Soft Tissue and Dentoalveolar Injuries

Abrasion

An abrasion is a wound caused by friction between an object and the surface of the soft tissue. This wound is usually superficial, denudes the epithelium, and occasionally involves deeper layers. Because abrasions involve the terminal endings of many nerve fibers, they are painful. Bleeding is usually minor because it is from capillaries and responds well to application of gentle pressure.

The types of abrasions most commonly seen by laypersons are the scrapes that children sustain on their elbows and knees from rough play. If the abrasion is not particularly deep, re-epithelialization occurs without scarring. When the abrasion extends into the deeper layers of the dermis, healing of the deeper tissues occurs with the formation of scar tissue, and some permanent deformity can be expected.

The dentist may see abrasions on the tip of the nose, lips, cheeks, and chin in patients who have sustained dentoalveolar trauma ( Fig. 24.1 ). The abraded areas should be thoroughly cleansed to remove foreign material. Surgical hand soap and copious saline irrigation are useful for this purpose. All particles of foreign matter must be removed. If these particles are allowed to remain within the tissue, a permanent “tattoo” that is difficult to treat results. In deep abrasions that are contaminated with dirt or other material, it may be necessary to anesthetize the area and use a surgical scrub brush (or toothbrush) to remove the debris completely.

Once the wound is free of debris, topical application of an antibiotic ointment is adequate treatment. A loose bandage can be applied if the abrasion is deep but is unnecessary in superficial abrasions. Systemic antibiotics are not usually indicated. Over the next week, reepithelialization will occur under the eschar, which is a crust of dried blood and serum that develops after an injury to soft tissue (e.g., a scab). The eschar will then drop off.

If a deep abrasion on the skin surface is discovered after wound cleansing, referral to an oral-maxillofacial surgeon is indicated because skin grafting may be necessary to prevent excessive amounts of scar formation.

The dentist may create abrasions iatrogenically, as occurs when the shank of a rotating burr touches the oral mucosa or when a gauze pack or other fabric (e.g., absorbent triangular pads) abrades the mucosa during removal from the mouth. Fortunately, the oral epithelium regenerates rapidly, and no treatment other than routine oral hygiene is indicated.

Contusion

A contusion is more commonly called a bruise and indicates that some amount of tissue disruption has occurred within the tissues, that resulted in subcutaneous or submucosal hemorrhage without a break in the soft tissue surface ( Fig. 24.2 ).

Contusions are usually caused by trauma inflicted with a blunt object but are also frequently found with concomitant dentoalveolar injuries or facial bone fractures. In this instance, the trauma to the deeper tissues (e.g., floor of mouth or labial vestibule) has occurred from the disrupting effect of the fractured bones. The importance of contusions from a diagnostic point of view is that when they occur, one should search for osseous fractures.

A contusion generally requires no surgical treatment. Once the hydrostatic pressure within the soft tissues equals the pressure within the blood vessels (usually capillaries), bleeding ceases. If a contusion is seen early, application of ice or pressure dressings may help constrict blood vessels and thereby decrease the amount of hematoma that forms. If a contusion does not stop expanding, a hemorrhaging artery within the wound is likely. The hematoma may require surgical exploration and ligation of the vessel.

Because there has been no disruption of soft tissue surfaces, over time, the body resorbs the hemorrhage formed within a contusion, and the normal contour is reestablished. In the next several days, however, the patient can expect areas of ecchymosis (i.e., purplish discoloration caused by extravasation of blood into the skin or mucosa; a “black and blue mark”), which turn a variety of colors (e.g., blue, green, yellow) before fading. These areas may extend down below the clavicles and cause alarm, but they are innocuous.

When no break has occurred in the surface of soft tissue, infection is unlikely, so systemic antibiotics are not indicated. If, however, the contusion results from dentoalveolar trauma, it is likely that communication may exist between the oral cavity and the submucosal hematoma. In this case, systemic antibiotics are warranted because coagulated blood represents an ideal culture medium.

Laceration

A laceration is a tear in the epithelial and subepithelial tissues. A laceration is perhaps the most frequent type of soft tissue injury and is caused most commonly by a sharp object such as a knife or a piece of glass. If the object is not sharp, the lacerations created may be jagged because the tissue is literally torn by the force of the blow ( Fig. 24.3 ). As with abrasions, the depth of a laceration can vary. Some lacerations involve the external surface only, but others extend deep into tissue, disrupting nerves, blood vessels, muscle, and other major anatomic cavities and structures.

The dentist frequently encounters lacerations of the lips, floor of mouth, tongue, labial mucosa, buccolabial vestibule, and gingiva caused by trauma. One should explore the oral cavity thoroughly to identify ones that are not gaping. For instance, lacerations within the vestibule can be overlooked unless the lips are retracted, allowing a laceration to gape. Lip lacerations are commonly seen with dentoalveolar trauma, but in many instances of trauma, teeth are uninjured because soft tissue has absorbed the force of the blow.

Soft tissue wounds associated with dentoalveolar trauma are always treated after the management of the hard tissue injury. Suturing soft tissue first is a waste of time because the sutures are likely to be stressed too much and pulled out of the tissue during intraoral manipulation, which is necessary to replant an avulsed tooth or treat a dentoalveolar fracture. Furthermore, once sutures have been pulled out of the tissue, it will be more difficult to close the tissue on the second attempt.

After adequate anesthesia is provided, the surgical management of lacerations involves four major steps: (1) cleansing, (2) debridement, (3) hemostasis, and (4) closure. These steps apply to lacerations anywhere in the body, including the oral cavity and perioral areas.

Closure of Wound

Once the wound has been cleansed and debrided and hemostasis achieved, the laceration is ready to be closed with sutures. However, not every laceration in the oral cavity must be closed with sutures. For example, a small laceration in the palatal mucosa caused by falling on an object extending from the mouth need not be closed. Similarly, a small laceration on the inner aspect of the lip or tongue caused by entrapment between teeth during a fall usually does not require closure. These small wounds heal well by secondary intention and are best left to do so.

If closure of a laceration is deemed appropriate, the goal during closure is proper positioning of all tissue layers. The manner in which closure proceeds depends totally on the location and depth of the laceration.

Lacerations of the gingiva and alveolar mucosa (or floor of mouth) are simply closed in one layer. If a patient has a laceration of the tongue or lip that involves muscle, resorbable sutures should be placed to close the muscle layer or layers, after which the mucosa is sutured. Minor salivary gland tissue protruding into a wound can be judiciously trimmed to allow for a more favorable closure.

For lacerations extending through the entire thickness of the lip, a triple-layered closure is necessary ( Fig. 24.4 ). If the laceration involves the vermilion border, the first suture placed should be at the mucocutaneous junction. Perfect alignment of this junction of skin and mucosa is imperative, or it can result in a noticeable deformity that can be seen from a distance. Once this suture is placed, the wound is closed in layers from the inside out. The oral mucosa is first closed with silk or resorbable suture. The orbicularis oris muscle is then sutured with interrupted resorbable sutures. Finally, the dermal surface of the lip is sutured with 5-0 or 6-0 nylon sutures. The wound will look as good at the completion of suturing as it ever will. If the alignment of tissues appears poor, consideration should be given to removing the sutures and replacing them in a more favorable manner. The dermal surface should then be covered with an antibiotic ointment.

Once a laceration is closed, the clinician must consider what supportive therapy can be instituted to bring about uneventful healing. Systemic antibiotics (e.g., penicillin) should be considered whenever a laceration extends through the full substance of the lip. In superficial lacerations, antibiotics are not indicated. The patient's tetanus status should be ascertained; if in doubt, patients should be referred to their general physicians. Patients should also be instructed in postsurgical diet and wound care.

In general, facial skin sutures should be removed 4 to 6 days postoperatively. When removing a suture, it should be cut and then pulled in a direction that does not cause the wound to gape. Adhesive strips can be placed at the time of suture removal to give external support to the healing wound.

Management of Dentoalveolar Injuries

Injuries to teeth and the alveolar process are common and should be considered emergency conditions because a successful outcome depends on prompt attention to the injury. Because proper treatment can be given only after an accurate diagnosis, the diagnostic process should commence immediately.

History

The first step in any diagnostic process should be to obtain an accurate history. A comprehensive history of the injury should be obtained from the patient, incorporating information on who, when, where, and how. The dentist must ask the following questions of the patient, parent, or a reliable respondent:

• 1

  Who is the patient? The patient's name, age, address, telephone number, and other pertinent demographic data should be included in the answer. It is imperative that these data be obtained quickly and no time wasted.

• 2

  When did the injury occur? This is one of the most important questions to ask because studies have shown that the sooner an avulsed tooth can be repositioned, the better the prognosis. Similarly, the results of treating displaced teeth, crown fractures (with and without exposed dental pulps), and alveolar fractures may be influenced by any delay in treatment.

• 3

  Where did the injury occur? This question may be important because the possibility and degree of bacterial or chemical contamination should be ascertained. For example, if a child falls on the playground and gets dirt in the wound, a tetanus prophylaxis history should be carefully established. However, if an injury occurs from a clean object held in the mouth, gross bacterial contamination from external sources is not expected.

• 4

  How did the injury occur? The nature of the trauma provides valuable insight into what the resultant tissue injury is likely to be. For example, an unrestrained car passenger who is thrown forward into the dashboard with sufficient force to damage several teeth may also have sustained occult injuries to the neck. The manner in which the injury occurred is valuable information and should make the clinician investigate the possibility of further injuries. Additional information that can be gained from this question may relate to the cause of the injury. If a patient cannot remember what happened, a preexisting medical condition such as a seizure disorder may have caused the accident producing the injury. Injuries caused by possible negligence by others are open for litigation. These considerations should caution the clinician to document the findings carefully and word any discussions with the patient thoughtfully. Child abuse is another factor that must be kept in the clinician's mind when examining children whose injuries do not seem to be a likely result of the injury described by the parent.

Unfortunately, child abuse has become more prevalent in recent years, and a high degree of suspicion may be the only manner by which it can be discovered by health care providers.

• 5

  What treatment has been provided since the injury (if any)? This question elicits important information regarding the original condition of the injured area. Did the patient or parent replant a partially avulsed tooth? How was the avulsed tooth stored before presentation to the dentist?

• 6

  Did anyone note teeth or pieces of teeth at the site of the accident? Before an accurate diagnosis and treatment plan are made, it is imperative to account for each tooth the patient had before the accident. If during the clinical examination a tooth or crown is found missing and no history suggests that it was lost at the scene, radiographic examination of the perioral soft tissues, the chest, and the abdominal region is necessary to rule out the presence of the missing piece within tissues or other body cavities ( Fig. 24.5 ).

  

• 7

  What is the general health of the patient? A succinct medical history is essential; it should not be ignored in the dentist's haste to replant an avulsed tooth. History taking, however, can be performed concomitantly with treatment or immediately thereafter. History with regard to drug allergy, heart murmur, bleeding disorder, other systemic disease, and current medications should be taken before treatment because the existence of these factors affects the treatment the dentist will provide.

• 8

  Did the patient have nausea, vomiting, unconsciousness, amnesia, headache, visual disturbances, or confusion after the accident? An affirmative answer to any of these questions may indicate intracranial injury and direct the dentist to obtain medical consultation immediately after completing treatment. Immediate referral should be made if the patient is still having any of the symptoms or if the patient does not feel or look well. The patient's life should not be jeopardized merely to save an avulsed tooth.

• 9

  Is there a disturbance in the bite? An affirmative answer to this question may indicate tooth displacement or dentoalveolar or jaw fracture.

Clinical Examination

The clinical examination is perhaps the most important part of the diagnostic process. A thorough examination of a patient who has had injury to the dentoalveolar structures should not focus only on that structure. Concomitant injuries may also be present; the history may direct the dentist to examine other areas for signs of injury. Vital signs such as pulse rate, blood pressure, and respiration should be measured. Such tests can usually be obtained during history taking. The mental state of the patient is also assessed throughout history taking and while performing the clinical examination by observation of the manner in which the patient reacts to the examination and responds to the questioning. During the clinical examination, the following areas should be examined routinely:

• 1

  Extraoral soft tissue wounds. Lacerations, abrasions, and contusions of the skin are common with dentoalveolar injuries and should be noted. If a laceration is present, the depth of it should also be determined. Does the laceration extend through the entire thickness of the lip or cheek? Are there any vital structures such as the parotid duct or facial nerve crossing the line of the laceration? An oral-maxillofacial surgeon best treats major lacerations such as these.

• 2

  Intraoral soft tissue wounds. Injuries to oral soft tissues are commonly associated with dentoalveolar injuries. Before a thorough examination, it may be necessary to remove blood clots, irrigate the area with sterile saline, and cleanse the oral cavity. Areas of bleeding usually respond to pressure applied through gauze sponges. Soft tissue injuries should be noted, and an examination should ascertain whether any foreign bodies such as tooth crowns or teeth remain within the substance of the lips, floor of mouth, cheeks, or other areas. The dentist should also note areas of extensive loss of soft tissue; blood supply to a segment of tissue may thereby be lost.

• 3

  Fractures of the jaws or alveolar process. Fractures of the jaws are most readily found on palpation. However, because pain may be severe after the injury, examination may be difficult. Bleeding into the floor of the mouth or into the labial vestibule may indicate a fracture of the jaw. Segments of alveolar process that have been fractured are readily detected by visual examination and palpation.

• 4

  Examination of the tooth crowns for the presence of fractures or pulp exposure. For adequate examination, teeth should be cleansed of blood. Any fractures should be noted. The depth of the fracture is an important point to note. Does it extend into dentin or into the pulp?

• 5

  Displacement of teeth. Teeth can be displaced in any direction. Most commonly, they are displaced in a buccolingual direction, but they may also be extruded or intruded. In the most severe type of displacement, teeth are avulsed—that is, totally displaced out of the alveolar process. Observation of the dental occlusion may provide assistance in determining minimal degrees of tooth displacement.

• 6

  Mobility of teeth. All teeth should be checked for mobility in the horizontal and vertical directions. A tooth that does not appear to be displaced but that has considerable mobility may have sustained a root fracture. If adjacent teeth move with the tooth being tested, a dentoalveolar fracture (in which a segment of alveolar bone and teeth are separated from the remainder of the jaw) should be suspected.

• 7

  Percussion of teeth. When a tooth does not appear to be displaced but pain is felt in the region, percussion determines whether the periodontal ligament has undergone some injury.

• 8

  Pulp testing of teeth. Although rarely used in acute injuries, vitality tests (which induce a reaction from teeth) may direct the type of treatment provided once the injury has healed. False-negative results may occur, so teeth should be retested several weeks later and before endodontic therapy is performed.