implantation

Examples of implantation in the following topics:

• Clinical Advances in Bone Repair

  • For osseointegrated dental implants, metallic, ceramic, and polymeric materials have been used, in particular titanium.
  • To be termed osseointegration the connection between the bone and the implant need not be 100%.
  • When osseointegration occurs, the implant is tightly held in place by the bone .
  • In addition, the porous structure allows for soft tissue adherence and vascularization within the implant.
  • These materials are currently deployed in hip replacement, knee replacement, and dental implant surgeries.

• Implantation

  • In humans, implantation of a blastocyst occurs between 6 to 12 days after ovulation.
  • In preparation for implantation, the blastocyst sheds its outside layer, the zona pellucida, which binds sperm during fertilization.
  • The trophoblast will give rise to the placenta after implantation.
  • During implantation, the trophoblast differentiates into two distinct layers: the inner cytotrophoblast, and the outer syncytiotrophoblast.
  • During implantation, extensions of the trophoblast, the syncytiotrophoblasts, embed within the endometrium and form chorionic villi.

• Bone Grafting

  • The most common use of bone grafting is in the application of dental implants to restore the edentulous (without teeth) area of a missing tooth.
  • Dental implants require bones underneath them for support in order to have the implant integrate properly into the mouth.
  • In this case, bone can be taken from the chin, or from the pilot holes for the implants, or even from the iliac crest of the pelvis and inserted into the mouth underneath the new implant.

• Breast Augmentation and Reduction

  • Breast augmentation denotes the breast implant and fat-graft mammoplasty procedures for correcting the defects, and for enhancing the size, form, and feel of a woman's breasts.
  • The surgical implantation approach effects global breast augmentation using either a saline-filled or a silicone-filled prosthetic breast; and it might also consist of corrections effected with transplanted skin flaps.
  • In breast reconstruction practice, the tissue expander is a temporary breast-implant device used to prepare the implant-pocket (recipient site), as part of a staged reconstruction mammoplasty procedure.
  • In non-implant breast augmentation practice, some fat-graft injection approaches feature tissue engineering, which is the pre-operative external tissue expansion of the recipient site.

• Fertilization

  • If pregnancy is considered to begin at the point of implantation, the process leading to pregnancy occurs earlier as the result of the female gamete, or oocyte, merging with the male gamete, or spermatozoon.
  • The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete until implantation occurs.
  • Nondisjunction during the completion of meiosis or problems with early cell division in the zygote to blastula stages can lead to problems with implantation and pregnancy failure.
  • The sperm and ovum unite through fertilization, creating a zygote that (over the course of 8–9 days) will implant in the uterine wall, where it will reside over the course of 9 months.

• Ectopic Pregnancy

  • An ectopic pregnancy is implantation and development of the embryo outside the uterus, typically in the fallopian tubes.
  • An ectopic pregnancy, or eccysis, is a complication of pregnancy in which the embryo implants outside the uterine cavity.
  • Most ectopic pregnancies occur in the Fallopian tube (so-called tubal pregnancies), but implantation can also occur in the cervix, ovaries, and abdomen.
  • This intratubal bleeding hematosalpinx expels the implantation out of the tubal end as a tubal abortion.
  • The pain is caused by prostaglandins released at the implantation site, and by free blood in the peritoneal cavity, which is a local irritant.

• Uterine (Menstrual) Cycle

  • During the menstrual cycle, the endometrium grows to a thick, blood vessel-rich tissue lining, representing an optimal environment for the implantation of a blastocyst upon its arrival in the uterus.
  • After ovulation, under the influence of progesterone, the endometrium changes to a secretory lining in preparation for the potential implantation of an embryo to establish a pregnancy.
  • If a blastocyst implants, then the lining remains as the decidua.
  • If implantation does not occur within approximately two weeks, the progesterone-producing corpus luteum in the ovary will recede, causing sharp drops in levels of both progesterone and estrogen.
  • High estrogen and progesterone levels stimulate increased endometrial thickness, but following their decline from a lack of implantation, the endometrium is shed and menstruation occurs.

• Artificial Pacemakers

  • Some combine a pacemaker and defibrillator in a single implantable device.
  • Device replacement is usually a simpler procedure than the original insertion as it does not normally require leads to be implanted.
  • Sometimes devices resembling pacemakers, called implantable cardioverter defibrillators (ICDs), are implanted.
  • Right atrial and right ventricular leads as visualized under fluoroscopy during a pacemaker implant procedure.
  • Identify the function of artificial pacemakers that are implanted in the heart

• Bilaminar Embryonic Disc Development

  • In humans, the formation of the embryonic disc occurs after implantation and prior to embryonic folding (between about day 14 to day 21 post-fertilization).
  • As the embryo progresses in implantation, a small space appears in the embryoblast and forms the amniotic cavity.

• Arthroplasty

  • This can lead to damage to surrounding bone and contribute to eventual failure of the implant.
  • These include ceramics and all-metal implants (as opposed to the original metal-on-plastic).