Mandibular Sagittal Split Osteotomy Research Articles

Pneumomediastinum after Orthognathic Surgery: Case Report and Review of the Literature

Orthognathic surgery in general addresses young patients and aims to improve their bite function and to harmonize their facial aesthetics. Secure surgical standards and a defined post-surgical protocol of after-care are indispensable to reduce surgical as well as anaesthesiological risks in this area of complex elective surgery. The development of pneumomediastinum is a rare incident but threatens the patients’ physical integrity. The case of a young healthy male who underwent Le Fort I osteotomy in combination with bilateral mandibular sagittal split osteotomy and postoperatively developed pneumomediastinum is presented, together with a discussion of the possible reasons for this rare complication of orthognathic surgery. The avoidance of life-threatening coincidences must be one main focus in the preparation and aftercare in elective orthognathic surgery.

Delayed progressive haematoma after Le Fort I osteotomy: A possible severe complication in orthognatic surgery.

Although the Le Fort I osteotomy is a safe surgical technique, many complications have been reported. We present a case of an extended cervico-facial haematoma due to delayed bleeding from the terminal branches of the maxillary artery after orthognatic surgery. A 23-year-old man was referred to our observation for the surgical correction of a class III asymmetric malocclusion. The patient underwent a Le Fort I osteotomy, with impaction of the maxilla, associated with an Epker mandibular bilateral sagittal split osteotomy, with maxillary advancement and rigid internal fixation of the mandible with four miniplates and another four for the upper maxilla as well. The first post-surgery day, the patient developed a gradual dispnea together with neck swelling. By second postoperative day, the patient's general condition improved with a progressive normalization of laboratory tests values. The Computerised Axial Tomography (CAT) scan confirmed a decrease in the parapharyngeal thickening. Total recovery was achieved within two months, the final clinical check showed a healthy appearance with good occlusion. An increased knowledge of the basic biology of the Le Fort I osteotomy, the development of instruments specially designed for the Le Fort I procedure and the use of hypotensive anaesthesia could reduce the morbidity and duration of this procedure.

Implant Handpiece With Adapted Drills in Orthognathic Surgery

The attachment of bilateral sagittal-split osteotomy of the mandibular ramus with bicortical screws or the combination of miniplates and a bicortical screw is complicated through the intraoral approach because of the angle required for insertion of screws, so it is necessary to use a trocater. This article aimed to report a technique developed and used in 60 patients, wherein an implant handpiece with adapted drills was used in the intraoral attachment. The setting was performed intraorally to prevent scarring and extraoral facial nerve damage, which may be caused by extraoral and transbuccal approaches routinely performed when using the trocater. The versatility of the handpiece implant allows for the insertion of monocortical and bicortical screws and rigid internal fixation of mandibular sagittal-split osteotomy, as well as surgical time reduction, decreasing postoperative morbidity.

Pseudoaneurysm of the facial artery occurred after mandibular sagittal split ramus osteotomy

IntroductionPseudoaneurysms are caused by rupture of arteries with extravasation of blood. The compressed perivascular tissue forms the wall of aneurysmal sac. Pseudoaneurysm directly related with surgical procedure of sagittal split ramus osteotomy (SSRO) was reported quite rarely especially related with facial artery during the vertical osteotomy.Case reportSSRO was carried out for a 19-year-old male; the patient visited the emergency room with notable swelling 3 weeks after the surgery. We experienced severe intra-oral bleeding with surgical exploration. Angiography revealed a pseudoaneurysm of the right facial artery that might be related with vertical osteotomy over lateral cortex of the mandibular body during orthognathic surgery. This implies that the minor vascular trauma from vertical osteotomy of the mandibular body during the conventional orthognathic surgery might cause later development of pseudoaneurysm.

Systematic review of neuropathic component in persistent postsurgical pain

Abstract Background/aim The aim of the current study was to assess the neuropathic component of persistent post-surgical pain (PPSP) following eleven types of surgery. Methods We performed a systematic PubMed, CENTRAL and EMBASE search to identify studies on PPSP following (i) thoracic surgery, (ii) breast surgery, (iii) groin hernia repair, (iv) prostatectomy, (v) major abdominal surgery, (vi) gynecologic surgery, (vii) iliac crest bone harvest, (viii) total hip arthroplasty (THA) or knee arthroplasty (TKA), (ix) varicose vein stripping or ablation, (x) mandibular sagittal split osteotomy and (xi) donor nephrectomy, and assessed the prevalence of Probable/Definite neuropathic pain using the recently published neuropathic pain probability grading criteria [1]. Results We included 291 relevant papers. Surgeries performed in the thoracic/breast area resulted in similarly high median PPSP prevalence of about 30–35%; bone and joint surgeries resulted in similar PPSP prevalence of about 20%; and surgeries on visceral organs resulted in lower PPSP prevalence of 10–14%. The reported ranges of PPSP prevalence were very wide, between 0 and 91%. The prevalence of Probable/Definite neuropathic pain among patients with PPSP was about 65% after thoracic and breast surgeries, about 32% after groin hernia repair and gynecologic surgery, and between 9 and 16% after bone and joint surgeries such as iliac crest bone harvest and THA/TKA. In varicose vein surgeries and mandibular sagittal split osteotomies more research is needed to investigate the contribution of neuropathic pain mechanisms. Conclusion PPSP after different surgeries is reported to be common and often neuropathic. This systematic review of the literature showed that reported PPSP prevalences range widely among studies, and only a minority of studies used methodology that enabled the estimation of Probable/Definite neuropathic pain prevalence.

Which kind of miniplate to use in mandibular sagittal split osteotomy? An in vitro study

This study verified the resistance to displacement of six miniplate fixation methods after sagittal split osteotomy (SSO). SSO was performed in 30 polyurethane synthetic mandible replicas. The distal segments were advanced (4mm) and specimens were grouped according to the fixation method: four-hole standard miniplate; four-hole locking miniplate; six-hole standard miniplate; six-hole locking miniplate; six-hole standard sagittal miniplate; six-hole locking sagittal miniplate. Biomechanical evaluation was performed by applying compression loads to three points on the second molar region, using an Instron universal testing machine until a 3mm displacement of the segments occurred. Compression loads able to produce 3mm displacement were recorded in kN and subjected to analysis of variance (P<0.01) and Tukey's tests for comparison between groups (P<0.05). The locking sagittal miniplate showed higher resistance to displacement than the regular four- and six-hole locking and standard miniplates. No significant differences were observed between the locking sagittal miniplate and the regular sagittal or the four-hole locking miniplates. Two of the three groups with the best results had locking plate fixation methods. Fixation of SSO with a single miniplate is better accomplished using six-hole locking sagittal miniplates, six-hole standard sagittal miniplates, or four-hole locking miniplates; these methods are more resistant to displacement.

Maxillomandibular advancement in the management of obstructive sleep apnea.

Maxillomandibular advancement (MMA) is a surgical option for obstructive sleep apnea (OSA). MMA involves forward-fixing the maxilla and mandible approximately 10 mm via Le Fort I maxillary and sagittal split mandibular osteotomies. We retrospectively reviewed outcomes from 24 consecutive OSA patients who underwent MMA at our institution. MMA resulted in an 83% reduction in the group mean apnea-hypopnea index (AHI) per polysomnography an average of 6.7 months after surgery. Forty-two percent of patients achieved a post-MMA AHI of less than 5 events/hour sleep and 71% achieved an AHI less than or equal to 10 events/hour sleep. The Epworth Sleepiness Scale score decreased by an average of 5 post-surgery. No parameters predictive of cure for OSA by MMA were identified.

Three-dimensional analysis of pharyngeal airway change of skeletal class III patients in cone beam computed tomography after bimaxillary surgery

Introduction: To evaluate the 3-dimensional changes in the pharyngeal airway of skeletal class III patients after bimaxillary surgery. Materials and Methods: The study sample consisted of 18 Korean patients that had undergone maxillary setback or posterosuperior movement and mandibular bilateral sagittal split osteotomy setback surgery due to skeletal class III malocclusion (8 males, 10 females; mean age of 28.7). Cone beam computed tomography was taken 1 month before and 6 months after orthognathic surgery. Preoperative and postoperative volumes of the nasopharyngeal, oropharyngeal, and laryngopharyngeal airways and minimum axial areas of the oropharyngeal and laryngopharyngeal spaces were measured. Moreover, the pharyngeal airway volume of the patient group that had received genioplasty advancement was compared with the other group that had not. Results: The nasopharyngeal and laryngopharyngeal spaces did not show significant differences before or after surgery. However, the oropharyngeal space volume and total volume of pharyngeal airway decreased significantly (P Conclusion: The results indicate that bimaxillary surgery decreased the volume and the minimum axial area of the oropharyngeal space. Advanced genioplasty did not seem to have a significant effect on the volumes of the oropharyngeal and laryngopharyngeal spaces.

Facial soft tissue changes after maxillary impaction and mandibular advancement in high angle class II cases.

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

Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism

IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism. Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22months (mean 17.8months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6months postoperatively. ResultsThe average setback was 6.9mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance. ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.

The versatile mandibular sagittal split osteotomy: tips to obtain great splits every time and avoid complications

Since it was introduced by Perthes in 1924 and with it's different modifications (Obwegesser 1955, Dalpont 1961, Wolford 1985) through-out the years, the mandibular sagittal split osteotomy has been the most reliable osteotomy to correct 3D mandibular discrepancies.

Which kind of miniplate to use in mandibular sagittal split osteotomy? An in vitro study

Which kind of miniplate to use in mandibular sagittal split osteotomy? An in vitro study

Comparative Evaluation of Vertical Body Osteotomy and Sagittal Split Osteotomy for Mandibular Corpus Distraction: Is There a Rationale for the New Technique?

Comparative Evaluation of Vertical Body Osteotomy and Sagittal Split Osteotomy for Mandibular Corpus Distraction: Is There a Rationale for the New Technique?

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An In Vitro Evaluation of Rigid Internal Fixation Techniques for Sagittal Split Ramus Osteotomies: Setback Surgery

The aim of this study was to evaluate the biomechanical features of 3 different methods of rigid internal fixation for sagittal split ramus osteotomy for mandibular setback in vitro. Sixty polyurethane replicas of human hemimandibles were used as substrates, simulating a 5-mm setback surgery by sagittal split ramus osteotomy. These replicas served to reproduce 3 different techniques of fixation, including 1) a 4-hole plate and 4 monocortical screws (miniplate group), 2) a 4-hole plate and 4 monocortical screws with 1 additional bicortical positional screw (hybrid group), and 3) 3 bicortical positional screws in a traditional inverted-L pattern (inverted-L group). After fixation, hemimandibles were adapted to a test support and subjected to lateral torsional forces on the buccal molar surface and vertical cantilever loading on the incisal edge with an Instron 4411 mechanical testing unit. Peak loadings at 1, 3, 5, and 10 mm of displacement were recorded. Means and standard deviation were analyzed using analysis of variance and Tukey test with a 5% level of significance, and failures during tests were recorded. Regardless of the amount of displacement and direction of force, the miniplate group always showed the lowest load peak scores (P < .01) compared with the other fixation techniques. The hybrid group demonstrated behavior similar to the inverted-L group in lateral and vertical forces at any loading displacement (P > .05). Molar load tests required more force than incisal load tests to promote the same displacement in the mandibular setback model (P < .05). For mandibular setback surgery of 5 mm, this study concluded that the fixation technique based on the miniplate group was significantly less rigid than the fixation observed in the hybrid and inverted-L groups. Mechanically, adding 1 bicortical positional screw in the retromolar region in the miniplate technique may achieve the same stabilization offered by inverted-L fixation for mandibular sagittal split ramus osteotomy setback surgery in vitro.

Cutaneous Sensibility Impairment After Mandibular Sagittal Split Osteotomy: A Prospective Clinical Study of the Spontaneous Recovery

The aim of this prospective study was to objectively evaluate the inferior alveolar nerve (IAN) sensory disturbances in patients who underwent sagittal split ramus osteotomy (SSRO) and its spontaneous recovery and to define the incidence of sensibility loss, time, and area at which the recovery occurs. Clinical evaluation of the IAN sensory disturbance was undertaken preoperatively and at the first week, fourth week, 2 months, and 6 months postoperatively in 30 patients who underwent SSRO at the Oral and Maxillofacial Surgery Division of the Araraquara Dental School--Unesp and at the Plastic Surgery Division of the Medical Sciences School--Unicamp. The 30 patients were examined at all periods regarding the IAN functionality by Semmes-Weinstein testing. The mean age of the patients included in this study was 29.36 years old. All patients showed sensibility loss at the 7-day evaluation time. The comparison between sides, gender, and age did not show any significant difference. In most of the examined zone, the data collected at 6 months were statistically similar to the data collected at the preoperative period. All zones presented significant recovery, starting from 30 days after surgery. Twenty patients had total spontaneous recovery at the final period, in all examined zones. The SSRO presents the disadvantage of temporary paresthesia; however, spontaneous nerve function recovery does occur. The Semmes-Weinstein test is a reliable, inexpensive, and easy-to-apply tool, which can be used for clinical evaluation on a daily basis at offices and hospitals.

Sagittal split mandibular osteotomies: a 5 year review of complications and incidence of hardware removal

Sagittal split mandibular osteotomies: a 5 year review of complications and incidence of hardware removal

Subjective Sensory Symptoms Associated With Axonal and Demyelinating Nerve Injuries After Mandibular Sagittal Split Osteotomy

The effect of the type of nerve injury on subjective sensory disturbances and recovery has not been addressed in orthognathic surgery. Using neurophysiologic monitoring during 19 bilateral sagittal split osteotomy operations, we were able to classify intraoperative inferior alveolar nerve injuries as either axonal or demyelinating. This study aimed to analyze the quality and extent of the subjective sensations experienced by the patients after these 2 injury types at different time points up to 12 months. Of the 36 injured nerves, 21 showed signs of demyelinating injury and 15 showed signs of axonal damage. The quality of subjective sensory symptoms was asked about at 2 weeks and 1, 3, 6, and 12 months postoperatively and classified into 4 categories: normal, negative, positive (including pain), and mixed sensations. In addition, the extent of the sensory alteration was determined by measuring the affected skin regions from symptom charts. The quantity, quality, and evolution of experienced subjective sensations differed between the injury types during follow-up: Subjective sensations normalized more rapidly after demyelinating-type injuries than after axonal-type injuries. Persistence of mixed sensation patterns at 3 months and appearance instead of disappearance of positive sensory phenomena after 3 months indicated axonal damage. Painful sensations at 1 month or later after surgery indicated axonal damage and predicted poor recovery and more long-term sequelae. Postoperative pain at 1 month and type of nerve injury are important prognostic factors for the persistence of subjective symptoms and development of neuropathic pain.

The role of cone beam computed tomography in the management of unfavourable fractures following sagittal split mandibular osteotomy

Cone beam computed tomography (CBCT) has been at the forefront of recent technological advances within the maxillofacial region. CBCT is useful in the accurate assessment and planning of patients undergoing orthognathic surgery. We propose that it also has a role in the post-operative evaluation of a subgroup of patients who have suffered complications at the time of surgery. We present two cases where unfavourable splits occurred during a bilateral sagittal split osteotomy (BSSO) of the mandible. Both cases were investigated post-operatively with CBCT with the aim of identifying the potential cause of the unfavourable split and to establish accurate localization of the condyle in the glenoid fossa following intra-operative attempts at proximal segment control. CBCT should be considered for evaluation of the mandible following an unfavourable split where it is deemed that plain radiographs would not provide adequate information.

Unilateral bimaxillary vertical elongation by maxillary distraction osteogenesis and mandibular sagittal split ramus osteotomy: a case report

Maxillary canting and vertical shortening of the unilateral mandibular ramus height is common in cases of severe facial asymmetry. Normally, mandibular distraction osteogenesis (DO) with horizontal osteotomy at the ascending ramus is used for vertical lengthening of the mandibular ramus to correct facial asymmetry with an absolute shortened ascending ramus. In this case report, vertical lengthening of the ascending ramus was performed successfully with unilateral DO and sagittal split ramus osteotomy (SSRO), where the posterior part of the distal segment can be distracted simultaneously in an inferior direction with maxillary DO, resulting in a lengthening of the medial pterygoid muscle. This case describes the acquired unilateral mandibular hypoplasia caused by a condylar fracture at an early age, which resulted in abnormal mandibular development that ultimately caused severe facial trismus. The treatment of this case included two-stage surgery consisting of bimaxillary distraction osteogenesis for gradual lengthening of the unilateral facial height followed by secondary orthognathic surgery to correct the transverse asymmetry. At the one year follow-up after SSRO, the vertical length was maintained without complications.