Stability of lingual plate osteotomy in orthognathic surgery for patients with severe facial asymmetry: A retrospective analysis with 1-year follow-up

This study aimed to evaluate the stability of lingual plate osteotomy after sagittal split ramus osteotomy (SSRO) in patients with severe facial asymmetry. It included 20 patients undergoing lingual plate osteotomy between January 2011 and January 2017. Cephalometric X-ray imaging and three-dimensional computed tomography (3DCT) were performed before the operation and then 1 day and 1 year after the operation. The relapse rate and postoperative complications were assessed. The operation time was compared between lingual plate osteotomy and transoral angle osteotomy.Specific values measured on cephalometric X-ray and 3DCT images showed significant changes 1 day after the operation, with 47.9% correction occurring in the occlusal plane angle (mean ± SD = 1.74 ± 0.84°, p < 0.05). However, no significant differences were found between measurements taken 1 day and 1 year after the operation, with a 5% change seen in the occlusal plane angle (mean ± SD = 0.1 ± 0.24°, p = 0.61), suggesting that the surgical outcomes can be well maintained for at least 1 year after surgery.Three patients experienced numbness postoperatively but recovered within 1 year. The operation time for lingual plate osteotomy was shorter than that for transoral angle osteotomy. Our findings indicate that lingual plate osteotomy after SSRO is stable, effective, and safe in patients with severe facial asymmetry.     

Orthognathic surgery complications: The 10-year experience of a single center

The retrospective cohort study aimed to assess the incidence and characteristics of these complications in patients who underwent orthognathic procedures.Data on the intraoperative and the postoperative complications were extracted from the patients’ medical files. Procedures were further subdivided into single-jaw procedures and bimaxillary procedures.A total of 209 orthognathic procedures were carried out in 190 patients. 184 (88%) were performed to treat angle class III malocclusion, while 25 (12%) aimed to treat class II malocclusion. A total of 94 complication events were observed (44.9% of 209 procedures). 22 of them occurred in single-jaw procedures (28.2% of 78 single jaw operations), and 72 occurred in bimaxillary procedures (55% of 131 bimaxillary operations). When compared regarding the type of complication, complication rates were comparable between the study groups with the exception of late-stage malocclusion. A significant difference (p-value = 0.028) in malocclusion incidences between the bimaxillary and single-jaw groups were observed (9 events, 4.3% and zero events, 0%, respectively).The majority of the complications during and following orthognathic surgical procedures are temporary or minor and require little or no treatment at all.     

Stability of fixation methods in large mandibular advancements after sagittal split ramus osteotomy: an in vitro biomechanical study

Sagittal split ramus osteotomy (SSRO) with large mandibular advancements is a common surgical procedure and could be indicated for patients with sleep apnoea. As a large variety of fixation methods is used for the stabilisation of SSRO, a biomechanical test model was used to analyse which fixation technique was most stable. For this in vitro study, 80 polyurethane hemimandibles with a prefabricated SSRO were used as substrates. Loads in Newtons were recorded at displacements of the mandibular incisive edge at 1 mm, 3 mm and 5 mm. The samples were divided into two groups: mandibular advancements of 10 mm and 15 mm. In both groups, four fixation techniques were used: (A) one four-hole miniplate; (B) two four-hole miniplates; (C) one four-hole miniplate plus one bicortical screw; and (D) three bicortical screws in an inverted-L arrangement. In group 1, three bicortical screws resulted in the best stability, and in group 2, two miniplates resulted in the best stability. The use of two miniplates did not show significant differences between both groups. Other fixation methods showed more stability with 10 mm advancements. This study therefore suggests that in SSRO with advancements exceeding 10 mm, the use of two miniplates is the optimal means of providing rigid fixation.     

Skeletal stability after mandibular setback surgery: Comparison between the hybrid technique for fixation and the conventional plate fixation using an absorbable plate and screws

PurposeThe purpose of this study was to compare the temporal changes in condylar long axis and skeletal stability after sagittal split ramus osteotomy (SSRO) with the hybrid fixation technique and the conventional plate fixation.Patients and methodsOf 44 Japanese patients diagnosed with mandibular prognathism, 22 underwent SSRO with the conventional plate fixation (1 u-HA/PLLA plate and 4 monocortical screws in each side) and 22 underwent SSRO with a hybrid fixation technique (1 u-HA/PLLA plate and 4 monocortical screws and bicortical screw in each side). The temporal changes in condylar long axis and skeletal stability were assessed by axial, frontal, and lateral cephalograms. After surgery, breakage of the plate and screws was checked by 3-dimensional computed tomography (3DCT).ResultsAlthough there was a significant difference between the groups regarding Me–Ag in T1 (P = 0.0138), there were no significant differences between the groups for the other measurements in lateral, frontal and axial cephalometric analysis in each time interval. In two cases, 4 sides in the conventional plate fixation group, failure of the absorbable plate was found by 3DCT. However, there was no breakage in the hybrid fixation group.ConclusionThis study suggested that there were no significant differences in the postoperative temporal changes between the two groups in mandibular setback surgery.     

Comparative study of biomechanical stability of resorbable and titanium fixation systems after sagittal split ramus osteotomy with a novel designed in-vitro testing unit

Introduction

Sagittal split ramus osteotomy (SSRO) is one of the most popular surgical procedures for correction of mandibular deformities. Several clinical and biomechanical studies exist in the literature which, comparing the stability of different osteosynthesis materials and techniques, were performed using two or three-point biomechanical test models. The aim of this study was to compare the stability of biodegradable and titanium materials for SSRO on one-piece polyurethane mandible samples which were fixed in a novel designed 6-point testing unit.

Bad split during bilateral sagittal split osteotomy of the mandible with separators: a retrospective study of 427 patients

An unfavourable fracture, known as a bad split, is a common operative complication in bilateral sagittal split osteotomy (BSSO). The reported incidence ranges from 0.5 to 5.5%/site. Since 1994 we have used sagittal splitters and separators instead of chisels for BSSO in our clinic in an attempt to prevent postoperative hypoaesthesia. Theoretically an increased percentage of bad splits could be expected with this technique. In this retrospective study we aimed to find out the incidence of bad splits associated with BSSO done with splitters and separators. We also assessed the risk factors for bad splits. The study group comprised 427 consecutive patients among whom the incidence of bad splits was 2.0%/site, which is well within the reported range. The only predictive factor for a bad split was the removal of third molars at the same time as BSSO. There was no significant association between bad splits and age, sex, class of occlusion, or the experience of the surgeon. We think that doing a BSSO with splitters and separators instead of chisels does not increase the risk of a bad split, and is therefore safe with predictable results.     

The inverted-L ramus osteotomy versus sagittal split ramus osteotomy in maxillomandibular advancement for the treatment of obstructive sleep apnea patients: A retrospective study

This study aimed to compare the effectiveness and feasibility of inverted-L osteotomy (ILO) and sagittal split ramus osteotomy (SSRO) on obstructive sleep apnea (OSA) treatment. According to different surgery procedures, 28 OSA patients who underwent maxillomandibular advancement (MMA) were divided into 2 groups (group A: ILO, n = 9; group B: SSRO, n = 19). Polysomnography (PSG) and Epworth sleepiness scale (ESS) on T0, T1and T2 were used to evaluate the effectiveness of OSA treatments. Patients’ airway structures and facial appearances were also evaluated. From T0 to T1, the mean apnea-hypopnea index (AHI,/per hour) dropped from 69.2 ± 8.4 to11.2 ± 2.4 (P < 0.01) in group A and from 54.6 ± 14.6 to 9.4 ± 5.4 (P < 0.01) in group B; LSpO2 (lowest pulse oxygen saturation, %) increased from 66.5 ± 7.7% to 88.2 ± 4.6 (P < 0.01) and from 76.6 ± 10.7%to 89.4 ± 2.4% (P < 0.01) while the mean ESS score decreased by 51% in group A and 44% in group B. Most patients (group A: 88.9%; group B: 84.3%) were satisfied with their postoperative appearance. Mild relapse was observed in both groups on T2. This study concluded that MMA containing ILO and MMA containing SSRO are both feasible and effective for selected OSA patients.     

Unilateral sagittal split ramus osteotomy: an alternative for some cases of asymmetric mandibular prognathism

The objective of this study was to propose a treatment protocol for patients with lateral prognathism based on the unilateral sagittal split ramus osteotomy (USSRO). This was a prospective study involving 31 patients with lateral prognathism, who required a bilateral sagittal split ramus osteotomy (BSSRO). Two groups were formed using the proposed protocol, with specific inclusion criteria for each group: BSSRO (n = 17) and USSRO (n = 14). Occlusal parameters (dental midline deviation, overbite, and overjet) were measured preoperatively (T0), at model surgery (T1), 1 month postoperative (T2), and 1 year after surgery (T3) and compared. P-values of <0.05 were considered significant. No significant difference was found between the USSRO and BSSRO groups for all occlusal parameters (T0, T1, T2, and T3). In both groups, there was a significant difference between T0 and T1 and no significant difference between T1 and T2 or T1 and T3 in all of the occlusal parameters; the exception was overbite between T1 and T2 in the BSSRO group, which showed a significant difference. No patient in either group showed signs or symptoms of temporomandibular joint dysfunction at T0 or T3. USSRO was found to be a stable alternative in patients with asymmetric mandibular prognathism. At the same time, it reduced the operating time and morbidity when compared to BSSRO.     

Position of the mandibular canal before and after bilateral sagittal split ramus osteotomy: a cone beam computed tomographic study

The aim of this study was to evaluate the position of the mandibular canal (MC) before and after bilateral sagittal split ramus osteotomy (BSSRO) using cone-beam computed tomography (CT), and to compare the position of the MC in Class II and Class III patients in the preoperative period. Patients were divided into two groups: Class II (n = 38) and Class III (n = 41). Measurements of the superior, inferior, buccal, and lingual distances of the MC in relation to the cortical bone were taken at three levels in the proximal segment of the mandible. Results were analysed using the Kruskal–Wallis test (p < 0.05). In the Class II group the superior distance of the MC at levels 2 and 3, and the inferior distance at level 3 significantly decreased after BSSRO. In the Class III group, no significant differences were found at any level, and the inferior distances at all levels were smaller preoperatively than those in the Class II group. In the Class II group the position of the MC altered in relation to superior and inferior cortical bone after BSSRO. However, the position of the MC remained stable in the Class III group. Our results also suggest a deeper cut in inferior cortical bone in Class III patients.     

Le Fort I osteotomy with segmentation for the treatment of maxillary dentoalveolar protrusion: a single-centre, 10-year outcome study

A retrospective study was conducted to evaluate the stability and complications of Le Fort I osteotomy with segmentation for the treatment of bimaxillary dentoalveolar protrusion. A total of 120 consecutive patients who had undergone orthognathic surgery between 2008 and 2017 at a single centre were recruited. Lateral cephalometric radiographs were taken before surgery, within 6 weeks after surgery, and at 2 years after surgery. U1–SN and U1–PP underwent mean uprighting of 8.7° and 9.6°, respectively, and mean relapse of 2.1° and 2.6°, respectively (both P < 0.05). The only significant risk factor for relapse was the use of intermaxillary fixation (risk ratio (RR) 1.2, P = 0.01). The most common complication was wound dehiscence (41.7%), which was a significant risk factor for wound infection (RR 3.3, P < 0.01) and fixation hardware exposure (RR 3.7, P < 0.01). Other common complications were gingival recession (40.8%), periodontal bone loss (40%), and blood loss requiring transfusion (26.7%), the latter of which was associated with the preoperative diagnosis of vertical maxillary excess (RR 2.4, P = 0.01). Some degree of relapse occurred in more than 90% of the patients by 2 years after surgery. The procedure is not without risks and complications but may be useful in severe cases.     

Use of single- and multi-drug regimens in the management of classic (idiopathic) trigeminal neuralgia: an 11-year experience at a single Sri Lankan institution

Aim: The aim of this retrospective study was to evaluate the outcome of medical treatment of classic trigeminal neuralgia and to assess the factors affecting the choice of drug regimen (single or multiple), and the duration of treatment for pain control. Methods: A total of 260 consecutive patients were included in the study. Sixty‐one patients with less than 6 months’ follow up were excluded. All patients were treated with carbamazepine alone or in combination with other drugs. The dosage was adjusted according to the level of pain control and side‐effects. Results: Treatment was terminated in 99 patients (49.7%) after a mean follow‐up period of 36.46 months (standard deviation: ±26.5). Of these, 39.4% were on a single drug. Carbamazepine was the drug used in 36 patients. The rest (61%) needed various combinations of drugs. One‐hundred patients (50.3%) continued with medical treatment during the follow‐up period. Of these, 67.4% were on multi‐drug therapy. Conclusion: The present study showed that the administration of multidrug regimens is a useful alternative in controlling trigeminal neuralgia in patients who are unable to tolerate higher doses of carbamazepine. Age, sex, ethnicity, and the side of affliction did not have a significant influence on the choice of drug regimen and the duration of treatment for pain control.     

Epidemiological analysis of maxillofacial fractures treated at a university hospital,Xinjiang, China: A 5-year retrospective study

PurposeTo investigate the epidemiological characteristics of maxillofacial fractures treated at a university hospital, Xinjiang, China over a 5-year period.Patients and methodsBetween 2006 and 2010, a total of 1350 patients with maxillofacial fractures were reviewed retrospectively. The data collected included demographics, aetiology, site of fracture, time regarding injuries, presence of associated injuries, treatment modalities, and complications.ResultsA total of 1860 maxillofacial fractures were seen in 1350 patients with a male to female ratio of 4.9:1. The most common aetiology of the fractures was motor vehicle accident, followed by interpersonal violence. The age group 21–30 years accounted for the largest subgroup in both sexes. The mandible was the most common site of fracture followed by the zygoma. Associated injuries were found in 48.3% of patients, with a prevalence of intracranial injuries (37.0%). Majority of fractures were treated with open reduction (62.4%), and 7.2% of patients presented post-operative complications.ConclusionRoad traffic accident is the most common cause of maxillofacial fractures in China, which is characterized by an increasing prevalence and resulting in more associated injuries. Thus, more attention should be paid on the prevention and treatment of these injuries caused by road traffic accidents in our country.     

Staged autogenous calvarial bone grafting and dental implants placement in the management of oligodontia: a retrospective study of 20 patients over a 12-year period

Oligodontia demands multidisciplinary management due to its repercussions on dentofacial growth. To place implants to realize implant-borne fixed denture, preimplant surgery may be necessary if bone volumes are insufficient. Our aim was to assess bone increase following autogenic bone grafting and to discuss prosthetic options. Twenty patients followed for oligodontia, who underwent bone grafting, were treated from 2008 to 2019. Transversal and vertical bone levels were measured pre- and postoperatively to assess alveolar ridge augmentation. Mean horizontal grafting increase was 4.60 mm [standard deviation (SD) 0.79 mm], mean sinus lift increase was 9.95 mm (SD 2.35 mm). Mean implants placed per patient was 9, mean implants placed on grafted site was 5 per patient. Overall implant survival rate was 100%. All patients benefited from prosthetic procedures when it was planned to perform implant-borne fixed dentures. Within the framework of a complete treatment plan (involving paediatric dentistry, dentofacial orthopaedics, oral and maxillofacial surgery, and prosthodontics), autologous bone grafting combined or not with orthognathic surgery is fully adapted to patients with oligodontia. It allows reconstruction of favourable bone volumes for placement of implants to realize implant-borne fixed dentures, with high implant survival rates and great improvements to quality of life.     

Direct percutaneous puncture digital-subtraction-angiography-based classification and treatment selection for soft-tissue arteriovenous malformations of maxillofacial region: a retrospective study

Treatment of arteriovenous malformations (AVMs) should be individualized based on the imaging findings. A total of 117 AVM cases were categorized into three types based on the angio-architectural characteristics: Type I (n = 14, no draining vein or diameter of the draining vein <2 mm); Type II (n = 64, draining vein diameter 2–6 mm); and Type III (n = 39, draining vein diameter >6 mm). Subjects were randomly allocated to one of two treatment groups: Group A (n = 59) received multipoint percutaneous ethanol injection (MPEI), while Group B (n = 58) received super-selective angiograms followed by embolization with gelfoam (EFAG) plus MPEI. Patients were followed up for 2–6 years. A significant between-group difference with respect to treatment outcomes was observed only for Type III cases (P < 0.05). Direct percutaneous puncture digital-subtraction-angiography-guided classification of AVMs provides easy-to-follow guidelines for its clinical management. EFAG plus MPEI with reduced procedure time and the amount of ethanol should be used for Type III AVMs.     

Comparative evaluation of stress distribution and transverse displacement of novel designs of miniplates for sagittal split ramus osteotomy in 10 mm advancements: a finite element analysis

The aim of this study was to evaluate the stress distribution and displacement values of six different miniplate systems in large mandibular advancement after sagittal split ramus osteotomy (SSRO) with finite element analysis (FEA). A three-dimensional model of a mandible was created and a 10 mm advancement SSRO was simulated. The model was fixed using a four-hole miniplate, a six-hole miniplate, a newly designed six-hole miniplate and their curved versions. Maximum principal stress values for bone, von Mises stress values for osteosynthesis materials, and the amount of displacement between segments were measured. The highest von Mises value was observed in the curved version of the newly designed six-hole miniplate; the lowest value was detected in the four-hole curved miniplate. The lowest value of maximum principal stress in the bone was found in the curved version of the novel design six-hole miniplate. The least displacements between segments were also recorded in the new design of straight miniplate; therefore, for large mandibular advancement surgery, this novel six-hole miniplate may be a promising option with positive biomechanical characteristics.     

The Marius implant bridge: surgical and prosthetic rehabilitation for the completely edentulous upper jaw with moderate to severe resorption: a 5-year retrospective clinical study

Background: Patients seeking replacement of their upper denture with an implant‐supported restoration are most interested in a fixed restoration. Accompanying the loss of supporting alveolar structure due to resorption is the necessity for lip support, often provided by a denture flange. Attempts to provide a fixed restoration can result in compromises to oral hygiene based on designs with ridge laps. An alternative has been an overdenture prosthesis, which provides lip support but has extensions on to the palate and considerations of patient acceptance. The Marius bridge was developed as a fixed bridge alternative offering lip support that is removable by the patient for hygiene purposes, with no palatal extension beyond normal crown‐alveolar contours. Purpose: Implant‐supported restorative treatment of completely edentulous upper jaws, as an alternative to a complete denture, is frequently an elective preference, and it requires significant patient acceptance beyond the functional improvement of chewing. Patients with moderate to severe bone resorption and thin ridges present additional challenges for adequate bone volume and soft‐tissue contours. The purpose of this investigation was to develop a surgical and prosthetic implant treatment protocol for completely edentulous maxillae in which optimal lip support and phonetics is achieved in combination with substantial implant anchorage without bone grafting. Materials and Methods: The Marius bridge is a complete‐arch, double‐structure prosthesis for maxillae that is removable by the patient for oral hygiene. The first 45 consecutive patients treated by one person (YF) in one center with this concept are reported, with 245 implants followed for up to 5 years after prostheses connection. Results: The cumulative fixture survival rate for this 5‐year retrospective clinical study was 97%. Five fixtures failed before loading, in five different patients, and two fixtures in the same patient failed at the 3‐year follow‐up visit. None of the bridges failed, giving a prostheses survival rate of 100%. The complications were few and mainly prosthetic: nine incidences of attachment component complications, one mesobar fracture, and three reports of gingivitis. All complications were solved or repaired immediately, with minimal or no interruption of prostheses use. Conclusions: Satisfactory medium‐term results of survival and patient satisfaction show that the Marius bridge can be recommended for implant dentistry. The technique may reduce the need for grafting, because it allows for longer implants to be placed with improved bone anchorage and prostheses support.