Trauma and Loss of One or More Maxillary Permanent Incisors
Loss of one or more maxillary permanent incisors directly or indirectly as the result of trauma is a shocking experience for the patient and patient’s family. It often requires dental first aid and subsequent dental intervention. Questions as to what future treatment will be required soon arise.
The long-term planning and related treatment usually are better placed in the hands of an orthodontist than a general dental practitioner. The latter does, of course, need the knowledge to collaborate intelligently in the long-term planning and to contribute his or her wider knowledge of the patient and patient’s family circumstances.
In this chapter consideration will be given successively to replantation, loss of a tooth either directly after trauma or at a later time, variations in loss, the time when trauma occurred, setting up of a treatment plan, particularly in regard to the dental arch relationships, principles of treatment, guidelines for the positioning of substituting teeth, and ultimately the problems of retention and the postretention period.
When a permanent tooth is dislodged in an acccident and the alveolar process is reasonably intact the tooth should be replaced as soon as possible. This is recommended not only for psychological reasons but primarily because it is often the most effective treatment from a dental point of view. However, every minute counts. After 30 minutes outside the alveolar process the prognosis for lasting success is already unfavourable, especially when the tissues around the tooth dry out.6 Finding the lost tooth very quickly is essential. This needs to be followed by the patient cleaning the root by sucking it in his or her mouth (or as second choice with milk or by rinsing it under a tap). Directly afterwards the tooth should be pushed back into place and held fast as well as possible. If that cannot be done, the patient (or parent) should keep the tooth in the mouth under the tongue until a dentist or oral surgeon can be reached who can replant it. If the above routine cannot be followed for unavoidable reasons, the next best thing is to place the tooth after cleaning it, but without interfering with the root surface (which should by no means be rubbed), in a cup with milk or in a water-soaked sterile gauze pad or other soft material, and seek professional help.
Professional dental attention is required for provision of a splint. This can be accomplished using composite resin reinforced with steel wire. This is better than ligating a preformed stainless steel wire splint in place with metal ligatures, which until recently was the preferred approach. Because the traumatized tissues may bleed, it may not be easy to maintain the perfectly clean field necessary for reliable bonding, but it is much easier on the patient, who has already suffered enough, than any other approach.
An antitetanus injection is essential if the patient is not currently protected. It will soon be necessary to perform a root canal treatment. Trauma involving damage of gingival tissues makes plaque removal more difficult and painful. By rinsing with a chlorhexidine solution, plaque accumulation can be reduced and healing enhanced.
Only after ample time has passed can an assessment of the future life of the replanted tooth be relied on. They seldom last more than 10 years. In devising a long-term treatment plan therefore, one must take account of the likely unfavourable prognosis, certainly when the tooth has been out of the alveolus for a long period and has become dry. Extraction of such teeth should be envisaged and planned for.
When avulsed teeth have not been replanted or subsequently have been lost, the loss is difficult for the patient and parents to cope with. They are anxious to know what must be done and what the end result will be. They will rightly ask their family dentist for information and advice. His or her task is to give them guidance about the possibilities and limitations of the treatment available both in general dentistry and orthodontics. Moreover, another aspect of the dentist’s task may be, if required, to provide a temporary prosthodontic appliance to camouflage the defect. Such an appliance should not interfere with spontaneous changes that may benefit orthodontic therapy.
If a tooth has suffered trauma but has not been knocked out, it may still be impossible or undesirable to retain it. This applies particularly to teeth of which the pulp vitality has been lost with a root which is only partly formed, especially where the root canal diverges at the apex. However, in certain cases apexification can still be obtained by filling the root canal with calcium hydroxide. When this treatment fails and a wide divergent apex remains, extraction is indicated. This also applies to teeth with one or more fractures. Extraction must also be considered when a major part of the crown has been fractured, because repair will have long-term limitations.4–6
Fortunately in many cases of trauma to maxillary incisors it is feasible to preserve the involved teeth. Teeth that have been well treated endodontically can be moved orthodontically without concern. If there is any reason to anticipate apical root resorption, the root canal filling might be placed a little short of the apex.201
Where a major fracture of the crown has occurred apical to the gingival margin, the provision of a crown restoration is improved and facilitated by first extruding the tooth in question. Such a procedure may also be useful with minor fractures, not just in the provision of a crown but also in building up the defect with composite resin.
After trauma (particularly intrusion), teeth may develop ankylosis. In such cases alveolotomy with “en bloc” surgical relocation of the involved teeth can be considered, particularly for adults.
In most cases trauma will involve one or two central incisors in the maxilla. In proportion, this will occur much more often in cases of large overjets than in normal incisor relationships. In addition, injuries to maxillary anterior teeth occur most in the age range of 7 to 10 years, and more often to boys than girls. It seems clear that the lack of lip coverage for the maxillary incisors will also contribute to their vulnerability. Injuries involving only a lost lateral incisor are rare.4, 39, 118, 149
It makes a difference if the trauma occurs in the first transitional period or (much) later. When loss of an incisor has occurred at an early age it is still possible to guide the development of the dentition (see 10.8), but such is not the case when an incisor is lost from a complete permanent dentition. In that situation a prosthodontic solution is more likely to be sought, although it is still possible to close the space using orthodontic appliances.
The moment when trauma occurred determines the time when it will be possible to make a diagnosis and formulate a treatment plan. Shortly after the accident a long-term treatment plan should be made. From this come measures that may be instituted prior to the use of appliances. Those measures will not be described further here but are found in Chapter 10. The train of thought that forms the basis of the treatment plan required after loss of maxillary incisors is largely the same as that involved in cases of agenesis of one or two maxillary lateral incisors. For example, extraction of a second (or first) deciduous molar should be considered on the side on which one central incisor has been lost.
With the traumatic loss of a maxillary incisor the possibility of transplanting an unerupted premolar should also be considered. This applies particularly when two incisors on one side have been lost. It is not possible to move a tooth across the median suture in the maxilla. The possibility of transplanting a tooth later does not detract from the importance of quickly replanting an avulsed tooth. Even if transplantation will be performed later, it will be better if a socket already exists from the replanted tooth than if it has to be constructed in a partly resorbed alveolar process. The indications and procedures involved in transplanting teeth can be found in the specialist fields of orthodontic and surgical treatment.103, 104, 112, 152, 200, 231
Moving a lateral incisor into the place of a lost central incisor usually involves building up the crown of the lateral incisor to a size more in keeping with its location. Thanks to the availability of composite resins and veneers of other tooth-coloured restorative materials, this alteration can be realised nowadays without grinding the tooth and without fear of pulp damage.72a, 182, 183, 183a Surgical adjustment of the cervical gingiva can be performed if the clinical crown height is too small and the gingival contour does not match that of the adjacent teeth.243 Finally the possibility of placing a metallic implant to substitute for a lost incisor is mentioned. This approach should be considered particularly when two incisors on one side have been lost. However, facial growth should be completed before the implant is inserted.
Generally speaking, the remarks made concerning dental arch relations and agenesis (see 10.7) also apply to this situation. Because most cases involving trauma to incisors exhibit molar disto-occlusion, a solution involving preservation or emphasis of this condition will usually be the most convenient.
Table 11-1 and Fig. 11-1 present a survey, if incomplete, of the standard orthodontic solutions to the problems related to loss of one or more maxillary incisors. Reference to the information given in Chapter 10 makes further description unnecessary. However, perhaps with excess zeal, a number of basic principles are recalled in the next para/>