Preliminary results on the photoluminescence and optically stimulated luminescence in Cu-doped and Ag-doped ZnB2 X4 (B = Li, Na, K: X = Cl, Br) compounds.

Photoluminescence, and optically stimulated luminescence in ZnB2 X4 (B; Li,Na,K: X; Cl,Br) compounds doped with Cu+ or Ag+ were studied. Double humped emission bands attributable to the activators were observed in all the samples. The observed photoluminescence of Cu+ and Ag+ could be identified with 3d9 4s1 ↔3d10 and 4d9 5s1 ↔5d10 transitions respectively. The longer wavelength band (400-500 nm range) could be attributed to the Cu+ or Ag+ ion replacing alkali ion at the octahedral alkali site whereas short wavelength band (340-400 nm range) is attributed to a Cu or Ag ion at tetrahedral zinc site. The short wavelength band was found to be intense compared with long wavelength and gave an indication that most of the Cu or Ag ions prefered a tetrahedral Zn site compared with the octahedral alkali site. All the samples exhibit optically stimulated luminescence (OSL). The sensitivity was found to be lattice dependent. The lowest sensitivity of about 1% compared with Al2 O3 :C was observed in lithium lattices whereas highest the sensitivity of about 290% was observed in the case of Cu-doped ZnNa2 Br4 .

Proton Triggered Colorimetric and Fluorescence Response of a Novel Quinoxaline Compromising a Donor-Acceptor System.

Quinoxaline-based novel acid-responsive probe Q1 was designed on the basis of a conjugated donor-acceptor (D-A) subunit. Q1 shows colorimetric and fluorometric changes through protonation and deprotonation in dichloromethane. With the addition of the trifluoroacetic acid (TFA), UV-vis absorption spectral changes in peak intensity of Q1 was observed. Moreover, the appearance of a new peaks at 284 nm 434 nm in absorption spectra with the addition of TFA indicating protonation of quinoxaline nitrogen and form Q1.H⁺ and Q1.2H⁺. The emission spectra display appearance of new emission peak at 515 nm. The optical property variations were supported by time resolved fluorescence studies. The energy band gap was calculated by employing cyclic voltammetry and density functional calculations. Upon addition of triethylamine (TEA) the fluorescence emission spectral changes of Q1 are found to be reversible. Q1 shows color changes from blue to green in basic and acidic medium, respectively. The paper strip test was developed for making Q1 a colorimetric and fluorometric indicator.

Factors influencing morbidity after surgical management of malignant thyroid disease.

OBJECTIVES: We performed a retrospective study of cases from 2005 to 2010 at an academic tertiary care center to analyze the factors that influence morbidity in surgical management of thyroid malignancy. METHODS: The rates of recurrent laryngeal nerve (RLN) injury and hypoparathyroidism (HPT) were analyzed in the entire cohort. The comparison groups were 1) primary surgery versus revision; 2) total thyroidectomy versus total thyroidectomy combined with neck node dissection; and 3) two groups defined by surgical technique according to the RLN approach: group 1, in which the RLN was identified inferiorly in the tracheoesophageal groove, and group 2, in which the RLN was identified near the cricothyroid joint point of entry. RESULTS: We reviewed 308 patients who underwent surgery for thyroid cancer. Thirty-six (11.7%) had temporary HPT, and 8 (2.6%) had permanent HPT. Of a total of 586 RLNs at risk, 16 (2.7%) had temporary damage and 2 (0.3%) had permanent damage. The incidences of temporary RLN injury significantly differed between the primary-surgery and revision-surgery groups (2.5% versus 15.6%; p = 0.001), and also between the groups with total thyroidectomy and thyroidectomy with neck dissection (1.2% versus 7.8%; p = 0.027). The incidences of temporary HPT were significantly different between the groups with primary surgery and revision surgery (6.6% versus 31.3%; p = 0.001), between the groups with total thyroidectomy and total thyroidectomy with neck dissection (4.7% versus 15.6%; p = 0.009), and between group 1 and group 2 (surgical technique in terms of RLN approach; 8.2% versus 17.9%; p = 0.011). Permanent HPT and permanent RLN injury both occurred rarely in this cohort, with no significant differences among comparison groups. CONCLUSIONS: Our study shows a higher incidence of temporary RLN injury and teniporary HPT in revision surgery cases and in total thyroidectomy with neck dissection. Temporary HPT was significantly more common when the RLN was identified near the cricothyroid joint.

Oral cancer: review of current management strategies.

BACKGROUND: India has one of the highest incidences of oral cancer and accounts for about 30% of all new cases annually. A high prevalence of smokeless tobacco use has led to an increasing incidence, which in combination with delayed presentation has made oral cancer a major health problem in India. Limited access to cancer care, relative lack of trained healthcare providers and financial resources are some of the challenges to the management of oral cancer in India despite improvements in diagnostic techniques and management strategies. METHODS: We reviewed the literature pertaining to the epidemiology, aetiopathogenesis, pre-malignancy, tumour progression, management of the primary site, mandible, neck lymph node metastases, reconstruction options and screening of oral cancer. The parameters evaluated were overall survival, disease-free survival, recurrence and loco-regional control. RESULTS: Nine studies on surgical intervention were reviewed. There were 23 studies on the management of chemotherapy and 30 trials analysing radiotherapy as an intervention. CONCLUSION: India has one of the highest incidences of oral cancer and delayed stage presentation is common. Surgery remains the treatment of choice and adjuvant treatment is recommended in high-risk patients. Elective neck dissection is warranted in clinically lymph node-negative neck for patients with thick tumours, imaging-suspected lymph nodes and those who may not have a reliable follow-up. Functional outcomes and treatment-related morbidity needs to be considered, and reconstruction with free tissue transfer provides the best results.

Determination of Acephate, Dinotefuran, and Emamectin Benzoate in a Pesticide Formulation: A Single-Laboratory Validation.

BACKGROUND: The advantage of simultaneous separation and quantification is the reduction of analysis time and consumption of solvents and reagents. OBJECTIVE: The objective of the present investigation was to optimize and validate a novel, rapid, and simple reverse-phase high-performance liquid chromatographic method for the simultaneous determination of acephate, dinotefuran, and emamectin benzoate in a pesticide formulation. METHOD: The chromatographic separation and quantification were accomplished by using Kromasil CN column (250 mm × 4.6 mm; 5 µm) with a mobile phase consisting of acetonitrile and water [0.1% (v/v) triethylamine, pH 2.7 with 10% (v/v) orthophosphoric acid] in the ratio of 50:50 (v/v) with a flow rate of 1.0 mL/min and diode array detection at the wavelength of (215 nm and 245 nm). RESULTS: The HPLC method was able to separate and quantify all the actives in the formulation by isocratic elution within 10 min. The method was fully validated in accordance with the SANCO and Collaborative International Pesticide Analytical Council guidelines concerning system suitability, specificity, linearity, precision, accuracy, and robustness. All the analytical parameters are within the range of acceptable limits in the guidelines. CONCLUSIONS: The validated method was successfully applied to a pesticide formulation. HIGHLIGHTS: The novelty of the current research work lies in the development of the simple and rapid HPLC method for simultaneous determination of acephate, dinotefuran, and emamectin benzoate in wettable granular formulation.

Cochlear stenting: how I do it.

Post-meningitis cases with profound sensorineural hearing loss are known to have progressive labyrinthine ossification; such cases need to be implanted early. In our region, often a substantial amount of time is spent procuring the necessary finances for a cochlear implant; therefore, here we describe our technique of maintaining cochlear lumen patency in post-meningitis cases with early ossification, for a complete functional electrode insertion at a later date. This is a descriptive case study of a patient having post-meningitis profound deafness, with imaging studies showing early cochlear ossification, who was rehabilitated with a cochlear implant. At a tertiary referral centre, a 1-year-old child with post-meningitis bilateral profound sensorineural hearing loss was rehabilitated with cochlear implantation. The left cochlea with early ossification was stented with a customised sterile electrode to prevent scalar occlusion; 3 months later the stent was replaced with a commercial Nucleus Contour Advance implant. A complete insertion of the functional electrode array replaced the stent. Categories of auditory performance (CAP) were used to assess the outcome in our case. The pre-operative CAP score was 1 (detects environmental sounds) and the score at 15 months post implant was 6 (understands some spoken words). In post-meningitis cases with progressive cochlear ossification, stenting the cochlear lumen prevents scalar occlusion and ensures a complete insertion of a functional electrode at a later date.

Incudostapedial joint arthroplasty using temporalis fascia/perichondrium ties.

Incudostapedial joint dislocation is the most frequently found ossicular chain defect. In these cases reconstitution of joint capsule is important in maintaining joint integrity. But reconstruction of dislocated incudostapedial joint is a challenging procedure as this joint is devoid of any muscular or soft tissue support. Here we describe a technique designed to reposition the incudostapedial joint in its anatomical position using temporalis fascia or perichondrium. Data have been collected and analyzed from 42 patients with incudostapedial joint discontinuity. The fascial ties used for reconstruction of joint capsule ensure a dynamic union of the repositioned incus with stapes, leading to a significant improvement in conductive hearing loss.

Bilateral Oval and Round Window Atresia on CT Temporal Bone: A Rare Anomaly Clinically Mimicking Otosclerosis in an Adult.

We present a rare adult case of bilateral oval and round window atresia. Clinical and audiologic findings were suggestive of otosclerosis. High resolution CT Temporal bones showed unequivocal findings of bilateral oval and round window atresia. Atresia of these windows is a rare temporal bone anomaly. Presentation as an adult can confound the clinicians and warranting a closer look on the CT for atretic windows and subtle signs of otosclerosis in patients with conductive hearing loss.

Stenotrophomonas skull base osteomyelitis presenting as necrotizing otitis externa: Unmasking by CT and MRI-case report and review.

Necrotizing or malignant otitis externa in patients presenting with mild clinical findings can pose as a tip of the iceberg; computed tomography (CT) and/or magnetic resonance imaging (MRI) unveils the clinical-imaging discrepancy and unmasks the presence of skull-base osteomyelitis (SBO). Pseudomonas aeruginosa is the most common causative pathogen of SBO, followed by fungal and other rare bacterial organisms. This report presents a rare case in an elderly diabetic patient, where the pathogen Stenotrophomonas maltophilia was isolated. There have been no previous reported cases in the literature of SBO caused by this pathogen. The hallmark of SBO on computed tomography or magnetic resonance imaging is soft tissue inflammatory changes under the central skull base with associated bone erosion. This may result in the peculiar appearance of the "Ovoid Gap" sign. SBO can be due to nonotogenic sources, namely: sinogenic, rhinogenic, pharnygogenic, or odontogenic infections. Low threshold for imaging is advised in immunosuppressed and elderly diabetic patients.

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst.

AIM AND OBJECTIVE: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. MATERIALS AND METHODS: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. RESULTS: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. CONCLUSION: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

Frozen section is not cost beneficial for the assessment of margins in oral cancer.

BACKGROUND: Routine use of frozen section (FS) is a costly procedure and sparsely available in resource poor countries. A proper cost benefit analysis may help to reduce its routine use and would empower surgeons to perform oral cancer surgeries without having FS facility. FS is performed to identify microscopic spread beyond gross disease that cannot be assessed clinically. OBJECTIVE: Our primary aim was to determine the cost benefit analysis of FS in the assessment of margins in oral cavity squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Retrospective study of prospectively collected data of 1311 consecutive patients who were operated between January 2012 and October 2013. The gross and microscopic margin status of each patient was extracted from the patient's chart. The cost estimates were performed to calculate the financial burden of FS as well as expenses incurred on adjuvant treatment resulting from inadequate margins. RESULT: Microscopic spread changed the gross margin status in 5.2% (65/1237) patients. Of this entire cohort of 1237 patients, FS helped 29 (2.3%) patients to achieve tumor free margin, and it changed the adjuvant treatment plan in 9 (0.7%) patients. The cost of FS for each patient was INR 11052. The cost-benefit ratio of FS was 12:1. Gross examination alone could have identified majority of the inadequate margins. CONCLUSION: Frozen section for assessment of margin status bears poor cost-benefit ratio. Meticulous gross examination of the entire surgical specimen is sufficient to identify majority of inadequate margins.

PHASE DEPENDENT OPTICALLY STIMULATED LUMINESCENCE IN CU-DOPED Sr4Si3O8Cl4.

Phase dependent optically stimulated luminescence (OSL) is studied in Cu-doped Sr4Si3O8Cl4. The Study shows that samples in which amount of contributing strontium metasilicate phase in Cu-doped Sr4Si3O8Cl4 is less, show intense OSL while those samples in which strontium metasilicate phase is more show weak OSL. The observed Cu luminescence is also found to be phase dependent. Sample in which Sr4Si3O8Cl4 phase is dominant, the observed Cu luminescence is around 350 nm whereas an additional longer wavelength band around 450 nm is observed when the strontium metasilicate phase is present in significant amount. The relatively phase pure, Cu-doped Sr4Si3O8Cl4 shows good OSL properties. The sensitivity of such material is 3.89 times more compared to commercial Al2O3:C (Landauer Inc.). High sensitivity, good linearity and reusability, along with low fading make this material as good OSL phosphor and may find applications in OSL based radiation dosimetry.

PHOTOLUMINESCENCE, THERMOLUMINESCENCE AND OPTICALLY STIMULATED LUMINESCENCE STUDIES IN ZINC-BASED FLUOROPERVOSKITES.

The optically stimulated luminescence, thermoluminescence and photoluminescence in various Cu and Ag doped zinc based fluoropervoskites are studied. In all the samples, photoluminescence of Cu+ and Ag+ is observed which could be attributed to 3d94 s1←→3d10 and 4d95 s1←→5d10 transitions, respectively. The observed emission is double humped and the main emission band shifts to the lower wavelength side with increasing ionic size of the alkali ion. All the studied fluoropervoskites show reasonable OSL sensitivity. Highest sensitivity is observed for Cu doped ZnNaF3 and is 25% compared to commercial Al2O3:C. Weak thermoluminescence is observed in all samples. In all Ag doped samples the TL peak is observed at 200°C whereas for Cu doped samples peak is observed at 150°C, and correlated with the OSL. The samples show good linear dose response in the 10 mGy-1.2 Gy range and show good reusability characteristics. This study will lead to the development of zinc-based fluoropervoskite phosphors for the radiation dosimetry using OSL.

Gingivobuccal mucosal cancers: resection to reconstruction.

PURPOSE OF REVIEW: Oral cancer is rapidly emerging as a major health problem across the globe. The Southeast Asian subcontinent has a high incidence of oral cancer and gingivobuccal complex forms the commonest subsite. The habit of chewing smokeless tobacco and areca nut are mainly responsible for this site predilection. The majority of literature and guidelines stem from the western world and there is ambiguity about tumor behavior among various continents. Thus, it is imperative to do this review for improving our understanding about this specific subsite, its behavior, treatment and outcomes. RECENT FINDINGS: Gingivobuccal mucosal cancers (GBCs) usually present as large lesions with early mandibular involvement and cervical node metastasis. Level I nodes are often the first echelon. Surgical resection of the mandible is often en bloc with primary GBCs. A marginal or segmental mandibular resection is based on paramandibular soft tissue involvement. Microvascular free tissue reconstruction is ideal. Prognostic factors include tumor depth greater than 4  mm, skin involvement, nodal metastases and extra capsular spread. SUMMARY: Early mandibular involvement and neck node metastases need to be considered in treatment planning. Appropriate reconstruction is key to early recovery and good quality of life.

Positron-emission tomography pitfalls related to oral prosthesis.

This case report describes false-positive positron-emission tomography/computed tomography (PET/CT) findings related to oral prostheses and its implications in cancer surveillance. In head and neck cancer management, F18-flurodeoxyglucose (FDG) PET/CT is widely accepted for evaluating treatment response and detecting recurrence. Interpretation of FDG PET/CT images in this setting is often challenging due to various prostheses and reconstruction methods. Following surgery for squamous cell carcinoma of the maxillary alveolus, a 61-year-old female had a FDG PET/CT scan on a 7-month follow-up that showed high FDG uptake along the resection site. Clinical examination showed no signs of inflammation or recurrence. Repeat FDG PET/CT without the prosthesis was normal. The PET/CT attenuation-corrected images demonstrated high FDG uptake (standardized uptake value: 11.6) along the resection site corresponding to contrast-enhanced CT images of the lesion. PET/CT nonattenuation-corrected images also confirmed increased activity. Repeat PET/CT without the prosthesis was normal. FDG is not tumor specific; it can accumulate in inflammation, infection, and post-therapy settings. Metallic and high-density prostheses show radial artifacts on CT and falsely elevated FDG uptake on PET/ CT in adjacent areas. Salivary pooling may concentrate FDG. The presence of oral prostheses has not been described as a cause of this high level of activity. PET/CT images that demonstrate intense activity corresponding to dense structures should be viewed with caution. A detailed history and physical exam as well as knowledge of artifacts are pertinent for the managing physician. Laryngoscope, 2012.

Efficacy of targeted middle meatal antibiotics and endoscopic sinus surgery.

BACKGROUND: Postoperative infection remains a significant comorbidity of endoscopic sinus surgery (ESS) delayed healing, synechia formation, etc. The objective of this study was to compare the incidence of postoperative infection after ESS in patients receiving conventional postoperative oral antibiotic prophylaxis versus a synthetic bioabsorbable antibiotic-soaked nasal sponge used in the middle meatus (MM) in lieu of oral antibiotics. METHODS: A prospective randomized multicenter trial included 321 chronic rhinosinusitis patients undergoing minimally invasive ESS who received either 1 week of oral antibiotics and a saline-soaked bioabsorbable MM sponge (control group) or no oral antibiotics and the placement of a bacitracin-soaked bioabsorbable sponge in the MM (study group). Evaluations performed at baseline, 3-weeks, and 3-months postoperatively included the 20-item Sino-Nasal Outcome Test and nasal endoscopic examination. RESULTS: The 3-week postoperative infection rate was not significantly different between the study (n = 165) and control groups (n = 156): 5.4% versus 3.8%; p > 0.05. In addition, there was no significant difference between the two patient groups on evaluation of MM granulations, synechia, middle turbinate lateralization, or sponge retention. CONCLUSION: Antibiotic-soaked synthetic bioabsorbable MM sponges show equivalent efficacy in controlling post ESS infections compared with conventional postoperative oral antibiotics. Topical antibiotic delivery to the MM via bioabsorbable sponges may reduce the need for postoperative systemic antibiotics and provide a cost-effective alternative that eliminates the issues of antibiotic side effects, drug-drug interactions, and medication compliance in the postoperative setting.

Functional swallowing outcomes following transoral robotic surgery vs primary chemoradiotherapy in patients with advanced-stage oropharynx and supraglottis cancers.

OBJECTIVES: To evaluate functional swallowing outcomes in patients undergoing transoral robotic surgery vs primary chemoradiotherapy for the management of advanced-stage oropharynx and supraglottis cancers. DESIGN: Prospective nonrandomized clinical trial. SETTING: Academic research. PATIENTS: We studied 40 patients with stage III or stage IVA oropharynx and supraglottis squamous cell carcinoma. Group 1 comprised 20 patients who received transoral robotic surgery with adjuvant therapy, while group 2 comprised 20 patients whose disease was managed by primary chemoradiotherapy. MAIN OUTCOME MEASURES: Patients completed the M. D. Anderson Dysphagia Inventory (MDADI) before treatment and then at follow-up visits at 3, 6, and 12 months. The MDADI scores were analyzed and compared. RESULTS: The median follow-up period for both groups was 14 months (range, 12-16 months). When comparing the median MDADI scores between group 1 and group 2, we found no statistically significant differences before treatment or at the 3-month follow-up visit. However, this difference was significant at the posttreatment visits at 6 months (P = .004) and 12 months (P = .006), where group 1 had better swallowing MDADI scores. We also found significant differences in swallowing MDADI scores between the groups at the 6-month posttreatment visit for patients with T1, T2, and T3 disease and at the 12-month follow-up visit for patients with T2 and T3 disease, where group 1 had significantly better MDADI scores. Comparing tumor subsites, group 1 fared significantly better at the follow-up visits at 6 months (P = .02) and 12 months (P = .04) for patients with primary tumor at the tonsil. Compared with group 2, group 1 patients having base of tongue cancers exhibited significantly better swallowing MDADI scores at the 6-month follow-up visit (P = .02), and group 1 patients having lateral oropharynx disease had significantly better swallowing MDADI scores at the 12-month follow-up visit (P = .04). CONCLUSION: Advanced-stage oropharynx and supraglottis cancers managed by transoral robotic surgery with adjuvant therapy resulted in significantly better swallowing MDADI outcomes at the follow-up visits at 6 and 12 months compared with tumors treated by primary chemoradiotherapy.

Management of early nasal polyposis using a steroid-impregnated nasal dressing.

BACKGROUND: Oral corticosteroids are the mainstay of medical management of sinonasal polyposis. However, systemic steroid-related side effects can be significant in both the short-term and long-term. Topical targeted steroids in optimal concentrations to the affected mucosa present an attractive alternative. The objective of this study was to compare the efficacy of steroid impregnated absorbable nasal dressing with oral steroids in the management of early nasal polyposis after endoscopic sinus surgery. METHODS: A total of 21 symptomatic patients with nasal polyposis presenting with endoscopic findings of early polyposis received triamcinolone-impregnated (20 mg/mL) nasal dressing (Nasopore; Stryker Canada). A control group of 20 similar patients were treated with a short course of oral steroids. Evaluation was based on Sinonasal Assessment Questionnaire (SNAQ-11) and Perioperative Sinus Endoscopy (POSE) score at baseline, 4-week, and 8-week follow-up intervals. RESULTS: At baseline, 4 weeks, and 8 weeks mean SNAQ scores were 18.42, 8.76, and 9.42 in the study group and 19.35, 7.15, and 7.60 in the control group, respectively. Mean POSE scores were 12.14, 5.04, and 6.04 in the study group and 13.52, 5.01, and 5.52 in the control group, respectively. No significant difference was found between the groups at 4 and 8 weeks in either SNAQ (p = 0.129, p = 0.235) or POSE (p = 0.803, p = 0.795) scores. CONCLUSION: Triamcinolone-impregnated absorbable nasal dressing is comparable to oral steroids in the management of early nasal polyposis after sinus surgery.

Our experience with split electrode array implant for obliterated cochlea.

UNLABELLED: To study the outcomes of split electrode array cochlear implantation in ossified cochlea using the CAP scoring system. Retrospective case study. Tertiary referral center. Six cochleae in three adult and three pediatric patients with ossification. INTERVENTION(S): All Patients underwent cochlear implantation with a split electrode array system. Major outcome parameter(s): Number of electrodes inserted during surgery, number of functioning electrodes on follow-up and auditory performance evaluation using the CAP score-Category of Auditory Perception [TSC Revised Version, based on Nottingham CI Program, 1995]. Six patients (three children and three adults) had insertion of split electrode array system. The mean number of electrodes inserted were 18.3 (range 15-21) and functioning electrodes at follow-up were mean of 14.3 (range 7-21). Auditory performance was measured using CAP score at 1 year post implant follow up, mean score in children was six and that in adult was eight. One pt had facial nerve twitching which was corrected by switching off the concerned electrode. No complications in sort of facial palsy or vestibular disorder were observed. Patients of ossified cochlea having profound deafness do well with split electrode array cochlear implantation as evaluated with CAP scoring system. The split electrode array results in more number of electrodes within the cochlear lumen. Retro graded apical array insertion has less chances of facial nerve stimulation as it is placed away from the nerve.