Radiographic condylar changes following vertical subsigmoid osteotomy in different setback magnitudes

Meeting Theme: The Future of Stem Cell Research in Clinical DentistryPoster Abstracts: P-01OBJECTIVES: The objective of this retrospective study was to compare the effect of different mandibular setback amount by vertical subsigmoid osteotomy (VSSO) on the pattern of radiographic condylar remodeling in one year time span post-surgically. Methods: 200 patients diagnosed of mandibular prognathism and underwent VSSO surgery with various setback amounts from 2007 until 2012 at the Prince Philip Dental Hospital were included in this study. Pre-surgical and 1 year post-surgical Postero-Anterior Cephalogram, Lateral Cephalograms and Cone Beam Computed Tomography (CBCT) Scans were retrieved. Tracings of plain cephalometric radiographs were performed. CBCT data sets were used to measure the linear and condylar axis angle value in multiplanar view. Finally the pre- and post-surgical 3D condyle-ramus units were superimposed using stable registration point of the condylar neck and ramal area above the lingula to assess the condylar bone remodeling by ...postprin

The value of tranexamic acid in orthognathic surgery

This journal suppl. entitled: 22nd International Conference on Oral & Maxillofacial Surgery, Melbourne, AustraliaOrthognathic Surgery is a common procedure for the correction of dentofacial deformity. It may be associated with significant blood loss especially in bimaxillary osteotomies with segmentalization. Different haemostatic measures have been advocated including the use of hypotensive anaesthesia and haemostastic agents such as aprotinin, desmopressin, Yunnan baiyao. Tranexamic acid (TA) is a lysine analogue which acts as a clot stabilizer. It has been marketed for decades and it is an affordable drug. Several clinical trials were carried out in the last decade and showed preoperative intravenous bolus of TA could significantly reduce blood loss in orthognathic surgery. Two studies even tried to use TA topically during bimaxillary osteotomy. We performed a randomized controlled trial with 61 patients from 2005 to 2008 and demonstrated a 30% reduction of mean blood loss in patients receiving a single preoperative bolus of TA with standard hypotensive anaesthesia during bimaxillary osteotomy. No adverse event or complication related to the use of TA was found. Although it appeared that TA was cost effective in reducing blood loss in orthognathic surgery, the studies available in the literature were based on small sample size. In the presentation, I will share and discuss our experience of using TA in orthognathic surgery. Analysis of data of 545 cases operated from 2008 to 2015 will be presented

Three-dimensional evaluation of postoperative facial contour: the current state of art

Organizer: The Hong Kong Association of Oral and Maxillofacial Surgeon

Accuracy of sentinel lymph node biopsy in early oral squamous cell carcinoma

Free Paper Session - Head & Neck OncologyObjective: This systematic review is performed to investigate and review the application of sentinel lymph node biopsy in early oral squamous cell carcinoma (OSCC), that is, clinical stage T1 and T2 with N0 neck, and no history of previously treated neck. Methods: In order to answer the question “Whether sentinel lymph node biopsy is an accurate diagnostic staging tool for clinical N0 OSCC patients?” An electronic search on PubMed, Medline and the Cochrane Library database was carried out for all relevant articles using specific search keywords. All articles were classified by their level of evidence. Results: A total of 34 studies were included in this review. The mean detection rate for sentinel lymph nodes ranged from 93 to 100%. A mean of 1.5 to 3.8 sentinel lymph nodes were detected per patient. The percentage of upstaging due to detection of occult metastasis present in the sentinel lymph nodes was 9–50% amongst the 34 studies. The mean sensitivity of the procedure is 60–100%, the negative predictive value is 80–100% and the false negative rate is 0–25%. The regional recurrence amongst the negative sentinel lymph node results were reported to be 0–12%. Centre and surgeon experience is crucial in order for the technique to be carried out with a higher sensitivity. Conclusion: Sentinel lymph node biopsy can be an alternative diagnostic strategy to evaluate cT1-T2N0 early oral cancer. It should only be offered as an alternative when the two criteria are met. (1) The equipment for SLNB is available and (2) surgeons performing the SLNB procedure has received adequate training. Copyright © 2017 Published by Elsevier Ltd

Effectiveness of vitamin B complex in reducing chronic temporomandibular joint disorder pain — double blind randomised clinical trial

2I Free Paper Session - TMJ 1 - no. OR575Background: Chronic temporomandibular joint disorder (TMD) pain management has always been challenging and usually requires long-term analgesics. Commonly used analgesics have a potential for adverse effects in long-term usage, thus there is a need to look for a safer alternative analgesic option. Objectives: To evaluate efficacy of vitamin B complex (VBC) [B1, B6, B12] in reducing chronic TMD pain. Methods: 26 patients with chronic TMD pain secondary to arthralgia, osteoarthritis and disc displacement were included. The patients were allocated randomly into two groups and received either VBC tablet (B1: 242.5 mg, B6: 250 mg, B12: 1 mg) or placebo once per day for six weeks. Clinical measurements were recorded at week 0 and week 2, week 4, and week 6 to evaluate the efficacy of the treatment. Pain intensity was measured by visual analogue score (VAS) and mandibular range of movement was measured by maximal comfortable mandibular opening and lateral excursion. Adverse effects and compliance rate towards treatment were also assessed. Findings: In this 6-week clinical trial, both groups showed significant VAS pain reduction (VBC 2.49 ± 1.71; placebo 1.41 ± 1.53; P < 0.05). The amount of VAS pain reduction in the VBC group was significantly higher than in the Placebo group at week 2 (1.19 ± 1.28 versus 0.23 ± 0.90) and week 4 (2.32 ± 1.42 versus 1.25 ± 0.75; P < 0.05). No statistically significant difference was noted in mouth opening improvement. Both VBC and placebo medications were well tolerated with minimal adverse effects. Conclusion: In this study a dose of VBC (B1: 242.5 mg, B6: 250 mg, B12: 1 mg) was significantly better than placebo in reducing chronic TMD pain at week two and week four. Copyright © 2017 Published by Elsevier Ltd

Two-dimensional and three-dimensional postsurgical temporomandibular joint condylar remodelling following vertical subsigmoid osteotomy setback surgery

14D Free Paper Session – Orthognathic & Aesthetic 7 - no. OR315Background: Vertical subsigmoid osteotomy (VSSO) for ramus setback has been suggested to exert less stress onto the condylar head causing more positive bone remodelling changes in the postoperative phase. However, it is unclear if the setback amount has any effect on the remodelling pattern. Objectives: This study aims to compare the postsurgical quantitative and qualitative condylar remodelling changes in various setback magnitudes using two-dimensional (2D) and three-dimensional (3D) radiography. Methods: Retrospective pre- and postoperative radiographic data of patients with mandibular prognathism that had undergone VSSO from 2007 to 2012 at the Prince Philip Dental Hospital were traced. 130 postero-anterior and lateral cephalographs, along with 174 cone-beam computed tomography (CBCT) scans were retrieved. 2D and 3D radiographic tracing were performed to measure the condyle-ramal morphometric values. Pre- and postoperative CBCT rendered condyle ramus segments were superimposed based on stable growth registration points to observe zonal and topographic changes. Findings and Conclusion: 2D radiographic tracing did not show significant condyle-ramal changes in different setback magnitudes. 3D radiographic tracing showed significant changes in axial condylar depth with more setback. Topography analysis also showed that in the postero-superior condylar surface, more bone deposition was found in larger setback. In the axial plane, the bone formation proportion at the condylar head was significantly increased in mid-anterior and posteromedial zones with larger setback except in the group with setback between 4.1–6 mm. In general the condylar remodelling pattern after VSSO for mandibular setback was considered to be stable despite various setback magnitudes. Copyright © 2017 Published by Elsevier Ltd

Distraction osteogenesis of the mandible: does postoperative infection affect stability?

Background: Up to the present time, no study has attempted to explore a possible association between skeletal stability and postoperative infection in mandibular advancement by distraction osteogenesis. Objectives: To determine any possible association between postoperative infection and skeletal stability of mandibular advancement by distraction osteogenesis for the treatment of Skeletal Class II patients. Methods: Retrospective study of 20 Class II patients previously treated by distraction osteogenesis for mandibular advancement. Clinical records of these patients were reviewed and lateral cephalograms were used. Prevalence and duration of postoperative infection were recorded. Skeletal relapse was calculated based on serial hand tracings of lateral cephalograms. Statistical analysis of the data was performed to determine any association between prevalence and duration of postoperative infection and skeletal relapse. Findings: 10 out of 20 patients presented with mild postoperative infection. None presented with more severe postoperative infections. All were treated with oral antibiotics and mouth rinse without surgical intervention. The percentage of horizontal relapse in patients with and without postoperative infections was 3.20% and 8.23% respectively (P > 0.05). When the duration of infection was plotted against the percentage of horizontal and vertical relapse, the relationship was weakly positive for both (R2 = 0.028 and 0.22, respectively). Conclusions: It appears that mild postoperative infection does not affect postoperative skeletal stability in Class II patients treated with distraction osteogenesis of the mandible. Future studies with larger sample size and wider range of postoperative infections are needed to further elucidate if more severe postoperative infection would affect stability of the advancement