trauma Flashcards
What are the appropriate tests to ensure an adequate diagnosis following dental trauma?
Clinical examination techniques for assessing the extent of injury to traumatized teeth include mobility testing, percussion sound, tenderness to percussion, and response to pulp testing. However, all these tests require clinical interpretation. For instance, mobility testing is not always clear as in the case of a luxation injury where the apex of the root may be locked in bone. A positive response to tenderness to percussion at the time of injury implies damage to the periodontal ligament and/or supporting structures. In contrast, persistent tenderness to percussion in the follow‐up period is usually related to pulp necrosis and infection. Furthermore, the assessment of pulp vitality following dental trauma is an important diagnostic challenge as temporary loss of sensibility often occurs following traumatic injuries to the teeth. For instance, pulpal edema can cause loss of sensibility as well as torn or severed neurovascular supply to the pulp. A non‐response to pulp sensibility testing also has prognostic significance in the follow‐up period. For example, a non‐ response to pulp sensibility may have prognostic significance, in relation to pulp canal obliteration after luxation injuries, tissue union following root fractures, and pulp necrosis in combined crown fracture luxation injuries. Even color changes in the crown are reversible over time and are not suggestive of pulp necrosis.Therefore, judicious clinical judgement is required in diagnosis following dental trauma. Photographic documentation is also important for complete trauma assessment and may be required for later treatment planning, research, or legal claims (Andreasen & Kahler 2015a).
All initial examinations should include a radio- graphic assessment. Important parameters include the stage of root development, injuries to the root and supporting structures, and any displacement of the teeth. It is recommended that radiographic assessment include three different angulations and a steep occlusal view.The use of cone beam‐com- puted tomography (CBCT) imaging has further enhanced trauma diagnosis, though generally CBCT should only be used when standard radiographic examination is unclear (Sigurdsson 2014; Andreasen
& Kahler 2015a). For instance, in this case presenta- tion, conventional radiographic techniques clearly diagnosed the avulsion and root fracture of tooth #8, obviating the need for CBCT imaging.
Radiographic observations indicating pulp necrosis and infection following root fracture include widening or a diffusely outlined periodontal space, a radiolucency adjacent to the root fracture, and external inflammatory root resorption usually apparent 2–8 weeks following the injury (Andreasen & Kahler 2015b). In traumatized teeth, even if the pulp is completely devitalized, no radiographic periapical lesion will develop unless the pulp becomes infected. However, traumatized teeth sometimes show radio- graphic transient apical breakdown, not due to pulpal infection (Andreasen 1986).
A clinician should therefore consider the patient’s presenting signs and symptoms, clinical test results and the radiographic assessments before deciding on any endodontic intervention. Often emergency care and further review may be all the treatment required.The aim of treating dental trauma is either to maintain or regain pulp vitality in traumatized teeth if possible (Sigurdsson 2014). However, this case report also highlights the importance of long‐ term follow‐up, as the adjacent teeth, which were seemingly unaffected at the time of injury, subsequently required endodontic management.
What are the important clinical parameters for outcomes for root‐fractured teeth?
In 2004, two landmark studies (Andreasen et al. 2004a, 2004b) of 400 root fractured teeth, showed 30% of teeth healed by hard tissue union of the fractured fragments, 5% healed with interposition of bone and connective tissue, 43% healed with interposition of connective tissue only, while only 22% showed non‐healing as a result of pulp necrosis and infection (Andreasen et al. 2004a). A young age, immature root formation, minimal mobility, positive pulp sensibility testing, and optimal positioning of the fractured fragments were positively associated with pulpal and hard tissue repair. Healing was progressively worsened with increased diastasis between the fragments. In these studies, the highest frequency of healing was associated with fiberglass splints (Andreasen et al. 2004b). Hence, as this case treatment was commenced in 2005, a fiberglass splint was employed. Unfortunately pulp necrosis and infection developed in this case and may have been due to the avulsion of the coronal fragment as discussed below.
What are the important clinical parameters for outcomes for avulsed teeth?
Many studies have reported higher failure rates for avulsed teeth with open apices when compared to mature teeth. In a study of 400 replanted teeth where revascularization was considered possible, only 34% subsequently showed this favorable healing outcome (Andreasen et al. 1995a). Pulp necrosis was generally evident after just three weeks. If revascularization did occur, pulp sensibility changes were usually noted at six months and often associated with signs of pulp canal obliteration (Andreasen et al. 1995b). In the presented case, a fractured root is similar to an open apex scenario, so the risk of pulp necrosis was higher. However, timely endodontic management prevented the common sequelae of inflammatory replacement resorption. The risk of cell death to the periodontal ligament cells and subsequent replacement resorption is related to increased extra‐alveolar storage time (Andreasen et al. 1995c). However, storage in milk for up to 3 hours has been shown to preserve the vitality of the periodontal ligament cells after extrac- tion in an animal model (Blomlöf et al. 1980). Therefore, immediate replantation is recommended. In this case replacement resorption was avoided.
What are the requirements for splinting of traumatized teeth?
The AAE guidelines for the treatment of trauma- tized teeth recommend that root fractured teeth should be splinted for four weeks. In contrast, an avulsed tooth should only be splinted for two weeks (Sigurdsson 2014). Clinical judgement was required in this rare concomitant injury of a root fracture and avulsion injury. A flexible splint is considered important for favorable healing of the periodontal ligament and less incidence of ankylosis and replacement resorption, presumably due to physi- ological stimulation at a cellular level (Kahler & Heithersay 2008). However, in high cervical root fractures a more rigid split with a longer splinting duration of four months is recommended (Sigurdsson 2014). Many studies have shown that the type of splint and splinting duration are not significant variables on either pulpal or periodontal
outcomes following trauma to the teeth (Andreasen et al. 1995b, 1995c; Andreasen et al. 2004b). In this case, a flexible splint was placed for three months as there had been significant bone loss along the lateral border of the tooth, and the family was away for two months for school holidays.The removal of composite resin is usually associated with some iatrogenic damage to the enamel. Recently, a new splinting regime has been advocated with resin activated glass‐ionomer cement suitable for ortho- dontic bracket cementation which has allowed the development of an alternative simplified splinting regimen for traumatized teeth, providing ease of application and removal with minimal or no iatro- genic to enamel (Kahler et al. 2016).
Endodontic management for infected root‐fractured teeth traditionally used long‐term calcium hydroxide (Ca(OH)2). What are the advantages/ disadvantages of using mineral trioxide aggregate (MTA)?
Pulp necrosis and infection following root fracture is usually limited to the coronal fragment. When the root canal is wide in immature teeth or mid‐root fractures, there are difficulties in achieving adequate obturation with gutta‐percha. Traditionally this has required the use of long‐term dressing with calcium hydroxide to create a hard tissue barrier at the fracture site, which then allows for a root filling to be placed.This procedure has been shown to have successful long‐term outcomes. However, the apical barrier is often irregular and consists of a cementum‐like calcific material that includes areas of soft connective tissue, and the procedure requires long‐term dressing with calcium hydroxide which may weaken the root. Furthermore, multiple appointments may be required before an adequate apical barrier is formed (Cvek 2007).
Mineral trioxide aggregate (MTA) placed at the level of the fracture site is an alternative to calcium hydroxide. MTA has excellent anti‐bacterial and osseo‐inductive properties. Histological studies have demonstrated a more homogenous calcific barrier for MTA barrier technique when compared to teeth treated with calcium hydroxide. MTA is resistant to microbial leakage due to its adaption to the root canal walls and penetration into the dentinal tubules (Parirokh &Torabinejad 2010). MTA also does not appear to weaken teeth as has been proposed for calcium hydroxide (Andreasen, Munksgaard & Bakland 2006). A number of case reports have shown good long‐term outcomes where MTA has been used.This case shows a successful 10‐year outcome.
