Background and Aim: The accuracy of linear measurements in CBCT images is one of the critical parameters in treatment planning. Slice THICKNESS and exposure parameters seem to affect the accuracy of linear measurements. In this study, we investigated the impact of the above factors on the accuracy of linear measurements in CBCT. Materials and Methods: For the in vitro experiment, three dry human maxilla and mandibles were selected and the roots of their teeth were used as markers at the points of the anterior, premolars, and molars on both sides and placed in the desired locations. A digital caliper was used to measure its height and width prior to placement as the Gold Standard. For each location, the images were examined in slice THICKNESS with dimensions of 0. 5, 1, 2 and 3 mm and a kVp = 84 and a kVp = 90 and the results were then compared with Gold standard. The data were analyzed using the ANOVA test. Results: The results of this study showed that the effect of slice THICKNESS, kvp, location and type of jaw were not significant for measuring the length of the marker (p>0. 05) but about measuring the width of marker, in maxillary anterior and molar area and in mandibular premolar and molar area slice THICKNESS was significant (p <0. 05) and the effect of kVp was not significant (p >0. 05). Similarly, the effects of slice THICKNESS and kVp were also significant in the maxillary premolar area (p <0. 05), whereas in the anterior mandibular area, the effect was not significant (p >0. 05). Conclusion: The accuracy of CBCT in measurement is very high although, for CBCT measurements to be as accurate as possible, it is desirable to use thinner slice THICKNESSes and higher voltages.

Purpose: To compare the anatomical and functional results of deep vitrectomy with and without ILM peeling for full THICKNESS macular hole.Materials & Methods: 37 eyes of 37 patients with full THICKNESS macular hole (FTMH), confirmed by clinical examination and optical coherence tomography (OCT), enrolled in this clinical trial. Based on the stage of FTMH (stage 2, 3, 4) as described by Gass and the techniques of surgery (with or without ILM peeling) the patients were randomized into two different groups. All patients underwent preoperative Act and at least one OCT image was obtained during the postoperative follow up.After obtaining informed consent, deep vitrectomy and 20% SF6 injection was performed. The patients were unaware of their allocation status. Patients data & surgical outcome were collected and statistically analyzed. Anatomical success was defined as hole closure at postoperative OCT and functional success was referred to any improvement in visual acuity. Macular hole index (MHI) was defined as a ratio of the greatest height to the base diameter of the hole on cross-sectional OCT images.Results: 37 eyes of 37 patients (15 men & 22 women) were enrolled. The mean age of the patients was 56.4±21.94 years and FTMH were traumatic in 13 cases (35%) and Idiopathic in 24 (65%) cases. Twenty cases underwent deep vitrectomy with ILM peeling (ILM group) and the remaining cases underwent vitrectomy without ILM peeling (no ILM group).The mean preoperative 10gMAR visual acuity was 1.38±1 in the ILM group and 1.22±0.13 in the no ILM group, these improved to 0.95±1 and 0.77±0.31 postoperatively in the ILM and no ILM group, respectively (P=0.871). The overall anatomical success rate was 64%. The hole was closed in 70% of ILM peeling and 47% in the no ILM group (Chi-square test, P=0.15). In anatomically successful cases the mean of postoperative VA was significantly improved (P=0.001).In traumatic subgroup, ILM peeling seems did not affect the anatomical (P=0.2) and visual Success rates (P=0.5). There was no significant differences in hole closure rates between the traumatic and idiopathic FTMH (P=0.968). Visual acuity significantly improved after operation In MHI ³ 0.5 group compared with the MHk 0.5 group. The stage of the hole did not affect the anatomical success rate (P=0.52) or visual acuity improvement (P=0.741). Macular hole index ³ 0.5 had a prognostic value for postoperative visual acuity improvement. The hole duration was not related to anatomical success rate but there is an inverse relation between duration of the symptoms and improvement in VA.Conclusion: Deep vitrectomy and SF6 injection was a safe & effective surgical technique for full THICKNESS macular hole and peeling of the ILM seems did not affect the anatomical or functional success rates. The hole duration, stage and origin of the hole (traumatic or idiopathic) does not related to the anatomical success or visual acuity improvement. MHI  ³ 0.5 seems to be a prognostic factor for postoperative visual improvement but not for closure rate.

The aim of present investigation was to evaluate the efficacy of the full THICKNESS flap with internal mattress, suture in eliminating deep periodontal pockets in maxillary anterior region, to gain attachment and to preserve the height of the papilla prior to the periodontal surgery. Ten patients suffering from adult periodontitis in maxillary anterior region with minimum of two pockets;≥6mm were Participated in this study. Prior to the above surgery the first chase of therapy was performed the following clinical parameters1- Pocket depth2- Attachment level3- Height of papilla were measured one dayBefore the surgery and three months after the surgery. The total of 34 Pocket ≥ 6 mm was treated and the height of 224 papilla was measured. The mean difference between first two parameters. (Post surgical compare to pre surgical...) were 3.235 and 1.93 mm respectively which the differences were significant. Also the mean difference for the 3rd parameter was 1.305 mm which despite of being significant was acceptable (the differences between 3rd parameters less or closer to zero to be more acceptable. This technique is useful for eliminating pockets in maxillary anterior region.

Background: Rotator cuff tendon tear injury is one of the most frequently seen orthopaedic conditions, and surgical repair of rotator cuff tears is a common procedure.The purpose of the present study was to determine the results of full-THICKNESS rotator cuff repair and to look for predictors of outcomes.Methods: we studied 27 patients (17 men and 10 women with a mean age of 57.7 years) who underwent open rotator cuff repair surgery for full-THICKNESS tear between 2001 and 2005 at the Imam Khomeini Hospital and were subsequently followed-up for 6 and 12 months after surgery. The shoulder function was assessed by Constant classification and factors potentially associated with outcomes were.Results: The mean of preoperative Constant score (CS) was 45.8±14.1 after 12 months, 6 patients (22.2%) had good results and 21 patients (77.8%) had excellent result according to CS. Pain relief was generally satisfactory. Using multiple regression analysis, treatment was significantly correlated preoperative CS and acromio-humeral interval (AHI) however, no correlation was found between the result of the treatment and pretreatment atrophy, tear size, acromial morphology, preoperative symptom duration and age.Conclusion: In this study, a standard rotator cuff repair technique reduced pain severity and was associated with good results, however larger studies are necessary to define the long-term outcome of this procedure.

Purpose: To compare macular THICKNESS in children with functional amblyopia and those without amblyopia using optical coherence tomography (OCT).Methods: This case‑control study was conducted on 93 children aged 3–10 years including 44 cases with unilateral amblyopia and 49 subjects without amblyopia. Amblyopic eyes were considered as the case group and their fellow eyes as internal controls; eyes of non‑amblyopic children served as the external control.Macular THICKNESS of all eyes were measured by optical coherence tomography in the center (foveola), 1 mm ring (fovea), and 3 and 6 mm rings and compared.Results: Although macular THICKNESS was generally not different between the study groups, there was a significant difference in central macular THICKNESS between eyes with moderate to severe amblyopia and the external controls (P=0.037). Foveal THICKNESS difference exceeding 10 microns between fellow eyes was detected in a larger number of amblyopic children as compared to non‑amblyopic controls (P=0.002). Mean foveal THICKNESS was greater in boys (P=0.037) but there was no significant difference in foveal THICKNESS among various types of refractive errors.Conclusion: Although there was no significant relationship between macular THICKNESS and amblyopia, foveolar THICKNESS in eyes with moderate to severe amblyopia was significantly greater than the external controls. Further studies with more cases of moderate to severe amblyopia are recommended.

In this paper, post-buckling behavior of cold-formed, thin-walled structures containing THICKNESS-tapered plate with initial imperfection is investigated. A computer program has been developed using the nonlinear Finite Strip Method for post buckling analysis of plates and plate assemblies under compression and bending. Axial and flexural stiffness of lipped channels, Z-shaped and T-shaped sections containing THICKNESS-tapered and THICKNESS constant plates are calculated for different geometries. Stress redistributions of those sections are also determined. Results for stress redistributions show that sectional geometries and applied strains have important effects on stress distributions.

Purpose: The association between central corneal THICKNESS and retinal fiber layer THICKNESS with refractive error (emmetropic, myopic and hyperopic eyes).Methods: 180 eyes (64 emmetropic eyes, 70 myopic eyes, 46 hyperopic eyes) in young subjects (18-35 years of age) were randomly selected. The participants in this study didn’t have any ocular pathology or any previous surgical history. Pachymetry pattern of RTVUE OCT in central corneal THICKNESS (CCT) and retinal nerve fiber layer (RNFL) THICKNESS were measured.Results: Mean CCT was 539.36±36.37 microns. Emmetropic eyes had thinner corneas (emmetropic eyes: 536.14, myopic eyes: 539.67, hyperopic eyes: 543.28 microns). Myopic subjects had thinner RNFL THICKNESS (myopic eyes: 114.21, emmetropic eyes: 121.05, hyperopic eyes: 120.45). Univariate analysis revealed that CCT is positively correlated with RNFL in hyperopic and myopic eyes.Conclusion: Our findings demonstrate that RNFL may have positively correlated with CCT in hyperopic and myopic eyes. RNFL had inversely correlated with the amount of myopia and positively correlated with hyperopia. CCT was not significantly correlated with refractive error.

Purpose: To examine the relationship between retinal nerve fiber layer (RNFL) measurements obtained using scanning laser polarimetry with variable corneal compensation (VCC) and central corneal THICKNESS (CCT) measurements using pentacam in myopic patients.Methods: The study included 45 eyes from 45 myopic patients with intraocular pressure (IOP) measurements£21 mmHg. All participants had normal optic discs and normal standard automated perimetry visual fields. All patients underwent imaging with the GDx VCC and pentacam. We examined the relationship between GDx VCC RNFL measurements and CCT.Results: Mean spherical equivalent (SE) was -3.65±1.1 D (range: -1.00 to -6.5 D). Mean CCT was 530.9±24.32 mm with a range of 488 to 596 mm. TSNIT (temporal, superior, nasal, inferior, temporal) average, inferior average, superior average, TSNIT standard deviation (SD) and nerve fiber indicator (NFI) were not correlated with CCT. There were no correlations between RNFL THICKNESS and refraction, age, corneal volume and mean keratometry. However, RNFL in patients with CCT£530 mm was significantly thinner than in those with thick corneas.Conclusion: RNFL measurements obtained using GDx VCC may not correlate with corneal THICKNESS (CCT) and refraction in myopic patients. Myopic patients with CCT£530 have thinner RNFL than in those with thick corneas.

An advantage of the flow-forming process is high accuracy of products. Most researches in the past decades studied product diametric accuracy but to the authors’ knowledge, they investigated rarely THICKNESS accuracy. In this paper, a procedure is proposed to predict effects of the process parameters such as pre-form THICKNESS variation and mandrel and rollers stiffness on product THICKNESS accuracy. For this purpose, rollers forces are calculated as a function of pre-form THICKNESS variation and mandrel and rollers deflections. Using this function, product THICKNESS variation and mandrel deflection are calculated and it is concluded that pre-form THICKNESS variation causes product THICKNESS variation with similar distribution but the amount of variation largely decreases. The experiments also verify this prediction.In addition, the applied force to the mandrel is investigated and it is also concluded that a periodic force with similar distribution to the pre-form THICKNESS is applied to the mandrel. Finally, it is shown that flow-forming with three rollers produce more accurate products than a two rollers case.