Guidelines for the treatment of tooth injuries


I present these guidelines as a service to the public and the dental profession. It is intended as guidance only. For a comprehensive discussion readers are referred to the excellent textbook by prof Jens Andreasen and co-workers, Textbook and Color Atlas of Traumatic Injuries to the Teeth.


The prognosis of all injuries is vastly improved when the correct treatment is carried out as soon as possible, preferably immediately, after the injury. All patients should be immediately transported to the office of a dentist. If any teeth had been totally fractured or avulsed (knocked out) the tooth fragment or tooth should be located and transported to the dentist. 


For the public


Supervisors, teachers, other children, doctors and nurses are often the first line of treatment for tooth injuries. The correct management of these injuries at the location of the accident (swimming pool, rugby field, ice rink, playground) can often make the difference between the permanent loss or otherwise of a permanent tooth. 


The first step is to check for other injuries which might require priority treatment, especially the eyes and brain. Look at the eyes, including the pupils. Abnormal dilatation might indicate brain trauma. If there is any sign of eye or brain trauma the patient should be transported to a hospital. Bleeding should be controlled and back or neck injuries should also be managed by professionals. In all these cases the priority of the tooth injuries should be secondary. However it should not be totally ignored. Of grave importance is to account for all teeth. If teeth had been knocked out locate the teeth. Failure to find all the teeth should be followed up because teeth may have been inhaled or ingested. 


In the absence of any serious or life threatening injuries the mouth should be examined and the extent of the injuries assessed. If any significant bleeding occurs from any site in the mouth or from the lips apply a wet tea bag to the area and ask the patient to bite on the tea bag. If any teeth appears to be fractured attempt to find the fragments (broken bits) and transport it with the patient to the dentist. Often these fragments can be bonded back to the teeth. 


The most significant impact on the well being of these patients by members of the public is the treatment of cases of the avulsed (knocked out) tooth. That is where the tooth has been totally knocked out of the mouth. Quick and correct management of these cases by an astute bystander can make a major difference. The best treatment is to immediately replace the tooth into the tooth socket. Any dirt or grass should be washed off first and the tooth gently put back into the tooth socket, taking care not to do it the wrong way around. If it is done properly and within 30 minutes chances are 90% that the tooth will grow back to the bone with no side effects. Once a blood clot has formed in the tooth socket a dentist should take the responsibility of removing the blood clot and replanting the tooth. If it is not possible (for the bystander or emergency treating person) to replant the tooth the patient should be taken to the dentist immediately. In cases like these the tooth should stored in a container of milk or saline, if that is available. 


Remember, the tooth can be replanted with great success for up to two hours after being knocked out. However when treatment is delayed beyond two hours the tooth will definitely require root canal treatment. Also, teeth have been replanted with some success even twenty four hours after accidents. 


For the dental profession


The first step in the treatment of all trauma cases is the taking of the medical and dental history. Of great significance is the history of the trauma and the exact time of injury. The prognosis of the condition is greatly influenced by the nature of the injury and the time delay and should be clearly documented for future treatment planning and possible legal and insurance issues. The prognosis must be communicated to the patient and parents. 


Examination of the extra-oral tissues should be carried out and should include some observation of vital signs (respiration, pulse, blood pressure, pupils, skin colour, behaviour). If any neurological, cardiovascular or ophthalmic injury is suspected the patient should be immediately hospitalized for observation. The facial structure and TM joints should be examined for lacerations and signs of mandibular, maxillary, alveolar or zygomatic fractures. The intra-oral soft tissues (tongue, cheeks, mouth flour, lips) should be examined for lacerations. Lacerations should be appositioned and sutured but highly visible facial lacerations should ideally be treated by a plastic and reconstructive surgeon. In emergencies the dentist will be obligated to provide this service.


The occlusion must be examined to assess the stage and nature of development. It is pointless to expend resources and energy at primary teeth which are due to exfoliate soon. (It is interesting to note that class two cases are more prone to trauma to maxillary teeth.) Unnatural posterior open bites may be a sign of jaw fractures. Shifted midline or trysmus may indicate condylar fractures.


The periodontium must be examined for signs of swelling, sulcular bleeding or lacerations. Lacerations should be sutured and sulcular bleeding noted for future reference because it may predispose to resorption. Swellings should be further investigated because it may be a sign of an alveolar fracture.


Finally the teeth must be examined visually and tested for vitality/sensibility. If possible the extent of the injuries should be recorded photographically. Fractures, displacements and mobility should be noted. Previous restorations and decay or discolouration should also be noted. The results of vitality/sensibility testing should be noted but not accepted in isolation. It is well known that trauma to teeth could give false positive or false negative responses for up to three months post-operatively. Teeth or pulps should not be lightly condemned to root canal treatment based upon the results of vitality/sensibility testing alone.


The clinical examination should be followed by radiographic examination. Fractured teeth should be investigated by at least two peri-apical radiographs. These can be supplemented by occlusal and or panoramic radiographs or even computed tomography.

All radiographs should be studied with extra care and all findings noted and communicated with the patient and or parent.


After the examination a clear and definitive diagnosis should be made, recorded and communicated. Treatment options and prognosis, including complications should be discussed without compromising the treatment unnecessary. The emergency nature of the treatment and the urgency of it arguably justifies the exercise of discretionary judgement unlike in the case of elective, normal dentistry. The dentist providing emergency treatment may be excused for using his or her own discretion rather than the parent�s wishes, if the latter were �unreasonable�. 


The differential diagnosis of trauma to teeth


The following is a classification of the most commonly seen conditions caused by trauma to the teeth.

Concussion

Crown fracture   

2.1Enamel  fracture                                                                                                      

2.2 Enamel and dentine without pulpal exposure                                                                

2.3 Enamel and dentine with pulpal exposure

Root fracture 

3.1 Vertical root fracture                                                                                   

3.2 Horizontal root fracture

Combination crown and root fracture

Subluxation 

5.1 Palatal sub-luxation                                                                                      

5.2 Labial sub-luxation                                                                                                       

5.3 Lateral sub-luxation                                                                                                      

5.4 Partial extrusion

Intrusion

Avulsion     



Treatment


Treatment of injuries to primary teeth


The treatment of injuries to primary teeth is primarily concerned with prevention of damage to the permanent successors. Overzealous treatment of the primary teeth may actually cause more harm than do any good and dentists are warned to beware of falling into the trap of unnecessary treatment. The most important part of the treatment is the examination, diagnosis and long term observation. The value of any treatment should always be weighed against the potential harm or side effects.


Concussion. Concussion is merely treated with tender, loving care and long term observation. There is no displacement and usually no bleeding or laceration. The only significance is the possible sequela of eventual pulpal necrosis. An initial and regular follow up clinical examination and peri-apical radiographs are indicated. One simple and highly significant clinical sign is a localised area of redness, or later a draining fistula, over the apex of the affected tooth. Pulpal necrosis and peri-radicular infection will be confirmed by a peri-apical radiolucency. This condition can develop months or even years after the incident of trauma. Treatment of definite infection (abscess) is root canal treatment, extraction or perhaps even observation only, in cases of low compliance.

Crown fractures without pulpal involvement can be treated by smoothing of sharp edges or if indicated, by resin composite restorations. When the pulp has been exposed,  root canal treatment has to be carried out, or the teeth extracted.

Root fractures are treated  by removal of any coronal fragments only. No attempt should be made to remove any apical fragments because the procedure may cause damage to the permanent teeth. Apical fragments left behind usually undergo spontaneous resorption.

Combination of crown and root fractures are similarly treated by removal of coronal fragments.

Sub-luxation injuries may require some repositioning which would necessitate anaesthesia. Palatal sub-luxation is of very little consequence because the apex would be transpositioned labially, posing no real threat to the permanent tooth. The tooth may be left as it is, as the tongue will eventually move the tooth back to its original position. Labial sub-luxation is a greater problem because the apex is forced palatally, resting against the crown of the permanent tooth. A labially sub-luxated tooth should be extracted or in very selected cases repositioned and splinted for one week. In the latter case the parents should be very well informed of the dangers and the case should be extremely well monitored. A laterally sub-luxated tooth or partially extruded tooth should  also be extracted and only rarely repositioned and splinted. A surprising number of sub-luxated primary teeth undergo spontaneous healing. It is therefore prudent to very carefully consider the value of any invasive therapy before it is initiated. Regualr re-examination is indicated with particular emphasis on the development of pulpal necrosis.

Intrusion does not present a great danger to permanent teeth, because the permanent teeth are situated palatally to the apices of the primary teeth. However a number of these injuries do lead to some discolouration of the permanent teeth. The most common lesion is a white spot on the labial surface of the permanent tooth. Extraction is the treatment of choice for the intruded primary tooth but in certain cases the tooth/teeth may be left as it is. This usually results in spontaneous re-eruption. Regular follow up re-examination is indicated

Avulsed primary teeth are not replanted, under any circumstances.


Treatment of injuries to permanent teeth


Concussion injuries are best left alone and regularly re-examined for signs of pulpal disease. Also remember to observe for signs of dystrophic calcifications in the pulp. It is often seen that permanent teeth respond to trauma by calcification in the pulpal space. This can become a problem eventually with almost total obliteration of the pulpal space. It is an open question if and when to initiate root canal treatment in these cases and the decision may be influenced by operator bias and ability. Some cases may eventually develop resorption as a result of the trauma to the periodontal ligament or more correctly the cementum. This resorption may be self limiting in the case of surface resorption but it may become aggressive in the case of pulpal necrosis because it will take the form of inflammatory resorption.

Crown fractures are treated according to common sense. One significant issue affecting treatment can be the availability of the fractured fragment. Tooth fragments can be successfully re-bonded with modern bonding agents and resin cements, not with regular cements. It is of vital importance to obtain a clean and dry working field using rubber dam and to follow the manufacturers� (of the bonding agent and resin cement)instructions to the letter. It is important, for instance, to etch, rinse and prime both the tooth in situ and the fragment as prescribed. Crown fractures involving a pulpal exposure will require either root canal treatment or a pulp capping procedure. In cases of incomplete root or apex formation it is of vital importance to maintain pulpal vitality because this can ensure root and or apex formation. In these cases the integrity of the pulp may be conserved by means of a pulp capping or a partial pulpotomy, pulpotomy or partial pulpectomy. The decision to do one of these procedures is dictated by the time of exposure to the oral environment and its bacteria. Fresh exposures can be capped by mineral trioxide aggregate(MTA) and restored by resin composite. The problem is that MTA requires moisture for optimal setting and resin composite requires a relatively dry environment, two mutually exclusive concepts. Another issue is that of disinfection of the exposed pulp. It makes good sense to disinfect the pulp but the choice of disinfection agent is difficult. A very mild solution of sodium hypochlorite or electrolysed saline can be used. The exposed and disinfected pulp is covered with MTA, the MTA  is covered with a wet cotton wool pledget which is encapsulated in a non-eugenol containing material such as polycarboxylate and the tooth then restored with resin composite. The pulp capping material is re-accessed one day later, the cotton wool pledget removed and the cavity restored. This procedure can be simplified by electing to skip the wet cotton wool pledget but that compromises the setting of the MTA somewhat. Regular re-observation is again indicated as pulpal necrosis and or resorption may develop at any stage.

Vertical root fractures are treated by extraction. There is no alternative. Fortunately these are rare. Horizontal root fractures are indeed one of the most interesting phenomena in dentistry because they require no treatment at all. There are a number of well documented cases which has shown that these teeth can heal totally without the need for any treatment. The exception to the rule are cases where the fracture line is close to or adjacent to the alveolar cresta. In these cases the tooth may be lost. Other cases with the fracture line slightly below the alveolar cresta may exhibit mobility which may benefit from some splinting. A few cases will develop necrosis of the coronal pulp requiring root canal treatment which can be limited to to the coronal part of the canal up to the fracture line. Once a true peri-apical radiolucency develops around a tooth with a horizontal fracture the tooth should in all probability be surgically removed.

Combinations of crown and root fractures are again treated by means of common sense and ingenuity. In a few cases it will be possible to re-bond the fragment in its entirety and in other cases an artificial prosthesis (resin composite or porcelain onlay) will follow root canal treatment and or periodontal crown lengthening procedure. In most cases these teeth will eventually make way for an implant supported prosthesis and the main intention of the emergency treatment will be to maintain the tooth until maturity and this in order to prevent resorption of bone.

Sub-luxation injuries of permanent teeth require repositioning, sometimes splinting and periodic re-evaluation. The immediate esthetic issue is of great concern to the patient but the essential problems of these injuries are pulpal and periodontal survival. These injuries are also sometimes complicated by concomitant alveolar bone fractures. Strangely the alveolar bone fractures are of no great consequence and may in fact be �beneficial�. When a root is forced against the alveolar bone the precementum is damaged and this predisposes to resorption. When the alveolar bone is fractured it means that the precementum has been spared the compression injury and resorption is less likely. The alveolar fragment, attached as it is to the tooth, is simply repositioned, together with the tooth and the tooth then splinted  for a period of one week. It will always be the labial bone plate that fractures, not the palatal. Various methods have been proposed for splinting eg orthodontic wire and resin composite but the simplest method is to etch the tooth and adjacent teeth and bond a section of very heavy fishing line (80 pound plus) to the labial surfaces. It allows for physiological movement, a prerequisite for healing. Partial extrusion cases sometimes present with a blood clot which had co-agulated apically and prevents repositioning. Extraction, curettage and intentional replantation may be considered in extreme cases. In al cases the keyword is follow up. Vitality/sensibility testing should be instituted at the sixth week and the case re-examined monthly. If signs of pulpal necrosis and or resorption become evident root canal treatment must be carried out without delay.

Intrusion injuries have a bad prognosis. The majority of cases will eventually require root canal treatment and despite this will develop resorption. The cause of this can be traced to the massive trauma to the precementum. Emergency treatment consists of  repositioning with the aid of extraction forceps and splinting for three to four weeks. Root canal treatment should be done at the earliest sign of pulpal necrosis or resorption.

Avulsion injuries are the most dramatic injury to teeth. It has a highly variable prognosis which is heavily influenced by the actions taken in the first two hours after the accident. Replantation within thirty minutes after avulsion has a 90 percent success rate, including maintaining pulpal vitality. Thereafter the prognosis worsens dramatically. Replantation after 30 minutes invariably requires root canal treatment.  The cells of the periodontal ligament have a reasonable chance of survival in the first two hours after avulsion and will do even better if reconstituted with an isotonic solution such as Hank�s Balanced Salt Solution (HBSS). Upon receiving the tooth lightly wash the tooth with HBSS and allow the tooth to lie in the solution for five minutes. Thereafter replant and splint. After two hours all the cells of the periodontal ligament would have died and must be removed before replantation. Scrape the surface of the root clean with an hand instrument and wash liberally with water as there is no need for HBSS. If possible the contents of the pulp chamber can also be removed before replantation. Splinting is done in the same way as for sub-luxation injuries and again for only one week. Regular follow up is scheduled and root canal treatment carried out when necessary. The worst complication following replantation is resorption. A large percentage of cases develop resorption. Certain teeth also undergo ankylosis and then replacement resorption, ultimately leading to loss of the tooth. Even in these cases the treatment is beneficial because the replacement reorption creates an almost ideal implant bed which would otherwise not have developed.


Lastly, every case should be carefully assessed for the need for a tetanus booster and or antibiotic therapy. This is largely dependent upon the extent of lacerations and soiling of wounds.

Dr Koos Marais practises in the east of Pretoria. His practice is limited to endodontics and orofacial pain.

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