Study Points

Oral and Maxillofacial Trauma

Course #50002 - $35 • 5 Hours/Credits

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  • Participation Instructions
    • Review the course material online or in print.
    • Complete the course evaluation.
    • Review your Transcript to view and print your Certificate of Completion. Your date of completion will be the date (Pacific Time) the course was electronically submitted for credit, with no exceptions. Partial credit is not available.
  1. Injuries to the oral and maxillofacial complex constitute what percentage of the injuries resulting in emergency dental treatment?

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    Injuries to the oral and maxillofacial complex constitute 5% of the injuries for which patients seek emergency dental treatment, with this figure approaching 20% for children [1]. The most common cause of injuries to permanent teeth is accidental falls, followed by motor vehicle accidents, violent encounters, and sports injuries [2]. This section will discuss the structural damage of the teeth resulting from trauma, from least to most extensive. While the ideal outcome is to retain and restore traumatized teeth, those with extensive damage requiring endodontic treatment, periodontal (crown-lengthening) surgery, and build-ups with or without posts prior to the fabrication of a crown involve a substantial monetary investment, which may be beyond the financial means of some patients. In such cases, extraction of these potentially restorable teeth and the placement of a removable prosthesis provide a means to eliminate pain and restore function and cosmetics.

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  2. The most common cause of injuries to permanent teeth is

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    Injuries to the oral and maxillofacial complex constitute 5% of the injuries for which patients seek emergency dental treatment, with this figure approaching 20% for children [1]. The most common cause of injuries to permanent teeth is accidental falls, followed by motor vehicle accidents, violent encounters, and sports injuries [2]. This section will discuss the structural damage of the teeth resulting from trauma, from least to most extensive. While the ideal outcome is to retain and restore traumatized teeth, those with extensive damage requiring endodontic treatment, periodontal (crown-lengthening) surgery, and build-ups with or without posts prior to the fabrication of a crown involve a substantial monetary investment, which may be beyond the financial means of some patients. In such cases, extraction of these potentially restorable teeth and the placement of a removable prosthesis provide a means to eliminate pain and restore function and cosmetics.

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  3. The least severe damage evident on a traumatized permanent tooth is

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    An infraction is the least severe damage evident on a traumatized tooth, featuring small cracks or craze lines with minimal depth and no lost enamel. Radiographs of the tooth appear normal, and the tooth is generally asymptomatic. Repeated traumatic incidents to the same tooth may result in a coalescence of these small cracks, which may then unite to form larger cracks and fracture of the enamel. Because no tooth structure is lost, restorative treatment is not needed, but areas with larger cracks may be etched and sealed with resin to prevent the development of stains and discoloration [3]. The prognosis for the retention of teeth with infractions is usually favorable, as is the pulpal response to the trauma. As the force that causes infractions is usually not of a magnitude that would compromise or sever the neurovascular supply of the tooth, pulpal complications are rare.

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  4. Restoring enamel fractures that involve the entire incisal edge of the anterior teeth may be complicated by

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    Treatment for fractured areas of enamel is commensurate with the extent of tooth loss. An intact segment of fractured enamel can be bonded directly back to the area of the tooth from which it was lost, or composite restorations may replace fractured areas that lack an intact enamel segment for bonding. Restoring enamel fractures that involve the entire incisal edge of the anterior teeth can present a cosmetic and restorative challenge. An edge-to-edge anterior occlusion, whereby the incisal edges of the maxillary and mandibular teeth lack the appropriate overlap and occlude directly against each other, can generate considerable force during functional excursions, making these restorations susceptible to fractures. Parafunctional habits such as bruxing (grinding) can also increase the risk of damage to restorations of the incisal edges of anterior teeth. Complicating circumstances such as these may require the use of less conservative restorations, such as porcelain veneers or crowns. These teeth are usually asymptomatic, but pulpal complications can occur if the traumatic force was enough to compromise the neurovascular supply to the tooth.

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  5. Extension of a crown fracture into the dentin

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    Uncomplicated crown fractures involving both the enamel and the dentin but not the pulp represent a progressive loss of tooth structure. The involvement of the dentin increases symptomology, complicates the ability to restore the tooth, and increases the chance of pulpal inflammation and degradation, for which endodontic therapy may be required.

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  6. Which of the following is a benefit of mineral trioxide aggregate (MTA) for pulp capping compared with calcium hydroxide?

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    Although calcium hydroxide remains the most popular and widely known of the direct pulp capping agents, mineral trioxide aggregate (MTA) is another agent that has become popular since its approval for use by the U.S. Food and Drug Administration in 1998 [14]. Some studies have suggested that MTA is a better pulp capping agent than calcium hydroxide as it is associated with a lesser inflammatory response upon its placement and it forms a stronger dentin bridge in a shorter time than calcium hydroxide [15]. While additional comparative studies are needed to further evaluate these direct pulp capping materials, one meta-analysis found that MTA has a higher success rate and results in less pulpal inflammatory response than calcium hydroxide [16].

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  7. Which of the following is among the most frequent criteria by which long-term success of a direct pulp cap intervention is evaluated?

    TRAUMATIZED PERMANENT TEETH WITH COMPLETELY FORMED (MATURE) ROOTS

    The most frequent criteria by which long-term success is evaluated for a direct pulp cap intervention are lack of patient-reported symptoms, positive tests for pulp vitality, and the lack of the development of an apical lesion secondary to necrotic pulp (evident on x-ray). Patients should be advised that root canal treatment is always a possibility for teeth that require direct pulp caps after traumatic injury, even if there is a protracted lack of symptoms. Before endodontic therapy is begun, the teeth should be examined carefully for cracks or fractures that could preclude the ability to obtain a successful result.

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  8. Uncomplicated fractures of permanent teeth with open apices are general amenable to treatment by

    TRAUMATIZED PERMANENT TEETH WITH OPEN APICES

    Uncomplicated fractures of permanent teeth with open apices are generally amenable to treatment by the placement of composite restorations. Complicated fractures involving the pulp in teeth in which the root apex is still open present unique challenges. The initial concern is the alleviation of the pain that accompanies the traumatic injury and restoration of the function and cosmetics of the tooth. The ultimate challenge is to maintain the vitality of the pulp, which is essential in the completion of the development of the root, the closure of its apex, and the developing and thickening of the walls of the root canal. If the pulp becomes necrotic, the tooth will not complete the maturation process and will be more vulnerable to fracture compared with teeth with fully developed roots.

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  9. The time to achieve apexification is usually

    TRAUMATIZED PERMANENT TEETH WITH OPEN APICES

    Direct pulp capping or partial pulpotomy techniques are not always successful in maintaining the vitality of the pulp. Large pulpal exposures and/or an extended length of time between the traumatic incident and the initiation of therapy may result in extensive bacterial contamination of the pulp chamber and ultimately necrosis of the pulp. If the immature permanent tooth has an open apex and is nonvital, apexification is indicated. This procedure is designed to induce the formation of a calcified apical barrier, which provides a definitive apical stop for a conventional root canal filling material, such as gutta-percha. Apexification involves removal of the coronal and non-vital tissue within the root and placement of an intra-canal medication (e.g., calcium hydroxide or MTA) to disinfect the canal space [24]. It is imperative that the temporary restoration that covers the access to the coronal pulp and canal has an adequate seal to prevent bacterial infiltration and reinfection. A definitive restoration such as a composite resin is then used to seal the access. The time to achieve apexification can range from 6 to 18 months, during which three-month recall appointments are necessary to monitor progress [25]. The development of a calcified barrier can be confirmed by radiographs or by the tactile sensation of a definitive apical stop as perceived by an endodontic instrument (e.g., a size 35 endodontic file). Conventional endodontic treatment may be completed after the apical barrier has been established. Patients should be advised that this procedure will not allow the root canal walls to develop and thicken, so the tooth and the root will remain more susceptible to fracture. Patients who engage in sports or any athletic activity should wear a protective mouth guard to decrease the potential for injury.

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  10. During oral and maxillofacial trauma, the most commonly damaged deciduous teeth are the

    TRAUMATIZED DECIDUOUS TEETH

    Among the deciduous teeth, the anterior teeth are most commonly damaged during oral and maxillofacial trauma. The restoration of traumatized deciduous teeth reflects their unique anatomy. Compared with permanent teeth, deciduous teeth have thinner enamel and dentin and larger pulp chambers, with pulp horns that can extend further toward the external surface of the tooth. The roots of deciduous teeth are narrower in a mesial-to-distal direction, and those of the deciduous molars have slender curvatures over the permanent bicuspids. The decision to restore a traumatized deciduous tooth should take into consideration its life expectancy, especially when a complicated fracture involves the pulp. Teeth that are traumatized and painful and expected to be exfoliated soon should be extracted; those with an extended life expectancy should be restored.

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  11. Root fractures in permanent teeth most commonly involve the

    ROOT FRACTURES OF DECIDUOUS AND PERMANENT TEETH

    Root fractures in permanent teeth are usually an extension of a fracture through the enamel and dentin; the pulp may or may not be involved. Root fractures are uncommon, but when they do occur, 68% involve the maxillary central incisors and 27% involve the maxillary lateral incisors [27].

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  12. Zone 1 horizontal fractures occur

    ROOT FRACTURES OF DECIDUOUS AND PERMANENT TEETH

    Horizontal root fractures are the most common type and commonly occur in the maxillary anterior region, usually in the central incisors [28]. Horizontal root fractures are classified according to several features, including the extent of the damage and the location of the fracture. The extent of the fracture(s) is categorized as either single, multiple, or comminuted (pulverized), the last of which is associated with a poor prognosis for retention of the tooth. Partial or total fractures refer to the extent that the coronal fragment is dislocated. If the fractured coronal segment is in alignment with the rest of the root, the fracture is not displaced; those that lack alignment are considered displaced fractures. The location of the fracture is also subject to classification. Those that occur from the occlusal/incisal edge to the alveolar crest are zone 1 fractures, (analogous to a crown fracture) while zone 2 fractures are located between the alveolar crest of bone and 5 mm below this level (i.e., a cervical-root fracture). Zone 3 fractures, also referred to as middle/apical root fractures, occur anywhere from the root apex to 5 mm below the alveolar crest [29]. Most horizontal root fractures possess a combination of these features, with the prognosis for the retention of the tooth reduced as the number and complexity of these factors increase. Fractures of the root may be accompanied by fractures in the clinical crown of the tooth, which adds to the complexity of restoring the tooth.

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  13. Healing of a root fracture by the formation of granulation tissue between the coronal and apical segments is considered type

    ROOT FRACTURES OF DECIDUOUS AND PERMANENT TEETH

    Healing of the root fracture occurs by one of four different histologic types. Type I healing features calcified tissue (callus formation) developing and forming a union between the fractured segments. Type II healing is characterized by connective tissue uniting the fractured segments and the development of peripheral rounding at the fracture's ends. The combination of bone and connective tissue maturation and a separation of the coronal and apical fractured segments (as seen on x-ray) is indicative of type III healing. Type IV is the least favorable mode of healing and features the formation of granulation tissue between the fractured coronal and apical segments; this is indicative of pulpal necrosis [1].

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  14. Extrusive luxation is

    LUXATION INJURIES TO PERMANENT AND DECIDUOUS TEETH

    Extrusive luxation is defined as the partial displacement of a tooth from its socket in an axial direction coronally. These teeth have an elongated appearance compared to the adjacent teeth and have mobility of varying degrees. Radiographs will demonstrate an increased dimension of the periodontal ligament space in the apical region.

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  15. The most important factor in ensuring the long-term retention of a replanted avulsed tooth is

    LUXATION INJURIES TO PERMANENT AND DECIDUOUS TEETH

    The amount of time that elapses between the actual avulsion of the tooth and its replantation into the socket remains the most important factor in ensuring the long-term retention of the tooth [41]. It is also critical that any portion of the periodontal ligament still attached to the avulsed tooth remains hydrated during transit to the dental office. Avulsed teeth that have been kept dry for 60 minutes will experience death of the cells of the periodontal ligament and a subsequent poor prognosis for replantation and retention [42]. Desiccation of the periodontal ligament will result in severe inflammation over much of the root surface upon replantation and decreases the likelihood of a successful replantation [43]. Commercially available transportation media solutions provide the best means of hydration for the periodontal ligament of an avulsed tooth, but because these accidents often occur without warning, alternative transport techniques may be employed. The avulsed tooth may be placed in the patient's buccal vestibule and immersed in the patient's saliva, with caution taken to avoid swallowing or aspirating the tooth. Patients may also expectorate into a clean container containing the avulsed tooth for transport. Cold milk or physiologic saline (0.9%) solutions are other options for transport media but are less beneficial than the commercial products or saliva [44]. Transport in water should only be considered if no other means of hydration is available, as its low osmolality can cause damage to the periodontal ligament if the tooth is immersed for more than 20 minutes [1].

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  16. Aside from commercially available solutions, the best means of hydration of the periodontal ligament of an avulsed tooth during transport is

    LUXATION INJURIES TO PERMANENT AND DECIDUOUS TEETH

    The amount of time that elapses between the actual avulsion of the tooth and its replantation into the socket remains the most important factor in ensuring the long-term retention of the tooth [41]. It is also critical that any portion of the periodontal ligament still attached to the avulsed tooth remains hydrated during transit to the dental office. Avulsed teeth that have been kept dry for 60 minutes will experience death of the cells of the periodontal ligament and a subsequent poor prognosis for replantation and retention [42]. Desiccation of the periodontal ligament will result in severe inflammation over much of the root surface upon replantation and decreases the likelihood of a successful replantation [43]. Commercially available transportation media solutions provide the best means of hydration for the periodontal ligament of an avulsed tooth, but because these accidents often occur without warning, alternative transport techniques may be employed. The avulsed tooth may be placed in the patient's buccal vestibule and immersed in the patient's saliva, with caution taken to avoid swallowing or aspirating the tooth. Patients may also expectorate into a clean container containing the avulsed tooth for transport. Cold milk or physiologic saline (0.9%) solutions are other options for transport media but are less beneficial than the commercial products or saliva [44]. Transport in water should only be considered if no other means of hydration is available, as its low osmolality can cause damage to the periodontal ligament if the tooth is immersed for more than 20 minutes [1].

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  17. The leading cause of mandibular fracture in men is

    TRAUMATIC INJURIES OF OTHER STRUCTURES WITHIN THE ORAL AND MAXILLOFACIAL COMPLEX

    The mandible is the only movable bone of the face and is the osseous structure most vulnerable to maxillofacial trauma [47]. The mechanism of injury of mandibular fractures differs by gender, with men most often sustaining fractures from assault (49.1%) and motor vehicle accidents (25.4%), and women most often sustaining them from motor vehicle accidents (53.7%), falls (23.7%), and physical assault (14.5%) [48]. Treatment of mandible fracture is completed in a hospital setting by an oral and maxillofacial surgeon or a general surgeon and is beyond the scope of this course. Instead, this section will focus on some of the most common oral complications secondary to trauma sustained by this structure.

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  18. Injury to the inferior alveolar nerve (IAN) from fractured segments of the mandible may result in

    TRAUMATIC INJURIES OF OTHER STRUCTURES WITHIN THE ORAL AND MAXILLOFACIAL COMPLEX

    Another complication that may occur during mandibular fracture is damage to the inferior alveolar nerve (IAN), which is a branch of the mandibular division (V3) of cranial nerve V (the trigeminal nerve). The IAN enters the mandible at the inner aspect of the ramus and proceeds anteriorly within the mandibular canal. The IAN provides motor innervation to some of the muscles of mastication and provides sensory innervation to the lower teeth and contiguous gingival tissues. The mental nerve branches from the IAN near the bicuspid area via the mental foramen and provides sensory innervation to surfaces of the lower lip. Fractured segments of the mandible can cause direct injury to the IAN via compression and result in paresthesia, which is described as a tingling ("pins and needles") feeling, within the affected area. The worst outcome occurs when force of the traumatic impact causes the nerve to be severed, which results in anesthesia, or a complete lack of sensation in the area. This type of injury to the IAN may also occur during surgical procedures, especially those that involve impacted mandibular wisdom teeth.

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  19. Which of the following injuries should be viewed with suspicion for possible child abuse?

    INJURIES ASSOCIATED WITH CHILD ABUSE

    The dental team is in an excellent position to evaluate potential cases of child abuse and neglect, as injuries to the head, neck, face, and intraoral regions are common among abused children. In one study, orofacial trauma was concurrent with 16% of proven cases of pediatric abusive head trauma ("shaken baby syndrome") [56]. As children mature, most will sustain bruises on their foreheads, knees, elbows, and other areas of bony prominences as a result of accidental injuries during athletic events or recreational activities. Injuries to soft tissues not supported by bone, such as the lips, the cheeks below the zygomatic arch, and the neck in various stages of healing, should be viewed with suspicion, especially if they are bilateral and/or inappropriate for the child's developmental age. A meticulous examination of the teeth, soft tissues, and perioral structures may reveal signs and symptoms that are suggestive, though not conclusive, of a pattern of abuse. The presence of bruise marks or petechiae on the soft palate may be a sign of forced oral sex. Bilateral bruising on the corners of the mouth may reflect the use of ropes or a gag placed in an effort to control or discipline the child. Similarly, bilateral bruising of the neck may be the result of an attempt to choke or shake a child. Torn frenal attachments or lacerations of the tongue, gingiva, or oral mucosa are also signs that bear further inquiry. Extensive traumatic damage to deciduous or permanent teeth, such as fractures, avulsions, or luxation, without a viable explanation is also suggestive of child abuse. When a parent or caregiver is reluctant to discuss the nature of the injuries or makes statements that are contradictory or inconsistent with the injuries, further investigation into their origin is warranted.

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  20. Which of the following statements regarding domestic violence is TRUE?

    INJURIES ASSOCIATED WITH DOMESTIC VIOLENCE

    The injury patterns indicative of physical abuse and domestic violence in adults may be severe. Domestic violence involves people of all ages, races, socioeconomic classes, religious affiliation, or gender identity. However, domestic violence is predominantly perpetrated by men against women [57]. Beyond physical abuse, domestic violence can include psychologic abuse, sexual assault/rape, coercive behavior, threatening words or gestures, stalking, and attempts to isolate the victim from family and friends. In the absence of an admission or a plea for help from the victim, there are clinical signs that are strongly suggestive (though not definitive) of domestic violence. The oral mucosa may be bruised when slaps or hits push the intraoral tissues against teeth or bony prominences; the skin over the affected area may also exhibit bruises. Bilateral bruises on the neck and petechiae or bruising patterns on the face or neck may reflect attempts to strangle or shake the victim. Current or previous fractures of the nose, maxilla, or mandible (as evidenced by radiographic findings) alone or in conjunction with soft tissue injuries in various stages of healing should result in nonjudgmental and sensitive questioning regarding possible abuse.

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  • Participation Instructions
    • Review the course material online or in print.
    • Complete the course evaluation.
    • Review your Transcript to view and print your Certificate of Completion. Your date of completion will be the date (Pacific Time) the course was electronically submitted for credit, with no exceptions. Partial credit is not available.