Additionally, avoid using lotions, powder, or makeup around the area where the patch is or will be placed. Backup contraception
If someone chooses to begin with their patch change day as day one of their menstrual cycle, the patch is able to take effect in time to prevent ovulation (see Mechanism of Action below) and no form of backup contraception is needed at all. In the case that one wishes to begin using the contraceptive patch following a first trimester abortion or miscarriage, patch application can be done immediately afterwards. This can be considered the same as a day one start above, and no backup contraception is required. If a user chooses to begin with their patch change day as the first Sunday following day 1, it is necessary to use a backup form of contraception such as spermicide or condoms for the first week of patch wear. If the user is late placing her patch in the first week, or more than two days late placing the patch in the second and third weeks, they should apply the patch immediately, and then use a backup form of barrier protection for a week. Mechanism of action
Like all combined hormonal contraceptives, Ortho Evra / Evra works primarily by preventing ovulation. A secondary mechanism of action is inhibition of sperm penetration by changes in the cervical mucus.
A primordial cyst is a developmental odontogenic cyst. It is found in an area where a tooth should have formed but is missing. Primordial cysts most commonly arise in the area of mandibular third molars. Under microscopes, the cyst looks like an odontogenic keratocyst (also called a Keratocyst odontogenic tumor) whereby the lesions displays a parakeratinized epithelium with palisading basal epithelial cells. The term "Primordial cyst" is considered an outdated term and should be avoided. Most "primordial cysts" are actually Keratocyst odontogenic tumors (KOTs). References

Kahn, Michael A. Basic Oral and Maxillofacial Pathology. Volume 1. 2001.