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.

Spatial deviations of the temporomandibular joint after oncological mandibular reconstruction.

Spatial deviations of the temporomandibular joint (TMJ) after oncological mandibular reconstruction are important to the aesthetic and functional rehabilitation. The aim of this study was to clarify whether and how three dimensionally (3D) printed patient-specific surgical plates, and the preservation of the condyle or ramus, affect spatial deviations of the TMJ. A total of 33 patients who underwent mandibular reconstruction via computer-assisted surgery were included. Regarding absolute deviations, patients in the 3D-printed plate group showed smaller TMJ deviations compared to those in the conventional plate group. There was no difference in absolute deviations of the TMJ regardless of whether the condyle or ramus was preserved. Regarding physiological deviations, the impact on the contralateral TMJ was smaller in the 3D-printed plate group. Patients with both the condyle and ramus removed had significantly higher deviations of the condyle and joint space. In summary, 3D-printed patient-specific surgical plates improved the spatial accuracy of the TMJ. Under physiological conditions, TMJ deviations on the operated side were mainly affected by the preservation of the condyle. Removal of both the condyle and ramus caused more severe spatial interference to the TMJ; this should be further confirmed.

Timing of arthrocentesis in the management of temporomandibular disorders: an integrative review and meta-analysis.

The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regard to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was performed. Relevant articles were selected after three search rounds for final review based on six predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including eight randomized controlled trials and three prospective clinical studies, were included in the review. The studies were divided into three groups based on the timing of arthrocentesis: (1) arthrocentesis as the initial treatment; (2) early arthrocentesis; and (3) late arthrocentesis. Meta-analysis was carried out to compare the efficacy of improvement in mouth opening and pain reduction in the three groups. All three groups showed improvement in mouth opening and pain reduction, with forest plots suggesting that arthrocentesis performed within 3 months of conservative treatment might produce beneficial results. We conclude that there is a knowledge gap in the current literature regarding the preferable timing to perform arthrocentesis in the management of temporomandibular disorders, and more high-quality randomized controlled trials are required to shed light on this subject.

Surgical morbidities of sagittal split ramus osteotomy versus intraoral vertical ramus osteotomy for the correction of mandibular prognathism: a randomized clinical trial.

The sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) are two common orthognathic procedures for the treatment of mandibular prognathism. This randomized clinical trial compared the surgical morbidities between SSRO and IVRO for patients with mandibular prognathism over the first 2 years postoperative. Ninety-eight patients (40 male, 58 female) with a mean age of 24.4±3.5 years underwent bilateral SSRO (98 sides) or IVRO (98 sides) as part or all of their orthognathic surgery. IVRO presented less short-term and long-term surgical morbidity in general. The SSRO group had a greater incidence of inferior alveolar nerve deficit at all follow-up time points (P< 0.01). There was more TMJ pain at 6 weeks (P= 0.047) and 3 months (P= 0.001) postoperative in the SSRO group. The SSRO group also presented more minor complications, which were related to titanium plate exposure and infection. There were no major complications for either technique in this study. Despite the need for intermaxillary fixation, IVRO appears to be associated with less surgical morbidity than SSRO when performed as a mandibular setback procedure to treat mandibular prognathism.

Is there a difference between the thicknesses of the rami in mandibular asymmetry?

The purpose of this retrospective study was to investigate whether the thicknesses of the two rami differ in patients with mandibular asymmetry. Preoperative cone beam computed tomography scans of 78 patients with mandibular asymmetry were assessed for ramus thickness, mandibular length, and mandibular shift. The results showed that the ramus was thinner on the longer side than on the shorter side in 85.9% of the patients. On average, the longer side of the mandible was 2.74mm longer (range 0.07-9.90mm, standard deviation 1.92mm) and 0.55mm thinner (range -0.61 to 2.02mm, standard deviation 0.59mm) than the shorter side (both P<0.001). This study indicates a trend in the discrepancy in ramus thickness between the longer and shorter side of about 8% of the mean thickness of the ramus. Regression analysis showed that for every 1-mm increase in the length of the mandible, the thickness of the superior aspect of the ramus was reduced by 0.041 mm (P=0.009) and the anterior aspect by 0.125 mm (P=0.001). Age and sex did not have a significant influence on the thickness of the mandible. It is concluded that the longer side of the mandible tends to be thinner at the ramus than the shorter side in patients with mandibular asymmetry. The implication of this finding could be important in relation to the sagittal split ramus osteotomy.

Oral Epstein-Barr virus-positive mucocutaneous ulcer: gingival presentation of a benign lymphoproliferative lesion.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a benign lymphoproliferative lesion related to iatrogenic or age-related immunosuppression in patients with prior Epstein-Barr virus (EBV) infection. Although the clinical presentation may resemble malignant disease, the course of EBVMCU is indolent, and regression is expected when immunosuppression is reduced. We present a case of EBVMCU in the gingiva of a 59-year-old male patient with long-standing pemphigus vulgaris. The initial presentation was suspicious for oral cavity cancer, which was ruled out by biopsy. After reduction of immunosuppression, the ulceration regressed and an area of exposed necrotic bone remained. Complete healing was achieved after sequestrectomy and primary closure with a local gingival flap.

A novel 'surgeon-dominated' approach to the design of 3D-printed patient-specific surgical plates in mandibular reconstruction: a proof-of-concept study.

Three-dimensionally (3D) printed patient-specific surgical plates have been proposed to facilitate mandibular reconstruction and are attracting extensive attention. We have recently reported the high accuracy of 3D-printed patient-specific surgical plates used in head and neck reconstruction. Based on this previous work, the current study proposes a novel 'surgeon-dominated' approach to the design of 3D-printed patient-specific surgical plates. The aim of this proof-of-concept study was to explore the workflow and technical procedures of the surgeon-dominated approach. The workflow includes virtual surgery, the design and printing of patient-specific surgical devices, and real surgery. The prototype of the patient-specific surgical plate was designed by surgeons and further optimized for 3D printing by engineers. Different types of mandibular defect were tested to confirm the wide applicability of this approach. Cases in which this approach was used were reviewed and the duration of time spent on each case studied. Based on a total of 16 patients, the time spent on virtual surgery and plate design was 18.83±13.19hours, and the time taken for 3D printing, post-processing, and product delivery was 162.9±55.15hours. Therefore, this novel surgeon-dominated approach is feasible and time-saving, which would likely promote the wide application of patient-specific surgical plates and lead to a new era of 'digitization and precision' in mandibular reconstruction. ClinicalTrials.gov registration: NCT03057223.