Man-Tin Lui

miR-196a Overexpression and miR-196a2 Gene Polymorphism Are Prognostic Predictors of Oral Carcinomas

BackgroundOral squamous cell carcinoma (OSCC) is prevalent worldwide, and survival in OSCC has not improved significantly in the last few decades. MicroRNAs have an important regulatory role in oral carcinogenesis. This study investigated the prognostic implications of miR-196 expression and the rs11614913 genotype of the miR-196a2 gene in OSCC.MethodsThe clinicopathologic implications of miR-196 in OSCC were investigated using expression assays and genotyping, and the functional role of miR-196 in OSCC pathogenesis was investigated using exogenous expression and knockdown.ResultsmiR-196 was up-regulated in OSCC tissue relative to control mucosa. High expression of miR-196a, but not miR-196b, was associated with tumor recurrence, nodal metastasis, and mortality. Plasma miR-196a levels could be used to distinguish patients from controls with a separating power of 0.75. Multivariate analysis showed that both high miR-196a expression and TT genotype were independent predictors for poor survival in OSCC. The risk of mortality was greatest for patients with high miR-196a level and positive node status. Expression of miR-196 enhanced oncogenesis of OSCC cells, while inhibition of miR-196 expression attenuated such effects.ConclusionsHigh miR-196a expression in tumor tissue and the presence of the TT variant of miR-196a2 gene indicate worse survival in OSCC.

A Method Using Vestibulo-sulcoplasty Combining a Split-thickness Skin Graft and a Palatal Keratinized Mucosa Graft for Peri-implant Tissue Secondary to Oral Cancer Surgery

Twelve patients presented with oral submucosal fibrosis and loss of keratinized gingiva in a compromised vestibule of a severely deficient mandibular edentulous ridge secondary to oral cancer surgery. They received implant rehabilitation with a total of 49 fixtures without major bone graft augmentation. To overcome vestibular compromise, soft tissue management consisting of simultaneous vestibulo-sulcoplasty, split-thickness skin graft (STSG), and palatal keratinized mucosa graft (KMG) was performed as a second stage when healing abutment was transferred to replace the cover screw of the dental implant. Postoperative follow-up of all patients consisted of clinical and radiographic examinations for an average of 4 years, revealing good stability of implant fixtures with a 91.8% success rate and generally healthy peri-implant tissue, the latter with an average sulcus depth of 2.9 +/- 0.6 mm. Satisfactory results were also demonstrated regarding improved morphology of the vestibule, cosmetics, and prosthetic functionality. Vestibulo-sulcoplasty combining STSG and palatal KMG offers a stable and convenient method for rebuilding peri-implant tissue without need for bone grafting in selected patients who have compromised atrophic ridges secondary to cancer surgery.

Predictors and impact of microsurgical complications in patients with locally advanced oral squamous cell carcinoma

Microvascular free flap transfer for post‐oncologic reconstructive surgery in oral cancer is considered to be a challenge due to the complexity of the anatomy and function of the region. We sought to identify possible factors associated with microsurgical complications and to assess the impact of these complications in relation to patient survival. Following the inclusion and exclusion protocol, 142 patients with stage III and IV oral squamous cell carcinoma (OSCC) who underwent immediate free flap reconstruction after tumor ablation were included in the study. Clinical and surgical procedural‐related factors were retrieved from a database and analyzed retrospectively; survival data were evaluated using the Kaplan–Meier method. Major complications that required re‐anastomosis of the flap vessels occurred in 23 patients (16.2%); total necrosis of the flaps, regardless of salvage treatment, occurred in seven cases, with 95.1% of full flap survival. The American Society of Anesthesiologists classification, types of neck dissection, and number of flaps were regarded as strong predictors for surgical complications. Patients with these complications appeared to have a shortened survival (5‐year cancer‐specific survival of approximately 60%, both in stage III and IV OSCC). However, the impact of surgical complications on survival was significant only in stage III OSCC (P = 0.037). Strategies to minimize surgical complications should be used to ensure better prognoses for these patients.

Use of panoramic radiography to predict postsurgical sensory impairment following extraction of impacted mandibular third molars

Background The purpose of this study was to use panoramic radiographic findings to predict postsurgical sensory impairment following the extraction of impacted mandibular third molars. Methods There were 120 patients enrolled in this study (55 male and 65 female). A total of 120 impacted mandibular third molars were included due to the proximity between the inferior alveolar nerve (IAN) canal and the roots of the impacted third molar on the panoramic radiograph. Seven radiographic signs were the predictor variables: (1) darkening of the root(s); (2) interruption of the radiopaque line of the inferior alveolar canal; (3) diversion of the inferior alveolar canal; (4) dark and bifid apex; (5) deflection of the root(s); (6) narrowing of the inferior alveolar canal; and (7) narrowing of the root(s). The outcome variable was the postoperative IAN sensory impairment. The retrospective cohort study model was used, and univariable and bivariable statistics was computed with the statistically significant level at p ≤ 0.05. Results Three of the radiographic signs were statistically associated with IAN sensory impairment (p < 0.05). They include: (1) interruption of the radiopaque line [sensitivity = 0.92, specificity = 0.45, positive predictive value (PPV) = 0.17, negative predictive value (NPV) = 0.02]; (2) diversion of the IAN canal (sensitivity = 0.77, specificity = 0.84, PPV = 0.37, NPV = 0.03); and (3) narrowing of the IAN canal (sensitivity = 0.69, specificity = 0.65, PPV = 0.19, NPV = 0.05). However, the other four radiographic signs, namely darkening of the root(s), dark and bifid apex, deflection of the root(s), and narrowing of the root(s), were not statistically associated with IAN sensory impairment (p > 0.05). Conclusion There are three radiographic signs: (1) interruption of the radiopaque line; (2) diversion of the IAN canal; and (3) narrowing of the IAN canal. These signs are valuable in presurgical evaluation of the risk of postoperative sensory impairment after surgical removal of impacted mandibular third molar.

Lateral trap-door window approach with maxillary sinus membrane lifting for dental implant placement in atrophied edentulous alveolar ridge

Abstract One of the most challenging and technically sensitive surgical procedures in conjunction with dental implant rehabilitation is sinus membrane lifting to increase the bone height or volume from the maxillary sinus floor. This important preprosthetic surgical technique has been available for >15 years, making possible the creation of bone volume in the edentulous posterior maxilla for the placement of dental implants in surgically compromised cases. Substantial literature exists regarding the most efficacious way to increase the predictability of this surgical procedure, and reduce its associated complications. In this article, we describe the regional anatomy of the maxillary sinus, the evolution of the sinus membrane lifting procedure, the current surgical technique, its survival rate and associated complications, the need for bone graft or bone substitutes, and current advances in the lateral approach through a trap‐door window for sinus membrane lifting for dental implants.

A Giant Venous Malformation of Face and Neck-A Case Report

We report a case of giant hemi-facial venous malformation involving tongue and mandible. The patient was a 41-year-old woman who had demonstrated a venous malformation since she was young. She received surgery twice and was still with residual lesion over right cervical, tongue and face regions. She came to our hospital due to fever, pain and swelling over right facial area. The antibiotics were first prescribed for the patient. In the same time, she denied any further invasive treatment, such as vascular embolization. Due to the patient still complained pain and discomfort, she received Gabapentin for treatment. The symptom was then subsided and she is still followed in our department.

Implant Rehabilitation of Severely Traumatised Anterior Alveolar Ridge

Abstract Objective: To propose a sequential treatment approach for implant rehabilitation of a traumatised and deficient maxillary or mandibular alveolar ridge. Patients and Methods: Patients with severely deficient alveolar ridge and loss of teeth due to injury underwent sequential reconstructive procedures at the maxillary or mandibular edentulous areas with autogenous symphyseal bone or allogeneic bone graft with guided bone regeneration; vestibuloplasty with or without keratinised palatal mucosal graft to rebuild the vestibule; and implant rehabilitation. Postoperative followup consisted of clinical and radiographic examinations. Results: Thirty six implant fixtures were placed in the maxilla or mandible in 12 patients. The average follow-up period after treatment was 4 years. Before surgery, all patients had severely deficient ridges with a compromised shallow vestibule. Satisfactory results were observed in regard to the long-term stability of the rehabilitation result, contour of the reconstructed ridge, morphology of the vestibule, health of the periimplant tissue, and functionality of the implant-retained prostheses. Conclusion: The proposed sequential reconstructive treatment approach for both hard and soft tissues offers a reliable method of implant rehabilitation after traumatic injury.

The expression of transglutaminase 2 (TG-2) in oral squamous cell carcinoma and its clinical significance

Background Glutamine has a very important role in the human body, including pH balance in an acidic environment, as well as supporting the TCA cycle in cancer cell growth. However, the expression of transglutaminase‐2 (TG‐2) in oral cancer growth related to renal function is unknown. Here we examined TG‐2 and its expression as a prognostic tool. Methods Fifty‐six oral squamous cell carcinoma (OSCC) tissues were collected with the inclusion of tumor in any region of oral area, and patients with creatinine (Cr) and blood urea nitrogen (BUN) results. The tissues were stained using immunohistochemistry (IHC) with a TG‐2 antibody [N3C3], then observed under the microscope. The staining were calculated using Adobe Photoshop CS software and statistical analyses using SPSS ver. 21. Results We found that TG‐2 expression showed a significant difference in the expression levels between tumor and the adjacent groups without disease‐free survival, disease‐specific survival, and recurrence between, with p < 0.05. The average staining intensity with 25th percentile of TG‐2 becomes a vital score for the diagnosis. Furthermore, our study demonstrates a good prognosis outcome if the intensity score showed a difference in TG‐2 expression between the adjacent and tumor tissue. Conclusion To our knowledge, this is the first clinical study on TG‐2 expression in OSCC, and it demonstrates that TG‐2 can serve as a predictor of tumorigenesis and prognosis outcome.

Solitary Diffuse Neurofibroma of Tongue-A Case Report

Neurofibromas are derived from the nerve sheath and are commonly located in the head and neck region. It is often related to neurofibromatosis, especially type I which also known as von Recklinghausens disease of the skin. Intraoral neurofibroma not related to neurofibromatosis is relatively uncommon. We present a case of solitary neurofibroma in a young female who denied family history of neurofibromatosis and lack of other signs of neurofibromatosis, presented with a painless submucosal mass over the left side of the tongue. She received total excision of the tumor and the pathology proved to be diffuse neurofibroma.

Primary Maxillary Leiomyosarcoma ─ A Case Report

We present a rare case of primary oral leiomyosarcoma (LMS) occurring at maxilla pterygoid plate area. The patient had symptom of pain and swelling for more than 10 months over left pre-auricular area. The patient went to see the neurologist for help and was diagnosed as trigeminal neuralgia after checking computed tomography (CT) without any finding. Medication was prescribed at first but without any regressive change. Then, the magnetic resonance imaging (MRI) was arranged and a tumor over left maxillary pterygoid area extending to temporal space was found. The biopsy was arranged under general anesthesia and the result showed compatible with sarcoma. The patient was treated by radical surgery and reconstruction with free anterior lateral thigh flap. The pathology showed leiomyosarcoma and the immunohistochemical examination revealed positive cytologic features of HHF-35, smooth muscle actin and h-Caldesmon. The distant metastasis to thoracic and lumbar spines were found after 6 months of surgery and the patient is still under palliative chemo and radiotherapy.