Rejection occurs when it is "easier" for your body to push the piercing out like a splinter than to heal a fistula (skin tunnel) around it. Rejection is most common with a surface piercing. We consider navel and eyebrow piercing as a surface piercing. Rejection can be affected by placement, blood flow, and irritation. However, abuse of the piercing area and your general health play the largest part. The healthier you are, and practice good hygiene, the less likely you are to have problems.

All the above considered, you could have everything done right, and the body still rejects the jewelry. You may want to re-pierce after healed with a higher grade metal like titanium or good gold.

The helix piercing is any piercing through the rim of the cartilage. You absolutely want this done by Professional Piercer, NOT A GUN. Piercing guns have been shown to be capable of causing cartilage to shatter, or at the very least crack. The solid stud used in gun piercing causes an entrance and exit wound like a gunshot. The picture here shows a proper piercing done with a special piercing needle, and the bump above the piercing is the scar damage left behind by a gun job.

An industrial piercing is two or more piercing connected by a single barbell. In normal usage it refers to an ear piercing whereby two helix piercing are connected by a single straight (or curved) barbell.

This piercing was first named by Erik Dakota in Body Play magazine #4 (1992), where it was pictured and titled, "Industrial Ear Project."

Most industrials are a straight bar connecting two helix points. These also can be done from any creative connection of the rook to helix piercing or inner or outer conch piercing, etc. another common industrial piercing includes the navel industrial, where the top of the navel rim is connected to the bottom navel rim piercing.

Placement:
The tongue piercing is generally placed centrally, and at a slight angle from front to back, through the body of the tongue. As long as the two main veins at the bottom of the tongue are avoided, the tongue can be pierced as creatively as you like. These could include tongue orbitals, venoms, and other surface piercing. A related piercing includes the tongue web piercing; this crosses the web beneath the tongue.

Healing and aftercare:
For the most part, the mouth tends to heal quickly. When a tongue piercing is first done, swelling will most likely occur. This can last as little as a few hours, or as much as a week. Some people experience no measurable healing discomfort, others may take as long as a month to go through the stages. Regardless, the discomfort is minimal. We may need to have you re-size to a longer bar during the healing time. Start out by calming the tongue with ice chips. Each time you eat, drink, or smoke, you need to rinse with mouthwash; better to not smoke for a while. If you follow the icing and mouth care instructions, you can reduce swelling to a minimum.

Long term health issues:
Virtually no infection or risks are directly related to the piercing. However, tooth chipping with some jewelry can happen. The risk of chipped teeth can be almost totally eliminated by wearing properly sized jewelry, and being mindful of your new pricing.

In the event of an unrelated emergency, some doctors who are inexperienced in dealing with a mouth piercing, are delayed if trying to insert a breathing tube.

It is important to note, the tongue piercing is an easy way to transmit STIs through unprotected oral sex, especially during healing.

In North America, body jewelry and needles are commonly identified by their gauge, using the American wire gauge system. This is in reference to the outer diameter. Other regions simply use metric sizing. The larger the gauge, the smaller the diameter. Most body piercings are initially performed at between 18ga and 10ga depending on the piercing. In my opinion, anything larger should be stretched to its size to have more flesh around the opening. You will note there are gaps in the gauge system which is filled in by fractional and metric measurements.