Wisdom Teeth

Wisdom teeth are also known as the third molars. The first molars are the forward most molar that comes in around age six. The second molars are also called “the twelve year” molars and they come in around…..age twelve. The wisdom teeth are the furthest back in a normal set of teeth are also the last to come in. A general window of time for wisdom teeth to come in is between seventeen and twenty five. Most people have 4 wisdom teeth. Some can have 3,2,1 or 0. Less frequently, people can have more than 4.

Issues with Wisdom Teeth

While some people can live with wisdom teeth their entire lives with no issues, many people will have issues. It is important to understand your particular situation and the likelihood that there will be issues soon or much later in life. If it is decided that you would like to extract some or all of your wisdom teeth, it is much much better to extract them at a young age because your bone is softer which will allow the teeth to release easier and you will heal much more quickly and fully.

The most commonly recognized issue with wisdom teeth is if they are not coming in straight. They can be tilted and could damage neighboring teeth, remain submerged (impacted), or partially erupt into the mouth (partially impacted). Sometimes teeth remain impacted in such a way that the decision might be to leave them there. The main concern with leaving an impacted tooth is that the cells that form the “sack” in which the tooth forms are “epithelial” cells which can later begin to produce “keratin” which is the substance of skin and mucosa. If keratin production begins in submerged epithelial cells, the pressure of the produced keratin expands and this is called a cyst. It could be painful and could distort the area. This would normally require surgery to remove the tooth and cyst. Because this is not particularly common, sometimes teeth are left if the patient is older or if extracting the teeth have other risks: i.e. roots that wrap around a nerve or teeth that are so far submerged that a lot of bone would need to be removed to access the tooth.
Another major factor contributing to the ease or difficulty of an extraction is root shape. Short roots that merge together in a shape similar to an “ice cream cone” will not deform the bone and will come out easily and quickly resulting in a speedy recovery. Longer roots require more force but are generally not a big concern. Roots that flare out from each other can require that the tooth is divided into different pieces so that each root can emerge from its own path which is different from it’s fellow roots. Curved roots or roots that become thicker at the tip of the root will not fit through the hole in the bone formed by the upper root. Depending on the severity of the curve, sometimes bone has to be removed to allow for the tip to come out. Roots that curve around an important structure (i.e. the main trunk of the lower jaw nerve) could damage that nerve permanently if the relationship is not diagnosed accurately and the tooth is extracted. This would involve having half of the lower lip permanently numb. With the advent of 3D imaging and the increasing prevalence of this technology in dental offices (especially in specialist’s offices) this problem is becoming extremely rare. Should there exist a situation where a tooth needs to be extracted for pressing reasons, the roots are in an awkward position and the nerve of the tooth is still vital (alive), there is a procedure called a coronectomy where the top (crown) of the tooth is removed but the roots are left. Remarkably, this procedure has a predictable and high success rate.

Inflammation of the gums just behind the wisdom teeth is an issue that usually manifests early on. When the wisdom tooth never erupts enough to fully emerge from the gums and a small portion of the gums actually remain on top of the tooth, this tissue is given a special name, an “operculum”. Operculums are very easy to irritate when food is crunched down on top of them or if food remains under this loose tissue behind the tooth causing an infection. If the operculums become repeatedly inflamed and problematic, they are removed “operculectomy” or the wisdom teeth are removed.
Probably the least commonly diagnosed issue associated with wisdom teeth is cleansability. In order to properly clean around any tooth, a toothbrush should be able to go past the tooth to some degree and to access a tooth that has fully erupted in order to clean the entire surface. The problem with lower teeth is that the jaw bone begins to rise and this can limit how far back a toothbrush can go, and oftentimes, these teeth are not fully erupted. With the upper wisdom teeth, the upper part of the lower jaw will swing forward as your jaw opens and will often move to a location close to the cheek side of the tooth. One remedy for this is to close half way and shift your chin to the same side that you want to brush which will tend to guide this part of the jaw bone away from the tooth. When jaw joints are young and undamaged, this is often not a problem. As we get older and many people sustain jaw joint issues from wear and tear, trauma from an accident, trauma from night time grinding or other issues, this shifting can sometimes be more difficult. In addition, most people do have some areas of oral home care that are lacking anyway so why not simplify matters early on. It seems to me that people with more cleansable teeth will have less cavities and less gum disease (gum disease is now linked to many system health issues). Therefore, unless someone truly has a jaw size that accommodates the wisdom teeth in a predictably cleansable arrangement, I normally recommend extracting wisdom teeth early.

When should wisdom teeth come out?

As discussed previously, younger bone is “spongy” and can be disformed to allow the teeth to release more easily. Younger bone also has a better blood supply and in general will heal faster and more fully. I used to tell people that an ideal age was between 18-22 years of age. Here are some other considerations:

As the roots of teeth form, rather than the roots moving downward, the top of the tooth is pushed up. There are situations where it is advantageous for the tops of teeth to push through the bone and therefore less bone is removed which in general means less discomfort after the procedure.
Converse to this is a newer trend to take out some teeth before the roots fully form. Because the shape of the roots and their proximity to other structures can complicate an extraction (as described several paragraphs up), we are seeing a trend to extract some teeth at about 16 years of age.

What types of imaging are used:

Let’s begin with a brief description of the various imaging techniques:

The smaller, individual x-rays that we are most familiar with are called “bite wings” or “PAs”. PA stands for Peri Apical which is Latin for “around the tip of the root” and bitewings typically image the top of the upper and lower tooth at the same time. Both bitewings and the PAs are two dimensional views. In two dimensional views, if a root curves to the right or left, we can see that but if it curves toward or away from you, you might not be able to know what the shape truly is.
A “panoramic” x-ray is a larger view that will encompass the entire upper and lower jaws and will nicely display the relationship of teeth to each other and to some structures of importance. The machine used to capture this type of view will typically rotate around the patient’s head. For many years, these were the preferred views by oral surgeons and are still common today. These are also two dimensional “2D” views which have limitations.
“Cone beam”, CAT Scan, CT scan or 3D scans are terms which are all used to describe an image that provides a 3 dimensional rendering of a tooth or structure. Initially, these machines were very expensive and there was concern over an increased amount of radiation needed to capture these images. In the last 5 years or so, the amount of radiation needed has come way down as has the price. The procedures which benefit the most from the use of such scans include extractions, jaw surgeries, implant placements and root canals. 3D technology continues to expand into other phases of dentistry.

When would local anesthetic be sufficient and when would nitrous oxide, oral sedation, i.v. sedation or general anesthetic be advantageous?

This is definitely a multi pronged question. Some people might require a higher level of dissociation than others just because of their anxiety. First I will give a brief description of each technique and then I will give common scenarios:

Local Anesthetic: Commonly called Novocaine (novocaine has not been used in many years due to a significant percentage of people being allergic to it), this refers to injections of anesthetic (commonly Lidocaine, Septocaine, Articaine, or others) which will provide a numbing anesthesia to an area of tissue but will not relieve any anxiety.
Nitrous oxide (Laughing Gas): This is administered as a mixture of Oxygen and Nitrous Oxide and has a wonderful euphoric effect for most but not all people to reduce anxiety but does not have a significant anesthetic effect. In dentistry, local anesthetics are frequently used in addition to Nitrous Oxide.
Oral Sedation: This refers to taking medications by mouth such as Valium or other sedating medications as single medications or as a grouping of a few medications.
I.V. Sedation refers to administering sedative medications through an I.V. (Intravenous) line directly into your bloodstream. One of the benefits of an I.V. route is that if there is an adverse reaction to a medication, many of those medications will have a reversal agent which can then be administered directly into the existing I.V. line. Typically, patients under I.V. sedation are awake and responsive although they will not remember anything at all. If a doctor asks the patient to open, the patient will understand the request.
General Anesthesia refers to someone who is truly asleep and unresponsive. Often, they are not breathing on their own and a machine is breathing for them. Almost always, these cases are performed in a surgery center or hospital with a designated anesthesiologist attending the patient’s anesthesia needs and the surgeon is focusing on the surgery.

When to choose a general dentist for a procedure and when to choose an oral surgeon.

There is no easy answer here. I have known some general dentists who had the training and experience to perform more complex oral surgery procedures competently and who were comfortable and experienced administrators of oral sedation or I.V. sedation. I am also familiar with dental anesthesiologists who will perform I.V. sedation in a general dentist’s office. For the most part, dentists will try to predict whether a procedure is within their comfort level and refer other procedures to a specialist. You as the patient have the ultimate decision whether or not to follow the suggestion of your dentist. Feel free to ask for a referral to a specialist if this will make you more comfortable or, you can seek a second opinion. Ideally, it would be nice to have a trusting relationship with your general dentist that is based on mutual respect. It is important to be able to have open and comfortable communication with all health care providers.