Dentists extract teeth for many reasons, but by far, the most common is that the patient is in pain and wants to relieve the pain as quickly, permanently and as inexpensively as possible. This does not mean that there are not other ways of relieving the pain. But the other methods are likely to be more expensive or inconvenient. Other reasons are:
The patient may choose extraction because the other alternatives are simply too expensive.
The dentist may decide that the tooth is not repairable, or may be impractical to repair under the circumstances, and extraction is the best of a bunch of bad alternatives. This includes teeth that are decayed below the gum line, or teeth that have lost too much bone due to periodontal disease.
Removal of the tooth may be a matter of health. This is the case in the decision to remove impacted wisdom teeth, teeth associated with cysts or tumors, or teeth that would otherwise compromise the patient's oral health if left in place. In some instances, an infected tooth can even bring a patient close to death by causing swelling that can stop breathing or initiating a brain abscess.
Teeth are frequently removed because they are crowded and their removal would create a situation which could be repaired in their absence. Orthodontists request extractions to give them more room to move teeth around. Dentists sometimes remove crowded front teeth and replace them with bridges, removable partial dentures or implants.
This x-ray shows a dark crescent in the root toward the right side of the film. This is decay, and it has reached the nerve. A cavity in this position cannot be filled without touching and killing the nerve necessitating a root canal which is an expensive procedure. Furthermore, the tooth has severe bone loss from periodontal disease. Thus the most expedient thing to do was to extract it.
The tooth above was extracted because of gum disease. The dark material on the root is not decay. It is calculus (hardened plaque) which built up on the root because the bone has been reabsorbed by the body below that point. If the root had been surrounded by bone, as it would in the healthy state, plaque could never have reached this far down on the root surface. This tooth was loose because, as the x-ray shows, only the very tip was held in place by bone. Click on the left-hand image above for more information about the root of a tooth extracted because of gum disease.
A Simple extraction is one in which the dentist can remove the tooth simply by loosening the gums around it, grasping the crown above the gum line with a plier-like forceps and then moving it side to side until it loosens from the bone. Teeth are normally held into the bone by a thin sheathe of soft tissue that separates it from the bone like a sock separates a foot from a shoe. This sheathe is called the periodontal ligament, and it is this structure which ultimately enables the dentist to remove the tooth. The key to simple extractions is to rock the tooth side to side slowly enlarging the socket in the bone while at the same time breaking the ligament which binds the tooth in the socket.
Unfortunately, not all extractions can be done by simply grasping the tooth with forceps and rocking it out. What if there is nothing left above the gum line to grasp? Or what if the crown breaks off leaving the roots still in the bone? These things can and do happen, and any dentist that extracts teeth will have to deal with them routinely. In these cases, it becomes necessary to surgically remove the tooth. This is frequently accomplished by prying the root out using a sharp instrument that can be forced between the root and the bone surrounding it. This technique is called "luxation". In the case of multiple rooted teeth, the roots are first separated so they can be removed individually. Unfortunately, not all roots or root fragments may be removed in this fashion. This means that the dentist must make an incision into the gums around the tooth and raise a flap of tissue exposing the tooth and its surrounding bone.
Sometimes, after the flap is raised, there is enough tooth exposed to grab and remove it as in a simple extraction (#1 above). Sometimes, the technique described above as luxation may successfully remove the tooth. If luxation fails, the dentist must take a handpiece (drill) and cut away some of the surrounding bone in order to gain a purchase on the tooth. After the tooth has been pried out of the artificially enlarged socket, the dentist then sutures (sews) the flap of tissue back in place so that healing can proceed normally.
When a tooth does not fully erupt into the mouth, but remains below the gums, it is said to be impacted. Impacted teeth can present special health problems for most patients, and they are generally removed to prevent future difficulties. The extraction of such teeth proceeds like the surgical extraction explained above with a few modifications. Sometimes, the only surgical procedure is the raising of the soft tissue flap. If after raising the flap, the extraction can proceed as a simple extraction, the tooth is said to be a "tissue impaction" because there was enough of the crown left above the bone to grab and extract with forceps.
But many times the crown is submerged below the level of the bone. The tooth may even be lying on its side under the bone which complicates the extraction further. In these cases, not only must the dentist remove surrounding bone in order to expose the tooth, but he must cut and break the tooth itself into sections so that each section can be removed separately. Teeth in this condition are said to be "bony impactions" and are further classified as vertical, horizontal or angular depending on the angle of the tooth under the bone.
When a tooth is extracted, the hole left in the jawbone is called a socket. Left alone, the socket fills with blood which clots and helps to form a matrix for healing. After this happens, a sort of race begins. Cells called osteoclasts and osteoblasts begin to infiltrate the clot and begin the process of remodeling the socket and building bone from the bottom up in the space formerly occupied by the tooth. At the same time, epithelial cells from the inside of the mouth begin to infiltrate the clot from the top down and begin to fill the socket with soft tissue. In the end, over a period of a year or so, the socket heals over having lost between 50% and 75% of the height it would occupy if the socket had filled entirely with bone. This process, carried out tooth after tooth, over the course of a lifetime causes the jawbone to atrophy (wither away), making it more and more difficult for the patient to wear full dentures. To learn more about the process of bone atrophy after extractions, click on the toothless skull above.
Until fairly recently, this process was impossible to stop. The jawbone would begin to atrophy as soon as the first tooth was extracted, and the process continued on and on until by the time a person reached late middle age, a person who had lost all their teeth would find that wearing their denture could be next to impossible.
Today, things can be different, and the bone loss from tooth extraction can be prevented. This is done by the dentist at the time of the extraction. For an extra fee, the dentist can place one of three fillings into the socket which prevent the epithelial cells from the inside of the mouth from populating the socket, and encourage the osteoclasts and osteoblasts to rebuild bone in the entire socket.
When a tooth is extracted, it is possible to replace it with an artificial tooth root called an implant. An implant is the most expensive form of socket preservation, but it is always considered the best thing to do after extracting a functioning tooth. The implant may be placed at the time a tooth is extracted. The dentist drills a perfectly shaped and sized hole in the empty socket, and screws a titanium "root" into it. This implant is then covered by suturing the gums over it, and allowed to heal for about six months. At the end of the healing period, the dentist uncovers the implant and attaches an abutment to it. The abutment sticks up out of the gums and serves as an anchor for a crown. This combination of implant, abutment and crown serves as a very firm and permanent tooth. With good hygiene, a crown/abutment placed on an implant can last as long as a healthy natural tooth.
The popularity of rootform implants is growing at an exponential rate. It is beginning to become popular to extract seriously damaged teeth that were formerly restorable and replacing them immediately with implants which have better long term prognoses. Implants have the additional benefit of not being susceptible to decay like a natural tooth.
Bone grafts are the best non-implant form of socket preservation. Bone grafts are very effective at preserving bone height, and they also create more bone for an implant later on. Bovine (cattle) bone is processed in such a way that all protein is removed leaving only the hydroxyapatite component. This is freeze dried and sold to the dentist as a coarse, granulated powder. The dentist mixes this powder with the patient's blood and forces it into the socket immediately after the tooth is extracted. The mixture is held in place either by tightly suturing the gums over the socket, or by suturing a collagen membrane over it. Over the course of six months, the patient's body resorbs the artificial bone and replaces it with his or her own. A bone graft is nearly 100% effective at preserving bone height. Click on the toothless skull above to read about bone grafts and collagen plugs in more detail.
Collagen is a component of connective tissue. The dentist places a sponge like material made of specially processed bovine collagen into the socket and sutures it in place. A collagen plug is a good deal less expensive than a bone graft, and the procedure for placing it is easier. This procedure generally preserves between 60% and 80% of the original bone height.Note:
Each of these methods of socket preservation are also effective in preventing dry sockets!Content for class "CenteredWhiteDiv60pct" Goes Here
A bacterial infection any place in the body causes a localized inflammatory reaction. Inflammation is characterized by four things: swelling, pain, heat and redness. An abscess is an inflammatory reaction surrounding a localized pocket of pus. When a localized inflammatory reaction happens in most areas of the body, it is not generally immediately life threatening, however when it happens in the lower jaw, the resulting swelling can place increasing amounts of pressure on the internal structures of the floor of the mouth, throat, and neck. This includes the trachea (windpipe). If the swelling becomes too severe, the trachea can become so severely constricted that the patient is unable to breathe, and may consequently die. Prior to 1942 when penicillin was first marketed (it was discovered in 1928, but not available to the public until 1942), this was a very common cause of death in persons of all ages. In 1836, a doctor named Wilhelm Frederick von Ludwig was the first to describe this condition as a scientific entity, and it was named Ludwig's angina in his honor. The term angina comes from the Greek word "ankhon", and means "strangling".
Upon occasion, especially in the case of an untreated abscess of an upper front tooth, the patient can get a brain abscess which can kill him. This brain infection is called cavernous sinus thrombosis. Click the image to the left to see my page explaining the mechanics of cavernous sinus thrombosis and its relationship to the "dangerous triangle".