Introduction to Dental Trauma
Managing Traumatic Injuries in the Primary Dentition
An injury to the teeth of a young child can have serious and long-term consequences, leading to their discoloration, malformation, or possible loss. The emotional impact of such an injury can be far reaching. It is therefore important that the dentist treating children is:
The purpose of this chapter is to provide a straightforward approach to managing dental injuries in the primary dentition. Techniques for diagnosis, treatment, and follow-up care are described. Fundamental issues covered in this chapter, such as classification of injuries, history, examination, and pathologic sequelae of trauma, pertain to both the primary and permanent dentitions. Chapter 34 will focus on management of injuries to young permanent teeth and will refer to this chapter for the information just noted. The principles gleaned from both chapters should enable the dentist to manage the great majority of dental injuries encountered in children.
The most frequently injured teeth in the primary dentition are the maxillary incisors. Primary molars are rarely injured, and when injury occurs it is usually due to indirect trauma (e.g., blows to the underside of the chin causing the mandible to close forcefully against the maxilla). Primary incisors tend to be luxated more than permanent teeth. This is due to the spongy nature of the bone in young children and to the lower root/crown ratio in comparison with that of permanent teeth.
Although reports of injuries in preschool children presenting for dental treatment show that the majority of children suffer from luxation injuries,1,2 epidemiologic studies in the community show that crown fractures are the most common injury to the primary teeth.3–5 These injuries, however, may result in only minor inconveniences that do not motivate parents to seek professional dental advice.
By the age of 5 years, up to 40% of boys and 30% of girls have experienced traumatic injuries to their teeth.6 The peak age of injuries to the primary teeth is 2 to 4 years when children are developing mobility skills. Children with protruding incisors, as in developing class II malocclusions, are two to three times more likely to suffer dental trauma than children with normal incisal overjets.
Another major cause of dental injuries in young children is automobile accidents. Unrestrained children who are seated or standing often hit the dashboard or windshield when the car is stopped suddenly. All states now have laws mandating use of child restraints in automobiles, and it is hoped that universal adoption of these laws will decrease the incidence of all trauma to children in automobile accidents.7
Children with chronic seizure disorders experience an increased incidence of dental trauma. Frequently, these high-risk children wear protective headgear, and the fabrication of custom mouth guards for them is indicated (see Chapter 40).
Another serious cause of dental injuries to young children is child abuse. Often overlooked by the dental profession, up to 50% of abused children suffer injuries to the head and neck. Cardinal signs of abuse are injuries in various stages of healing, tears of labial frena, repeated injuries, and injuries whose clinical presentation is not consistent with the history presented by the parent.3 Battered children frequently lie to protect their parents or out of fear of retaliation. Dentists are required by law to report cases of suspected child abuse (see Chapter 1 for more specific details).
Tooth fractures may involve the crown, root, or both (Figures 15-1 to 15-3; see also Figures 34-1 to 34-3). Fractures of the crown may be limited to the enamel, may involve the dentin, or may include the pulp. Injury to the pulp is the most complicated and demanding to manage.
As just mentioned, luxation (displacement) injuries are the most common types of injuries to primary teeth that are treated in the dental office. These injuries damage supporting structures of the teeth, which include the periodontal ligament (PDL) and the alveolar bone (see Figure 15-1). The PDL is the physiologic “hammock” that supports the tooth in its socket. Maintaining its vitality is the primary objective in the management of all luxation injuries. Several types of luxation injury occur.6
FIGURE 15-4 A, Intruded maxillary left primary central incisor. B, Periapical radiograph showing the left maxillary primary central incisor after intrusion. The shortened and more opaque image of the intruded tooth, as compared with that of the right central incisor, indicates that the root has been pushed labially and away from the underlying permanent tooth. (From McTigue DJ: Managing injuries to the primary dentition, Dent Clin North Am, 53:627–638, 2009.)
4. Extrusion: This is a central dislocation of the tooth from its socket (Figures 15-5 and 34-16, A). The PDL is usually torn in this injury.
FIGURE 15-5 Extrusion of the left maxillary primary central incisor. A, Clinical view. B, Radiographic view. Notice the pulp canal obliteration in the right maxillary primary central incisor, which resulted from a previous injury.
Obtaining an adequate medical and dental history is essential to proper diagnosis and treatment. The medical history should already be on record if the child suffering an injury is brought to his or her regular dentist. Frequently, however, a parent will take an injured child to the closest dentist or to one known to treat children. Thus, with the confusion of a young injured child entering the office for possibly the first time and disrupting the day’s schedule, the potential to forget to gather important historical information is great. The use of a trauma assessment form to help record data and organize the management of care is highly recommended (Figure 15-8).
The issue of tetanus protection is particularly important when a child has suffered a dirty wound (an avulsion), a deep laceration, or an intrusion injury in which soil is embedded in the tissues. Wounds containing necrotic tissue, dirt, and foreign material should be cleaned and debrided as an essential part of tetanus prophylaxis. Children acquire active immunity through a series of five injections of adsorbed tetanus toxoid, usually completed by the age of 4 to 6 years. These are normally administered as part of the diphtheria-tetanus-pertussis immunizations. Children should then receive a booster of tetanus toxoid at 11 to 12 years of age and again 5 years later.8 An increasing number of reports have indicated that children in the United States are not receiving their childhood immunizations appropriately. If there is any question about the adequacy of a child’s tetanus protection, the child’s physician should immediately be consulted.
Three important questions are asked in gathering the dental history: when, where, and how did the accident occur? The time elapsed since the injury occurred is a major factor in determining the type of treatment to be provided. The dentist should also determine whether the tooth had been injured previously or whether the injury had first been treated elsewhere.
Where the injury occurred sheds light on its severity. Did the toddler slip and hit the coffee table in the living room, or did she fall off her parent’s bicycle in the park? This information can help determine the need for tetanus prophylaxis as well as signal a need to rule out more serious injury to the child.
How the accident occurred obviously provides the dentist with the most information regarding severity. Serious head injuries should be ruled out by the dentist’s asking if the child lost consciousness, has vomited, or is disoriented as a result of the accident. Positive findings indicate potential central nervous system injury, and medical consultation should be immediately obtained.9 Tecklenburg and Wright note that significant head injuries can lead to symptoms many hours after the initial trauma, and they caution parents to watch for the signs noted previously for 24 hours, which includes waking the child every 2 to 3 hours through the night.10
As previously discussed, the possibility of child abuse can also be ruled out through a careful dental history. Any history of previous dental injuries should also be determined because their sequelae may complicate diagnosis of the current injury.
Directing attention to the specific teeth involved, the dentist should ask the child if there is spontaneous pain from any teeth. Positive findings here may indicate pulp inflammation that is due to a fractured crown or injuries to the supporting structures such as extravasation of blood into the PDL. Does the child experience a thermal change with sweet or sour foods? If so, dentin or pulp may be exposed. Are the teeth tender to touch or tender while chewing? Does the child note a change in occlusion? These findings may indicate a luxation injury or an alveolar fracture.
Once the medical and dental histories are complete, the dentist is ready to begin the clinical examination. It is very tempting to focus immediately on a fractured or displaced tooth and thus miss other important injuries. A disciplined approach to a complete clinical examination should be followed in diagnosing every traumatic injury.
A complete examination should rule out injuries to the child’s facial bones.11 The facial skeleton should be palpated to determine discontinuities of facial bones. Extraoral wounds and bruises should be recorded. The temporomandibular joints should be palpated, and any swelling, clicking, or crepitus should be noted. Mandibular function in all excursive movements should be checked. Any stiffness or pain in the child’s neck necessitates immediate referral to a physician to rule out cervical spine injury.
All soft tissues should be examined and any injuries recorded. The presence of foreign matter in lacerations of the lips and cheeks, such as tooth fragments or soil, should be identified. Removal at the initial appointment will eliminate chronic infection and disfiguring fibrosis.
Each tooth in the mouth should be examined for fracture, pulp exposure, and dislocation. In some crown fractures, only a very thin layer of dentin remains over the pulp, so that the pulp’s outline can be seen as a pink tinge on the dentin. The dentist should be very careful not to perforate this dentin with an instrument.
Displacement of teeth should be recorded, as well as horizontal and vertical tooth mobility. Increased mobility of an injured primary tooth is an indication of damage to the PDL unless the tooth is near natural exfoliation. Reaction to palpation and percussion of teeth is recorded. Percussion sensitivity is a good indicator of PDL inflammation.
Pulpal vitality testing is not routinely performed in the primary dentition. This is because the testing requires a relaxed and cooperative patient who can report reactions objectively, and some young children lack the ability to do so.
Radiographs are an important part of the diagnosis and management of dental injuries. They allow the clinician to detect root fractures, extent of root development, size of pulp chambers, periapical radiolucencies, extent and type of root resorption, degree of tooth displacement, position of unerupted teeth, relationship between the injured primary teeth and their permanent successors, jaw fractures, and the presence of tooth fragments and other foreign bodies in soft tissues. Although some radiographs will show negative findings at the initial appointment, they are nonetheless important as baseline documentation. Subsequent radiographic evidence can thus be compared with the initial films.
There is no “standard series” of radiographs for dental injuries. All films taken should clearly show the apical areas of traumatized teeth (see Figure 18-15, C). In cases in which root fractures are suspected, a second or third radiograph should be made from slightly different angles both vertically and horizontally to verify the location and extent of the fracture.
To determine the presence of foreign bodies such as tooth fragments in the lips or tongue, one fourth of the normal exposure time is used. The film is placed beneath the tissue to be examined, and the radiograph is exposed (Figure 15-9).
As noted previously, many pathologic changes are not immediately apparent in radiographs. After approximately 3 weeks, periapical radiolucencies that are due to pulpal necrosis can usually be detected. In addition, inflammatory root resorption may be evident at this time. After approximately 6 to 7 weeks, replacement resorption, or ankylosis, can be seen. Thus there is adequate rationale to obtain postoperative radiographs at 1 month following the injury. In the absence of any clinical signs or symptoms, such as development of swelling, fistula, mobility, tooth discoloration, or pain, additional films are not indicated until 6 months after the injury. If changes are to appear radiographically, they usually do so by this time.
Enamel cracks and small fractures are common findings in primary teeth (see Figure 15-2). It is believed that even fractures exposing dentin in primary teeth have no deleterious effect on the pulp and need not be covered. In the case of larger fractures, treatment is often indicated to restore aesthetics. Various methods have been suggested to restore the fractured crown, including use of strip crowns, preformed aesthetic crowns, and open-faced steel crowns (see Chapter 21).
If it is decided to avoid crown restoration, possibly due to the child’s age and/or behavior, sharp edges at the fracture line can be smoothened with abrasive disks to prevent irritation to the tongue and lips. The exposed dentin should be carefully examined to ensure that there is no exposure of the pulp. If tooth fracture is associated with a wounded lip, then a radiograph of the lip s/>