Ultrasensitive detection of tumor-specific mutations in saliva of patients with oral cavity squamous cell carcinoma.

BACKGROUND: Oral cavity squamous cell carcinoma (OCSCC) is the most common head and neck malignancy. Although the survival rate of patients with advanced-stage disease remains approximately 20% to 60%, when detected at an early stage, the survival rate approaches 80%, posing a pressing need for a well validated profiling method to assess patients who have a high risk of developing OCSCC. Tumor DNA detection in saliva may provide a robust biomarker platform that overcomes the limitations of current diagnostic tests. However, there is no routine saliva-based screening method for patients with OCSCC. METHODS: The authors designed a custom next-generation sequencing panel with unique molecular identifiers that covers coding regions of 7 frequently mutated genes in OCSCC and applied it on DNA extracted from 121 treatment-naive OCSCC tumors and matched preoperative saliva specimens. RESULTS: By using stringent variant-calling criteria, mutations were detected in 106 tumors, consistent with a predicted detection rate ≥88%. Moreover, mutations identified in primary malignancies were also detected in 93% of saliva samples. To ensure that variants are not errors resulting in false-positive calls, a multistep analytical validation of this approach was performed: 1) re-sequencing of 46 saliva samples confirmed 88% of somatic variants; 2) no functionally relevant mutations were detected in saliva samples from 11 healthy individuals without a history of tobacco or alcohol; and 3) using a panel of 7 synthetic loci across 8 sequencing runs, it was confirmed that the platform developed is reproducible and provides sensitivity on par with droplet digital polymerase chain reaction. CONCLUSIONS: The current data highlight the feasibility of somatic mutation identification in driver genes in saliva collected at the time of OCSCC diagnosis.

Circulating tumour cells in head and neck cancers: Biological insights.

Tumour metastasis is one of the leading cause of cancer-related mortality. Circulating tumour cells (CTCs) have been implicated in loco-regional and distant metastasis and its role is being extensively studied in various malignancies, including those from the head and neck region. The main challenge in understanding their significance lies in the rarity of these cells in the blood. However, newer technologies have attempted to overcome these pitfalls. This review explores the evolution of CTC research and other related areas, including its biological significance, sustainability within the circulating vascular environment and possible clinical implications.

Correlation of transverse mandibular dimension with naso-pharyngeal and oro-pharyngeal airway using computed tomographic analysis - A retrospective observational study.

PURPOSE: The aim of the study was to investigate changes in the naso-pharyngeal and oro-pharyngeal airway with varying degrees of mandibular flare. METHODS: The investigators implemented a retrospective, observational study including CT data from patients fitting the inclusion criteria. Linear and angular measurements were used to assess the flare and transverse dimension of the mandible, while standard reference planes were used for assessment of airway dimensions. The primary outcome measures were to correlate and quantify the naso-pharyngeal and oro-pharyngeal volumes with mandibular flare. Secondary outcome measures were to study the intra-variable correlation. Significance level was fixed at 5% (α = 0.05). RESULTS: The sample included CT data from 30 individuals with apparently normal craniofacial skeleton (53% males and 46.7% female with a mean age of 29.53 years). Both nasopharyngeal and oropharyngeal volumes demonstrated moderate positive correlations with inter-condylar width (p = 0.020 and p = 0.038) and inter-condylar angles (p = 0.041 and p = 0.005) respectively. Linear regression modelling demonstrated that for every millimetre increase of the Inter-condylar width, the naso-pharyngeal and oro-pharyngeal airway volume increased by 0.423 cm3 (p = 0.020) and 0.381 cm3 (p = 0.038) respectively, and every degree increase of inter-condylar angle produced an increase the nasopharyngeal and oropharyngeal volumes by 0.376cm3 (p = 0.041) and 0.496cm3 (p = 0.005) respectively. CONCLUSION: Parameters of mandibular flare demonstrate statistically significant correlation to pharyngeal airway volume, which may be a relevant predictor to evaluate airway in patients undergoing corrective skeletal surgery.

Selective embolization of lingual artery in transoral robotic surgery for the management of recurrent base of tongue carcinomas.

BACKGROUND: The incidence of oropharyngeal carcinoma has been on the rise in recent decades. About 30% of patients who undergo definitive chemoradiation as the initial treatment present with residual/recurrent disease. In such a situation, surgical salvage either in the form of traditional open surgery or transoral robotic surgery (TORS) remains a viable treatment option. However, the extensive vascular supply of the posterior tongue and tonsillar bed increases the risk of perioperative bleeding, which is a key concern. The article describes the technique of selective pre-operative embolization to reduce the risk of perioperative bleeding and enumerate its advantages in providing a bloodless field during surgery. METHODS: Prospective study of 5 patients with recurrent or residual midline BOT tumours who underwent TORS after selective lingual artery embolization at our centre. RESULTS AND CONCLUSIONS: None of the patients had any major perioperative bleeding or post procedural complications. All the patients after TORS had their tongue vascularity preserved with adequate recovery of tongue functions. Selective embolization of the feeder vessels provides a favorable bloodless surgical field without affecting the vascular integrity of the remnant tongue. This added advantage helps restoring the normal oral phase of swallowing.

Utility of Chitra-HASi Granules in Cystic Defects of the Maxillofacial Region: A Pilot Study.

BACKGROUND: Cystic defects that are critical sized or larger require bone replacement strategies. However, due to inherent disadvantages of the various types of grafts, none of the available materials are best suited for these defects. Among the alloplastic materials, hydroxyapatite (HA)-based grafts are the most popular, due to their osteoconductive nature and resemblance to mineral bone. The aim of the study was to assess the utility of the novel material "Chitra-HASi" as a bone substitute in the maxillofacial region. MATERIALS AND METHODS: In a single-arm, prospective study, patients with radicular and dentigerous cysts were included and the minimum defect size was standardized at 20 × 20 mm or above. The Chitra-HASi material was developed by a wet precipitation technique and adopted for use following multiple in vitro and in vivo studies, confirming its safety and biocompatibility profile. All cysts underwent enucleation, followed by peripheral ostectomy and apicectomy of the teeth involved. The HASi graft was packed inside the cystic defect in a granular form and covered with a mucoperiosteal flap. Panoramic radiographs were taken preoperatively and at 3, 6, and 12 months postoperatively. RESULTS: Twenty-three patients were included in the study, of which only 10 patients could be followed up for 12 months after graft placement. The mean preoperative bone density was found to be 14.9% ± 4.97 (standard deviation), whereas the postoperative 3-month, 6-month, and 12-month densities had a mean difference of -11.3%, -22.9%, and -37.3%, respectively, and the differences were statistically significant. Minor complications such as sinus formation (n = 7) and extrusion of granules (n = 4) were noted, which were managed conservatively. Only two patients required graft removal secondary to infection, leading to a persistent sinus tract. CONCLUSION: The results of the study suggest that Chitra-HASi granules show potential as an alternative to other bone substitutes. The addition of silica to the porous HA material offers superior strength characteristics and needs long-term evaluation to assess its stability in large cystic defects.

Dentists' Knowledge, Attitude and Practice in Treating Patients Taking Oral Antithrombotic Medications - A Survey.

INTRODUCTION: India lists high on patients suffering from diabetes, hypertension, stroke and myocardial infarction. Hence, a large proportion of the population is on long term Oral Antithrombotic Medications (OAM). Though several guidelines exist on dental management of these patients, previous surveys have shown variation among the dentists. AIM: The purpose of this study was to assess the knowledge, attitude and practice of dentists in Chennai, India, towards dental management of patients taking OAM using a questionnaire survey. MATERIALS AND METHODS: The survey was conducted among 256 dentists in Chennai, India using a printed questionnaire containing 16 questions, at their university location. Descriptive statistical analysis was used to analyze the data. RESULTS: Of the final population of dentists who were included in the survey (n =212), majority of them were aware about drugs such as warfarin and aspirin compared to other newer drugs (dabigatran, rivaroxaban). Most participants took physician's opinion before proceeding with any invasive dental procedure and thromboembolic events were their major concern while treating patients on OAM. CONCLUSION: The survey revealed dentists are knowledgeable about management of patients on OAM. However, they tend to overestimate the bleeding risk, thus being cautious in their treatment approach. Based on the results of the study, the authors suggest that continuing dental education programs and further training on management of such medically complex patients will be beneficial in order to provide optimum dental care to people taking OAM.