Thamar University

Dhamār, Yemen

Thamar University

Dhamār, Yemen
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Murshid S.A.,Thamar University
Archives of Oral Biology | Year: 2017

Objective To explore the types of orthodontic force-induced mechanical stimuli that regulate osteocyte function. Design In orthodontics, a tooth can be moved through the alveolar bone when an appropriate orthodontic force is applied. These mechanical loads stimulate cells within the bone tissue around the tooth. These cellular responses lead to bone resorption on the side of the tooth where the pressure has been applied and bone deposition on the side of the tooth experiencing tension. Recently, osteocytes were identified to function as mechano-sensory cells in bone tissue that direct bone resorption and bone formation. Based on recent literature, the proposed function of osteocytes during orthodontic tooth movement is explored with better understanding. Results Several stimuli regulating osteocyte function have been highlighted, and their potential roles in events initiating osteocyte sensing of orthodontic force have been explored in detail. The most popular hypotheses for osteocyte response include stress-induced bone matrix deformation/microcrack formation and fluid-flow shear stress. Conclusions Understanding osteocyte function under mechanical stress may have profound implications in future orthodontic treatments. © 2016 Elsevier Ltd


Al-Moraissi E.A.,Thamar University | Ellis E.,University of Texas Health Science Center at San Antonio
Journal of Oral and Maxillofacial Surgery | Year: 2015

Purpose Bilateral sagittal split ramus osteotomy (BSSO) and intraoral vertical ramus osteotomy (IVRO) are used for mandibular setbacks. The purpose of this study was to determine differences in skeletal stability and neurosensory disturbance (NSD) of the mental nerve after mandibular setback using these operations. Materials and Methods A systematic review and meta-analysis on these topics was performed. An electronic search of several databases with specific keywords, a reference search, and a manual search from database inception to December 2014 was performed with inclusion criteria of clinical human studies, randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies, with the predictor variable being BSSO or IVRO after mandibular setback surgery. The outcome variables of horizontal and vertical relapse using cephalometrics and NSD using trigeminal somatosensory-evoked potential and subjective tests were statistically analyzed. Results The initial PubMed search identified 716 studies of which 13 met the inclusion criteria - 4 RCTs, 3 CCTs, and 6 retrospective studies. No statistically significant difference was found between the 2 groups regarding horizontal skeletal stability, but the BSSO group had more stability in the vertical dimension (P =.02). There was a statistically significant difference between BSSO and IVRO with regard to NSD of the inferior alveolar nerve (IAN; P =.001). Conclusion The results of this meta-analysis suggest that BSSO and IVRO have good stability when used to set back the mandible. Furthermore, the results showed that IVRO statistically decreased the incidence of NSD of the IAN after mandibular setback surgery compared with BSSO. © 2015 American Association of Oral and Maxillofacial Surgeons.


Al-Moraissi E.A.,Thamar University | Ellis E.,University of Texas Health Science Center at San Antonio
Journal of Oral and Maxillofacial Surgery | Year: 2015

Purpose The purpose of this study was to test the hypothesis that there is no difference in skeletal stability and material-related complications for titanium or biodegradable fixation when used for various orthognathic surgeries. Materials and Methods A systematic and electronic search of several databases with specific keywords, a reference search, and a manual search through September 2014 was performed. The inclusion criteria were clinical human studies, including randomized controlled trials, controlled clinical trials, and retrospective studies, with the aim of comparing titanium and biodegradable osteosynthesis after various orthognathic surgeries. The outcome variables of horizontal and vertical relapse using cephalometrics and material usability were statistically analyzed. Results The initial PubMed search identified 557 studies, 22 of which met the inclusion criteria (8 randomized controlled trials, 10 controlled clinical trials, and 4 retrospective studies). No statistical difference was found between the 2 groups regarding skeletal stability after various orthognathic surgeries. There was no statistical difference with regard to wound problems, plate and screw removal, and palpability between biodegradable and titanium osteosynthesis, but there was a statistical difference with regard to intraoperative fracture of plates and screws in the biodegradable group. Conclusion The results of this meta-analysis support the hypothesis that biodegradable fixation devices offer similar skeletal stability as titanium fixation for orthognathic surgery. The results of this study also show that titanium fixation produced fewer broken screws during surgery compared with biodegradable screws. © 2015 American Association of Oral and Maxillofacial Surgeons.


Al-Moraissi E.A.,Thamar University | Ellis E.,University of Texas Health Science Center at San Antonio
Journal of Oral and Maxillofacial Surgery | Year: 2015

Purpose The aim of this study was to answer the following question: in patients with nasal bone fractures (NBFs), does closed reduction under local anesthesia (LA) produce comparable outcomes as closed reduction under general anesthesia (GA)? Materials and Methods A systematic review with meta-analysis and a comprehensive electronic search without date and language restrictions was performed in August 2014. The inclusion criteria were studies in humans, including randomized or quasi-randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies whose aim was comparing clinical outcomes between LA and GA for closed reduction of NBFs. Results Eight publications were included: 3 RCTs, 2 CCTs, and 3 retrospective studies. Three studies showed a low risk of bias, and 5 studies showed a moderate risk of bias. There was no statistical difference between LA and GA for closed reduction of NBFs with regard to patient satisfaction with anesthesia, patient satisfaction with function of the nose, need for subsequent retreatment (septoplasty, septorhinoplasty, or rhinoplasty with refracture), and a patient's chosen treatment for a refracture of the nose. There was a statistical difference between LA and GA for closed reduction of NBFs with regard to patient satisfaction with the appearance of the nose. Conclusion Regardless of the cost and risks associated with GA, the results of the meta-analysis showed that GA provides better patient satisfaction with anesthesia, appearance and function of the nose, and preference of treatment for a refracture of the nose. In addition, the meta-analysis showed that GA decreased the number of subsequent corrective surgeries (septoplasty, septorhinoplasty, and rhinoplasty) required. © 2015 American Association of Oral and Maxillofacial Surgeons.


Al-Moraissi E.A.,Thamar University | Ellis E.,University of Texas Health Science Center at San Antonio
Journal of Oral and Maxillofacial Surgery | Year: 2015

Purpose The purposes of this study were to identify significant differences in clinical outcomes between open reduction and rigid internal fixation (ORIF) and closed treatment (CT) for adult mandibular condylar fractures (MCFs) and to support or refute the superiority of one method over the other. Materials and Methods To address our purpose, we designed and implemented a systematic review with meta-analysis. A comprehensive electronic search without date and language restrictions was performed in May 2014. The inclusion criteria were studies in humans, including randomized or quasi-randomized controlled trials, controlled clinical trials, and retrospective studies, that compared ORIF and CT regarding maximal interincisal opening, laterotrusive and protrusive movements, pain, malocclusion, chin deviation on mouth opening, and temporomandibular joint signs or symptoms for the management of unilateral or bilateral adult MCFs. Meta-analysis was conducted only if there were studies of similar comparisons reporting the same outcome measures. For binary outcomes, we calculated a standard estimation of the odds ratio by the random-effects model if heterogeneity was detected; otherwise, a fixed-effects model with a 95% confidence interval was performed. Weighted mean differences or standard mean differences were used to construct forest plots of continuous data. Results Twenty-three publications were included: 5 randomized controlled trials, 16 controlled clinical trials, and 2 retrospective studies. Five studies showed a low risk of bias, whereas 18 showed a moderate risk of bias. There were statistically significant differences between ORIF and CT regarding maximal interincisal opening, laterotrusive movement, protrusive movement, malocclusion, pain, and chin deviation on mouth opening (P =.001, P =.001, P =.001, P =.001, P =.001, and P =.05, respectively). Conclusions The result of the meta-analysis confirmed that ORIF provides superior functional clinical outcomes (subjective and objective) compared with CT in the management of adult MCFs. © 2015 American Association of Oral and Maxillofacial Surgeons.


Al-Moraissi E.A.,Thamar University
International Journal of Oral and Maxillofacial Surgery | Year: 2015

The objective of this study was to assess the clinical outcomes of the following three surgical methods for the management of internal derangement (ID) of the temporomandibular joint (TMJ): arthroscopic lysis and lavage (ALL), arthroscopic surgery (AS), and open surgery (OS). A systematic and electronic search of several databases with specific key words was performed from their inception through November 2014. Clinical human studies, including randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies, with the aim of comparing the three surgical methods for the management of ID of the TMJ were included. Seven publications were identified: three RCTs, two CCTs, and two retrospective studies. A significant difference was found between OS and AS in pain reduction (P = 0.05), but no significant difference with regard to maximal inter-incisal opening (MIO > 35 mm), mandibular function impairment, and clinical findings (clicking, joint tenderness, and crepitation) (P = 0.52, P = 0.34, and P = 0.19, respectively). The results of the meta-analysis showed that the use of OS is superior to AS in pain reduction, with comparable MIO, jaw function, and clinical findings. In addition, the results of the present study showed that ALL provides greater improvement in MIO and comparable pain reduction when compared to AS. © 2015 International Association of Oral and Maxillofacial Surgeons.


Abdulwahab A.M.,Thamar University
Journal of Physics and Chemistry of Solids | Year: 2016

Lithium sodium sulfate (LiNaSO4)single crystal is synthesized and grown by the slow evaporation of supersaturated aqueous solution at constant temperature (303 K). Powder X-ray diffraction is measured at room temperature in order to identify the grown crystal. Transmittance and reflectance measurements are used to study the optical properties of this crystal at room temperature phase (β-LiNaSO4). The type of transition is determined. The values of optical energy gap, phonon energy and phonon equivalent temperature are calculated. Refractive index and extinction coefficient are calculated as functions of photon energy. The obtained optical data of β-LiNaSO4 crystal are used to check the validity of both Wemple-DiDomenico and Cauchy-Sellimaier dispersion relations. Normal dispersion parameters of this crystal are calculated for the first time. © 2016 Elsevier Ltd


Jassim S.A.J.,Thamar University | Zumaila A.A.R.A.,University of Aden | Waly G.A.A.A.,University of Aden
Results in Physics | Year: 2013

CdS thin films were deposited onto glass substrates at three different temperatures (20, 100 and 200°C) by vacuum thermal evaporation at 10-5Torr using pure crystal as evaporated targets. The effects of substrate temperature on structural, electrical and optical properties were studied. Structural analysis using X-ray diffraction (XRD) and scanning electronic microscope (SEM) revealed that the films are polycrystalline in nature with a hexagonal wurtzite structure having (002) plane as the preferred orientation. The crystalline size (D), dislocation density (δ), strain (ε) and texture coefficient TC(hkl) were calculated. All the films have high optical transmittance (>80%) in the visible range. The optical band gap values are found to be in the range of (2.3-2.43eV) and found to decrease with increase in substrate temperature. DC electrical conductivity was carried out at room temperature indicating a very low electrical conductivity. © 2013 The Authors.


El-Shekeil Y.A.,University Putra Malaysia | Sapuan S.M.,University Putra Malaysia | Jawaid M.,University Putra Malaysia | Al-Shuja'a O.M.,Thamar University
Materials and Design | Year: 2014

Kenaf (Hibiscus Cannabinus) bast fiber reinforced poly(vinyl chloride) (PVC)/thermoplastic polyurethane (TPU) poly-blend was prepared by melt mixing method using Haake Polydrive R600 internal mixer. The composites were prepared with different fiber content: 20%, 30% and 40% (by weight), with the processing parameters: 140°C, 11min, and 40rpm for temperature, time and speed, respectively. After mixing, the composite was compressed using compressing molding machine. Mechanical properties (i.e. tensile properties, flexural properties, impact strength) were studied. Morphological properties of tensile fracture surface were studied using Scanning electron microscope (SEM). Thermal properties of the composites were studied using Thermogravimetric Analyses (TGA). PVC/TPU/KF composites have shown lower tensile strength and strain with increase in fiber content. Tensile modulus showed an increasing trend with increase in fiber content. Impact strength decreased with increase in fiber content; however, high impact strength was observed even with 40% fiber content (20.2kJ/m2). Mean while; the 20% and 30% fiber contents showed higher impact strength of 34.9, 27.9kJ/m2; respectively. SEM showed that there is poor fiber/matrix adhesion. Thermal degradation took place in three steps. In the first step, composites as well as the matrix had a similar stability. At the second step, matrix showed a slightly better stability than the composites. At the last step, composites showed a better stability than the matrix. © 2014 Elsevier Ltd.


Al-Moraissi E.A.,Thamar University | Al-Moraissi E.A.,Cairo University
International Journal of Oral and Maxillofacial Surgery | Year: 2015

The aim of this study was to assess whether arthroscopy or arthrocentesis is most effective and feasible in the management of internal derangement of the temporomandibular joint (TMJ), specifically in relation to joint movement and pain. A comprehensive electronic search without date or language restrictions was performed in January 2014. Inclusion criteria were the following: study in humans; randomized or quasi-randomized controlled trials (RCTs), controlled clinical trials (CCTs), and retrospective studies; comparison of arthrocentesis and arthroscopy in the treatment of internal derangement. Six publications were included in the review, two RCTs, two CCTs, and two retrospective studies. Two studies showed a low risk of bias and four studies showed a moderate risk of bias. There were statistically significant differences between arthrocentesis and arthroscopy with regard to maximal inter-incisal opening and pain reduction, but no difference between the two groups for postoperative complications. The results of this meta-analysis on the management of internal derangement of the TMJ revealed arthroscopy to have superior efficacy to arthrocentesis in increasing joint movement and decreasing pain. Both arthroscopy and arthrocentesis have comparable postoperative complication rates. However, the current meta-analysis is incomplete due to the paucity of good quality studies in the high-impact, peer-reviewed literature; therefore, further better-designed studies are required to address this important question before final conclusions can be drawn as to the true comparative outcomes of TMJ arthrocentesis versus TMJ arthroscopy. © 2014 International Association of Oral and Maxillofacial Surgeons.

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