The evaluation of nasolacrimal duct injury in Le Fort I osteotomy patients / Evaluación de la lesión del conducto nasolagrimal en pacientes con osteotomía Le Fort I

Background: Although Le Fort I surgeries are safe and successful procedures; nasolacrimal duct injuries may be observed due to these surgeries. The study aimed to investigate the prevalence of nasolacrimal duct injury in Le Fort I osteotomy patients. Material and Methods: The authors conducted a retrospective cohort study consisting of patients who underwent Le Fort I osteotomies between 2017 and 2021 in the Erciyes University Faculty of Dentistry. The primary predictor variables were the distance of the nasolacrimal canal to the outer cortex of the maxilla and the nasal floor, as well as the superior-inferior level of the superiorly positioned screw inserted in the maxilla aperture region relative to the nasolacrimal canal. The outcome variable was the presence of a nasolacrimal duct injury. Mann Whitney U test was used for quantitative variables between the two groups. A Pearson chi-squared analysis was used to compare categorical data. A p-value <0.05 was considered statistically significant.Results: A total of 290 nasolacrimal canals were evaluated in 145 patients, 87 females, and 58 males. The mean age was 23.47± 6.67. There was a statistically significant relationship between screw level and nasolacrimal canal perforation (p<0,001). The distance between the most anterior border of the nasolacrimal canal and the outer cortical of the maxilla was significantly less in the perforation group (p<0,001). The fixation screw was significantly closer to the nasolacrimal canal in the perforation group (p<0,001). Conclusions: In Le Fort I surgery, nasolacrimal duct injury may occur during screw fixation to the aperture region. Superiorly positioned fixation screws in the aperture region may damage the nasolacrimal canal. In patients where the nasolacrimal canal is close to the outer cortex, care should be taken when applying the fixation screws to the aperture region to avoid damaging the canal.(AU)

Dental discoloration following Le Fort 1 osteotomy, a systematic review.

INTRODUCTION: This study was conducted to review current knowledge concerning factor and how to proceed with dental discoloration after Le Fort 1 osteotomy (LF1O). MATERIAL & METHODS: A systematic search of the literature was performed in PubMed/Medline and Cochrane library until December 1, 2020 using the following key words: "dental discoloration and osteotomy", "dental discoloration and Le Fort", "dental discoloration and orthognathic", "dental discoloration and surgery", "tooth discoloration and osteotomy", "tooth discoloration and Le Fort", "tooth discoloration and orthognathic", "tooth discoloration and surgery". RESULTS: 705 studies were located by initial screening; 232 were duplicate, 468 did not meet the eligibility criteria, leaving 5 studies. The post-operative follow-up period of the included studies ranged from 6 months to 2 years. CONCLUSION: The present revue found dental discoloration can occur after LF1O in 3.56% of the cases. The follow-up before treatment should be around one years. If the discoloration persisted and pulpal sensibility test is negative, the tooth should be treated. If the pulpal sensibility test is positive, follow-up should be carry on.

An extremely rare pseudoaneurysm of posterior superior alveolar artery arising after orthognathic surgery.

Le Fort 1 osteotomy is one of the most versatile techniques in orthognathic surgery employed for the correction of dentofacial deformities and is considered technically safe. Pseudoaneurysms (PAs) which can cause life-threatening hemorrhage are rare after corrective jaw surgery. Here, we describe a clinical case of delayed postoperative epistaxis secondary to an extremely rare PA of the posterior superior alveolar artery followed by Le Fort 1 osteotomy subsequently managed with endovascular selective embolization.

A case of extreme skeletal class III Malocclusion beyond the envelope of discrepancy, managed effectively by a modified ortho-surgical protocol.

Correction of severe anteroposterior skeletal discrepancy, as described in this case of Extreme Skeletal Class III Malocclusion, can be challenging and fraught with difficulties. Conventional, single stage Bi-jaw Orthognathic surgery, with pre-and post-surgical orthodontics is associated with drawbacks such as risk of relapse and an unsatisfactory outcome, with persisting occlusal discrepancies and skeletal abnormalities, especially when the magnitude of skeletal correction is large. Excessive mandibular setback restricts tongue space, narrows the posterior airway and pharyngeal spaces, and is prone to relapse from the forward pterygomasseteric pull; while large maxillary advancements are accompanied by wound dehiscence, bone exposure and delayed union at the site of pterygomaxillary disjunction, and risk of relapse due to backward palatopharyngeal pull. Bi-jaw surgeries invariably involve considerable blood loss and prolonged operating time with its attendant anaesthetic risks. These drawbacks may be obviated by employing a two staged protocol of Bi-jaw surgeries allowing a minimum time period of 3 months to elapse between them, which allows the oral and maxillofacial musculature to adapt itself to the new jaw position following the first surgery, thus creating a better and more stable environment for the succeeding one. This reduces the chance of relapse thereafter, and produces more effective and stable long term results. The intervening time period also allows for observation of the repositioned jaw and arch relations achieved, and scrutiny for any positional changes in this post-surgical phase, which thereby allows modifications in the planned surgery of the next jaw, thereby achieving the most ideal final outcome.

A Case of Extreme Skeletal Class III Malocclusion Beyond the Envelope of Discrepancy, Managed Effectively by a Modified Ortho-Surgical Protocol.

INTRODUCTION: Correction of a severe anteroposterior skeletal discrepancy, as described in this case of extreme skeletal class III malocclusion, can be quite challenging and fraught with difficulties. Conventional, single-stage bi-jaw orthognathic surgery with pre-and post-surgical orthodontics is associated with drawbacks such as the risk of relapse and an unsatisfactory overall long-term outcome, with persisting occlusal discrepancies and skeletal abnormalities, especially when the magnitude of skeletal correction required is large. Excessive mandibular setback can restrict tongue space, cause narrowing of posterior airway and pharyngeal space, and be prone to relapse from the forward pterygomasseteric muscle pull, while large maxillary advancements are often accompanied by wound dehiscence and bone exposure at the site of pterygomaxillary disjunction, delayed union or malunion at the osteotomy and disjunction sites, and risk of relapse due to backward palatopharyngeal muscle pull. In addition, bi-jaw surgeries invariably involve an appreciable blood loss and a prolonged operating time with its attendant anaesthetic risks such as respiratory insufficiency. AIM AND OBJECTIVES: To develop an orthosurgical protocol wherein excessive skeletal discrepancy can be successfully managed, achieving the desired magnitude of correction, with little or no relapse. To assess its efficacy and superiority over the hitherto-employed single-stage bi-jaw procedures in the management of severe skeletal discrepancies. MATERIALS AND METHOD: A two-staged, shorter 'single-jaw at a time' operative procedure with an intervening period of three months between the two surgical phases was employed. RESULTS: Drawbacks of conventional orthognathic surgery may be obviated by employing a two-staged protocol of bi-jaw surgeries allowing a minimum time period of 3 months to elapse between them. This period of time intervening between the maxillary advancement and mandibular setback allows the oral and maxillofacial musculature to adapt itself to the new jaw position following the first surgery, thus creating a better and more stable environment for the succeeding one, thereby reducing the chances of relapse thereafter, and producing more effective and stable long-term results. Moreover, the intervening time period also allows for observation of the repositioned jaw and arch relations achieved, and scrutiny for any positional changes in this post-surgical phase, which thereby allows modifications in the planned surgery of the next jaw, so as to achieve the most ideal final outcome following the second jaw surgery. A shorter operating time, reduced operator fatigue and less blood loss are other obvious advantages over the conventional bi-jaw procedures. CONCLUSION: An effective and stable correction of the extreme class III skeletal deformity and malocclusion was achieved, with a dramatic enhancement of facial balance, symmetry and proportion in this patient, following a modified orthosurgical management protocol. The staged protocol of 'maxilla first and mandible after' orthognathic surgery with conventional pre- and post-surgical orthodontics helped in pushing the envelope of skeletal discrepancy correctable by orthognathic surgery, thereby achieving large quantum of jaw movements, with ideal and stable functional as well as aesthetic results. This is suggestive of its efficacy and superiority over the hitherto-employed single stage bi-jaw procedures in the management of severe skeletal discrepancies.

Comparison of Postoperative Stability Between BSSRO and Le Fort 1 Osteotomy with BSSRO in Skeletal Class III Malocclusion with Severe Open Bite.

INTRODUCTION: We aimed to investigate postoperative stability after orthognathic surgery in patients with skeletal class III malocclusion with severe open bite by comparison between bilateral sagittal splitting osteotomy (BSSRO) and BSSRO with Le Fort 1 osteotomy. MATERIALS AND METHODS: Seventeen patients with skeletal class III malocclusion with severe open bite who were needed more than 6 degree counterclockwise rotation of distal segment by only BSSRO in preoperative cephalometric prediction. The subjects were divided into group A, where 9 patients were treated by BSSRO, and group B, where 8 patients were treated by BSSRO with Le Fort 1 osteotomy. Patient's characteristics of age, gender, preoperative over jet (OJ) and over bite (OB) were not found to be significantly different between the two groups. Counterclockwise rotation of distal segment in preoperative cephalometric prediction by only BSSRO was not found to be significantly different between group A of 7.6 (6-10.6) degree and group B of 9 (6-13) degree. The amount of rotation was reduced to 5.4 (3-10) degree by bimaxillary surgery using BSSRO and Le Fort 1 osteotomy in group B. OJ and OB were measured as occlusal stability factor. Distance between ANS-to-PNS plane and the edge of upper incisor (NF-U1Ed), and distance between Menton and edge of lower incisor (Me-L1Ed) were measured as skeletal stability factor using cephalometric analysis. These lengths were measured at pre-surgery (T0), 2 weeks after surgery (T1) and 1 year after surgery (T2), and these differences between the two groups were statistically analyzed. RESULTS: OJ and OB kept a good relation at any experimental periods. The change of Me-L1Ed was significantly larger in group A (1.21 mm at T0-T1, 1.02 mm at T0-T2) than in group B (0.14 mm at T0-T1, 0.16 mm at T0-T2). The change of NF-U1Ed was not significantly different between group A (1.07 mm at T0-T1, 0.57 mm at T0-T2) and group B (0.51 mm at T0-T1, - 0.05 mm at T0-T2). CONCLUSION: In case with more than 6 degree counterclockwise rotation of distal segment, skeletal stability was better after bimaxillary surgery than only BSSRO; however, OJ and OB kept a good relation.

Evaluation of the Therapeutic Effect of Bi-Maxillary Osteotomy Using the Stress Distribution on the Temporomandibular Joint When Doing Anterior Teeth Occlusion.

The purpose of this study was to investigate how sagittal split ramus osteotomy (SSRO) and Le Fort 1 osteotomy affected the stress distribution of the temporomandibular joint (TMJ) during an anterior teeth bite using the three-dimensional (3D) finite element (FE) method. Fourteen orthognathic surgery patients were examined with mandibular prognathism, facial asymmetry, and mandibular retraction. They underwent Le Fort 1 osteotomy in conjunction with SSRO. In addition, ten asymptomatic subjects were recruited as the control group. The 3D models of the mandible, disc, and maxilla were reconstructed according to cone-beam computed tomography (CBCT). Contact was used to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. Muscle forces and boundary conditions corresponding to the anterior occlusions were applied on the models. The stresses on the articular disc and condyle in the pre-operative group were significantly higher than normal. The contact stress and minimum principal stress in TMJ for patients with temporomandibular disorder (TMD) were abnormally higher. The peak stresses of the TMJ of the patients under anterior occlusions decreased after bimaxillary osteotomy. No postoperative TMD symptoms were found. Maxillofacial deformity led to excessive stress on the TMJ. Bimaxillary osteotomy can partially improve the stress distributions of the TMJ and relieve the symptoms of TMD.

Complications after orthognathic surgery: our experience on 423 cases.

INTRODUCTION: Orthognathic surgery is widely used to correct dentofacial discrepancies. However, this procedure presents numerous possible complications. The aim of our study is to review intraoperative and postoperative complications related to orthognathic surgery based upon a 10-year period in the Maxillofacial Surgery Department of Federico II University of Naples. MATERIALS AND METHODS: Medical records of 423 patients who undergone orthognathic surgery in a 10-year period were retrospectively analyzed and complications was noted. Statistical analysis was conduced in order to understand if the type of surgical procedure influenced complications rate. RESULTS: One hundred eighty-five complications in 143 (33.8%) of the 423 treated patients were reported. Complications detected were nerve injury (49 cases, 11.9%), infections (10 cases, 2.4%), complications related to fixation plates or screws (30 cases, 7.1%), bad split osteotomy (8 cases, 1.9%), secondary temporo-mandibular joint disorders (36 cases, 8.5%), dental injuries (21 cases, 5%), condilar resorption (2 cases, 0.5%), and necessity of a second-time surgery (24 cases, 5.7%). CONCLUSIONS: Serious complications seem to be quite rare in orthognathic surgery. Some of the surgical complications found are related to the surgeon experience and not strictly to the risks of the operation itself. Understanding potential complications allows the surgeon to guarantee safe care through early intervention and correctly inform the patient in the preoperative colloquy.

Le Fort 1 osteotomy and calvarial bone grafting for severely resorbed maxillae.

INTRODUCTION: Long standing maxillary edentulism leads to alveolar ridge resorption which prevent implant placement and causes prosthetic malocclusion. The aim of the study was to assess vertical and transversal bone increase following Le Fort 1 osteotomy associated with calvarial bone grafting. MATERIALS AND METHODS: 66 patients who presented severely atrophic maxillae were treated with Le Fort 1 osteotomy with bone grafting from 2003 to 2014. Vertical and transversal bone level was measured preoperatively and 6 months post-operatively to calculate the alveolar ridge augmentation. Follow up ranged from 10 months to 11 years. RESULTS: The mean increase of bone height was 9.3 mm and the mean increase of bone width was 6 mm 417 endosseous implants were placed in the grafted maxilla. Mean endosseous implant length was of 10.7 mm at the first molar site (range: 8-16 mm). A total of 25 implants failed, the overall implant survival rate is of 94%. The definitive prosthetis was fixed in 65% of the patients and removable in 35% of the patients. DISCUSSION: Le Fort 1 osteotomy associated with calvarial bone grafting is the main treatment option able to offer fixed bridge and perfect class 1 occlusion in cases of severe maxillary atrophy.

Influence of third molars in Le Fort 1 osteotomy.

BACKGROUND: The influence of maxillary third molar (M3) on the outcomes of Le Fort 1 osteotomy is not deeply investigated. AIM: To investigate the influence of M3 on Le Fort 1 osteotomies. SETTING: Tertiary Referral Center, operated by a single surgeon, prospective study. PERIOD: January 2005 to December 2010. PATIENTS: Consecutive Le Fort 1 osteotomy patients with both M3. PREDICTOR VARIABLE: Gender, position, M3 root morphology, and degree of impaction. OUTCOME VARIABLE: Time taken after all osteotomy cuts to point of time when maxilla is placed in predetermined plane. RESULT: A total of 658 M3 in line of cut were studied. Of all M3, 312 were impacted, 28.9% were partially impacted and 23.7% were erupted. Of all the M3, 2.9% had their cuspal tips above the horizontal cut, 13.8% along the line of cut, and in 20.7% below the line but not erupted. Buccoverted tooth took shortest time (7.74 minutes), while palatoversion required more time (8.44 minutes) (P = 0.000). When the cuspal tip of M3 was located above the horizontal line of cut, the mean time required to achieve the planned position was 7 minutes, while the completely erupted teeth took a mean of 8.24 minutes (P = 0.000). CONCLUSION: When the M3 is placed higher, it takes lesser time to prepare basal bone to receive the maxilla at its predetermined level. Angulation of M3 influences the outcome. Deeply placed M3 reduces the manipulation of the greater pterygoid palatine vessels in the area thereby minimizing the bleeding in the surgical field.