Acute Abducens Nerve Palsy in a Patient who Sustained Mechanical Trauma to the Orbit.

BACKGROUND: Abducens nerve (Cranial Nerve VI) innervates the lateral rectus (LR) muscle. Head trauma is one of the most common causes of abducens nerve palsy. Orbital and/or facial injuries could also affect the LR muscle directly or the orbital course of abducens nerve and lead to palsy. We present a case of a young man with multiple orbital fractures and an impingement of the LR muscle resulting in a complete loss of abduction. CASE REPORT: A 29-year-old male reported falling 15 feet. He presented with diplopia and had complete abduction deficit of the left eye. Orbital CT imaging revealed a bony spur from his left zygomatic bone impinging on the lateral rectus muscle. In view of -4 abduction deficit, he was operated upon to remove the bony spur. This led to a gradual, but complete recovery of his abduction. DISCUSSION: The abducens nerve has a tortuous course and as a result is commonly injured during head trauma, in particular due to its vulnerability as it passes into Dorello's canal, or its journey through the cavernous sinus. The case report highlights orbital causes such as direct muscle avulsion or injury to the orbital portion of the abducens nerve, as reasons for how LR weakness could be easily overlooked, unless specifically examined with high-resolution orbital imaging. CONCLUSION: Orbital mechanical causes can be overlooked in LR palsy. We emphasise the role of orbital imaging in any patient with abducens nerve or LR Palsy and reaffirm that not all cases are associated with an intracranial cause.

Bilateral taurodontism in permanent maxillary first molar.

Taurodontism is a dental anomaly caused due to the failure of Hertwig's epithelial sheath to invaginate at the proper horizontal level. A huge pulp chamber, displacement of the pulpal floor apically, and no constriction at the level of the cementoenamel junction are the key features representing a taurodontic tooth. This condition is most commonly associated with permanent molars. This clinical entity occurs in the form of an isolated, singular trait in majority of the cases. However, seldom, it may be associated with syndromes or ectodermal anomalies. The large and deep pulp chamber makes instrumentation of canals difficult, thereby challenging an endodontist. This case report describes the endodontic challenge faced in cases of taurodontism as well as the clinical steps involved in its successful endodontic management. Furthermore, it shows the typical presence of bilateral hypertaurodontism with respect to the maxillary first molar.

Permanent maxillary first molar with three mesiobuccal canals.

It is mandatory for every clinician to have a thorough knowledge about the normal internal anatomy of teeth; equally important is the awareness about variations in internal anatomy that could be seen with different teeth. The outcome of a root canal therapy depends significantly on the clinician's awareness about root canal anatomy, followed by their clinical skills. Literature states that the permanent maxillary first molar shows a wide variation in the number of canals particularly with respect to the mesiobuccal root. This case report describes the endodontic management of a permanent maxillary first molar with three distinct mesiobuccal canals.

Efficacy of rotary and reciprocating single-file systems on different access outlines for gutta-percha removal in retreatment: An in vitro study.

INTRODUCTION: The aim of this study is to compare the effectiveness of reciprocating and continuous rotary nickel-titanium instruments during retreatment performed through two different access outlines. METHODOLOGY: A total of 48 freshly extracted mandibular first and second premolars with single root and canal were selected. Initial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented with F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity. For retreatment, specimens were divided into two groups (n = 24) on the basis of access outline, CEC or traditional endodontic cavity. Retreatment was initiated using ProTaper Retreatment instruments (D1-D3). Specimens were further divided (n = 12) and reinstrumented up to Neoniti 25/0.08 or WaveOne 25/0.08. Irrigation was performed using 3% sodium hypochlorite and 17% ethylene diamine tetraacetic acid. Retreatment time was recorded. Teeth were sectioned and photographed, and the percentage of remaining obturation material was measured. RESULTS: Data were collected, and statistical analysis was performed using one-way analysis of variance and Tukey honestly significant difference multiple post hoc procedures (P < 0.05). CONCLUSION: None of the systems completely removed the root filling material from root canals. However, ProTaper/Neoniti instruments removed more GP when compared to Protaper/WaveOne instruments with both the access outlines. Both the instruments with traditional access outline required less time for removal of obturating material when compared to CEC.

Rotary science and its impact on instrument separation: A focused review.

Efficient endodontic treatment demands thorough debridement of the root canal system with minimal procedural errors. The inherent weakness of nickel-titanium alloys is their unexpected breakage. Modifications in the design, manufacturing, thermomechanical and surface treatment of alloys and advancements in movement kinetics have shown to improve the fatigue properties of the alloys, reducing the incidence of separation. This review enlightens the impact of these factors on fatigue properties of the alloy.

A clinical correlation between stature and posterior tooth length.

INTRODUCTION: Exploration and determination of the relationship between stature and length of tooth is essential in Paleontology, Forensic Odontology and Endodontology. This study aimed to determine any association between stature and posterior tooth length in a group of patients who required root canal treatment. METHODS: Age, sex and standing height of adults were considered for posterior tooth length measurement. Molars and Premolars of apparently normal males (n=115 for molars, n= 75 for premolars) and females (n=124 for molars, n=80 for premolars), aged 20-50 years with intact cuspal morphology, which required RCT were selected for this study. Females and males were divided into 2 groups each based on their heights females > 155 cm and ≤ 155 cm, males > 165.10 and ≤ 165.10cm. The tooth length of permanent molars and premolars in both groups were measured using RVG and Electronic apex locator. Measurements obtained were compared separately for males and females using descriptive statistics and Pearson correlation coefficient. RESULTS: In females MB, ML, D roots of molar showed significant association (P=0.021), (P=0.027), (P=0.010) and roots of premolars showed significant association (P=0.002), (P=0.006) between both the groups respectively In males MB, ML, D roots of molar showed significant association (P=0.009), (P=0.004), (P=0.015) and roots of premolars showed significant association (P=0.006), (P=0.020) between both the groups respectively. CONCLUSION: The present clinical study reveals that there is a positive association between stature and posterior tooth length in both males and females.

Comparative evaluation of effect of rotary and reciprocating single-file systems on pericervical dentin: A cone-beam computed tomography study.

AIM AND OBJECTIVE: The aim of this study is to evaluate and compare the effect of one shape, Neolix rotary single-file systems and WaveOne, Reciproc reciprocating single-file systems on pericervical dentin (PCD) using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 40 freshly extracted mandibular premolars were collected and divided into two groups, namely, Group A - Rotary: A1 - Neolix and A2 - OneShape and Group B - Reciprocating: B1 - WaveOne and B2 - Reciproc. Preoperative scans of each were taken followed by conventional access cavity preparation and working length determination with 10-k file. Instrumentation of the canal was done according to the respective file system, and postinstrumentation CBCT scans of teeth were obtained. 90 µm thick slices were obtained 4 mm apical and coronal to the cementoenamel junction. The PCD thickness was calculated as the shortest distance from the canal outline to the closest adjacent root surface, which was measured in four surfaces, i.e., facial, lingual, mesial, and distal for all the groups in the two obtained scans. RESULTS: There was no significant difference found between rotary single-file systems and reciprocating single-file systems in their effect on PCD, but in Group B2, there was most significant loss of tooth structure in the mesial, lingual, and distal surface (P < 0.05). CONCLUSION: Reciproc single-file system removes more PCD as compared to other experimental groups, whereas Neolix single file system had the least effect on PCD.

An improvised pressure gauge for regional nerve blockade/anesthesia injections: an initial study.

High injection pressure is one of the warning signs of intraneural injection, with animal models suggesting pressures higher than 69 or 176 kPa as high risk, and is normally detected subjectively and inaccurately. We describe a system improvised from common clinical components that uses Boyle's law to objectively measure injection pressure. The objectives of the study were to (1) Validate our improvised pressure gauge (IPG) by comparing the injection pressure as calculated by Boyle's law against the measured pressure and (2) Use the IPG to measure the range of injection pressures by two groups of anesthetic professionals using the "syringe feel" technique. Our IPG system consists of an extended 1 ml syringe attached to a 3-way stopcock, inserted between the syringe containing the local anesthetic injectate and the needle. The IPG was validated against a pressure calibration reference. 20 anesthesiologists and 20 anesthetic assistants were recruited to apply pressure to the 20 ml syringe in vitro while blinded to the attached IPG. The pressures were measured on three separate occasions for each participant. There was good agreement (<8 percent difference) between the measured and theoretical pressure values. Anesthesiologists exceeded the threshold of 69 kPa in 18 of a total of 60 attempts whereas anesthetic assistants exceeded the threshold in 30 attempts out of 60 attempts. Anesthetic assistants exerted a higher overall pressure of 80 kPa compared to 51 kPa for anesthesiologists-this was statistically significant (p = 0.027). Our improvised system is easily and rapidly assembled from common clinical equipment and shows promise as a monitor for inadvertent intraneural injection.

Evaluation of antibacterial and antifungal activity of new calcium-based cement (Biodentine) compared to MTA and glass ionomer cement.

OBJECTIVE: To evaluate the antibacterial and antifungal properties of calcium-based cement, Biodentine (Ca3SiO2), compared to commercial glass ionomer cements (GICs) and mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Pellets of GICs, ProRoot MTA, and Biodentine were prepared to test the influence of these cements on the growth of four oral microbial strains: Streptococcus mutans, Enterococcus faecalis, Escherichia coli, and Candida albicans; using agar diffusion method. Wells were formed by removing the agar and the manipulated materials were immediately placed in the wells. The pellets were lodged in seeded plates and the growth inhibition diameter around the material was measured after 24-72 h incubation at 37°C. The data were analyzed using analysis of variance (ANOVA) test to compare the differences among the three cements at different concentrations. RESULTS: Test indicates that the antimicrobial activity of Biodentine, on all the microorganisms tested, was very strong, showing a mean inhibition zone of 3.2 mm, which extends over time towards all the strains. For Biodentine, GIC, and MTA, the diameters of the inhibition zones for S. mutans were significantly larger than for E. faecalis, Candida, and E. coli (P < 0.05). CONCLUSION: All materials showed antimicrobial activity against the tested strains except for GIC on Candida. Largest inhibition zone was observed for Streptococcus group. Biodentine created larger inhibition zones than MTA and GIC.

Comparison of marginal adaptation of mineral trioxide aggregate, glass ionomer cement and intermediate restorative material as root-end filling materials, using scanning electron microscope: An in vitro study.

AIM: The present study compares the marginal adaption of Mineral Trioxide Aggregate (MTA), Glass Ionomer Cement (GIC) and Intermediate Restorative Material (IRM) as root-end filling materials in extracted human teeth using Scanning Electron Microscope (SEM). MATERIALS AND METHODS: Thirty single rooted human teeth were obturated with Gutta-percha after cleaning and shaping. Apical 3 mm of roots were resected and retrofilled with MTA, GIC and IRM. One millimeter transverse section of the retrofilled area was used to study the marginal adaptation of the restorative material with the dentin. Mounted specimens were examined using SEM at approximately 15 Kv and 10(-6) Torr under high vacuum condition. At 2000 X magnification, the gap size at the material-tooth interface was recorded at 2 points in microns. STATISTICAL ANALYSIS: One way ANOVA Analysis of the data from the experimental group was carried out with gap size as the dependent variable, and material as independent variable. RESULTS: The lowest mean value of gap size was recorded in MTA group (0.722 ± 0.438 µm) and the largest mean gap in GIC group (1.778 ± 0.697 µm). CONCLUSION: MTA showed least gap size when compared to IRM and GIC suggesting a better marginal adaptation.

Surgical management of mandibular central incisors with dumbbell shaped periapical lesion: a case report.

Dental traumatic injuries may affect the teeth and alveolar bone directly or indirectly. Pulpal necrosis and chronic and apical periodontitis with cystic changes are the most common sequelae of the dental traumatic injuries, if the teeth are not treated immediately. This case report focuses on the conventional and surgical management of mandibular central incisors. A twenty-four-year-old male patient presented with pain in the mandibular central incisors. Radiographic examination revealed mandibular central incisors with dumbbell shaped periapical lesion. After root canal treatment, parendodontic surgery was performed for mandibular central incisors. After one-year recall examination, the teeth were asymptomatic and periapical lesion had healed.

Quantitative evaluation of apical extrusion of intracanal bacteria using K3, Mtwo, RaCe and protaper rotary systems: An in vitro study.

AIM: This aim of this study was to evaluate the number of bacteria extruded apically during root canal preparation using Four Rotary instrumentation techniques. MATERIALS AND METHODS: A total of 50 extracted mandibular premolars were selected, access cavities prepared and inserted in to rubber stoppers of 10 mL glass vial. Root canals were contaminated with a suspension of Enterococcus faecalis (E. faecalis) American Type Culture Collection (ATCC) 29212 and incubated for 24 h at 37°C. Debris extruded from the apical foramen during instrumentation was collected into vials. The numbers of Colony-forming units were determined for each sample. STATISTICAL ANALYSIS: The data obtained were analyzed using the one-way ANOVA followed by post-hoc tukey's test with a P = 0.05 as the level for statistical significance. RESULTS: Results suggested a statistically significant difference in the number of colony forming units between four experimental rotary Nickel-Titanium instrumentation groups (P < 0.001). CONCLUSION: Although, extrusion of bacteria was found in all the experimental groups. There was less bacterial extrusion in K3 Group while more bacterial extrusion was seen in Mtwo Group.

Effects of hydroquinone on retinal and vascular cells in vitro.

AIM: To explore the molecular pathophysiology that might explain the epidemiologic association between cigarette smoke and age-related macular degeneration (AMD) by examining the effects of hydroquinone (HQ), a toxic compound present in high concentration in cigarette smoke-related tar, on human retinal pigment epithelial cells (ARPE-19), rat retinal neurosensory cells (R-28), and human microvascular endothelial cells (HMVEC). MATERIALS AND METHODS: ARPE-19, R-28, and HMVEC were treated for 24 h with four different concentrations of HQ (500 µM, 200 µM, 100 µM, 50 µM). Cell viability, caspase-3/7 activation, DNA laddering patterns, and lactate dehydrogenase (LDH) levels were analyzed. RESULTS: At 50 µM HQ, R-28 cells showed a significant decrease in cell viability compared with the dimethyl sulfoxide (DMSO)-treated controls. At the 100-500 µM concentrations, all three cell lines showed significant cell death (P < 0.001). In the ARPE-19, R-28, and HMVEC cultures, the caspase-3/7 activities were not increased at any of the HQ concentration. CONCLUSION: Our findings suggest that the mechanism of cell death in all three cell lines was through non-apoptotic pathway. In addition, neuroretinal R-28 cells were more sensitive to HQ than the ARPE-19 and HMVEC cultures.

Congenital ectropion uvea and mechanisms of glaucoma in neurofibromatosis type 1: new insights.

OBJECTIVE: To describe the clinicopathologic features of congenital ectropion uvea associated with glaucoma in neurofibromatosis-1 (NF-1). DESIGN: Retrospective case series. PARTICIPANTS AND CONTROLS: Five cases of NF-1 associated with glaucoma, from which enucleated eyes were available, and 2 eye bank eyes used as controls. METHODS: The clinical features and courses of these patients were reviewed. Formalin-fixed, paraffin-embedded eyes were examined by light and electron microscopy. Immunohistochemistry using antineurofibromin, anti-glial fibrillary acidic protein, and antivimentin was performed in 3 patients. Gene expression of the mitogen-activated protein kinase (MAPK) signaling pathway was examined in corneal endothelial cells in 1 patient. MAIN OUTCOME MEASURES: Cause of glaucoma in patients with ectropion uvea and NF-1. RESULTS: The age of patients at the time of glaucoma diagnosis ranged from birth to 13 years. Four of the 5 patients had megalocornea and buphthalmos at presentation. Ectropion uvea was noted clinically in 2 patients, but was demonstrated histopathologically in all 5 patients. On histopathologic examination, all patients had varying degrees of angle closure secondary to endothelialization of the anterior chamber angle. Uveal neurofibromas were noted in all patients; anteriorly displaced ciliary processes were noted in 4 of 5 patients who demonstrated ciliary body involvement with neurofibromas. Absence of Schlemm's canal was observed. The endothelial cells lining the closed angle demonstrated positive stain results with the vimentin antibody. Positive antineurofibromin immunolabeling was detected in normal control corneal endothelium, but was absent in corneal endothelium in patients with endothelialization of the angle. Upregulation of genes from the MAPK signaling pathway was demonstrated in the corneal endothelial cells isolated from the NF-1 eyes. CONCLUSIONS: Ectropion uvea in NF-1 glaucoma is secondary to endothelialization of the anterior chamber angle and is associated commonly with severe pediatric glaucoma in NF-1 patients. The endothelial cell proliferation may be related to overexpression of the Ras (Rat sarcoma)-MAPK genes in these eyes.

Anti-retinal antibodies in serum of laser-treated rabbits.

PURPOSE: Retinal injuries that affect the photoreceptors and/or the retinal pigment epithelium (RPE) may result in the leakage of retinal proteins into the systemic circulation. This study was designed to determine whether an immune response is elicited after an acute retinal injury resulting in circulating anti-retinal antibodies in the serum. METHODS: Fifty laser burns of different grades (minimally visible lesion [MVL], grade II [GII], or grade III [GIII] lesions) were created in the retinas of Dutch Belted rabbits. The degree of laser burns was confirmed by fundus imaging and histology. Serum samples were collected from the animals 3 months after the retinal injury. Candidate autoantigens were identified by two-dimensional (2-D) Western blots of rabbit retinal lysate probed with sera from either control or laser-treated animals. Candidate autoantigens were further characterized by immunostaining to confirm their retinal localization. RESULTS: Seven and 11 protein spots were selected from the MVL and GII laser-treated samples, respectively, for autoantigen identification. No protein spots were detected in the GIII laser-treated samples. Four candidate autoantigens were common to both MVL and GII lesions: dihydropyrimidinase-related protein 2, fructose-bisphosphate aldolase C, chaperonin-containing T-complex polypeptide 1 subunit zeta, and pyruvate kinase isozyme. CONCLUSIONS: Laser-induced retinal injuries resulted in circulating anti-retinal antibodies that were detectable 3 months after the injury. The response appeared to vary with the severity of the laser retinal damage. The identification of the candidate antigens in this study suggest that this approach may permit future development of new diagnostic methods for retinal injuries.

Evaluation of the toxicity of triamcinolone acetonide and dexamethasone sodium phosphate on human lens epithelial cells (HLE B-3).

PURPOSE: The purpose of this study was to compare the in vitro effects of triamcinolone acetonide (TA) and dexamethasone sodium phosphate (DEX) on human lens epithelial cells (HLE B-3). METHODS: HLE B-3 cells were exposed for 24 h to commercially available TA (c-TA) and dimethylsulfoxide-solubilized TA (s-TA). The cells were treated with 1,000 (clinical dose), 750, 500, 200, and 100 µg/mL concentrations of c-TA, s-TA, and supernatant for 24 h. The cells were also treated with DEX at 2, 1, 0.5, 0.2, 0.1 (clinical dose), and 0.05 mg/mL. Cell viability, caspase-3/7 activity, and DNA fragmentation analyses were performed. RESULTS: The mean cell viabilities of HLE B-3 after exposure to c-TA at 1,000, 750, 500, 200, and 100 µg/mL were significantly reduced compared with control untreated cells. The s-TA also significantly reduced cell viability at 1,000, 750, and 500 µg/mL compared with dimethylsulfoxide control. The supernatant did not reduce cell viability. Caspase-3/7 activity significantly increased after treatment with c-TA and s-TA. DNA laddering revealed bands at 200 bp intervals with both c-TA at≥100 µg/mL and s-TA at ≥500 µg/mL. The cell viabilities of HLE B-3 after 24 h exposure to DEX were significantly reduced at 2 and 1 mg/mL but not at lower concentrations tested. Caspase-3/7 activities in HLE B-3 cells were not increased significantly after treatment with DEX at any dose tested. DNA laddering did not reveal any band at any dose tested. CONCLUSION: This study showed that TA at its clinical dose (1,000 µg/mL) in both commercial preparation and solubilized forms decrease HLE B-3 cell viability through an apoptotic pathway. DEX at its clinical dose (0.1 mg/mL) does not decrease cell viability or cause any increase of caspase-3/7 activity. This study suggests that for long-term sustained-release devices, DEX may be less damaging to human lens cells than TA.