary separation after down-fracture.

The main objective of our study was to assess the clinical implications of concomitant intraoperative removal of maxillary third molars (M3M) with the Le Fort I osteotomy 'twist' technique (LF1twist). A prospective comparative study was carried out regarding the necessity of bone trimming around the pedicle, intra- and postoperative complications, surgery time, and the level of pterygomaxillary junction (PMJ) separation following LF1twist with concomitant intraoperative removal of M3M (test group) versus LF1twist alone (control group). Outcome parameters were assessed from clinical and radiographic measurements. In total, 100 surgery sites were included (50 in each group). The mean surgery time was 53.4 ± 7.8 min, with nonsignificant differences between groups. The frequency of intraoperative complications was negligible, with no significant differences between groups - though all bleeding events (n = 4) occurred when M3M was not removed concomitantly. No postoperative complications were recorded. Percentages of disarticulations occurring at the PMJ were similar in both groups. In conclusion, the results demonstrate that removal of M3M in conjunction with LF1twist does not imply additional surgery time, or differences regarding the level of PMJ separation or perioperative complications. Furthermore, the concomitant procedure reduces the amount of maxillary and palatal bone in the disjunction area, which facilitates down-fracture and field clearing for maxillary repositioning.

Surgery-First Orthognathic Approach for Correction of Dentofacial Deformity in Unilateral Cleft Lip and Palate.

BACKGROUND: Although several studies have reported the advantages of the surgery-first approach for orthognathic correction of class III deformity, there is no report of the success of this approach for patients with cleft lip and palate. Therefore, the purpose of this study was to evaluate the stability and outcome of bimaxillary surgery for cleft-related dentofacial deformity using a surgery-first approach. METHODS: Forty-one patients with unilateral cleft lip and palate who consecutively underwent Le Fort I and bilateral sagittal split osteotomies for skeletal class III deformity were included. Cone-beam computed tomographic scans before surgery, 1 week after surgery, and after orthodontic treatment were used to measure the surgical and postsurgical changes in jaw position by landmarks, and outcomes of jaw protrusion and relation, incisor angle and occlusion, and menton deviation after treatment. Self-report questionnaires regarding satisfaction with overall appearance of the face and seven facial regions were administered after treatment. RESULTS: A clinically insignificant relapse was found in the maxilla (<1 mm) and mandible (<2 mm). There was a significant improvement in the jaw protrusion and relation, incisor angle and occlusion, and menton deviation. Responses from the self-report questionnaires completed after treatment indicated that patient satisfaction was high. CONCLUSION: These findings demonstrate surgical-orthodontic treatment with a surgery-first approach can successfully improve cleft-related dentofacial deformity in patients with unilateral cleft lip and palate. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Objective assessment of visual attention in orthognathic surgery training based on eye tracking.

The aim of this study was to investigate the differences in visual attention between novices and orthognathic experts, as well as to provide evidence for use in developing and optimizing training strategies for orthognathic surgery. Novice and orthognathic experts were recruited, and their distributions of visual attention were monitored via an eye-tracking device while they watched orthognathic surgery videos. The percentages of visual fixation duration devoted to the areas of interest - surgical objects, instruments controlled by the main surgeon, and instruments controlled by the assistants - in each orthognathic surgery section were analyzed and compared between the two groups using repeated-measures factorial analysis of variance (ANOVA). In total, there were 18 participants, comprising both novices (n = 9) and experts (n = 9). For all sections of orthognathic surgery, the percentage of fixation duration on surgical objects was significantly higher for the novices than for the experts (p = 0.031, p = 0.005, p = 0.026, p = 0.047, p = 0.047, p = 0.031, p = 0.027, p = 0.034, p = 0.008, and p = 0.016). During the maxillary segment separation as part of Le Fort I osteotomy and the splitting of the mandible as part of bilateral sagittal split osteotomy, the novices also had a higher percentage of fixation duration on the instruments controlled by the main surgeon, as compared with the experts (p = 0.007 and p = 0.048, respectively). Novices invested great cognitive effort into the surgical objects in each section of orthognathic surgery, including the instruments controlled by the main surgeon in the maxillary segment separation and the splitting of the mandible. Strengthening this aspect of instruction could help novices reduce their cognitive load and achieve mastery more efficiently.

Does Anesthesiologist Experience Influence Early Postoperative Outcomes Following Orthognathic Surgery?

BACKGROUND: Anesthesia provider experience impacts nausea and vomiting in other surgical specialties but its influence within orthognathic surgery remains unclear. PURPOSE: The study purpose was to evaluate whether anesthesiologist experience with orthognathic surgery impacts postoperative outcomes, including nausea, emesis, narcotic use, and perioperative adverse events, for patients undergoing orthognathic surgery. STUDY DESIGN, SETTING, SAMPLE: This is a retrospective cohort study of subjects aged 12 to 35 years old who underwent orthognathic surgery, including Le Fort 1 osteotomy ± bilateral sagittal split osteotomy, at Boston Children's Hospital from August 2018 to January 2022. Subjects were excluded if they had incomplete medical records, a syndromic diagnosis, or a hospital stay of greater than 2 days. PREDICTOR VARIABLE: The predictor variable was attending anesthesia provider experience with orthognathic surgery. Providers were classified as experienced or inexperienced, with experienced providers defined as having anesthetized ≥10 orthognathic operations during the study period. MAIN OUTCOME VARIABLES: The primary outcome variable was postoperative nausea. Secondary outcome variables were emesis, narcotic use in the hospital, and perioperative adverse events within 30 days of their operation. COVARIATES: Study covariates included age, sex, race, comorbidities (body mass index, history of psychiatric illness, cleft lip and/or palate, chronic pain, postoperative nausea/vomiting, gastrointestinal conditions), enhanced recovery after surgery protocol enrollment, and intraoperative factors (operation performed, anesthesia/procedure times, estimated blood loss, intravenous fluid and narcotic administration, and anesthesiologist's years in practice). ANALYSES: χ2 and unpaired t-tests were used to compare primary predictor and covariates against outcome variables. A P-value <.05 was considered significant. RESULTS: There were 118 subjects included in the study after 4 were excluded (51.7% female, mean age 19.1 ± 3.30 years). There were 71 operations performed by 5 experienced anesthesiologists (mean cases/provider 15.4 ± 5.95) and 47 cases by 22 different inexperienced providers (mean cases/provider 1.91 ± 1.16). The nausea rate was 52.1% for experienced providers and 53.2% for inexperienced providers (P = .909). There were no statistically significant associations between anesthesiologist experience and any outcome variable (P > .341). CONCLUSIONS AND RELEVANCE: Anesthesia providers' experience with orthognathic surgery did not significantly influence postoperative nausea, emesis, narcotic use, or perioperative adverse events.

Hemostatic Efficacy of Oxidized Regenerated Cellulose Powder in Le Fort 1 Osteotomy.

A challenging aspect of Le Fort I osteotomy is bleeding control. Osteotomy techniques, devices, drugs, and anesthetic management have been reported to reduce bleeding; however, there are no reports on the use of hemostatic agents. We aimed to evaluate the hemostatic efficacy of a new topical absorbent hemostatic agent, Surgicel Powder, consisting of oxidized regenerated cellulose (ORC). We reviewed the records of 40 patients who underwent Le Fort I surgery for jaw deformities, with or without cleft lip and palate. Twenty of the 40 patients did not have cleft lips or cleft palates (CLCP); the remaining 20 had CLCP. In each group, an absorbent hemostatic agent was used in 10 patients but not in the other 10. Total blood loss and operative time for each group were evaluated. In the jaw deformity without CLCP group, the amount of bleeding with or without ORC was 112.0±33.8 and 158.6±75.3 mL, respectively, with a significant difference between groups ( P <0.05). Operative time with or without ORC was 206.4±31.3 and 238.3±42.5 minutes, respectively, with a significant difference observed between groups ( P <0.05). In the jaw deformity with CLCP group, the amount of bleeding with or without ORC was 199.7±64.6 and 476.8±104.8 mL, respectively, with a significant difference between groups ( P <0.05). Operative time with or without ORC was 213.7±27.6 and 220.8±41.5 minutes, respectively, with no significant difference between groups ( P =0.329). In conclusion, oxidized regenerated cellulose powder may be a beneficial hemostatic agent for reducing blood loss during Le Fort I osteotomy.

[Three-dimensional comparative study on the stability of bimaxillary simultaneous genioplasty and simple genioplasty].

PURPOSE: To establish a three-dimensional method to evaluate whether there is a difference in stability between bimaxillary simultaneous genioplasty and simple genioplasty. METHODS: This study was a retrospective study. Sixty patients who underwent genioplasty were selected. They were divided into bimaxillary simultaneous genioplasty group (n=30) and simple genioplasty group (n=30). The spiral CT data of patients at 2 months before operation (T0), 7 days after operation (T1) and 12 months after operation (T2) were collected, reconstructed and separated, and the three-dimensional model of maxilla and mandible was obtained. A three-dimensional analysis method of stability was established by 3D-matching. Recurrences in three-dimensional space 12 months after surgery were analyzed in two groups of patients. Statistical analysis of the data was performed with SPSS 26.0 software package. RESULTS: In simple genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.54±0.38) mm, and the sagittal recurrence rate was 12.27%. In bimaxillary simultaneous genioplasty, the maximum amount of the chin recurrence was sagittal backward recurrence (0.60±0.31) mm, and the sagittal recurrence rate was 12.96%. Rotation occurred in both groups 12 months after operation, which was 1.98±2.70° in the simple genioplasty group and 1.01±1.61° in the bimaxillary simultaneous genioplasty group(P＜0.05). There was no significant difference in the sagittal movement of the chin between the two groups, and in the sagittal recurrence(P＞0.05). CONCLUSIONS: The three-dimensional method established in this study can be used to evaluate the stability after genioplasty. The recurrence after genioplasty mainly occurred in the sagittal direction. The rotation trend of chin after genioplasty is worthy of attention. There was no increased risk for bimaxillary simultaneous genioplasty.

Does mandibular osteotomy affect the infraorbital nerve? a prospective study.

OBJECTIVES: The aim of this study was to evaluate the sensory function of the infraorbital nerve after orthognathic surgery (OS). MATERIALS AND METHODS: Patients who underwent Le Fort I osteotomy with or without BSSO for dentofacial deformity treatment were studied. Two groups were created according to whether BSSO was performed. Class A tests were performed to determine the degree of peripheral nerve damage. The Class B test was performed if decreased sensation was detected in at least one of these tests. A Class C test was performed if abnormal sensation was detected. RESULTS: Twenty-eight patients (n=56) who underwent OS were included in this prospective study. Of the patients, 57.1% were female, 42.9% were male, and the mean age was 24.6 (±3.8). Seven patients were in group 1 (n=14), and 21 patients were in group 2 (n=42). In both groups, there were statistically significant differences between T1 and T2 (p<0.001), and the mean NSD score at T2 was higher than that at T1. The mean NSD score in the single jaw group was higher than that in the double jaw group at all time points. CONCLUSIONS: Bimaxillary surgeries had a negative effect on the somatosensory changes that developed in the early period. The upper lip's somatosensorial recovery was faster than IOR and single jaw recovery was faster than double jaw. CLINICAL RELEVANCE: Maxillofacial surgeons performing orthognathic surgery should be aware that in double jaw operations, changes in the somatosensory function of the ION are more severe.

Factors affecting the relapse of maxilla and soft tissues of nose, upper lip and velopharyngeal structures after maxillary advancement in cleft patients.

The objectives of this study were to find the factors affecting the relapses after maxillary advancement in cleft patients. This retrospective study included 25 cleft patients. The serial lateral cephalograms were used for the evaluation of the maxilla and the soft tissue relapses in 1-year post-operative period. The skeletal relapse rate correlated with the amount of skeletal movement only in horizontal direction (r = 0.483, p = 0.015). The patients with significant skeletal relapse did not have different amount of soft tissue relapses when compared to the patients without significant skeletal relapse, except for the A' point. Relapses of the soft tissue parameters of the upper lip and nose were correlated with the upper incisor tip position horizontally and vertically. When comparing the patients who underwent maxillary distraction (DO) with the patients who underwent conventional orthognathic surgery (CO), the DO group had greater NLA relapse and increase of pharyngeal depth than the CO group.

Avaliação da fixação dos avanços maxilares pela técnica de osteotomia Le Fort I / Evaluación de la fijación de avances maxilar mediante la técnica de osteotomía Le Fort I / Evaluation of the fixation of maxillary advancements by the Le Fort I osteotomy technique

Introdução: A osteotomia Le Fort I possibilita a correção de deformidades dentofaciais que envolvem o terço médio da face. Para sua fixação, convencionou-se o emprego de quatro mini-placas nos pilares zigomático-maxilar e nasomaxilar. Propôs-se então, a dispensa da fixação do segmento posterior, surgindo questionamentos relacionados à capacidade biomecânica do sistema. Objetivos: Comparar o estresse biomecânico gerado em três meios distintos de fixação da osteotomia Le Fort I frente ao movimento de avanço sagital linear maxilar de 7mm. Metodologia: Trata-se de uma pesquisa experimental laboratorial, utilizando-se da análise de elementos finitos como ferramenta analítica, a fim de constatar qual das técnicas sofrerá maior estresse biomecânico. Resultados: Constatou-se que o estresse biomecânico gerado é maior quando aplicado em 4 pontos do que quando aplicado em apenas 2 pontos. Conclusão: Os resultados obtidos fornecem informações aos cirurgiões sobre a real necessidade do uso de fixação adicional de acordo com o método de fixação planejado. No entanto, deve ser interpretado de forma cautelosa, considerando-se as limitações deste estudo. Sendo assim, uma análise incipiente, que tem como intuito o fornecimento de evidência científica de grande significância.

Introducción: La osteotomía Le Fort I permite la corrección de deformidades dentofaciales que involucran el tercio medio de la cara. Para su fijación se acordó utilizar cuatro miniplacas en los pilares cigomaticomaxilar y nasomaxilar. Entonces se propuso prescindir de la fijación del segmento posterior, planteando interrogantes relacionados con la capacidad biomecánica del sistema. Objetivos: Comparar el estrés biomecánico generado en tres medios diferentes de fijación de la osteotomía Le Fort I frente a un movimiento de avance sagital lineal maxilar de 7mm. Metodología: Se trata de una investigación experimental de laboratorio, utilizando como herramienta analítica el análisis de elementos finitos, con el fin de comprobar cuál de las técnicas sufrirá un mayor estrés biomecánico. Resultados: Se encontró que el estrés biomecánico generado es mayor cuando se aplica en 4 puntos que cuando se aplica solo en 2 puntos. Conclusión: Los resultados obtenidos brindan información a los cirujanos sobre la necesidad real de utilizar fijación adicional de acuerdo al método de fijación planificado. Sin embargo, debe interpretarse con cautela, considerando las limitaciones de este estudio. Por tanto, un análisis incipiente, que pretende aportar evidencias científicas de gran trascendencia.

Introduction: The Le Fort I osteotomy allows the correction of dentofacial deformities involving the middle third of the face. For its fixation, it was agreed to use four mini plates on the zygomaticomaxillary and nasomaxillary pillars. It was then proposed to dispense with the fixation of the posterior segment, raising questions related to the biomechanical capacity of the system. Objectives: To compare the biomechanical stress generated in three different means of fixation of the Le Fort I osteotomy against a 7mm maxillary linear sagittal advancement movement. Methodology: This is an experimental laboratory research, using finite element analysis as an analytical tool, in order to verify which of the techniques will suffer greater biomechanical stress. Results: It was found that the biomechanical stress generated is greater when applied to 4 points than when applied to only 2 points. Conclusion: The results obtained provide information to surgeons about the real need to use additional fixation according to the planned fixation method. However, it should be interpreted with caution, considering the limitations of this study. Therefore, an incipient analysis, which aims to provide scientific evidence of great significance.