The Purpose of the Teeth
Teeth start their journey while the baby is in utero. Their shape is formed during this initial stage, and their morphology evolves. Once teeth erupt through the gums, they serve many purposes besides forming the foundation of a pleasant smile. They are used for mastication so food may be digested, give the mouth its shape, assist with talking, and are important to a person’s overall health. Teeth are diphyodont. This term means that people will have two sets during their lifespan—baby or deciduous teeth and adult or permanent teeth. The initial set of teeth is not visible or functional at birth. While they are present in the jaw, they only begin to erupt through the gums between six months to one year of age. They will end their journey by forming two rows of ten teeth on the top and bottom of the mouth. Eventually, thirty-two permanent teeth replace the deciduous teeth and have different shapes and functions, with structures becoming visible by age three.
Anatomy of Teeth
Parts of a Tooth
Every tooth has a designated construction with a characteristic makeup. Anatomically, teeth consist of three parts: the crown, neck, and root. Our analysis will begin by looking inside the mouth. The visible aspect of the teeth not covered by the gums is the anatomical crown. Like an iceberg, only part of the structure is visible. Lurking below the surface is the root which anchors the tooth into the jaw or alveolar process. The root is the largest part of the tooth and makes up about two-thirds of the structure. The number of roots vary from one to three, but their purpose is to anchor the teeth in place. As a rule of thumb, “[I]ncisors, canines, and premolars will have one root whereas molars will have two or three.”
The neck or dental cervix is the anatomic designation for the part of the tooth that separates the crown from the root. However, there is a lot more to the structures than these three parts so let us drill down to expose the various aspects of the teeth in more detail.
Types of Dental Tissue
Teeth consist of four types of dental tissue. There are three hard tissues; enamel, dentin, and cementum. The last type is the pulp. This multifaceted tissue includes nerves, blood vessels, and connective structures.
Enamel
Enamel is the thin white covering of the tooth. Its main task is to form a protective casing to prevent decay. Enamel is the hardest element in the body and is stronger than iron and steel. In this way, it shields the tooth from distress when eating or consuming hot or cold substances. This complex element is primarily formed from calcium phosphate. Nevertheless, teeth are susceptible to breaking, trauma, and disease. Once they are damaged, they have no inherent ability to regenerate because enamel consists primarily of non-living materials. This is why a damaged tooth can be painful or subject to decay.
Enamel varies in size and is the thickest over the biting and chewing edges of the tooth. Microscopically, it consists of an array of tiny rods that are positioned parallel to each other with the inner part communicating with the dentin, or surface just under the enamel, and the outer portion forming the surface of the tooth. Symptoms generated by enamel erosion include increased sensitivity to hot or cold, discoloration caused by the undersurface of the tooth being exposed, and fractures, indentations, or chips in a tooth’s outer surface.
Dentin
Dentin constitutes the bulk of the tooth and is the middle avascular layer of the structure. It is fashioned from the odontoblasts of the pulp’s uppermost coating. It is softer than enamel, thereby helping the tissue absorb the impact from chewing. Its color varies from grey to black but is usually a yellow hue. Dentin supports the enamel that makes up the outer surface of the tooth and offers a hard shell for the internal pulp and the tooth’s roots. This mineralized layer grows slowly during the life of the structure. Dentin has regenerative powers that allows its tissue to be replaced if it decays.
Contained within the dentin are minute channels; dentinal tubules. These structures are aligned parallel to each other and abut the enamel at the top of the tooth and the pulp on the inner side. In turn, this tissue includes cells and fluid that provide the dentin with some absorbency which can intensify painful sensations and quicken the advancement of decay.
Cementum
Cementum is a connective tissue that forms the third layer of the tooth. It allows the periodontal ligament to attach to the tooth and is located within the gum’s socket. Along with other structures and tissues, it helps hold a tooth in place. Cementum grows slowly and is formed when the root of the tooth emits cementoblasts. Chemically, it is like bone but has no blood supply.
Pulp
Pulp is the last layer of the tooth and forms the nerve center of the structure. It resembles jelly and consists of nerves and blood vessels that nourish and provide feeling to the structure. It can be found within the central space of a tooth: the pulp’s chamber. Pulp, which is also known as the endodontium, creates the dentin layer of the tooth and provides nutrients to the structure. Because it is the nerve center of the tooth, it is the main generator of tooth pain.
The pulp reacts to cold or hot stimuli, and dispatches signals to the brain similarly to how the sensory nerves of the body operate. The pulp also bathes the dentin, permitting it to maintain its pliability. However, if bacteria circumvent the dentin and enamel and makes its way to the dental pulp, pulpitis develops causing inflammation to the area. The dental pulp is filled with nerve fibers that allow a person to sense damage to a tooth as well as alterations in temperature or pressure. These nerve fibers send the sensory signals to the trigeminal nerve. This cranial nerve transmits “pain, touch and temperature sensations from your face to your brain.”
Anatomically, the root of the tooth mimics the bottom of an iceberg. It is below the gum line and anchors the tooth into the jaw or alveolar process. The number of roots assigned to a tooth varies from one to three, and these anchors are always more prominent than the visible aspect of the tooth.
Surfaces of the Teeth
Dentistry has coined its own terms, so it is helpful to understand some of these words. In medicine, lateral refers to the outside and medial describes the inside aspect of a body part or location. Dentists do not describe the teeth in this manner. Instead, surfaces are referred to as facial and lingual. A facial surface describes an area closest to the cheeks. Lingual depicts something closest to the tongue.
The teeth in the rear of the mouth are posterior, while those in the front are incisal. In turn, occlusal surfaces are those areas devoted to chewing. Cervical surfaces are where the crown and root meet, while apical surfaces are situated close to the top of the root. In anatomy, proximal and distal explain something closer to or away from a body part. Dentists will employ the term “mesial” to discuss something closer to the middle of the face, and distal refers to an area further away. The ridges of teeth are elevations while a cusp refers to the mound on the crown aspect of the tooth.
Arches of the Mouth
Teeth are not aligned in a straight line. Rather, they enjoy a curved or “U” shaped appearance which allows the teeth to fit inside the mouth. These arches form the outline of the mouth and are known as the maxillary and mandibular arches. Most adults have sixteen teeth in both the upper and lower arches.
The maxillary arch forms the upper jaw. It contains two irregularly shaped bones in the face that provide the footing for the upper teeth. This arch links to the left and right cheeks or zygomatic bones. The rounded movable surface in the lower jaw is the mandibular arch. This bone is the largest in the face and holds the lower teeth in place. In a standard anatomical array, the upper arch is bigger than the lower one, and the upper teeth overlap the ones in the lower jaw. This arrangement allows for a proper bite.
Malocclusion refers to when the teeth in the upper and lower jaws do not align. An orthodontist is the specialist who treats this type of abnormality and usually employs braces and other appliances to correct the problem.
Tissue of the Mouth
It would be easy to refer to the pink-colored keratinized mucosa surrounding the teeth as gums, but the proper term is gingiva. These soft tissues line the mouth and act as a seal. Contrary to the tissues covering the lips and cheeks, gums are secured to the underlying bone. This attachment helps the gingiva reduce the friction caused by food passing over them. Gums play an integral role in supporting and maintaining the teeth in the mouth. In turn, the teeth are fastened to the jaw by periodontal ligaments. This soft tissue can be described as a “fibrous joint that anchors the root of the tooth to the alveolar bone socket.” These structures permit some minor movement of the teeth within the bones and allow for sensation when pressure is applied to the teeth. Healthy gingiva serves as a protective covering to the various periodontal insults that occur to the deeper tissues.
A dental professional may take “pocket depth measurements” of the gums. This procedure calculates the periodontal attachment to the teeth and bones to ascertain the extent of gum disease. Periodontal disease limited to the gums is gingivitis. However, when the condition becomes advanced, causing the gums to pull away from the teeth, bacteria can accumulate, resulting in an infection. This problem, which involves bone and tissue, is periodontitis.
Healthy people’s gums are pink and smooth. However, gingiva may be darker in people of color. In healthy individuals, an aperture is created, the gingival sulcus, which is one to three millimeters deep. Between each tooth, gums form a triangular peak called the papilla, which closes the opening between each tooth.
Permanent Teeth
A child will start to lose their baby teeth around six years of age. This process usually begins with the front teeth, and the remaining ones will follow from the front to the back. An exception is the top eye teeth which generally fall out after the first molars. Occasionally, the baby teeth do not loosen and may require extraction to make room for the permanent teeth.
Permanent teeth refer to adult teeth that are not uniform in shape, size, or function. They are classified as incisors, canine, premolars, and molars. These teeth erupt through the gums in the following manner:
- First molars: 6 years of age
- Central incisors: 7 years of age
- Lateral incisors: 8 years of age
- First premolars: 9 years of age
- Second premolars: 10 years of age
- Canines: 11 years of age
- Second molars: 12 years of age
- Third molars or the wisdom teeth: 17 to 25 years of age
This sequence of eruption is an approximation because every individual is different.
As for the teeth themselves, adults will have eight incisors, four in the upper and four in the lower quadrants. The central incisors are the teeth in the front and center of the mouth. They are thin and flat and are employed to tear food apart. The central incisors on the top and bottom of the jaw resemble each other but are different in size. The upper central incisors are broad and the most noticeable teeth in the mouth. In contrast, the ones in the mandible are narrow and slighter in stature. The next teeth on either side are the lateral incisors, which have only one root, and a sharp incisal edge. The adjacent tooth on either side as one continues around the jaw is the maxillary lateral incisors. This arrangement is followed by the canines or cuspids. These corner teeth, which are also called eye teeth, look like fangs. They are the most prolonged and stable teeth in the mouth. An individual will typically have four such teeth, two in the upper and two in the lower jaw. Generally, the cuspids are the last teeth to protrude through the gums, a process that usually occurs between the ages of 1 and 13.
In between the cuspids and the last teeth are the premolars. Also known as bicuspids, these structures are transitional teeth. The enjoy the characteristics of both molars and canines. Their function is to grind and break down food.
The remaining teeth consist of twelve large molars whose job is to grind food. Therefore, they have a wider surface than the other teeth. The molars in the upper jaw are the maxillary molars because of their position in the maxillary bone. Those in the lower jaw are the mandibular molars. The last molar on each side of the jaw are wisdom teeth, totalling four such structures. At one time, wisdom teeth served a useful function. The diets of our primitive ancestors relied upon raw plants, hard nuts, and tough meats for nutrition. These teeth were needed to grind these matters for digestive purposes. Current food processing and eating instruments have made wisdom teeth obsolete. Those teeth are extracted when they have insufficient room to grow or if they are impacted even if asymptomatic.
Numbering System
Many patients recognize teeth by their names like molar, incisor, or canine. However, dentists classify teeth differently. They assign a number to each tooth. This provides a simple and exact way for identification, the transmission of information, and dental record maintenance. A numbering system also assists in labeling and classifying dental issues involving a specific tooth clinically and radiographically.
Various systems exist for numbering the teeth. The American Dental Association Universal Numbering System has been adopted in the United States. The International Standards Organization System is employed in most other countries. The Universal Numbering System assigns a number for each permanent tooth from 1 to 32. However, these numbers are allocated from the perspective of the dentist viewing the oral cavity, “clockwise starting from the distal-most right maxillary teeth.” A limitation is that no consideration has been made for individuals with extra teeth.
The teeth are numbered one after another, beginning with the third molar in the back right side of the upper jaw. This tooth is assigned the number 1. This enumerator continues around the maxillary arch until it reaches the last molar on the left side, which is given the number 16. The same process is followed in the mandible, where the last tooth on the right-hand side is numbered 17. The teeth are then assigned a sequential number until the last molar is reached on the bottom left, which is assigned the number 32. To provide an example, the wisdom teeth are labeled 1, 16, 17, and 32. The canines are numbered 6, 11, 22 and 27.
Periodontium
Teeth are anchored into the jaw to provide them with a solid foundation. The teeth in the maxilla are sheathed in bone that has large spaces. This support mechanism is called cancellous bone and can withstand significant pressure but is softer than the other bones in the mouth. The mandibular consist of compact bone that is highly dense and able to withstand even greater stresses.
The periodontium is the soft tissue that acts as the interface between the jaw and mouth. This anatomical part refers to specialized tissue that assists in attaching the teeth firmly to the jaw. The periodontium is connective tissue made up of four parts: cementum, the periodontal ligament, alveolar bone, and gingiva. This tissue is critical to the overall health of the teeth. The periodontium and bones serve as the underpinning for supporting the teeth, similarly to how a foundation supports a building. The failure of this support system can cause the loss of teeth, a process known as periodontal disease. The gingiva encases the tooth and is secured to the bone and cervical aspect of the tooth. In turn, the periodontal ligament, which consists of collagen fiber, serves as a shock absorber and secures the tooth to the alveolar bone. As noted previously, the cementum covers the tooth’s roots and aids the periodontal ligament’s attachment to a tooth.
In a healthy mouth, this place in the narrative could stop because the explanation would be sufficient. However, the mouth contains bacteria making the internal structures vulnerable to disease. More than 700 types of germs can be discovered in this orifice. Some are innocuous, while others are harmful and can cause cavities and disease. The ratio of these bacteria can change due to a poor diet, faulty oral hygiene, and other health issues. This alteration can permit harmful bacteria to take over. The result is halitosis, tooth decay, gum disease, and tooth loss.
Bacteria, acid, food, and saliva can also mix to form plaque. This sticky substance adheres to the teeth and back molars, just above the gum line, and at the edges of fillings making them susceptible to disease. If this substance is not removed, it is transformed into tartar or calculus. This development can irritate the gums, causing gingivitis and periodontitis.
Cavities are permanently injured areas in the hard surface of the teeth that create fissures or holes in the enamel or dentin. This development is one of the most frequent health difficulties around the world. If left untreated, cavities will enlarge and implicate the deeper strata of the structure. No one is exempt from tooth decay, and this disorder is linked to sugar, starches, and plaque.
The warnings and indications for cavities are diverse, based upon the extent and location of the problem. A person is often unaware that a cavity has developed since it is frequently painless and is discovered only on routine dental examination or x-ray. Several forms of cavities exist: root or coronal cavities, and recurrent decay.
If the cavity is left untreated, the person may develop an infection or abscess. This occurs when the nerve or gum becomes infected. The problem is generally associated with tooth decay, but trauma can also play a role. An accumulation of pus within the pulp may also ooze out through the nerve roots, causing pressure to build up under the tooth. These conditions should not be taken lightly because a severe infection can in rare cases lead to death.
Dental Trauma
Dental trauma encompasses many types of injuries to the teeth and mouth. It can refer to damage to the teeth, periodontal tissue, the bone that secures the teeth, or the soft tissue of the mouth, such as the lips and tongue. In fact, it is expected that about fifty percent of children will experience a dental injury during their youth. Various types of trauma can damage the teeth resulting in either tooth loss or the need to repair the damaged area. Examples include falls, which account for forty percent of all dental injuries, automobile accidents make up thirty-three percent, violence has a twenty-one percent rate, and occupational accidents account for five percent of these injuries.
Treatment depends upon the extent of the injury. It can differ from a simple filling to a complicated dental restoration involving a crown or tooth replacement. While most of these injuries are minor, such as a chipped tooth, the structures can also be loosened, knocked out, or broken so significantly that extraction is the only recourse. A gum laceration may compromise the tooth’s integrity, destroying the supporting structure. Damage to the bone is also a common cause of tooth loss.
Repair of Damaged Teeth
If a person sustains a dental injury, what might one expect to see by way of repair? The primary goal of the dentist is to save the tooth by restoration. This process is defined as the application of an artificial substance or structure to replace missing teeth or part of a tooth to safeguard the mouth’s ability to eat, chew, and speak. Available options include fillings, inlays, crowns, and bridges, a choice that will depend upon the severity of the injury.
Repair is usually the best choice for a tooth that has sustained a minor impairment, such as a small chip, surface anomaly, grooves, and tooth deterioration. A repair is undertaken because the tooth remains fundamentally sound and functions appropriately. The dentist has a variety of tooth restoration approaches to restore the structure to optimum fitness. These remedial measures include bonding, filling the tooth, composite or amalgam, and using a veneer or a crown, which is an artificial cap.
Teeth that have more significant damage—like a large crack, missing part, or progressive tooth decay—may no longer be fundamentally sound, so it is prudent to extract the tooth and insert an artificial tooth or bridge. An implant is mandated if allowing the tooth to remain would trigger the spread of infection or cause future problems. A bridge involves dental crowns connected in one continuous piece by artificial teeth. In turn, a false tooth or teeth will be anchored by crowns that have been cemented to the adjacent structure.
Endodontic Injury
Dental trauma can injure the nerves and blood supply with no visible injury to the teeth or supporting structures. In addition to blunt-force trauma, there is a link between a nerve injury and certain dental procedures such as tooth removal, numbing injection, intervention to revise the jaw’s shape, using dental implants, or fixing a broken jaw. Sample nerves that may be affected include the lingual, inferior aveolar, mental, and buccal nerves. While pain is the most common sign of a nerve injury, the person may also experience a lack of feeling, trouble speaking or masticating, drooling, tingling or pulling sensation, radiating pain, and an alteration in taste.
The primary purpose of dental intervention is to eliminate pain. Common remedies include pulling the tooth or root-canal therapy. The latter remedy is done to repair and save a tooth instead of extracting it. Initially, it must be noted that a root canal is an anatomical part of a tooth and not a procedure. It refers to the hollow part of a tooth that houses the nerves, blood vessels, and pulp.
Several steps must be taken to perform a root canal. The dentist starts by removing the pulp inside the tooth. The area will then be cleaned and disinfected. This is accomplished by employing very small files and irrigation materials. The canals of the root will then be shaped, and the tooth will be filled with a rubber-like substance to seal the space. Because the tooth is now frailer, a restoration may be used to cover the structure.
Repairing a Chipped or Broken Tooth
A tooth fracture can be remedied in various ways based upon the gravity of the break. The fissure may injure the enamel, cementum, dentin, or pulp. The cause of the injury is frequently a direct blow to the tooth, biting down on a hard object, or indirect trauma that is transmitted through the jaw. Fractures run the gamut, from a simple chipped tooth merely implicating the enamel or as complex as a division down the middle of the structure that spreads from the enamel to the root.
Filling
A chipped tooth involving a small aspect of the enamel may be remedied by a filling. However, the same type of injury to a front tooth has aesthetic implications, so the tooth should be bonded. This process uses a tooth-colored composite resin so that everything blends, making the repair invisible. Larger breaks mandate more extensive restoration. Inlays or onlays are artificial materials produced by a laboratory from precious metal such as gold or ceramic to restore and support the damaged tooth. If the fracture is extensive, a crown will be required. A crown must be made by a laboratory and can range in materials from cast metal to porcelain that is then fused to precious metal and finally covered in ceramic. A crown may also be made entirely of ceramic. The function of an artificial crown is to mimic the original outer surface of the tooth because the original area has been damaged by a fracture or decay.
Crown
A different remedy must be pursued if a large portion of the tooth has been lost or the structure has advanced decay. This presentation requires the dentist to file the remaining portion of the tooth and cover it with a crown. This is a tooth-shaped cap created to safeguard the tooth and enhance its appearance. This artificial structure is constructed from stainless steel, metals, porcelain, resin, and ceramics.
Several steps must be undertaken to complete this process. To accommodate a crown, the tooth will be filed down across the top and sides to provide space for the prosthetic. Following this tooth modification, a paste or putty is employed to create an impression of the tooth that will receive the crown. The replica will be a sent to a laboratory with a color specification to make the covering. This process takes a few weeks. In the interim, the dentist will create a temporary structure to cover the tooth. Once the permanent replacement is received, the patient will return to the office, the temporary cap will be removed, and the permanent crown will be cemented in place. It is anticipated that the crown will last up to fifteen years.
Tooth Extraction
Sometimes a tooth may not be saved, and extraction is the only alternative. Extreme tooth decay, trauma, infection, and crowding can necessitate tooth extraction. Chemotherapy and organ transplant may also require diseased teeth to be removed to maintain the mouth in a healthy condition. In any event, healthy bone should always be preserved to support any future restorative needs.
Tooth extraction may be done one of two ways. A simple extraction is like pulling a stake from the ground. It is nearly impossible to pull the stake straight out of the earth. Usually, it is essential to rock the stake back and forth to enlarge the space it occupies. Once the ground has been loosened, the stake can be extracted. Pulling a tooth involves a similar process. Following the introduction of a numbing agent, the tooth will be rocked back and forth to enlarge the socket that holds it in place. Simultaneously, the dentist will rotate the tooth to disengage it from the ligament that secures it to the bone. A special instrument, an elevator, is used to loosen the tooth, expand the space in the bone, and break the ligament that attaches the tooth to the bone. After the tooth has been dislodged, it is removed with forceps. Following the extraction, the dentist will place a gauze pad on the wound and have the patient bite down to help stop the bleeding. A blood clot will typically develop in the socket, and the healing process starts. Occasionally, it may be necessary for the dentist to stitch the gum to close the area over the extraction site.
If the tooth is impacted, the procedure may turn into a surgical extraction where the person is put to sleep. The dentist will then cut open the gum to expose the tooth and underlying bone. An extraction forceps will be used to grab the tooth and move it about to loosen it from the bone and attached ligaments. A tooth that will not release may have to be broken into pieces to accomplish its removal.
Bone Regeneration
Several causes are responsible for bone loss around teeth. It is a frequent occurrence with dental trauma, tumors, missing teeth, and gum disease. This development is consequential as the jawbone anchors the teeth. Advancements in technology offer several choices in remedying bone loss, including bone regeneration. If the constitution of the bone has been compromised, a membrane can be employed to promote bone growth, thereby returning the damaged area back to an acceptable level. This process is known as dental bone regeneration and involves bone grafting. Its purpose is to add bulk and thickness to the areas where bone loss has taken place. As an analogy, “a dental bone graft is like a scaffold on which . . . bone tissue can grow and regenerate.”
This procedure requires an incision in the gum to uncover the underlying bone. The area will be cleansed to remove any infection and graft material will be inserted. The transplant will be taken from another part of the body, from a cadaver, or synthetic material may be utilized. Once the graft is in place, a membrane to retard the downgrowth of the gingiva into the bone may be used. The dentist may also add platelet-rich plasma to the graft to encourage healing and tissue rebuilding.
Dentures
A denture is a removable substitute for missing teeth and adjacent tissues. These appliances come in two forms: complete and partial dentures.
Partial Dentures
Partial dentures may be used when at least one tooth is present in the upper or lower jaw. Partial dentures are available in various forms and qualities. The device, however, will consist of artificial teeth fastened to a pink-colored base. The partial denture usually is made from plastic or a combination of metal and plastic. This removable device may be equipped with clasps to secure the device in the person’s mouth.
Complete Dentures
The other type of removable appliance is the full or complete denture. This is a choice of last resort and requires all the teeth in the jaw to be eliminated. Complete dentures take up the whole mouth and cover the jaw areas and gums. These dentures can be fitted for the top or bottom gum line and are secured by suction and/or with oral adhesive. Dentures also prevent the facial muscles from sagging and help a patient’s ability to speak and eat. This appliance has a self-life of about seven to ten years.
Dental Bridge
A bridge is used if a person lacks one or more teeth. These missing structures create gaps ultimately triggering a shift in the remaining teeth, causing bad teeth alignment. The development may also cause gum disease and temporomandibular joint disorders. This type of prosthesis is called a fixed partial denture or bridge and can be utilized to “bridge” the gaps between lost teeth. A bridge offers an alternative to a partial denture.
Installing the device requires the abutting teeth to be prepared to receive the appliance that contains artificial crowns for the missing teeth. The bridge, which contains artificial teeth, is then anchored to the other teeth with cement or implants. These abutments anchor the bridge and are cemented in place. A replacement tooth, also called a pontic, is affixed to the crowns that encase the abutments. A bridge usually lasts ten years.
Dental Implants
Artificial teeth may be used to replace missing teeth without disturbing any other tooth in the process. This surgery substitutes tooth roots with screwlike posts and exchanges damaged or absent teeth with an artificial structure that resembles the original tooth. This process maintains the integrity of the surrounding teeth while providing an excellent fixed replacement. Artificial teeth are particularly beneficial when there are no back teeth since the person cannot use a removable denture given the lack of tooth support for a bridge. Since the screw fuses with the jawbone, the implant will not move or cause bone damage. This is a major advantage over a fixed bridge or denture. The surgery, however, does present some risk. This includes an infection at the implant location, damage to the surrounding structures, nerve damage, and sinus problems.
This process can take months to complete since the surrounding bone must integrate with the implant. If the bone in the jaw is too soft or not robust, a bone graft will be needed before the dental implant can be anchored in place. While a dentist may perform this procedure, an oral surgeon tends to be the most qualified.
Legal Consideration
Dentists are not immune from malpractice lawsuits. A dissatisfied patient may advance a claim even if the care rendered was proper. The National Practitioner Data Bank reported that 139,774 separate medical malpractice payments were made between 2010 and 2021and dental professionals accounted for 11.5% of the expenditures. These statistics do not reflect the number of claims advanced, lawsuits that were dismissed, or other incidents that may have mandated defense expenses. Common dental malpractice claims include the following:
- Incorrect tooth removals;
- Failure to diagnose dental problems like an infection or oral cancer;
- Lack of informed consent;
- The failure to correctly treat a complication;
- Not properly supervising an employee;
- Not referring the patient to a specialist; and
- Improper administration of anesthesia.
According to one source, patients received an average of more than $81,000 per dental malpractice claim, and the most common complaint focused on tooth extractions. Overall, there are 445 reported case in which an award or settlement was reached in excess of $1 million. The highest jury award located was rendered to a woman in Georgia in the amount of $10 million who suffered a permanent injury during a root-canal procedure. Demographically, the most common claimant is a female older than forty-five who is employed in a health-related field and uses dental terminology.
Most of the claims seek compensatory damages and include a request for pain and suffering damages and the cost of dental treatment related to the injury. Disability claims for dental injuries seldom arise and the AMA’s Guides to the Evaluation of Permanent Impairment does not address the issue as a separate topic. Instead, teeth are discussed in a cursory fashion under “Oral Region” along with the mouth, tongue, hard and soft palates, the palatine tonsil, and oropharynx.
Informed Consent
Informed consent imposes on a health care provider the duty to provide the patient with the necessary information to make an informed and knowledgeable choice on whether to undergo a suggested treatment or operative intervention. Informed consent is part of the fabric of American jurisprudence and denotes “the right to bodily integrity.” The tenet is premised on shared decision-making and was created to help counteract the imbalance of power in the doctor-patient relationship. “[R]equiring physicians to provide more information to their patients . . . help[s] to redress the power imbalance problems created by the inequality of knowledge.”
Informed consent is not a legal requirement that immediately springs to mind when a patient obtains dental care. However, “a dentist owes the same duty to a patient as a physician owes to a patient.” As noted by the Honorable Richard B. Klein, a Pennsylvania appellate and trial judge,
I have handled dental malpractice cases as part of the general medical malpractice docket. Dentists are medical professionals just as much as doctors. Often the issue is whether there was dental malpractice or whether the condition was such that it just could not be fixed. And often, the issue is that the plaintiff let a bad condition go on too long. Some of this occurs in “normal” malpractice cases, but it may occur a little more in dental malpractice cases.
In Cole v. Tischler, the court opined that a claim premised upon a lack of informed consent mandates proof that (1) the dentist failed to inform the patient of the options and reasonably foreseeable risks and advantages to the treatment that an average dental professional would divulge in like situations to allow a knowledgeable evaluation; (2) a reasonably prudent person would forgo the treatment if fully informed; and (3) the lack of information was a proximate cause of patient’s harm. Cole v. Tischler involved a plaintiff who underwent a bilateral sinus lift and bone graft to lay the foundation for dental implants. Subsequently, the plaintiff developed a staph infection, which the dentist treated with antibiotics. It was admitted by the parties that the medication was the proper protocol. The drug was partially successful, but it did not completely eliminate the infection. Six weeks later, the plaintiff was hospitalized with osteomyelitis and had to have the bone graft removed.
A lawsuit was filed against the dentist, alleging that he was negligent and failed to obtain the patient’s informed consent. The facts revealed that the plaintiff was a nursing student and signed a consent form admitting her understanding of alternative procedures and acceptance of the risks. These dangers included infection and graft rejection. The student had attended a talk given by the dentist on implants, frequently consulted with the defendant, and acknowledged that she read and understood the consent form. The patient also consulted with a specialist in dental implants who told her that she was a suitable candidate for the procedure. Nevertheless, the student maintained that the defendant misrepresented the dental implant risks by comparing it to the dangers associated with a tooth removal. However, no proof was provided by the patient to support this allegation. The court found that no issues of material fact existed on the informed consent claim and dismissed that allegation but determined that factual issues barred a summary judgment ruling.
The opposite result was reached in Foote v. Rajadhyax, where the court found that a factual issue existed on an informed consent claim. The plaintiff underwent a root canal and was left with numbness in her jaw. This condition was subsequently diagnosed as a mandibular nerve injury causing permanent paresthesia. The jury found the dentist was not negligent but failed to consider the lack of informed consent allegation. This was error because a lack of informed consent has nothing to do with whether the procedure was performed carefully. Lack of informed consent is not the cause of the injury. Rather, the question is whether the treatment is a proximate cause of the injury or condition at issue.
In this matter, there was a dispute between the experts concerning each element involving the lack of informed consent allegation. The witnesses disagreed whether, given the location of the nerve to the site where the root canal was to be done, the plaintiff should have been told that permanent paresthesia might occur. The witnesses also disagreed on whether the standard of care mandated that the patient be told that she could be sent to an endodontist and whether she was informed that extraction was a viable alternative. Because the jury never considered these issues, the finding in favor of the defendant was reversed.
A sticking point in informed consent litigation is what exact information must be disclosed. Matthies v. Mastromonaco lays out the general rule. A healthcare provider is required to disclose the information that allows a reasonable patient “to consider and weigh knowledgeably the options available and the risk attendant to each.”
In DeGennaro v. Tandon, the defendant purchased the practice of another dentist. While setting up the office, a patient of the former dentist called the defendant because of a toothache. The defendant examined the woman and noted that she was going to remove the old filling and install a new medicated one. Because the dentist’s new equipment had not arrived, she used the office’s old drill and attachments which were twenty-five years old. As the dentist started to drill the tooth, the bur came into contact with the patient’s tongue causing it to bleed profusely. This injury caused several complications including the loss of sensation to the area, a lisp, drooling, and a visible scar on the tongue.
The patient sued the dentist for negligence and lack of informed consent, which was based solely on the defendant’s failure to tell her that the dentist lacked experience with the old equipment, her new office had not yet been set up, and the inability to have any staff available to help with the drilling. The jury agreed and awarded the patient $50,000. The defendant appealed and maintained that insufficient evidence existed for the jury to find lack of informed consent. The dentist claimed that the plaintiff was familiar with having her teeth drilled so no duty existed to tell the patient to keep her tongue still during the procedure.
The court on appeal upheld the award. The defendant had a duty to tell the patient that she was understaffed, was unfamiliar with the equipment, and was using an office that was not yet set up. A reasonable person would have considered these omissions important in weighing the risks of the dental procedure and determining whether a viable alternative existed to locate another dentist.
The opposite result was reached in Binder v. Traub. The court ruled that the defendant had no duty to inform the patient of the tools that he was going to use for the procedure, that he might place the implants too close together causing them to fail, or that he did not have dental malpractice insurance. Likewise in Pope v. Davis, the court determined that a dentist had no obligation to disclose the risks of marcaine to relieve pain and that the injection was not a major surgical procedure requiring informed consent.
Dental Malpractice
Dentists are no different from any other healthcare professional when it comes to being sued for malpractice. This type of professional negligence can happen when a patient is injured through the rendering of substandard care. Dental malpractice requires a claimant to demonstrate:
- the existence of a dentist-patient relationship;
- the appropriate duty of dental care under the circumstances;
- how that standard of care was violated; and
- the nature and extent of the patient’s injury.
A Westlaw search of the term “dental malpractice” reveals 2,132 reported decisions. Those cases arise in various contexts. The following are a few examples. In Hummer v. Levin, a four-million dollar award was rendered against an endodontist for malpractice involving a root canal. Lidocaine was administered through a mandibular block. After the medication wore off, the thirty-four-year-old patient discovered that she had sustained extensive nerve damage to her tongue and mouth. This injury left her with impaired speech, an uncontrollable drool, and difficulty swallowing. She had to learn American Sign Language and communicate through note writing, electronic devices, and interpreters.
The plaintiff testified that when the defendant administered the nerve block, he quickly introduced the needle into the tissue on the inner side of her right jaw joint. The dentist administered two additional cartridges of medication. This action caused such intense pain that she sprang forward into an upright position. The plaintiff’s expert testified that the defendant breached the standard of care by injecting the needle too quickly, failing to withdraw it when the patient reacted to the injection, and by changing the carpule while the needle was still lodged in the patient’s jaw. The defendant attempted to call his three technicians who were nearby to say that they did not see or hear the alleged incident. They also wanted to testify about the dentist’s custom in administering pain blocks. The trial judge barred this testimony.
On post-trial motions, the lower court granted the endodontist’s motion for a new trial concluding that it had erred in excluding the testimony of the dentist’s assistants, who would have provided “negative evidence” about the happening of the event. The plaintiff maintained that no error was committed because the exclusion of the evidence was correct.
The appellate court agreed with the plaintiff. It noted that the law recognizes “negative evidence,” which tends to prove the non-existence of a fact, as having some probity. However, such testimony “is admissible as some evidence of the negative inference only upon a showing that the witness so testifying was in a position to hear or see or would have heard or seen.” The proffered witnesses in this case could only say that, if they had been in the room, which they could not say, they would have remembered the plaintiff’s reaction. On the other hand, the plaintiff affirmatively stated that at least one of the witness was in the room at the time of the incident. Where a witness attempts to offer negative evidence, but fails to remember whether she was present or in a position to observe the disputed events, that testimony “does not meet the foundational requirements for negative evidence and has no relevance for refuting the testimony of one who was present.” Therefore, the trial judge abused its discretion and the award was reinstated.
Dental Malpractice and Res Ipsa Loquitur
Res ipsa loquitur is an evidentiary rule that permits a matter to be submitted to the factfinder without the requirement that the plaintiff prove what went wrong in causing the injury. This term is Latin for “the thing speaks for itself” and permits negligence to be inferred in certain circumstances. It use in dental malpratcie cases has resulted in mixed results. For instance, in Gutierrez v. Gradney, a dental hygienist administered three anesthetic injections for a deep cleaning teeth procedure that left the plaintiff with nerve damage. When the hygienist administered the third needle, there was an “instant pop” in the plaintiff’s mouth accompanied with severe pain. The patient permitted the defendant to complete the cleaning, but she developed continued pain and swelling in the face and head, ear ringing, left eye tearing, dripping from her left nostril, and problems with facial control. The defendant moved for summary judgment based upon an expert witness who opined the treatment rendered by the defendant satisfied the standard of care for hygienists in the dental community. The plaintiff countered with her own statement that the injection was negligently dispensed and injured her trigeminal nerve. This declaration was based upon conversations she had with doctors. The plaintiff claimed that res ipsa loquitur automatically required the defense motion to be denied.
This decision was upheld on appeal. Once the defense provided expert opinions that he was not negligent, the patient was required to counter that testimony with her own expert to establish the basis for the application of the doctrine. A plaintiff who is harmed from a common injection may be entitled to res ipsa jury instructions, but such charge is proper without expert testimony only “where a layman is able to say as a matter of common knowledge and observation that the consequences of professional treatment were not such as ordinarily would have followed if due care had been exercised.” The plaintiff provided “no evidence, apart from her own declaration, to show why her injury does not normally occur in the absence of negligence.” Because of the testimony from the defense experts, the patient was required to offer expert opinion testimony that the kind of nerve injury she sustained would not have occurred from an anesthetic absent negligent actions.
In Roper v. Blumenfeld, the plaintiff broke off a part of her molar while eating a piece of chocolate. The defendant told her that she had irreversible nerve damage, so the patient elected to have the tooth pulled. The extraction was difficult, and the patient needed five injections to numb the area. During the procedure, the tooth fractured, and part of the root was left embedded in the bone. Roper was sent to an oral surgeon the next day, who removed the root by making an incision in the gum. She left the office with numbness to her lip, chin, and jaw. The next day, her face became swollen, she was drooling and was unable to sense hot things.
Suit was filed against the dentist, and plaintiff’s expert confirmed the numbness in the lip and chin. He further noted that a tooth extraction should not cause any permanent injury to the alveolar nerve as was sustained in this case. The expert believed that the dentist used excessive force and manipulation to the tooth. The expert for the defense countered that the dentist did not deviate from acceptable standards of care and that numbness can occur in a tooth extraction in the absence of negligence. The jury found for the defendant, and an appeal was taken.
The court noted that a plaintiff in limited situations might demonstrate negligence without an expert opinion if the evidence would allow the jury to infer the harm would not have happened but for the doctor’s negligence. This res ipsa loquitur rule is one of circumstantial evidence but requires expert testimony that the medical community “recognizes that an event does not ordinarily occur in the absence of negligence.” Plaintiff’s evidence was that an injury of the type in question does not happen without a deviation in the standard of care. The plaintiff’s expert noted that a nerve injury during a tooth extraction is “medically unacceptable and is an occurrence which bespeaks negligence.” The trial judge refused to charge the jury on res ipsa, and that failure was error. If the jury believed the testimony of the plaintiff’s expert, an inference could have been made that, more likely than not, the dentist was negligent and caused the injury.
Products Liability
Dentist and dental products have been the subject of claims sounding in strict liability. For the most part, the courts have refused to extend the principles of products liability to professionals. For instance, Goldfarb v. Teitelbaum involved a claim in which the defendant, as part of the process to place caps in the plaintiff’s mouth, inserted a mandibular prosthesis. The patient suffered injury and filed suit containing counts for malpractice, strict products liability, and breach of warranty. The court refused to dismiss the counts for products liability and breach of warranty so the defendant appealed that decision. The appellate court reversed the ruling and dismissed the counts because the insertion of a prosthetic in the plaintiff’s mouth was not a sale of a good as required by a products liability and breach of warranty claims. The placement of the device “was only a procedure incidental to medical treatment.”
A similar result was reached in Appleby v. Miller, which involved a medical intake form. The patient asserted that the form was defective because it did not ask whether she had a history of a heart murmur, cardiac valvular disease, or mitral valve prolapse. Other claimed defects included the failure to ask whether she took prophylactic antibiotics, and the form failed to make a “complete inquiry or listing of a potential patient’s medical history, and/or the potential consequences thereof.”
As the result of these failures, the plaintiff claimed to have contracted bacterial endocarditis and sustained a brain aneurysm and hemiparesis. The defendant filed a motion to dismiss, which was granted. To state a cause of action in products liability, a “product” must be at issue. This determination is made by examining the social policy reasons for the adoption of strict liability instead of a dictionary definition of a “product.” In this case, the intake form was merely a service offered to the dentist and not a product covered by strict liability law. Because of the generalization of the questions and their brevity, it was not reasonable to assume that the form was designed to provide a detailed review of a patient’s medical history. The form was not a product, so the court found the count for strict liability was deficient and properly dismissed.
Anesthesia Complications
Many dental anesthesia options exist, and the type of medication used varies based on the patient’s age, health, duration of the procedure, and prior complications. How the anesthetic works depends upon the agent employed. It may last for a short period when applied to a specific area or last much longer when complicated surgery is involved.
There are two primary forms of anesthesia: local and general. The first provides a numbing sensation for about thirty to sixty minutes. It is used in various dental tasks, from filling cavities to root canal procedures. Typical agents include prilocaine, lidocaine, mepivacaine, and bupivacaine. In contrast, general anesthesia induces a state of unconsciousness. This option is used for prolonged and extensive oral surgeries that may generate more discomfort than local anesthesia can mitigate. An advantage of general anesthesia is that it will immobilize a patient and keep that person still for interventions that require great precision. This type of sedation is usually administered through a regulated and continued quantity of medication given through an IV or a face mask. Common sedations in this category include propofol, ketamine, diazepam, and methohexital.
Local anesthetic injections are routinely administered and are generally thought to be safe invasive procedures. However, they are not without risk. Adverse reactions can range from mild and tolerable to severe and hazardous, such as anaphylactic shock and toxicity. It is no surprise that complications can lead to lawsuits against dental professionals.
One tragic case is demonstrated by a six-year-old girl who was injected with two cartridges of 2% Lidocaine with 1:100,000 epinephrine for the repair of four maxillary teeth. Because the pain did not abate, two additional dosages were administered. Despite this overload of medication, the child was still not feeling comfortable after thirty minutes, so two more injections were given. The child soon fell unconscious, and her lips and nails turned dark. The dentist began positive-pressure ventilation, but the child never recovered and died.
Suit was instituted against the dentist for local anesthetic overdose. The case settled for over one million dollars. Liability was based upon the defendant’s failure to appreciate the early warning signs of an aesthesia overdose when the child became resistant about thirty minutes into the procedure. Instead, he injected even more sedation. The maximum dose of anesthetic for the weight of the child was two carpules, but the dentist administered multiple doses which constituted a deviation in the proper standard of care.
Just because a person sustains an injury during the administration of anesthesia does not mean that the dentist is responsible. Use of anesthesia has certain attendant risks. In Schofield v. Hlousek, the plaintiff sued his dentist, claiming he was negligent in the delivery of an inferior alveolar block during the filling of a cavity. The patient was given a shot of Lidocaine in the rear of the mouth, which numbed all sections of the oral cavity. This condition lasted for months, and the plaintiff alleged that the dentist repeatedly assured him that this was normal. Subsequently, the patient needed another tooth filled, so the defendant used articaine because it was a quicker acting agent. Several days later, the plaintiff complained that he was stilling feeling numb. The defendant noted that he might have accidentally hit a nerve during the injection or that the area was bruised. The patient was told that the feeling might not wear off for weeks or months. When the numbness persisted, the dentist referred the patient to a specialist on nerve injuries who determined that the patient had suffered a “needle stick injury to [his] right lingual nerve.” This specialist testified that a person could incur nerve damage from an inferior alveolar nerve block even when a dentist acts appropriately and within the proper standard of care. The problem is that the nerve block is a blind procedure performed using a set of known landmarks and the risk of a nerve injury is 0.6% to 2%. There is no way to predict when this type of injury will occur.
The defendant moved for a summary judgment because no evidence existed that the dentist deviated from the proper standard of care. The patient filed no response to this motion, and the case was dismissed. The plaintiff filed a motion for reconsideration, but that motion was denied. The court found the dentist met his burden of proof by offering supporting evidence that he did nothing wrong. The dentist testified that the use of articaine was proper to numb a location, that the plaintiff exhibited no disturbing signs at the time of the shot, and that the plaintiff seemed fine when he left the office. The defendant’s expert also noted that hitting the lingual nerve during a nerve block, “is not, in and of itself, indicative of a breach of the standard of care” because the injection is done blindly and it is foreseeable that the nerve may be hit by the needle. The plaintiff offered no factual evidence to contradict the defendant’s proof, so the dismissal was proper.
Insurance Coverage Issue
Dental litigation does have its share of unusual cases, especially with coverage decisions. A leading candidate for one of the more bizarre lawsuits involves a prank by a dentist involving a potbellied pig named Walter and the insurance carrier’s failure to defend the dentist under his malpractice policy. One of the dentist’s employees owned a pet pig, and the dentist frequently made comments to her about the animal.
The employee chipped a tooth, and the employer agreed to repair it. While the patient was anesthetized, the dentist placed false teeth shaped like boar tusks in her mouth and took pictures while her eyes and mouth were pried open. Upon seeing the photographs, the worker quit and sued the dentist under a variety of theories. The dentist settled with the patient for $250,000 and obtained a bad-faith verdict against his malpractice carrier for $750,000. This decision was reversed on appeal since the court did not believe the dentist’s prank to humiliate his employee was within the scope of coverage. The court opined that no reasonable person could think that the dentist was rendering professional services by placing boar tusks in a patient’s mouth while under anesthesia to take pictures to ridicule her.
Likewise, the court in Niedzielski v. St. Paul Fire & Marine Insurance Co. found that an alleged sexual assault by a dentist of a patient was not covered under a malpractice policy. A ten-year-old child was bought to the dentist because of a cavity. The dentist sexually assaulted the child during the examination. He was sued over the incident and tendered the claim to his malpractice carrier, which declined coverage. This promoted the filing of a declaratory judgment. The trial court determined that the policy had no exclusion for criminal or intentional acts “but ‘unambiguously’ limits coverage to occurrences that ‘arise out of the performance of or failure to perform professional services.’” The judge also opined that it found that the insured’s actions “did not arise out of the rendition of professional services.”
This decision was appealed by the victim of the assault who argued that her presence in the insured’s office was solely for the rendering or receiving dental care. In rejecting this assertion, the court noted that it had to view the nature of the conduct and interpret the plain meaning of the policy accordingly. A professional act or service stems “out of a vocation, calling, occupation, or employment involving specialized knowledge, labor, or skill . . . [that] is predominantly mental or intellectual, rather than physical or manual.” Therefore, the court must review the nature of the act committed, and not the professional designation of the actor. The breadth of professional services does not encompass all types of professional actions merely because the insured is a dentist. The child’s presence on the insured’s premises does not permit a classification that would make all acts taking place in a dental office a professional service or failure to deliver a professional service.
The plaintiff referenced Public Service Mutual Insurance Co. v. Goldfarb, which did allow coverage under the dentist’s policy for sexual assault, but that decision rested on the policy’s language. The policy in the cited case explicitly encompassed claims premised upon “assault, slander, libel [or] undue familiarity.” This policy language demonstrated an intent to indemnify for claims based upon improper physical contact happening during a dental exam.
Conclusion
Teeth are multifunctional structures that are critical for elementary human acts like chewing, talking, and smiling. Every tooth has a specific anatomic construction with a customary composition. However, teeth are subject to various insults that can damage them, requiring repair or extraction. Dentists are no different than other health care professionals and are subject to various claims by dissatisfied patients. Dental professionals account for 11.5% of the total expenditures made by insurance companies to resolve medical malpractice claims.
While the awards tend to be smaller than malpractice verdicts against physicians, a variety of cases have yielded million-dollar results. Lawsuits involving dental professionals arise in many contexts from failed teeth extractions to death resulting from an untreated infection or anesthesia mishap. This article has provided an overview of the oral cavity and its various structures. Dentistry also has its vocabulary, and some of the more common terms have been explained so attorneys can better appreciation the teeth for when they read dental records and evaluate cases involving these structures.
