Does Maxillomandibular Fixation Technique Affect Occlusion Quality in Segmental LeFort I Osteotomy?

BACKGROUND: Segmental maxillary osteotomies require precise occlusal control due to variability in individual segment positioning. The role of maxillomandibular fixation (MMF) technique on occlusal control has not been validated. PURPOSE: The purpose is to measure and compare the accuracy of occlusal positioning among MMF techniques. STUDY DESIGN, SETTING, SAMPLE: This was a double-blinded in vitro study on experiment models to simulate a 3-piece LeFort I osteotomy. The models were constricted posteriorly and expanded using 3 different MMF techniques and compared to the unaltered baseline occlusion. Based on sample size calculation, 32 separate attempts were made for each MMF technique. PREDICTOR VARIABLE: The predictor variable was MMF technique (brackets, MMF screws, and embrasure wires). MAIN OUTCOME VARIABLES: The primary outcome variable was the visual occlusal analysis score, a 1.00 to 4.00 continuous scale measuring the similarity of the achieved occlusion to the planned (control) occlusion assessed by an oral and maxillofacial surgeon and an orthodontist. High visual occlusal analysis score indicated greater occlusal accuracy, with 3.50 defined as the threshold for accuracy. The secondary outcome variable was the linear error of the achieved occlusion at the canine and first molar teeth, with lower error indicating greater accuracy. An a priori accuracy threshold of 0.5 mm was set for this variable. COVARIATES: None. ANALYSES: Kruskal-Wallis test with post hoc testing was used to analyze the difference in the outcome variables of interest. P value < .05 was considered statistically significant. RESULTS: Thirty-two attempts for each technique showed that brackets had higher VAOS than MMF screws and embrasure wires (median differences 1.49 and 0.48, P < .001), and had lower linear occlusal error (median differences 0.35 to 0.99 mm, P < .001). CONCLUSION AND RELEVANCE: MMF technique influences the quality of occlusal control, with greater visual rating scores and lower linear errors seen with brackets than with embrasure wires or MMF screws.

Monitoring of Home Respiratory Polygraphy During Mandibular Distraction Osteogenesis Succeeded by LeFort I Osteotomy in Adult Patients With Obstructive Sleep Apnea.

BACKGROUND: Bilateral internal ramus distraction (BIRD) is now part of select protocols for treating obstructive sleep apnea (OSA). Introducing a home monitoring protocol offers a valuable alternative to overnight laboratory polysomnography (PSG). PURPOSE: The purpose of this study was to evaluate and compare OSA parameters obtained via home respiratory polygraphy (HRP) and hospital PSG in a cohort of patients undergoing mandibular distraction for OSA management. STUDY DESIGN, SETTING, SAMPLE: Hospital Universitario La Princesa (Madrid) researchers conducted a prospective cohort study with patients diagnosed with moderate (apnea-hypopnea index (AHI) = 15 to 30) to severe (AHI>30) OSA undergoing BIRD followed by LeFort maxillary osteotomy. Exclusion criteria were as follows: severe systemic diseases, central apneas, smoking, poor dental hygiene, or prior OSA interventions. PREDICTOR VARIABLE: The predictor variable was PSG and HRP techniques. MAIN OUTCOME VARIABLES: The main outcome variable comprises a collection of OSA parameters, including the AHI, oxygen desaturation index (ODI), and time spent below 90% oxygen saturation (T90). These data were measured both before and after distraction, as well as after 6 mm, 9 mm, and 12 mm of mandibular distraction. COVARIATES: The covariates were age, sex, cardiovascular risk parameters, and the Epworth sleepiness scale. ANALYSES: Pearson's correlation analyzed AHI, ODI, and T90 values from PSG and HRP. Wilcoxon Signed Rank-Sum Test compared 2 distraction stages, and the Friedman Test evaluated 3 stages (P < .05). Multiple regression analysis assessed if covariates were independent risk factors for postoperative persistent OSA. RESULTS: The study included 32 patients (25% with moderate and 75% with severe OSA). Final AHI was 10.9 ± 8.9 (events/hour) with HRP, compared to 15.2 ± 13.4 with PSG (r = 0.7, P < .05). ODI was 9.0 ± 8.1 (des/h) with HRP and 8.7 ± 9.5 with PSG (r = 0.85, P < .05). T90 was 1.6 ± 2.2 with HRP and 1.3 ± 3.0 with PSG (r = 0.6, P < .05). Based on HRP data, AHI improved from D1 (34.0 ± 19.5) to D2 (20.8 ± 14.1) and D3 (12.5 ± 10.4) (P < .05). ODI decreased from D1 (26.1 ± 19.0) to D2 (16.0 ± 12.6) and D3 (9.4 ± 8.8) (P < .05). T90 reduced from D1 (8.2 ± 12.6) to D2 (4.1 ± 5.2) and D3 (1.9 ± 2.8) (P < .05). Multiple regression analysis of comorbidities produced nonsignificant results. CONCLUSION AND RELEVANCE: Monitoring BIRD through HRP has demonstrated efficacy in yielding results that align with PSG.

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.

Assessment of the Change in the Nasal Septum and Nasal Profile After Le Fort I With Cone Beam Computed Tomography.

OBJECTIVE: This study aimed to determine the relationship between nasal changes and the amount of advancement, impaction, and downward movement of the maxilla after Le Fort I osteotomy. METHODS: The study included 48 patients who underwent Le Fort I surgery and had pre- and postoperative cone-beam computed tomography records. Changes in the nasal septum were evaluated by measuring septal deviation angles and volumes. In addition, nasolabial angle and width of nasal and alar base were examined. Groups were determined according to the movement of point A (the deepest point on the curvature of the maxillary alveolar process), using a threshold of 1.5 mm for vertical movements and 4 mm for sagittal movements. This resulted in the comparison of 6 groups of 8 people each. Results are presented as mean and standard deviation or median and range depending on the data distribution. Significance level was accepted as P < 0.05. RESULT: There were no significant differences for each group on its own septal deviation volume or angle values pre/postoperatively. Groups 3 and 5, which both had at least 1.5 mm of impaction, showed significant changes in both deviation angle and volume between the preoperative and postoperative measurements. Nasolabial angle did not show significant changes between groups. Alar base width and nasal width increase was significantly highest in Group 1, which has more than 4 mm sagittal movement and less than 1.5 mm vertical movement. CONCLUSIONS: Le Fort I osteotomy may lead to undesirable changes in the spatial positioning of the nasal septum. The results of this study suggest that maxillary advancement does not significantly impact septal deviation, whereas maxillary impaction increases the amount of deviation. In addition, nasal width and alar base width tended to increase, and the nasolabial angle tended to decrease slightly, regardless of the direction of movement of the maxilla after orthognathic surgery. CLINICAL RELEVANCE: Surgeons should consider increased nasal septal deviation risks when planning impaction of the maxilla. The soft tissue changes in the nose vary according to different directions and amounts of Le Fort I surgery.

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).

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.

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.

Stability between single and segmental maxillary osteotomies in bimaxillary surgery for cleft-associated class III deformity: a CBCT study.

OBJECTIVE: Segmental Le Fort I osteotomy through the cleft is a common strategy to narrow the alveolar cleft in adults. This study compared skeletal stability between single and segmental Le Fort I osteotomies in patients with unilateral cleft lip and palate (UCLP). MATERIALS AND METHODS: This retrospective analysis examined 45 adults with complete UCLP-associated class III deformities who underwent bimaxillary surgery with either single (n = 30) or segmental (n = 15) Le Fort I advancement. Cone beam computed tomography (CBCT) scans of the facial skeleton were acquired before surgery, 1-week postsurgery, and at follow-up. Measures of landmarks from the CBCT images for the two treatment groups were compared for translation (left/right, posterior/anterior, superior/inferior) and rotation (yaw, roll, pitch). RESULTS: Postsurgery, the downward movement of the maxilla was larger in the segmental group than the single group. At follow-up, the maxilla moved backward in both groups, and upward in the segmental group. The mandible moved forward and upward and rotated upward in both groups. The amount of upward movement and rotation was larger in the segmental group than the single group. CONCLUSIONS: Two years after bimaxillary surgery in patients with UCLP-associated class III deformity, greater relapse was found after segmental Le Fort I osteotomies in vertical translation of the maxilla and mandible, and pitch rotation of the mandible compared with single Le Fort I osteotomies. CLINICAL RELEVANCE: The vertical relapse of the maxilla was larger after segmental Le Fort I advancement compared with single Le Fort I advancement in clefts.

Site and severity of facial asymmetry after bimaxillary surgery for class III deformity: a case-control study.

OBJECTIVES: The study aimed (1) to evaluate the site and severity of facial asymmetry in Class III patients before and after bimaxillary surgery, and (2) to identify the influence of initial severity and positional jaw asymmetry on residual facial asymmetry. MATERIALS AND METHODS: Preoperative and postoperative cone-beam computed tomography of 65 patients with Class III facial asymmetry who underwent bimaxillary surgery were evaluated. Five midline and 14 paramedian facial soft tissue landmarks were identified to assess facial asymmetry. The outcomes were compared to a control group consisting of 30 age- and gender-matched Class I subjects. The postoperative positional jaw asymmetry (i.e., shift, roll, yaw) of each osteotomy segment (maxilla, mandible, chin, ramus) was also measured. RESULTS: Before surgery, the asymmetry was more severe at the chin, middle and lower contour. Bimaxillary surgery effectively corrected facial asymmetry, particularly in achieving normalization of chin deviation. However, significant asymmetry persisted postoperatively in the middle and lower contour (p < 0.001 and p < 0.01, respectively), which was affected by the positional ramus asymmetry in the roll and shift. CONCLUSIONS: Deviation of the chin, middle and lower contour contributed significantly to overall facial asymmetry in Class III asymmetry. Despite normalization of the chin deviation after bimaxillary surgery, asymmetry persisted at the middle and lower contour, primarily as the result of insufficient correction of the positional ramus asymmetry. CLINICAL RELEVANCE: Understanding the residual asymmetry after bimaxillary surgery is important for minimizing deviation and optimizing the surgical planning for its correction.

Lefort 1 Osteotomy Study of Maxillary Bone in Caprine Skull Model: Comparison of Different Osteotomy Techniques (Piezo Versus Lindemann Bur Versus Manual Chisel).

OBJECTIVE: In this study, we aimed to compare the efficiency of different osteotomy techniques for Lefort 1 osteotomy in an experimental caprine skull model. METHODS: Twelve caprine skulls were used for the study. Skulls were divided into 3 groups: (1) manual chisel group, (2) Lindemann bur group, and (3) piezo osteotomy group. Bilateral osteotomies were performed on each skull. Results were evaluated with three-dimensional computerized tomography scans and macroscopic observations of the mucosal tears and soft tissue. RESULTS: The mean length of the bone gap in the manual, Lindemann, and piezo groups was 4.8 (±0.7), 3.38 (±1.49), and 1.39 (±0.3) mm, respectively ( P < 0.05). The mean number of comminuted fractures in the manual, Lindemann, and piezo groups was 5.5 (±1.4), 1.6 (±0.3), and 0.6 (±0.5), respectively ( P < 0.05). Mucosal tearing and soft tissue damage based on subjective inspection observations were negligible in the piezo technique. Soft tissue and mucosal damage were observed significantly more in the manual chisel osteotomy method compared with the other 2 techniques. CONCLUSION: We anticipate that piezo, which has started to be used in new application areas besides rhinoplasty, will continue to be used more widely, especially in reconstructive orthognathic surgery, due to the minimal damage it causes to tissues. With the long-term results, much healthier interpretations can be made.

Comparison of Skeletal Stability after Le Fort I Osteotomy With Bone Fixation Using Biodegradable and Titanium Systems: A Retrospective Study.

The titanium osteosynthesis system used for fixing bone segments after maxillary osteotomy provides reliable outcomes owing to its biocompatibility and adequate strength. In addition, several studies have evaluated the skeletal stability after maxillary osteotomy with fixation using a biodegradable system. However, the indications for applying a biodegradable system after maxillary osteotomy remain controversial. Therefore, this study aimed to compare the long-term skeletal stability of bone segments after maxillary osteotomy with bone fixation using biodegradable and titanium osteosynthesis systems and to assess the usefulness of a biodegradable osteosynthesis system. Patients who underwent Le Fort I osteotomy of the maxilla to correct jaw deformities between April 2008 and March 2021 were included in this study. A total of 45 patients were included, with 28 in the biodegradable osteosynthesis system group and 17 in the titanium group. Cephalometric and computed tomography analyses were performed to evaluate the skeletal stability of the bone segments after maxillary osteotomy with bone fixation using biodegradable or titanium osteosynthesis systems. The maxillary segment was repositioned anteriorly with a clockwise rotation. Skeletal stability was similar between the biodegradable and titanium osteosynthesis systems. Segmental changes occurred mainly in the first 6 months after surgery, and the segment was completely stable between 6 and 12 months after surgery. This study revealed no significant differences in skeletal stability after maxillary osteotomy between the biodegradable and titanium osteosynthesis systems. However, the findings in this study should be interpreted with caution owing to the small sample size and small amount of maxillary-segment movement.

Rehabilitation of Severely Atrophic Maxilla with Le Fort I Advancement Surgery and Subperiosteal Implant in a Patient With Ectodermal Dysplasia.

OBJECTIVES: In this case, the patient with ectodermal dysplasia lost his teeth and acquired maxillary insufficiency. The aim of this case is to advance the maxilla using Le Fort I surgery and make fixation with a subperiosteal implant. METHODS: On the three-dimensional model, a surgical guide for Le Fort I osteotomy and subperiosteal implant design was planned. In the surgery, Le Fort I osteotomy was made according to the guide, and maxillary advancement was obtained, then a subperiosteal implant was fixated. Prosthetic rehabilitation was made after 1 month. RESULTS: Maxillary repositioning is obtained according to virtual planning and subperiosteal implant is used for both fixation and prosthetic rehabilitation. Proper fixation is ensured and full arch prosthetic rehabilitation supported by a subperiosteal implant is performed. CONCLUSION: With this technique, in the rehabilitation of atrophic maxilla, sagittal insufficiency is corrected with Le Fort 1 surgery, whereas the patient's treatment period is shortened by placing a subperiosteal implant at the same time.

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.

The Efficiency of Segmental Le Fort I Surgery in Clear Aligner Therapy of Skeletal Class III Deformity: A Pilot Study.

INTRODUCTION: The purpose of this study was to investigate the efficiency of segmental Le Fort I osteotomy in clear aligner therapy of skeletal Class III deformities and to explore whether Le Fort I segmental osteotomy was effective for maxillary incisor axis correction and reduced the duration of perioperative orthodontics. MATERIALS AND METHODS: Patients who had skeletal Class III deformities (ANB<0) treated with extraction of the maxillary first premolars, segmental Le Fort I osteotomy, and clear aligners therapy were included in this retrospective study. We measured the amount of tooth extraction space that was closed by surgery and recorded the preoperative orthodontic and total treatment duration. Lateral cephalograms were analyzed to measure changes of maxillary incisor inclination before treatment (T0), 1 week before surgery (T1), 1 week after surgery (T2), and after total orthodontic treatment (T3). Statistical analyses were performed, and the P value was set at 0.05. RESULTS: The sample was composed of 15 patients aged 19 to 30 (M=22.9) years. The average preoperative orthodontic treatment duration was 16.2±5.22 mo, with 33.5 pairs of clear aligners. The gap at the extraction site decreased from 5.42±1.57 mm to 0.80±0.62 mm on average after surgery. U1-SN and U1-NA(deg) increased sparingly with preoperative decompensation, decreased in quantity after surgery, and then slightly increased with postoperative compensation (T20.05). CONCLUSIONS: Le Fort I segmental osteotomy assisted decompensation of the upper anterior teeth and reduced the duration of preoperative orthodontics with clear aligners.

Mandibular Body Osteotomy Combined with Sagittal Split Ramus Osteotomy for the Treatment of Severe Skeletal Class â ¢ Malocclusion with Ankylosed Teeth.

This study presents a combination of 2 different surgery procedures performed on the mandible as part of the treatment aiming to improve the facial profile and occlusal function of patients with severe skeletal class Ⅲ malocclusion and bilateral edentulous gaps. The teeth next to the edentulous gaps were found to be ankylosed. Mandibular setback by bilateral sagittal split ramus osteotomies and mandibular body osteotomies, combined with Le Fort Ⅰ level maxillary advancement were performed, since the chief complaint of the patient was a concave profile. As a result, the skeletal class Ⅲ malocclusion had been corrected, a satisfying facial profile had been achieved, and no apparent adverse effect was found. Thus, it has been proved that the combination of sagittal split ramus osteotomy and mandibular body osteotomy is available for correcting skeletal class Ⅲ malocclusion.

The Evaluation of Condylar Position Change in the Asymmetric Mandible Following Sagittal Split Osteotomy.

BACKGROUND: The change of condyle position following orthognathic surgery affects the stability of treatments. This study aims to assess the correlation between the amount of condyles' position change and the severity of mandibular asymmetry following BSSO. MATERIALS AND METHODS: This is a cross-sectional study. Subjects with asymmetric mandibular prognathism following BSSO were studied. Subjects were classified into 2 groups: group 1, subjects had mandibular asymmetry without occlusal cant and underwent BSSO. Group 2, subjects had mandibular asymmetry with occlusal cant and underwent BSSO+ Lefort I osteotomy. The condyle position was evaluated using cone-beam computer tomography (CBCT). Pearson's correlation test was used to assess any correlation between the condyle changes and the change in the mandible in sagittal and anterior-posterior directions. RESULTS: A total of 44 subjects were studied. In group 1, the condyle tilted outward in the deviated condyle and inward in the non-deviated condyle immediately after osteotomy. After 12 months, both condyles showed a rotation relative to the original position. In group 2, the condyles of the deviated sides and non-deviated sides moved inferiorly after surgery (condylar sagging), which was more significant in the non-deviated sides. The condyle rotation was similar to group 1. The severity of asymmetry and occlusal cant correlate with the condylar position change in the two groups. CONCLUSION: The severity of mandibular asymmetry correlates with the amount of condyles' position change immediately after BSSO. However, the condyles tend to return to their original position 12 months later.

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 .

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.

Determination of safety margin of nasal septum osteotomy for sphenoid sinus in cleft lip and palate patients.

BACKGROUND: Nasal septum osteotomy is used for separating the nasal septum and maxilla during a Le Fort I osteotomy. If this osteotomy is applied too high or is tilted into the nasal cavity, the sphenoid sinus and various adjacent vital structures may be damaged, and serious bleeding, neurological complications, blindness or even death may occur. The aim of this study is to determine the safety margin of the nasal septum osteotomy for sphenoid sinus during the Le Fort I surgery in cleft lip and palate (CLP) patients. METHODS: Twenty cleft lip and palate (the CLP group) and 20 healthy individuals (the control group) were included in this study. Three values (two lines and an angle) were measured by cone beam computed tomography (CBCT). The first line is the line passing through the junction of the spina nasalis anterior point and the lower point of the perpendicular lamina of the palatine bone. The undersired line is the line passing through the junction of the spina nasalis anterior point and the lower anterior border of the base of the sphenoid sinus. The osteotomy angle is the angle between these two lines. RESULTS: In the control group; a surgical line of 44.11-61.14 mm (mean 51.91 ± 4.32), an undesired line of 52.48-69.58 mm (mean 59.14 ± 5.08) and an angle of 18.22-27.270 (mean 22.66 ± 2.55) were found, while in the CLP group, a surgical line of 34.53-51.16 mm (mean 43.38 ± 4.79), an undesired line of 46.86-61.35 mm (mean 55.02 ± 3.24) and an angle of 17.60-28.810 (mean 22.60 ± 2.81) were found. CONCLUSIONS: Although the angle to the sphenoid sinus was not significantly affected by CLP, careful planning and consideration of these anatomical differences are crucial to prevent complications and ensure the safety of Le Fort I surgery in CLP patients. Further research with larger sample sizes and subgroup analysis of unilateral and bilateral CLP cases is needed to improve our understanding of these anatomical variations and improve surgical approaches to individuals with CLP undergoing orthognathic procedures.

Detection of multidrug-resistant bacteria in the nasal cavities and evaluation of sinus disorders in patients undergoing Le Fort I osteotomy.

INTRODUCTION: Orthognathic surgery can lead to sinus alterations, including sinusitis, attributed to the exposure of maxillary sinuses during Le Fort I osteotomy. Furthermore, being a hospital-based procedure, there is potential risk of complications arising from bacteria prevalent in such environments. This study evaluated maxillary sinusitis occurrence and the presence of multidrug-resistant bacteria in the nasal cavity before and after orthognathic surgery. METHODS: Ten patients with dentofacial deformities underwent Le Fort I osteotomy. Clinical evaluations using SNOT-22 questionnaire were performed, and nasal cavity samples were collected pre-surgery and 3-6 months post-surgery to quantify total mesophilic bacteria and detect Staphylococcus aureus, Acinetobacter baumannii, and Klebsiella pneumoniae. Cone Beam Computed Tomography (CBCT) was performed pre- and post-operatively, and the results were evaluated using the Lund-Mackay system. This study was registered and approved by the Research Ethics Committee of PUCRS (No. 4.683.066). RESULTS: The evaluation of SNOT-22 revealed that five patients showed an improvement in symptoms, while two remained in the same range of interpretation. One patient developed post-operative maxillary sinusitis, which was not detected at the time of evaluation by SNOT-22 or CBCT. CBCT showed a worsening sinus condition in three patients, two of whom had a significant increase in total bacteria count in their nasal cavities. The Brodsky scale was used to assess hypertrophy in palatine tonsils, where 60% of the subjects had grade 1 tonsils, 20% had grade 2 and 20% had grade 3. None of the patients had grade 4 tonsils, which would indicate more than 75% obstruction. Two patients harboured S. aureus and K. pneumoniae in their nasal cavities. Notably, K. pneumoniae, which was multidrug-resistant, was present in the nasal cavity of patients even before surgery, but this did not result in maxillary sinusitis, likely due to the patients' young and healthy condition. CONCLUSION: There was an improvement in signs and symptoms of maxillary sinusitis and quality of life in most patients after orthognathic surgery. However, some patients may still harbour multidrug-resistant bacteria, even if they are asymptomatic. Therefore, a thorough pre-operative assessment is essential to avoid difficult-to-treat post-operative complications.