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There are significant differences in the adult and pediatric dentitions that impact their treatment in the Emergency Department (Figure 182-1). The pediatric dentition is known as the primary or deciduous dentition and consists of 20 teeth, which includes 8 incisors, 4 canines, and 8 molars. The adult dentition consists of 32 teeth and is composed of 8 incisors, 4 canines, 8 premolars, and 12 molars. The variable absence of a tooth or the addition of an extra tooth is common in either dentition. The teeth in both the pediatric and adult dentitions erupt in a predictable sequence, albeit with considerable individual variation (Figure 182-1). Treatment strategies differ for permanent versus deciduous (primary) teeth as well as by the age of the adult tooth. Exercise great care when evaluating patients with a “mixed” dentition, roughly between the ages of 6 and 12 years.
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The anatomy of a tooth is rather simple (Figure 182-2). The tooth itself consists of a neurovascular pulp surrounded by supportive dentin, which is surrounded by a hard thick crown of enamel. The crown portion lies above the gum line or gingiva. The root portion lies embedded within the alveolar bone of the jaw, anchored by a thin layer of cementum and the periodontal ligament. The alveolar bone, periodontal ligament fibers, and fragile cementum cell layer taken together are considered a functional unit known as the attachment apparatus. A complete attachment apparatus requires a fully formed root apex. Immature adult teeth do not have a fully formed apex and necessitate special attention to maintain pulpal viability.2,4,5
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Mechanisms of tooth injury include direct trauma (i.e., a blow) or occlusive trauma (i.e., biting on a hard object or a seizure). These mechanisms can result in a spectrum of injury patterns that vary from simple sensitivity to complete tooth avulsion. The fracture of any portion of the tooth, whether the crown or the root, falls in the middle of this spectrum and is frequently seen in the Emergency Department.4
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Appropriate treatment of dental injuries requires a thorough history and meticulous examination of the oral cavity, including subsequent radiographs after ruling out more serious injuries. Historically, important points include the age of the patient, the time of the trauma, the mechanism of injury, teeth or tooth pieces at the scene, subjective disturbance of bite, and treatments provided since the time of the incident. The physical examination must include an assessment of the extraoral and intraoral soft tissues, bony displacement, missing teeth, crown fractures, pulp exposures, tooth sensitivity, and tooth mobility. This chapter focuses primarily on tooth fractures, while luxation and avulsion injuries are dealt with in Chapter 181.
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The need for radiographs with dental trauma is worth emphasizing. A tooth that is missing, both by history and physical examination, may be found completely intruded below the gum line, impacted within the perioral soft tissues, floating within the maxillary sinus or stomach, or even aspirated. Obtain facial films if a tooth, or a portion of a tooth, cannot be unequivocally located by history or physical examination. Strongly consider obtaining chest and abdominal radiographs if the tooth, or portion in question, is not visualized on the facial films.6–11 Any available tooth fragments, whether retrieved from the scene, the patient's perioral soft tissues, or the patient's pocket should be saved and stored for potential use during the definitive care process by the Dentist.9,12–14 Bonding techniques in the Emergency Department are not prudent due to multiple potential complications including bond failure and tooth fragment aspiration.
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Fractures involving the crown of the tooth are commonly described in the emergency literature using the Ellis classification system (Figure 182-3).2,4–6,15,16 An Ellis I fracture involves only the enamel portion of the tooth. These injuries typically are not sensitive or painful. They can result in a sharp edge of enamel that may irritate the tongue and other adjacent soft tissues. Emergency treatment may be as simple as smoothing the rough edge with an emery board or similar instrument.2,4,14,17 These injuries frequently involve the prominent anterior teeth and may be cosmetically unappealing. Reassure patients with these concerns that aesthetic restorations are possible by their Dentist.4–6,15,18 Forewarn patients with even minor trauma and sensitivity that unseen or undiagnosed trauma at the apex of any traumatized tooth, even with an appropriately treated crown fracture, can compromise the blood flow to the pulp and obviate the need for root canal therapy.4,18 Both primary and permanent teeth with these fractures can be treated in a similar fashion.14,19
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The Ellis II fracture involves the dentin. It can be recognized by the yellow to pink hue of the dentin in contrast to the white of enamel. This fracture allows for potential contamination of the dentin microtubular networks by oral bacteria that may eventually compromise the pulp if not treated. Dentin is alive and formed by the pulp. It is sensitive to temperature, osmotic gradients, and mechanical forces. Dentin is laid down concentrically from within the pulp chamber as the tooth ages. Therefore, children have less dentin than pulp (as compared to adults) and their pulp is less insulated against trauma and subsequent infection. Children under the age of 12 years with Ellis II fractures have a higher risk of complications and require more expeditious follow-up.2,5,14,18 Refer these patients to a General or Pediatric Dentist as soon as possible.
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Emergency treatment for Ellis II fractures consists of applying a protective dressing which is also sedative to the pulp. Examples include Dycal (L.D. Caulk Co., Milford, DE) and IRM (L.D. Caulk Co., Milford, DE). These materials need to cover the entirety of exposed dentin (and therefore the dentinal tubules) in order to protect the pulp from contamination. These materials are then often covered with a sealant such as Copalite (Cooley & Cooley, Houston, TX), clear acrylic nail polish, or a dental bonding resin.2,3,5,6,14,15,18,20 Some authors have suggested that a non-light cured glass ionomer cement replace the long held standard of Dycal.3 While these materials may offer some advantages, they can be expensive and tricky to use.18
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Tissue adhesives such as Dermabond (Ethicon, Inc., Somerville, NJ) have been suggested as alternative dressings in the treatment of Ellis II dental fractures.21–23 This should be discouraged as its effects on pulpal tissues via exposed dentinal tubules have not been studied and are unknown. Physicians may actually be causing harm by using this material on exposed dentin.
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Both primary and permanent teeth with Ellis II fractured can be treated in a similar fashion. However, like immature permanent teeth, primary teeth with Ellis II fractured require special care and more expeditious follow-up.14,19
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The Ellis III fracture involves exposure of both the dentin and the pulp. This is identified as a reddish tinge or subtle bleeding from the exposed dentin. Frank pulpal exposures are obvious. The pulp is highly vascular and exquisitely sensitive due to exposed nerve endings. The pulp is exceedingly vulnerable to bacterial infection if exposed. These fractures constitute a true dental emergency and should be evaluated immediately by a Dentist for possible emergent root canal therapy or extraction. Although less than ideal, minimal pulp exposures (less than 1 to 2 mm) may be treated as Ellis II fractures with dental follow-up within 24 hours.2–6,14,15,18,19 Complete coverage of the fractured crown may be difficult in these cases. Dental dry foil or tin foil may provide adequate coverage. Any root canal manipulation is fraught with complications, even in the hands of Endodontists. Emergency Physicians are well advised to avoid these procedures.2,15,18
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Fractures of the root are much less common than crown fractures and occur in less than 7% of dental injuries.2,4 Root fractures are uncommon in primary teeth as they have short roots.2 Root fractures may be described as either horizontal or vertical. Horizontal root fractures are described according to their location along the tooth root (Figure 182-4). Vertical root fractures occasionally extend into the crown. All root fractures are prone to infection and impaired healing, and may ultimately lead to pulpal necrosis and tooth loss.
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The clinical diagnosis of root fractures is challenging at best, even with the aid of radiographs readily available in the Emergency Department setting (i.e., Panorex). Root fractures classically present with pain, mobility, and sometimes displacement of a tooth fragment. However, these fractures are often insidious and found only on dental radiographs after follow-up reveals continued sensitivity. Emergency Physicians must maintain a high level of clinical suspicion for these injuries and probably err on the side of cautious overtreatment.2,4
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Vertical root fractures and root fractures in the coronal portion of the root have a poor prognosis. Horizontal root fractures elsewhere along the tooth root have a good prognosis if treated before a coagulum can develop between the fragments, generally within 24 to 72 hours.2,15 Immediate reduction and immobilization with one of the various splinting techniques is the treatment of choice. Refer to Chapter 181 for the details regarding dental splinting techniques. Root fractures in the primary teeth require extraction.19