Sensory innervation around immediately vs. delayed loaded implants:a pilot study

Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed ...     

Effect of Galla chinensis on the remineralization of two bovine root lesions morphous in vitro

The present study aims to evaluate the effect of Galla chinensis compounds on the remineralization of two artificial root lesions morphous in vitro.Sixty bovine dentine blocks were divided into two groups and individually treated with two levels of demineralization solutions to form erosive and subsurface artificial carious lesions in vitro.Each group was then divided into three subgroups,each of which were treated with a remineralization solution(positive control),deionized water(negative control),or 4 000 mg?L 21 aqueous solutions of Galla chinensis extract.The dentine blocks were then subjected to a pH-cycling regime for 7 days.During the first 4 days,the daily cycle included 21-h deal and 3-h demineralization applications.The dentine blocks were dealt with the entire day during the remaining 3 days.Two specimens from each of the treatment groups were selected and observed under a polarized light microscope.Data collected using a laser scanning confocal microscope were computerized and analyzed.Galla chinensis extract clearly enhanced the remineralization of both erosive lesion and subsurface lesion patterns in the specimens(P,0.05).The level of remineralization of the erosive lesion by Galla chinensis extract was lower than that of the subsurface lesion(P,0.05).In addition,the remineralization of the subsurface lesion by Galla chinensis extract was higher than that of the remineralization solution(P,0.05).No significant difference between the remineralization of erosive lesions by Galla chinensis extract and the remineralization solution was observed(P.0.05).So Galla chinensis extract has the potential to improve the remineralization of artificial root lesions under dynamic pH-cyclic conditions,indicating its potential use as a natural remineralization medicine.     

Influence of acrylamide monomer addition to the acrylic denture-base resins on mechanical and physical properties

The aim of the study was to evaluate the effect of adding acrylamide monomer （AAm） on the characterization, flexural strength, flexural modulus and thermal degradation temperature of poly（methyl methacrylate） （PMMA） denture-base resins. Specimens （n= 10） were fabricated from a conventional heat-activated QC-20 （Qc-） and a microwave heat-activated Acron MC （Ac-） PMMA resins. Powder/ liquid ratio followed the manufacturer＇s instructions for the control groups （Qc-c and Ac-c） and for the copolymer groups, the resins were prepared with 5% （-5）, 10% （- 10）, 15% （- 15） and 20% （-20） acrylamide contents, according to the molecular weight ratio, respectively. The flexural strength and flexural modulus were measured by a three-point bending test. The data obtained were statistically analyzed by Kruskal-Wallis test （a=O.05） to determine significant differences between the groups, The chemical structures of the resins were characterized by the nuclear magnetic resonance spectroscopy. Thermal stabilities were determined by thermogravimetric analysis （TGA） with a heating rate of 10 ~C.min-1 from 35 ~C to 600 ~C. Control groups from both acrylic resins showed the lowest flexural strength values. Qc-15 showed significant increase in the flexural strength when compared to Qc-c （P〈O.01）. Ac-10 and Ac-15 showed significance when compared to Ac-c （P〈O.01）. Acrylamide incorporation increased the elastic modulus in Qc-10, Qc-15 and Qc-20 when compared to Qc-c （P〈0.01）. Also significant increase was observed in Ac-10, Ac-15 and Ac-20 copolymer groups when compared to Ac-c （P〈0.01）. According to the 1H-nuclear magnetic resonance （NMR） results, acrylamide copolymerization was confirmed in the experimental groups. TGA results showed that the thermal stability of PMMA is increased by the insertion of AAm.     

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients （TECs）, when zirconia ceramics were coloured at green stage. Zirconia blocks （N=240; 6 mm x 7 mm x 7 mm） were manufactured from two materials namely, ICE Zirconia （Group 1） and Prettau Zirconia （Group 2）. In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid （shade A2）, Three different veneering ceramics with different TEC （ICE Ceramic, GC Initial Zr and IPS e.max Ceram） were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys （Esteticor Plus） veneered with ceramic （VM 13） （n= 16） acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine （0.5 mm-min-1）. Neither the zirconia core material （P=0.318） nor colouring （P=0.188） significantly affected the results （three-way analysis of variance, Tukey＇s test）. But the results were significantly affected by the veneering ceramic （P=0.000）. Control group exhibited significantly higher mean bond strength values （45.7__.8） MPa than all other tested groups （（27.1__.4.1）-（39.7__.4.7） and （27.4__.5.6）-（35.9___4.7） MPa with and without colouring, respectively） （P~0.001）. While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering ~ 1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered 1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested.     

Efficacy of two calcium phosphate pastes on the remineralization of artificial caries： a randomized controlled double-blind in situ study

To test the efficacy of two calcium phosphate pastes compared to that of fluoride toothpaste on remineralizing artificial caries in situ, this study had a double-blind crossover in situ design, involving three experimental phases of 14 days each, with an 8-day washout period between phases. Nine healthy subjects participated in the study. The subjects wore removable palatal appliances mounted with six human enamel slabs with artificial caries lesions, and in each of the experimental phases, used one of the following methods two times/day： group A, brushing with 1.0 g of Colgate Regular Flavor, followed by applying 0.25 g of Tooth Mousse Plus; group B, brushing with 0.25 g of Clinpro Tooth Crbme; and group C, brushing with 1.0 g of Colgate Regular Flavor. After 14 days, the enamel slabs （54 slabs/ group） were embedded in resin, sectioned and examined with a polarized-light microscope, and the lesion areas were quantified using Image-Pro Plus. All experimental groups showed a significant reduction in lesion area compared to the initial lesion area （paired t-test, P〈O.O01）. The mean reduction in lesion area of Groups A, B and C were （0.029__.0.010）, （0.030_＋0.009） and （0.027_＋0.009） mm2, respectively. There were no statistical differences between groups （KruskaI-Wallis test, P〉0.05）. All three groups remineralized the enamel slab lesions, indicating model sensitivity to fluoride. Given the differences in usage amounts and treated regimens, Clinpro Tooth Crbme provided similar benefits to the fluoride toothpaste; however, no additional benefit of Tooth Mousse Plus was observed when used in conjunction with the fluoride toothpaste.     

Preliminary Findings from Our Experience in Anterior Palatoplasty for the Treatment of Obstructive Sleep Apnea

Objectives

Obstructive sleep apnea (OSA) is a common disorder affecting at least 2% to 4% of adult population characterized by the collapse of the pharyngeal airway. It is well established that retropalatal region is the most common site of obstruction. Consequently, many surgical techniques have been introduced. The purpose of this study is to present our preliminary results in the anterior palatoplasty (AP) compared with results of uvulopalatal flap (UPF).

Methods

Thirty-eight consecutive patients with mild-moderate OSA were prospectively enrolled into a randomised surgical protocol. Surgical success was measured primarily by satisfactory reduction in snoring, as reported by snoring assessment questionnaire (SQ) of sleep partners. Secondary outcomes measures included improvement in the Epworth Sleepiness Scale (ESS) scores, changes in the magnitude of pharyngeal collapse, and postoperative pain intensity.

Results

The ESS after AP improved from a preoperative value 8.5±3.7 to a postoperative mean of 4.9±3.2 (P<0.001) after UPF improved from a preoperative value of 8.1±3.5 to 5.2±3.2 postoperatively (P<0.001). The results of satisfactory reduction in the volume of snoring and response at polysomnographic data were also similar in both procedures. We reported a statistically significant difference of the collapse noted at Müller manoeuvre that improved from 2.7±1.0 on average, to 1.1±0.9 (P<0.001) after AP and with a lesser extent, (from 2.8±1.1 on average to 1.8±1.1; P<0.05), after UPF. The mean duration of pain was 10.8 days for UPF patients and 7.1 days for AP patients. The mean pain score in the first 3 days, was 6.8 in UPF patients and 5.1 in AP patients.

Conclusion

The subjective and objective improvements evidenced may suggest how AP is far superior to other techniques aimed at creating a palatal fibrotic scar. In the light of these results we can suggest AP procedure as more practical and comfortable when compared to UPF.     

Functional Benefit after Modification of Radial Forearm Free Flap for Soft Palate Reconstruction

Objectives

To compare the velopharyngeal function, swallowing and speech of the conventional and modified radial forearm free flap (RFFF) for soft palate reconstruction.

Methods

Retrospective clinical study. Twenty-eight patients who underwent oropharyngeal reconstruction with RFFF were divided into two groups: 10 patients had conventional folded RFFF and 18 patients underwent modified method.

Results

The average speech intelligibility score in modified RFFF group was 8.0±2.4, and 6.2±2.2 in conventional RFFF group (P<0.05). The nasalance was 27.4±7.8% in modified group and 38.6±2.7% in conventional group during no nasal passage reading and 43.6±7.3% in modified group, 55.2±7.6% in conventional group during high nasal passage reading (P<0.05). The subjective swallowing functional score was 2.8 in modified group and 2.1 in conventional group.

Conclusion

The speech assessment and nasalance demonstrate a more favorable outcome in modified group than conventional group.     

Optimal continuous positive airway pressure level in korean patients with obstructive sleep apnea syndrome

Objectives

The aim of this study was to investigate optimal continuous positive airway pressure (CPAP) level, to examine the factors affecting optimal CPAP level, and to develop a predictive equation for optimal CPAP level in Korean patients with obstructive sleep apnea syndrome (OSAS).

Methods

A total of 202 patients with OSAS who underwent successful manual titration for CPAP treatment were included in this study. Correlations between the optimal CPAP level and baseline data including anthropometric and polysomnographic variables were analyzed. A predictive equation for optimal CPAP level was developed based on anthropometric and polysomonographic data.

Results

The mean optimal CPAP level in 202 patients with OSAS was 7.8±2.3 cm H₂O. The mean optimal CPAP level in the mild, moderate, and severe OSAS groups was 6.0±1.3, 7.4±1.9, and 9.1±2.1 cm H₂O, respectively. The apneahypopnea index (AHI) (r=0.595, P<0.001), arousal index (r=0.542, P<0.001), minimal SaO₂ (r=-0.502, P<0.001), body mass index (BMI) (r=0.494, P<0.001), neck circumference (r=0.265, P<0.001), and age (r=-0.164, P=0.019) were significantly correlated with optimal CPAP level. The best predictive equation according to stepwise multiple linear regression analysis was: Optimal CPAP level (cm H₂O)=0.681+(0.205×BMI)+(0.040×AHI). Forty-two percent of the variance in the optimal CPAP level was explained by this equation (R²=0.42, P<0.001).

Conclusion

A predictive equation for optimal CPAP level in Korean patients with OSAS was developed using AHI and BMI, which can be easily measured during the diagnostic process.     

A Genome-Wide Association Study of Chronic Otitis Media with Effusion and Recurrent Otitis Media Identifies a Novel Susceptibility Locus on Chromosome 2

Chronic otitis media with effusion (COME) and recurrent otitis media (ROM) have been shown to be heritable, but candidate gene and linkage studies to date have been equivocal. Our aim was to identify genetic susceptibility factors using a genome-wide association study (GWAS). We genotyped 602 subjects from 143 families with 373 COME/ROM subjects using the Illumina Human CNV370-Duo DNA Bead Chip (324,748 SNPs). We carried out the GWAS scan and imputed SNPs at the regions with the most significant associations. Replication genotyping in an independent family-based sample was conducted for 53 SNPs: the 41 most significant SNPs with P < 10⁻⁴ and 12 imputed SNPs with P < 10⁻⁴ on chromosome 15 (near the strongest signal). We replicated the association of rs10497394 (GWAS discovery P = 1.30 × 10⁻⁵) on chromosome 2 in the independent otitis media population (P = 4.7 × 10⁻⁵; meta-analysis P = 1.52 × 10⁻⁸). Three additional SNPs had replication P values < 0.10. Two were on chromosome 15q26.1 including rs1110060, the strongest association with COME/ROM in the primary GWAS (P = 3.4 ×10⁻⁷) in KIF7 intron 7 (P = 0.072), and rs10775247, a non-synonymous SNP in TICRR exon 2 (P = 0.075). The third SNP rs386057 was on chromosome 5 in TPPP intron 1 (P = 0.045). We have performed the first GWAS of COME/ROM and have identified a SNP rs10497394 on chromosome 2 is significantly associated with COME/ROM susceptibility. This SNP is within a 537 kb intergenic region, bordered by CDCA7 and SP3. The genomic and functional significance of this newly identified locus in COME/ROM pathogenesis requires additional investigation.     

Chemical composition of Galla chinensis extract and the effect of its main component(s) on the prevention of enamel demineralization in vitro

To determine the chemical composition of Galla chinensis extract(GCE) by several analysis techniques and to compare the efficacy of GCE and its main component(s) in inhibition of enamel demineralization,for the development of future anticaries agents,main organic composition of GCE was qualitatively determined by liquid chromatography-time of flight-mass spectrometry(LC-TOF-MS) and quantified by high-performance liquid chromatography-diode array detector(HPLC-DAD).Inorganic ions were tested by inductively coupled plasma-atomic emission spectroscopy and F was especially measured by ion chromatography.Then,bovine enamel blocks were randomly divided into four treatment groups and were subjected to a pH-cycling regime for 12 times.Each cycle included 5-min applications with one of four treatments:4 g?L 21 GCE solution,4 g?L 21 gallic acid(GA) solution,1 g?L 21 NaF solution(positive control),deionized water(DDW,negative control),and then 60-min application in pH 5.0 acidic buffer and 5-min application in neutral buffer.Acidic buffers were retained for calcium analysis.The main organic composition of GCE were GA and its isomer,and,to a lesser extent,small molecule gallotannins.The content of GA in GCE was 71.3%60.2%(w/w).Inorganic ions were present in various amounts,of which Ca was(13662.82) mg?g 21,and Zn was(6.860.1) mg?g 21.No F was detected in GCE.In pH cycling,GA showed an effect similar to GCE in inhibiting enamel demineralization(P.0.05).GA was found to be the main effective,demineralization inhibiting component of GCE and could be a promising agent for the development of anticaries agents.     

A novel protein-repellent dental composite containing 2-methacryloyloxyethyl phosphorylcholine

Secondary caries due to biofilm acids is a primary cause of dental composite restoration failure.To date,there have been no reports of dental composites that can repel protein adsorption and inhibit bacteria attachment.The objectives of this study were to develop a protein-repellent dental composite by incorporating 2-methacryloyloxyethyl phosphorylcholine(MPC) and to investigate for the first time the effects of MPC mass fraction on protein adsorption,bacteria attachment,biofilm growth,and mechanical properties.Composites were synthesized with 0(control),0.75%,1.5%,2.25%,3%,4.5%and 6%of MPC by mass.A commercial composite was also tested as a control.Mechanical properties were measured in three-point flexure.Protein adsorption onto the composite was determined by the microbicinchoninic acid method.A human saliva microcosm biofilm model was used.Early attachment at 4 h,biofilm at 2 days,live/dead staining and colony-forming units(CFUs) of biofilms grown on the composites were investigated.Composites with MPC of up to 3%had mechanical properties similar to those without MPC and those of the commercial control,whereas 4.5%and 6%MPC decreased the mechanical properties(P<0.05).Increasing MPC from 0 to 3%reduced the protein adsorption on composites(P<0.05).The composite with 3%MPC had protein adsorption that was 1/12 that of the control(P<0.05).Oral bacteria early attachment and biofilm growth were also greatly reduced on the composite with 3%MPC,compared to the control(P<0.05).In conclusion,incorporation of MPC into composites at 3%greatly reduced protein adsorption,bacteria attachment and biofilm CFUs,without compromising mechanical properties.Protein-repellent composites could help to repel bacteria attachment and plaque build-up to reduce secondary caries.The protein-repellent method might be applicable to other dental materials.     

Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains （ATCC） by Piper betle L. extract

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of Po betle was identified using liquid chromatography-mass spectrophotometry （LC-MS/MS）. Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments： （i） in the absence of P. betle extract; and in the presence of P. beUeextract at respective concentrations of （ii） 1 mg.mL-1; （iii） 3 mg.mL-1; and （iv） 6 mg.mL- 1 The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates （μ）. Scanning electron microscopy （SEM） was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the p-values of the treated cells were significantly different than those of the untreated cells （P〈0.05）, indicating the fungistatic properties of the P. beUe extract. The candidal population was also reduced from an average of 13.44× 10^6 to 1.78×10^6 viable cell counts （CFU）.mL-1, SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity.     

Factors predictive of an academic otolaryngologist’s scholarly impact

ObjectivesDescribe the h index as a bibliometric that can be utilized to objectively evaluate scholarly impact. Identify which otolaryngology subspecialties are the most scholarly. Describe if NIH funding to one’s choice of medical school, residency, or fellowship has any impact on one’s scholarly output. Determine other factors predictive of an academic otolaryngologist’s productivity.Study designAnalysis of bibliometric data of academic otolaryngologists.MethodsActive grants from the National Institutes of Health (NIH) to otolaryngology departments were ascertained via the NIH Research Portfolio Online Reporting Tools Expenditures and Reports database. Faculty listings from these departments were gleaned from departmental websites. H index was calculated using the Scopus database.ResultsForty-seven otolaryngology programs were actively receiving NIH funding. There were 838 faculty members from those departments who had a mean h index of 9.61. Otology (h index 12.50) and head and neck (h index 11.96) were significantly (P < 0.0001) more scholarly than the rest of subspecialists. H index was significantly correlative (P < 0.0001) with degree of NIH funding at a given institution. H index was not significantly higher for those that attended medical school (P < 0.18), residency (P < 0.16), and fellowship (P < 0.16) at institutions with NIH funding to otolaryngology departments.ConclusionsH index is a bibliometric that can be used to assess scholarly impact. Otology and head and neck are the most scholarly subspecialists within otolaryngology. NIH funding to an individual’s medical school, residency, or fellowship of origin is not correlative with one’s scholarly impact, but current institutional affiliation and choice of subspecialty are.     

Role of saliva proteinase 3 in dental caries

Salivary analysis can be used to assess the severity of caries. Of the known salivary proteins, a paucity of information exists concerning the role of proteinase 3 (PR3), a serine protease of the chymotrypsin family, in dental caries. Whole, unstimulated saliva was collected from children with varying degrees of active caries and tested using a Human Protease Array Kit and an enzyme-linked immunosorbent assay. A significantly decreased concentration of salivary PR3 was noted with increasing severity of dental caries (P<0.01); a positive correlation (r=0.87; P<0.01; Pearson''s correlation analysis) was also observed between salivary pH and PR3 concentration. In an antibacterial test, a PR3 concentration of 250 ng·mL⁻¹ or higher significantly inhibited Streptococcus mutans UA159 growth after 12 h of incubation (P<0.05). These studies indicate that PR3 is a salivary factor associated with the severity of dental caries, as suggested by the negative relationship between salivary PR3 concentration and the severity of caries as well as the susceptibility of S. mutans to PR3.     

Long-term effectiveness and safety of endoscopic vidian neurectomy for the treatment of intractable rhinitis

Objectives

Vidian neurectomy could be considered the treatment of choice for intractable rhinitis, because it is the only method that can permanently block the pathophysiological mechanism of rhinitis. The goal of this study was to evaluate the effect of vidian neurectomy on nasal symptoms and tear production, and to assess for possible complications.

Methods

Six patients with intractable rhinitis who underwent endoscopic transnasal vidian neurectomy were enrolled. The degree of symptom improvement and complications were assessed through retrospective review of medical records prior to, and 1 year following surgery, and telephone survey after 6.9±2.1 years. Schirmer''s test was performed before surgery, and these values were compared to postoperative results at 1 day, 1 month, and 2 months.

Results

Changes in the visual analogue scale were significant in nasal obstruction (8.5±2.5 to 3.0±2.0, P<0.05) and rhinorrhea (9.0±2.2 to 2.0±1.6, P<0.05). Improvements persisted for up to 7 years after the primary surgery. Patients complained of mild dry eyes for 1 month after vidian neurectomy. However, five out of six reported marked improvement of xerophthalmia after 2 months. Aside from mild crusting of the nasal cavity and mild postoperative pain, there were no major complications. During the entire follow-up period, no patient needed additional treatment, such as antihistamines or corticosteroids.

Conclusion

Vidian neurectomy is effective in alleviating nasal symptoms in patients with intractable rhinitis refractory to other treatments. This effect is sustained for at least 7 years with minimal postoperative complications.     

Direction-fixed positional nystagmus following head-roll testing:how is it related with a vestibular pathology?

ObjectiveThe goal of this study is to analyze the clinical view of patients with direction-fixed positional nystagmus (DFPN) following head-roll maneuver.MethodsSixty patients with DFPN were reviewed retrospectively. Patients were categorized into 3 groups according to the direction of nystagmus based on rotation side. Associated problems were documented, and cumulative data were compared between groups. One-way analysis of variance (ANOVA test) was used for statistical analysis (P < 0.05).ResultsThirty-three patients (55%) had stronger nystagmus beating towards the direction of head-roll (Group-A). Three patients developed geotropic LC-BPPV. Fourteen patients had inner ear disease. Sixteen patients (27%) had stronger nystagmus beating against the direction of head roll (Group-B). Nine patients had inner ear disease. None of the patients tested with head-shaking had change of direction of nystagmus. Eleven patients (18%) had DFPN with equal velocity during right or left head-roll maneuver (Group-C). Of those, nine patients had inner ear disease. None of the patients had change of direction of nystagmus. Comparison of the incidence of associated problems (migraine, vestibular neuronitis, Meniere’s disease etc.) in each group was not statistically significant (P˃0.05).ConclusionPatients with DFPN should be followed for a possibility of vestibular pathology since vestibular problem was documented for more than half of the patients in the follow-up. On the other hand, DFPN could be related with a temporary reason (thermal, physical or drug effect etc.) in some patients who do not exhibit any associated disease. Head-shaking testing is recommended to expose the lateral canal BPPV. But the incidence is low.     

Porous titanium granules in critical size defects of rabbit tibia with or without membranes

Recently, porous titanium granules （PTGs） have been indicated for the preservation of the dimensions of post-extraction sockets, as a filler in sinus lift procedures and for the treatment of peri-implant and periodontal defects, based on the osteoconductivity and dimensional stability of the titanium granules. However, there is a lack of information regarding the use of this material in larger defects and in conjunction with membranes. The objective of this study is to test the behavior of PTGs used to fill critical size defects in rabbit tibiae, with and without membranes. Critical defects were created in both tibiae of rabbits, divided randomly into three groups： Group A （defect filled with PTG）, Group B （defect filled with PTG＋collagen membrane） and a control group （empty defect）. After six weeks, histomorphometric analysis was performed. The results showed more defect closures at the cortical area （87.37%±2.2%） and more bone formation at the marrow area （57.6%± 1.3%） in Group B, in comparison with the other groups （P〈0.05）; the use of membranes improved the material stability expressed as more percentages of the original material when membranes were used （P〈0.05）. Finally, inflammatory reactions were observed when the granules were not protected by membranes. In spite of the limitations of this animal study, it may be concluded that PTG particles are osteoconductive and allow bone growth. The PTG particles must be covered by a membrane, especially when grafting larger defects, in order to control particle migration, promote clot stabilization and separate the PTG graft from undesired soft tissue cells.     

Gentamicin is Primarily Localized in Vestibular Type I Hair Cells after Intratympanic Administration

Intratympanic (IT) gentamicin injections are effective in the control of episodic vertigo due to Ménière’s disease. Histological studies in animals have found that the loss of type I vestibular hair cells far exceeds that of type II cells after IT gentamicin treatment. The objective of this study was to determine whether this selective toxicity for type I hair cells might be due to selective concentration of the drug by these cells. Gentamicin was localized within the vestibular epithelium by both direct and indirect methods. Gentamicin conjugated to Texas Red® was used as a direct tracer, and anti-gentamicin antibody provided an indirect means of localization. Conjugated or unconjugated gentamicin was injected into the left tympanic space of chinchillas. The animals were killed and fixed 1 or 3 weeks post-treatment. Confocal fluorescence microscopy was used to determine the localization of gentamicin in semicircular canal cristae. Results from the animals killed within 1 week of administration showed that numerous type I hair cells still remained throughout the epithelium. The mean intensity in grayscale units (0–255) of anti-gentamicin labeling for type I hair cells was 28.14 (95% CI 24.60–31.69), for type II hair cells was 17.09 (14.99–19.20), and for support cells was 5.35 (5.34–5.46; p < 0.001, ANOVA). Anti-gentamicin antibody labeling appeared in the majority of type I hair cells throughout their cytoplasm, but with greater intensity at the apex (p < 0.001). Intensity of fluorescence with Texas-Red conjugated gentamicin was 25.38 (22.83–27.94) in type I hair cells, 15.60 (14.73–16.48) in type II cells, and 12.62 (12.06–13.17) in support cells (p < 0.001, ANOVA). These results suggest that type I hair cells are more susceptible to gentamicin because they more avidly take up or retain the drug in the early period after administration.     

Rapid Increase in Neural Conduction Time in the Adult Human Auditory Brainstem Following Sudden Unilateral Deafness

Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.     

Evaluation of the Esthetic and Functional Outcomes of Extracorporeal Septoplasty for Rhinoplasty in Asian Patients

ObjectivesIn extracorporeal septoplasty (ECS), the entire septal cartilage is harvested, and a neo-L strut is built extracorporeally. Thus, ECS can simultaneously achieve septum straightening and tip projection. This study evaluated the functional and esthetic outcomes of the ECS technique for rhinoplasty in Asian patients.MethodsWe conducted a retrospective review of 64 patients who underwent rhinoplasty using ECS between January 2016 and March 2018. Subjective patient satisfaction was assessed and objective surgical outcomes were evaluated. Improvement in nasal obstruction was rated using a visual analog scale (VAS). Anthropometric changes were compared between preoperative and postoperative facial photographs. Complications and revisions were also analyzed.ResultsThe participants comprised 64 patients (48 males and 16 females, with a mean age of 29.3 years). The mean operative time was 89.3 minutes. In total, 61 patients were satisfied with the esthetic outcome, and the overall objective rhinoplasty outcome score was 3.45. Preoperative nasal obstruction symptoms (7.9±1.2 on VAS) improved postoperatively (3.1±1.3, P<0.001), and significant improvements were also observed in the nasofrontal angle (152.3° to 148.1°, P<0.001), nasolabial angle (88.8° to 92.0°, P<0.001), and nasal tip projection (0.62 to 0.66, P<0.033). Recurrent deviation of the nasal septum and external nose or tip deprojection did not occur in any patients, and there were no cases of revision during the mean follow-up period of 13.3 months.ConclusionECS might be an esthetically and functionally satisfactory alternative rhinoplasty technique for Asian patients with a shortage of septal cartilage.