Study of Morphokinetics in Day 3 Embryo with Implantation Potential and Effect of Sperm Cryopreservation on Embryogenesis

2017 ◽  
Vol 8 (2) ◽  
pp. 61-67
Author(s):  
Harsha K Bhadarka ◽  
Nayana H Patel ◽  
Kruti B Patel ◽  
Nilofar R Sodagar ◽  
Yuvraj D Jadeja ◽  
...  

ABSTRACT Aim In recent past, many studies had come up with the combination of time-lapse (TL) imaging of embryo morphokinetics as a noninvasive means for improving embryo selection and in vitro fertilization (IVF) success. The primary objective of the study was to find out if there is significant variation in morphokinetics of embryos with different implantation potential and also to study the effect of sperm freezing on time points of embryogenesis events in embryos with implantation potential. Materials and methods Kinetic data and cycle outcomes were analyzed retrospectively in 142 patients who had undergone IVF/intracytoplasmic sperm injection (ICSI) cycles using semen with normal parameters and embryo transfer (ET) on day 3. For the surety of specificity of morphokinetics, only cases with single ET cycles were included in the study. Timing of specific events, from the point of ICSI, was determined using TL imaging. Kinetic markers like time to syngamy (t-pnf), t2, time to two cells (c), 3c (t3), 4c (t4), 5c (t5), 8c (t8), tMor, CC2, CC3, t5–t2, t5–t4, s1, s2, and s3 were calculated. The cleavage synchronicity from the 2–8 cell stage (CS2–8), from 4 to 8 cell stage (CS4–8), and from 2 to 4 cell stage (CS2–4) were calculated as defined elsewhere. Deoxyribonucleic acid replication time ratio (DR) was also included in the comparison. Analysis of variance test was used for comparison of the mean timing of cell division and cell cycle intervals. Results Morphokinetics t-pnf, t2, t8, CC2, S2, S3, CS2–8, CS4–8, and CS2–4 differed significantly between embryos with and without implantation potential, when embryos were developed using fresh semen, while t3, t4, t5, CC2, S2, t5–t2, CS2–4, and DR differed significantly between the embryos with and without implantation potential when frozen semen was used. No significant difference was found in mean value of any of the above-stated parameters when comparison was done between implanted embryos fertilized by either fresh or cryopreserved sperm. Conclusion Many morphokinetics parameters of embryogene­sis vary significantly between embryos with different ability to implant; therefore, the criteria developed in our IVF lab can be useful for selection of suitable embryo even at day 3 of development with more chances of implantation. Clinical significance Study indicates necessity of development of individualized selection model based on morphokinetics for every IVF lab and also confirms freezing as an important tool for fertility preservation of males as it does not affect events of embryogenesis. How to cite this article Bhadarka HK, Patel NH, Patel KB, Sodagar NR, Jadeja YD, Patel NH, Patel MN, Patel AV, Patel DH, Patel JS. Study of Morphokinetics in Day 3 Embryo with Implantation Potential and Effect of Sperm Cryopreservation on Embryogenesis. Int J Infertil Fetal Med 2017;8(2):61-67.

2010 ◽  
Vol 22 (1) ◽  
pp. 296 ◽  
Author(s):  
K. Imai ◽  
T. Somfai ◽  
M. Ohtake ◽  
Y. Inaba ◽  
Y. Aikawa ◽  
...  

We previously reported that follicular wave synchronization by dominant follicle removal on Day 5 and the start of a superstimulatory treatment on Day 7 after ovum pick-up (OPU) was effective to increase oocyte quality (Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). The present study was designed to examine the effect of superstimulatory treatment-induced follicular wave synchronization on quality of embryos obtained by OPU and in vitro production. Japanese Black cows were reared under the same feeding and environmental conditions and 2 OPU sessions were conducted in each cow. The first OPU session was performed in 7 cows at arbitrary days of estrous cycle using a 7.5-MHz linear transducer with needle connected to an ultrasound scanner. Then, follicles larger than 8 mm in diameter were aspirated and CIDR was inserted on Day 5 (the day of first OPU session = Day 0). The cows then received 30 mg of FSH twice a day from Days 7 to 10 in decreasing doses (4, 4, 3, 3, 2, 2, 1, 1 mg per shot) by i.m. injections. Cloprostenol (PGF; 0.75 mg) was administered in the morning of Day 9. The second OPU session was performed 48 h after PGF administration (Day 11) and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Grade 1 and 2 cumulus oocyte complexes were in vitro matured, fertilized (IVF), and cultured as described by Imai et al. (2006 J. Reprod. Dev. 52, Suppl. S19-29). Some zygotes were fixed and stained to check their sperm penetration. Embryo development was monitored by time-lapse cinematography for 168 h after IVF. Cleavage pattern of embryos was classified morphologically into normal and abnormal (including those with multiple fragments, protrusions, 3 to 4 blastomeres, and uneven cell division) groups at their first cleavage. Normal penetration rate of second OPU session was significantly (P < 0.05) higher than that of the first OPU session. There were no differences in the mean percentage of total blastocyst and grade 1 blastocyst rates between the first (45.2 and 46.9%, respectively) and second (47.5 and 41.8%, respectively) OPU sessions. However, the rates of blastocysts developing from embryos that were beyond the 4-cell stage at 48 h after IVF was significantly (P < 0.05) higher after the second OPU session (81.2%) than after the first OPU session (67.4%). Furthermore, a significant difference (P < 0.05) was found in the rates of normal cleavage at the first cell division in embryos that developed to the blastocyst stage between the first and second OPU sessions (53.3% and 73.9%, respectively). These results indicate that superstimulatory treatment-induced follicular wave synchronization improved the normality of fertilization and development of cattle oocytes obtained by OPU. This work was supported by the Research and Development Program for New Bio-industry Initiatives.


2010 ◽  
Vol 22 (1) ◽  
pp. 287 ◽  
Author(s):  
M. C. Abraham ◽  
A. Ruete ◽  
Y. C. B. Brandt

Fertility among cattle breeds can vary. The Swedish Red and White dairy breed (SRB) has been systematically bred for good reproductive traits since 1970 and might therefore have retained a better oocyte quality than other dairy breeds. The aim of this study was to determine if the breed of oocyte donor affects the development of embryos using IVM, IVF, and IVC. Oocyte developmental competence in vitro was compared between the SRB (n = 77 animals), the Swedish Holstein breed (SLB, n = 49), and beef breeds (mixed breeds, n = 97). The oocytes (n = 1380, 18 batches) were aspirated from abattoir-derived ovaries from healthy animals with known identity. Statistical analyses were performed using Student’s t-tests and generalized linear mixed models with random effects. The time of collection in relation to slaughter and time of day, as well as aspiration and the following in vitro procedures, were consistent throughout the experiment. The oocytes were matured, fertilized (frozen semen), and cultured according to conventional protocols without serum. Data are presented as mean ± SEM. The SRB and SLB groups were comparable in age [SRB: 66% cows (over 3 years of age), 27% young cows (calved at least once but not over 3 years of age), and 7% heifers; SLB: 63% cows, 20% young cows, and 17% heifers], carcass classification (scale 1-15, where 15 = highest amount of muscle; SRB: 3.8 ± 0.2, SLB 3.5 ± 0.3), body fat (scale 1-15, where 15 =highest amount of fat; SRB: 8.4 ± 0.4, SLB 8.8 ± 0.5) and kilograms of carcass weight (SRB: 297.3±7.4, SLB: 311.6 ± 9.0). The beef group had a significantly higher mean carcass classification (6.2 ± 0.2) and a different age distribution with a higher proportion of heifers (38% cows, 12% young cows, and 50% heifers), but was comparable in body fat content (8.5 ± 0.4) and kilograms of carcass weight (310.9 ± 7.9). Cleavage rate, number of embryos developed beyond the 2-cell stage by 44 h post-fertilization, and the number of blastocysts developed by Days 7 and 8 were noted. All blastocysts were graded and stained with Hoechst 33 342 and the number of nuclei was determined. Cleavage rate was not different among the breeds (SRB: 71.9 ± 0.03%, SLB: 72.5 ± 0.02%, beef: 73.9 ± 0.03%). The percentage of embryos developed beyond 2-cells (from cleaved) did not differ between the beef and SRB (beef: 65.1 ± 6.1%; SRB: 70.4 ± 4.9%) but SLB was significantly greater than than the other breeds (75.4 ± 4.5%). The percentage of blastocysts developed by Day 8 was significantly higher in the beef (21.1 ± 2.7%) and SRB (23.3 ± 3.5%) breeds compared with the SLB (12.5 ± 2.4%). There was no significant difference in blastocyst grades among breeds (scale 1-4, where 1 = highest grade; SRB: 2.4 ± 0.1, SLB: 2.4 ± 0.2, beef: 2.1 ± 0.2), but the number of nuclei in Day 8 blastocysts was significantly lower in the SLB (SRB: 98.9 ± 7.7, SLB: 79.2 ± 8.7, beef: 101.4 ± 6.9). In conclusion, the breed of origin of the oocytes is an important factors affecting the development during in vitro embryo production in cattle. Funded by Formas.


Zygote ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 187-193 ◽  
Author(s):  
So Gun Hong ◽  
Goo Jang ◽  
Hyun Ju Oh ◽  
Ok Jae Koo ◽  
Jung Eun Park ◽  
...  

SummaryBrain-derived neurotrophic factor (BDNF) signalling via tyrosine kinase B receptors may play an important role in ovarian development and function. It has been reported that metformin elevates the activity of Tyrosine kinase receptors and may amplify BDNF signalling. The objective of this study was to investigate the effect of BDNF during in vitro maturation (IVM) and/or in vitro culture (IVC) (Experiment 1), and to evaluate the collaborative effect of BDNF and metformin treatment on the developmental competence of bovine in vitro fertilized (IVF) embryos (Experiment 2). In Experiment 1, BDNF, which was added to our previously established IVM systems, significantly increased the proportions of MII oocytes at both 10 ng/ml (86.7%) and 100 ng/ml (85.4%) compared with the control (64.0%). However, there was no statistically significant difference in blastocyst development between the control or BDNF-supplemented groups. In Experiment 2, in order to investigate the effect of BDNF (10 ng/ml) and/or metformin (10−5 M) per se, TCM-199 without serum and hormones was used as the control IVM medium. The BDNF (48.3%) and BDNF plus metformin (56.5%) significantly enhanced the proportions of MII oocytes compared with the control (34.4%). Although, BDNF or metformin alone had no effect in embryo development, BDNF plus metformin significantly improved early embryo development to the 8–16-cell stage compared with the control (16.5 vs. 5.5%). In conclusion, the combination of BDNF and metformin may have a collaborative effect during the IVM period. These results could further contribute to the establishment of a more efficient bovine in vitro embryo production system.


Development ◽  
1987 ◽  
Vol 100 (2) ◽  
pp. 279-295 ◽  
Author(s):  
L. Dale ◽  
J.M. Slack

We have further analysed the roles of mesoderm induction and dorsalization in the formation of a regionally specified mesoderm in early embryos of Xenopus laevis. First, we have examined the regional specificity of mesoderm induction by isolating single blastomeres from the vegetalmost tier of the 32-cell embryo and combining each with a lineage-labelled (FDA) animal blastomere tier. Whereas dorsovegetal (D1) blastomeres induce ‘dorsal-type’ mesoderm (notochord and muscle), laterovegetal and ventrovegetal blastomeres (D2–4) induce either ‘intermediate-type’ (muscle, mesothelium, mesenchyme and blood) or ‘ventral-type’ (mesothelium, mesenchyme and blood) mesoderm. No significant difference in inductive specificity between blastomeres D2, 3 and 4 could be detected. We also show that laterovegetal and ventrovegetal blastomeres from early cleavage stages can have a dorsal inductive potency partially activated by operative procedures, resulting in the induction of intermediate-type mesoderm. Second, we have determined the state of specification of ventral blastomeres by isolating and culturing them in vitro between the 4-cell stage and the early gastrula stage. The majority of isolates from the ventral half of the embryo gave extreme ventral types of differentiation at all stages tested. Although a minority of cases formed intermediate-type and dorsal-type mesoderms we believe these to result from either errors in our assessment of the prospective DV axis or from an enhancement, provoked by microsurgery, of some dorsal inductive specificity. The results of induction and isolation experiments suggest that only two states of specification exist in the mesoderm of the pregastrula embryo, a dorsal type and a ventral type. Finally we have made a comprehensive series of combinations between different regions of the marginal zone using FDA to distinguish the components. We show that, in combination with dorsal-type mesoderm, ventral-type mesoderm becomes dorsalized to the level of intermediate-type mesoderm. Dorsal-type mesoderm is not ventralized in these combinations. Dorsalizing activity is confined to a restricted sector of the dorsal marginal zone, it is wider than the prospective notochord and seems to be graded from a high point at the dorsal midline. The results of these experiments strengthen the case for the three-signal model proposed previously, i.e. dorsal and ventral mesoderm inductions followed by dorsalization, as the simplest explanation capable of accounting for regional specification within the mesoderm of early Xenopus embryos.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Francesca Cattoni ◽  
Giulia Teté ◽  
Alessandro Mauro Calloni ◽  
Fabio Manazza ◽  
Giorgio Gastaldi ◽  
...  

Abstract Background Aesthetic porcelain veneers proved to be a long-term reliable prosthetic solution, ensuring minimal invasiveness. The use of veneers requires an adhesive cementation technique, so maintaining as much enamel as possible is to ensure lasting success. A diagnostic mock-up is a key tool that allows a preview of the outcome of the aesthetic restoration: it is obtainable both in an analog and digital way. With the recent developments in impression technology and the ever so fast growing use of CAD-CAM technologies it is useful to understand the pros and cons of either one of these techniques (analog and digital) in order to identify the easier and more convenient workflow in aesthetic dentistry. Methods After taking pictures and impressions of the dental arcs of a patient in need of aesthetic rehabilitation, 52 resin models were produced and a digital drawing of the smile was outlined. Both an analog and a digital wax-up were obtained from two of the 52 models: the latter was obtained using digital impressions and a dedicated software. The analog wax-up was then used to produce 25 matrices that have later been used to mould 25 resin mock-ups using a traditional moulding protocol (Control Group - CG). The digital wax-up was used to mill 25 PMMA mock-ups. Each mock-up, both milled and moulded (total 50), was then laid on the other 50 resin models as a digital impression of it was taken. The STL. files of the milled mock-ups were compared with the 3D CAD wax-up made using a specific software. The STL. files of the analog printed mock-ups were compared with the traditional wax-up design. A statistical analysis was carried out to evaluate the difference between the groups. Results The statistical analysis showed a significant difference (P > 0.01) between the mean value of the distance between the points of the overlapping STL. meshes in GC (0.0468 mm) and in TG (Test Group - TG) (0,0109 mm). Conclusions The study showed a difference in accuracy between traditional moulded and milled mock-ups compared to their original wax-up. The data analysis reports that the digital method allows for greater accuracy. Within the limitations of this study, a fully digital workflow is to considered more reliable when it come to creating an esthetic mockup: the digital procedure has been shown to be more accurate than the one made manually which is much more operator dependent and it brings an increase to the chance of error, and that could ultimately affect the final result.


2005 ◽  
Vol 17 (2) ◽  
pp. 190
Author(s):  
W.C. Chang ◽  
J. Xu ◽  
S. Jiang ◽  
X.C. Tian ◽  
X. Yang ◽  
...  

The aim of this experiment was to determine the effect of the sucrose concentration (0 to 0.33 M) in the dilution medium on the viability, fertilizability, and development of vitrified bovine oocytes. Bovine oocyte-cumulus complexes were collected from slaughterhouse ovaries and in vitro-matured as reported previously. After 24-h maturation in TCM199-based medium under 5% CO2 humidified air at 39°C, these were exposed to hyaluronidase and carefully pipetted to remove all except the 3–5 innermost layers of cumulus. Oocytes were put into the pre-equilibration medium for 3 min and then into vitrification solution containing HEPES-buffered TCM199 supplemented with 20% FBS, ethylene glycol, and dimethylsulphoxide for 25–30 s; they were then vitrified by modified solid surface vitrification (Dinnyes et al. 2000 Biol. Reprod. 63, 513–518).The oocytes were warmed at 39°C by placing them in holding medium with 0, 0.08, 0.17, 0.25, or 0.33 M sucrose. Non-vitrified oocytes were used as controls. Oocytes were inseminated 30 min after warming, and the presumptive zygotes were cultured in CR1-aa medium supplemented with 6 mg/mL BSA at 39°C in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 for eight days. Data were analyzed by one-way ANOVA. As shown in Table 1, there was no significant difference in survival rate (P > 0.05) of the vitrified oocytes that were placed in dilution solution containing 0.17, 0.25, or 0.33 M sucrose and the non-treated controls. On Day 2 (fertilized on Day 0), cleavage to the 8-cell stage was similar for the 0.17, 0.25, and 0.33 M dilution groups, but the rates for all three were significantly lower (P < 0.05) than for the control group. The blastocyst rate on Day 8 was significantly higher for the 0.25 M group than for any other experimental group but still significantly lower than for the control. In conclusion, this study suggests that with this vitrification/warming procedure the optimum concentration of sucrose in the dilution solution is 0.25 M. Table 1. Oocyte survival after vitrification/warming and subsequent embryo development The authors would like to thank Ms Colleen Shaffer for the preparation of bovine oocytes.


2019 ◽  
Vol 31 (12) ◽  
pp. 1862 ◽  
Author(s):  
N. A. Martino ◽  
G. Marzano ◽  
A. Mastrorocco ◽  
G. M. Lacalandra ◽  
L. Vincenti ◽  
...  

Time-lapse imaging was used to establish the morphokinetics of equine embryo development to the blastocyst stage after invitro oocyte maturation (IVM), intracytoplasmic sperm injection (ICSI) and embryo culture, in oocytes held overnight at room temperature (22–27°C; standard conditions) before IVM. Embryos that developed to the blastocyst stage underwent precleavage cytoplasmic extrusion and cleavage to the 2-, 3- and 4-cell stages significantly earlier than did embryos that arrested in development. We then determined the rate of blastocyst formation after ICSI in oocytes held for 2 days at either 15°C or room temperature before IVM (15-2d and RT-2d treatment groups respectively). The blastocyst development rate was significantly higher in the 15-2d than in the RT-2d group (13% vs 0% respectively). The failure of blastocyst development in the RT-2d group precluded comparison of morphokinetics of blastocyst development between treatments. In any condition examined, development to the blastocyst stage was characterised by earlier cytoplasmic extrusion before cleavage, earlier cleavage to 2- and 4-cell stages and reduced duration at the 2-cell stage compared with non-competent embryos. In conclusion, this study presents morphokinetic parameters predictive of embryo development invitro to the blastocyst stage after ICSI in the horse. We conclude that time-lapse imaging allows increased precision for evaluating effects of different treatments on equine embryo development.


2007 ◽  
Vol 19 (1) ◽  
pp. 203 ◽  
Author(s):  
A. Aroyo ◽  
S. Yavin ◽  
Z. Roth ◽  
A. Arav

Heat stress is a major contributing factor to low fertility among dairy cattle, as reflected by the dramatic reduction in conception rate during the hot months. The effects of thermal stress on oocyte competence and embryonic development have been well documented. However, timing of embryonic cleavage, which may be considered a parameter for the identification of good-quality embryos, and its association with elevated temperatures have not been studied. Two experiments were performed to examine and characterize seasonal effects (i.e. thermal stress) on cleavage timing of bovine parthenogenetic embryos. Oocytes were aspirated from ovaries collected at the local abattoir in 2 seasons: cold (Dec–Apr) and hot (May–Nov). Matured oocytes were chemically activated (ionomycin followed by 6-DMAP) and cultured in vitro; cleavage timing to the 2- and 4-cell stages was observed and documented. The one-way ANOVA procedure was used for statistical analysis. In the first experiment (n = 5416 oocytes), cleavage was documented at specific time points during development post-activation. The peak in embryonic development to the 2-cell stage was earlier (22 to 27 vs. 27 to 40 h after activation) and the cleavage rate higher (39 vs. 21%; P &lt; 0.0001) during the cold season relative to the hot season, respectively. Similarly, the peak in 4-cell-stage development was also observed earlier (46–52 vs. 52–70 h after activation) and corresponded with a higher proportion of developing embryos (33 vs. 21%; P &lt; 0.0001) during the cold season as compared to the hot season, respectively. These results indicate that embryonic development is delayed and a lower proportion of embryos cleaved during the hot season. To better understand the delay in cleavage timing, a second experiment (n = 308 oocytes) was performed through two consecutive hot seasons. A time-lapse system (EmbryoGuard; IMT, Ltd., Ness-Ziona, Israel) was employed to collect accurate data on the first cleavage division, known to be indicative of embryo quality. The time-lapse system was pre-programmed to take photos at 1-h intervals such that culture dishes did not need to be removed from the incubator. Similar to the pattern noted for the hot season in the first experiment, a wide distribution of cleavage timing (18-40 h after activation) was observed. Further analysis revealed that embryos cleaved in 2 distinct waves: cleavage timing of the first wave (18 to 25 h after activation) was characterized by a time frame similar to that in the cold season, suggesting good-quality embryos; however, the second wave, from 27 to 40 h after activation, presented a delay in cleavage timing, suggesting that these late-cleaving embryos are of inferior quality. Taken together, the results of the 2 experiments lead to the assumption that oocytes harvested from lactating cows during the hot season are of reduced developmental potential, which may be explained, in part, by the pattern of 2 cleavage waves. Furthermore, cleavage timing appears to be a good indicator of embryo potential and may increase the chances of selecting better in vitro-derived embryos during the hot season for embryo transfer.


2015 ◽  
Vol 27 (1) ◽  
pp. 210
Author(s):  
M. Taniai ◽  
M. Takayama ◽  
O. Dochi ◽  
K. Imai

Bovine IVF embryos are evaluated morphologically using light microscopy just before transfer. However, this evaluation method is subjective, and an objective method with more certainty is needed. Sugimura et al. (PLoS ONE 2012 7, e36627) reported a promising system for selecting healthy IVF bovine embryo by using time-lapse cinematography and 5 prognostic factors. This study was to investigate the efficacy of a 2-step evaluation system of IVF embryos using microscopy for selecting high developmental competence IVF embryos. Cumulus-oocyte complexes (COC) were collected by ovarian follicular aspiration (2 to 5 mm diameter) obtained from a local abattoir. The COC (n = 488) were matured in TCM-199 medium supplemented with 5% calf serum (CS) and 0.02 IU mL–1 of FSH at 38.5°C for 20 h in an atmosphere of 5% CO2 (20 COC 100 µL–1 droplets). After 10 h of gametes co-culture (5.0 × 106 sperm cells mL–1), the presumptive zygotes were cultured in 125 µL of CR1 aa medium supplemented with 5% CS in well of-the-well culture dishes (AS ONE, Japan; 25 zygotes well–1) at 38.5°C in an atmosphere of 5% CO2, 5% O2, and 90% N2 for 9 days. Two-step evaluations of embryos were done at 27 and 55 h post-IVF (hpi). In the first step of evaluation, cleavage patterns at 27 hpi were categorized as mono-cell, 2-cell with even blastomeres and without fragments (normal cleavage), 2-cell with uneven blastomeres, and ≥3 blastomeres. During the second step of evaluation, embryos were classified by their number of blastomeres (2 to 5 cells, 6 to 8 cells, and >8 cells) and the absence or presence of multiple fragments (<20 or >20%) at 55 hpi. The data were analysed by chi-square test. The blastocyst rate (BL%) of embryos cleaved before 27 hpi (56.6%, n = 106) was higher (P < 0.01) than those of embryos cleaved after 27 hpi (37.0%, n = 235). A greater percentage (P < 0.05) of 2-cell embryos with normal cleavage (68.0%, n = 50) developed to blastocysts than from with =3 blastomeres at 27 hpi (40.6%, n = 32). Superior BL% (P < 0.01) was obtained from embryos categorized as 6- to 8-cell stage (58.6%, n = 140) and >8 cell stage (70.6%, n = 25) compared with those embryos at the 2- to 5-cell stage at 55 hpi (26.1%, n = 176). Embryos with no fragments (58.0%, n = 467) had higher BL% (P < 0.01) compared with those with <20% fragments (30.7%, n = 127) and having with >20% fragments (17.5%, n = 25) at 55 hpi. The highest of BL% was observed in embryos showing a normal cleavage to 2-cells with at 27 hpi and having >6 cells with no fragments at 55 hpi (95.2%, n = 21, P < 0.01). These results demonstrate that the 2-step evaluation system at 27 and 55 hpi using microscopy is an effective method for selecting IVF embryos with high developmental competence.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Miao Zhou ◽  
Hui Zhou ◽  
Shu-yi Li ◽  
Yuan-ming Geng

Abstract Purpose Implant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro. Material and methods A total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad). Results In IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements. Conclusions Dental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.


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