1.Trueness of 3D printed partial denture frameworks: build orientations and support structure density parameters
Mostafa Omran HUSSEIN ; Lamis Ahmed HUSSEIN
The Journal of Advanced Prosthodontics 2022;14(3):150-161
PURPOSE:
The purpose of the study was to assess the influence of build orientations and density of support structures on the trueness of the 3D printed removable partial denture (RPD) frameworks.
MATERIALS AND METHODS:
A maxillary Kennedy class III and mandibular class I casts were 3D scanned and used to design and produce two 3D virtual models of RPD frameworks. Using digital light processing (DLP) 3D printing, 47 RPD frameworks were fabricated at 3 different build orientations (100, 135 and 150-degree angles) and 2 support structure densities. All frameworks were scanned and 3D compared to the original virtual RPD models by metrology software to check 3D deviations quantitatively and qualitatively. The accuracy data were statistically analyzed using one-way ANOVA for build orientation comparison and independent sample t-test for structure density comparison at (α = .05). Points study analysis targeting RPD components and representative color maps were also studied.
RESULTS:
The build orientation of 135-degree angle of the maxillary frameworks showed the lowest deviation at the clasp arms of tooth 26 of the 135-degree angle group. The mandibular frameworks with 150-degree angle build orientation showed the least deviation at the rest on tooth 44 and the arm of the I-bar clasp of tooth 45. No significant difference was seen between different support structure densities.
CONCLUSION
Build orientation had an influence on the accuracy of the frameworks, especially at a 135-degree angle of maxillary design and 150-degree of mandibular design. The difference in the support’s density structure revealed no considerable effect on the accuracy.
2.Role of Endogenous Bone Marrow Stem Cells Mobilization in Repair of Damaged Inner Ear in Rats.
Ahmed M ELBANA ; Seddik ABDEL-SALAM ; Ghada M MORAD ; Ahmed A OMRAN
International Journal of Stem Cells 2015;8(2):146-154
BACKGROUND AND OBJECTIVES: The utilization of the stem cells is widely used in the last few years in different fields of medicine, either by external transplantation or endogenous mobilization, most of these studies still experimental on animals; few were tried on human as in the spinal cord injury or myocardial infarction. As regard its use in the inner ear, stem cell transplantation was examined in many previous studies, while the mobilization idea is a new method to be experimented in inner ear hair cell regeneration. The present work assessed the possibility of mobilizing endogenous bone marrow derived stem cells (SCs) in rats using granulocyte colony stimulating factor (G-CSF) to induce regeneration and repair to experimentally damaged inner ear hair cells by Amikacin injection. METHODS: The study included thirty adult Sprague Dawley male rats. Experimental induction of inner ear damage was done by repeated intratympanic injection of amikacin sulfate. Mobilization of bone marrow SCs was provoked by subcutaneous injection of GCSF. Cochlear integrity, induction of hearing loss and functional recovery of sensory hearing loss were assessed using Distortion Product Otoacoustic Emission (DPOAEs). The morphological alteration and recovery of the organ of Corti was assessed histologically using the light and scanning electron microscopes. RESULTS: After six month duration, there was improvement in 50% of the sensorineural DPOAE results. Functional recovery coincided with the repair of structural components of organ of Corti. CONCLUSIONS: SCs mobilization by G-CSF is a promising alternative method for replacement therapy in sensorineural hearing loss.
Adult
;
Amikacin
;
Animals
;
Bone Marrow*
;
Colony-Stimulating Factors
;
Ear, Inner*
;
Granulocyte Colony-Stimulating Factor
;
Granulocytes
;
Hair
;
Hearing
;
Hearing Loss
;
Hearing Loss, Sensorineural
;
Humans
;
Injections, Subcutaneous
;
Male
;
Myocardial Infarction
;
Organ of Corti
;
Rats*
;
Regeneration
;
Spinal Cord Injuries
;
Stem Cell Transplantation
;
Stem Cells*
3.Mandibular shape prediction using cephalometric analysis: applications in craniofacial analysis, forensic anthropology and archaeological reconstruction
Ahmed OMRAN ; David WERTHEIM ; Kathryn SMITH ; Ching Yiu Jessica LIU ; Farhad B. NAINI
Maxillofacial Plastic and Reconstructive Surgery 2020;42(1):37-
Background:
The human mandible is variable in shape, size and position and any deviation from normal can affect the facial appearance and dental occlusion.
Objectives:
The objectives of this study were to determine whether the Sassouni cephalometric analysis could help predict two-dimensional mandibular shape in humans using cephalometric planes and landmarks.
Materials and methods:
A retrospective computerised analysis of 100 lateral cephalometric radiographs taken at Kingston Hospital Orthodontic Department was carried out.
Results:
Results:
showed that the Euclidean straight-line mean difference between the estimated position of gonion and traced position of gonion was 7.89 mm and the Euclidean straight-line mean difference between the estimated position of pogonion and the traced position of pogonion was 11.15 mm. The length of the anterior cranial base as measured by sella-nasion was positively correlated with the length of the mandibular body gonion-menton, r = 0.381 and regression analysis showed the length of the anterior cranial base sella-nasion could be predictive of the length of the mandibular body gonion-menton by the equation 22.65 + 0.5426x, where x = length of the anterior cranial base (SN). There was a significant association with convex shaped palates and oblique shaped mandibles, p = 0.0004.
Conclusions
The method described in this study can be used to help estimate the position of cephalometric points gonion and pogonion and thereby sagittal mandibular length. This method is more accurate in skeletal class I cases and therefore has potential applications in craniofacial anthropology and the ‘missing mandible’ problem in forensic and archaeological reconstruction.
4.Mandibular shape prediction using cephalometric analysis: applications in craniofacial analysis, forensic anthropology and archaeological reconstruction
Ahmed OMRAN ; David WERTHEIM ; Kathryn SMITH ; Ching Yiu Jessica LIU ; Farhad B. NAINI
Maxillofacial Plastic and Reconstructive Surgery 2020;42(1):37-
Background:
The human mandible is variable in shape, size and position and any deviation from normal can affect the facial appearance and dental occlusion.
Objectives:
The objectives of this study were to determine whether the Sassouni cephalometric analysis could help predict two-dimensional mandibular shape in humans using cephalometric planes and landmarks.
Materials and methods:
A retrospective computerised analysis of 100 lateral cephalometric radiographs taken at Kingston Hospital Orthodontic Department was carried out.
Results:
Results:
showed that the Euclidean straight-line mean difference between the estimated position of gonion and traced position of gonion was 7.89 mm and the Euclidean straight-line mean difference between the estimated position of pogonion and the traced position of pogonion was 11.15 mm. The length of the anterior cranial base as measured by sella-nasion was positively correlated with the length of the mandibular body gonion-menton, r = 0.381 and regression analysis showed the length of the anterior cranial base sella-nasion could be predictive of the length of the mandibular body gonion-menton by the equation 22.65 + 0.5426x, where x = length of the anterior cranial base (SN). There was a significant association with convex shaped palates and oblique shaped mandibles, p = 0.0004.
Conclusions
The method described in this study can be used to help estimate the position of cephalometric points gonion and pogonion and thereby sagittal mandibular length. This method is more accurate in skeletal class I cases and therefore has potential applications in craniofacial anthropology and the ‘missing mandible’ problem in forensic and archaeological reconstruction.
5. Molecular characterization of Cysticercus tenuicollis of slaughtered livestock in Upper Egypt governorates
Mosaab Adl Eldin OMAR ; Layla Omran ELMAJDOUB ; Mohammad Saleh AL-ABOODY ; Ahmed Mahmoud ELSIFY ; Ahmed Osman ELKHTAM ; Abdelnasser A. HUSSIEN
Asian Pacific Journal of Tropical Biomedicine 2016;6(8):706-708
Objective To present the molecular characterization of Cysticercus tenuicollis (C. tenuicollis) of Taenia hydatigena (T. hydatigena) from livestock isolates in Egypt, and to introduce a detailed image of C. tenuicollis infection in ruminant animals in Upper Egypt. Methods The prevalence rates of C. tenuicollis infections among the slaughtered animals from different organs were determined using the amplification of sequencing of the MT-CO1 gene. Results In the present study the infection rates of C. tenuicollis were found to be 16% and 19% in sheep and goat samples respectively. Firstly we report one larval stage of T. hydatigena detected in the camel liver in Egypt. C. tenuicollis infection manifested a higher prevalence in females than in males. Those above two years of age manifested a higher infection rate than younger animals. The preferred site for the infection was the omentum: a 70% preference in sheep and a 68% preference in goats. The molecular characterization using the MT-CO1 gene of isolates from sheep, goats and camels corresponded to T. hydatigena. For this study, molecular characterizations of T. hydatigena were done for the first time in Egypt. Molecular tools are of great assistance in characterizing the C. tenuicollis parasite especially when the morphological character cannot be detected, because the metacestodes are frequently confused with infection by the hydatid cyst, especially when these occur in the visceral organs. In the present study, C. tenuicollis manifested high identity in the goat and sheep samples, while differences were found more frequently in the camel samples (10 base pair). Conclusions Clearly molecular diagnosis for C. tenuicollis infection significantly helps to differentiate it from such other metacestodes as hydatidosis, which manifests a completely different pathogenicity and requires different control programs.