Extra-oral examination
A general appraisal of the patient should he made andany cuts, abrasions, swelling, or bruises noted. A simple line drawing can bemade in the notes to indicate the extent of the injuries. The bony borders ofthe maxilla and mandible should be palpated, unless the extent of any oedemamakes this too uncomfortable. In addition, the tcmporo-mandibular joint shouldbe palpated during opening and closing of the mouth. Deviation on opening andclosing may indicate a fracture of the neck of the condyle on one side.Extra-oral wounds, particularly of the lips, should be palpated gently todetect the presence of any tooth fragments or foreign bodies.
Intra-oral examination
The oral soft tissues and gingivae are examined forbruises, abrasions, or cuts, general health, and a careful record made.
The slide of occlusal development should be examined,and any occlusal problems, especially related to the trauma, noted. A fullorthodontic assessment, taking into account any specific problems withindividual traumatized teeth can be made at a later date. This avoids hasty,and often inappropriate, decisions being made at a time when the child andparents are in an emotional state.
A full dental charting is carried out so that anyother relevant problems, such as dental caries, are not overlooked.
The traumatized teeth may now be examined moreclosely. A note is made of the extent of any coronal injury from slight craningof the enamel to complex coronal fractures involving enamel, dentine, pulp and(sometimes) cementurn. The position of the tooth/teet h should be noted asshould any abnormal mobility, tenderness, or displacement. It is often usefulto draw the extent of any dental injury on the trauma record proforma. If teethhave been displaced, il should now lie determined if there is interference withthe opposing teeth, pre venting proper closure. Tenderness of a tooth or groupof teeth is suggestive of displacement or alveolar fracture.
Special investigations
Assessment of vitality
Teeth which have recently been injured, frequentlyfail to respond to conventional vitality testing. Also, the patient may be sodistressed following their accident, that it is impossible to obtain a reliableinterpretation of any stimulus applied to the teeth—for example, the slight pressure from an electric pulptester probe, placed on a tooth which is tender to palpation, may bemisinterpreted as a positive response to electrical stimulation. Nevertheless,il is important (O attempt to obtain a response fo such testing lo provide abaseline for the interpretation of future results and to assist in assessingthe prognosis for maintenance of tooth vitality in the long term.
Several methods for assessing pulp vitality have beendescribed. For general clinical purposes, thermal and electrical stimulation ofteeth is satisfactory. However, teeth tested soon after trauma may be concussedand fail to respond. If can be several months before the ability of the toothto respond returns: decisions with regard lo loss of vitality may, therefore,have to be delayed for a considerable period. Apparently undamaged adjacentteeth are often used as a ‘control’, but the fact that these teeth may alsohave been injured should not be overlooked.
Thermalvitality lasting
Ethylchloride is usually used for this test—a cotton pledget or roll is soaked withethyl chloride, evaporation allowed for some seconds and the resulting verycold cotton wool applied to the labial surface of the tooth. It is a simple,cheap method, but the intensity of the stimulus is not controlled and may.therefore, be difficult to reproduce.
Hot guttapercha has also been used—a stick of gutta percha is softened in a hot airhealer and then applied to the middle of the labial surface of the tooth to betested. It is important to coat the tooth surface first with petroleum jelly(Vaseline) lo prevent the gutta percha from sticking to the tooth and causingpain. Despite difficulties in standardizing this test, it does provide a reasonablyreliable result even in teeth with immature roof form.
Electricalvitality testing
A varietyof electrical devices have been developed for testing pulp vitality. One designwhich has been found to give consistent and reliable results is the Analytictechnology pulp tester. The instrument delivers an electric current in acontinuous series of 10 millisecond pulses with the stimulus level indicated bya digital read-out with a scale range of 0-80. The tooth is dried, theconducting tip of the tester is coaled with a suitable electrolyte (e.g.acidulated phosphate fluoride gel) and placed against the tooth. When rubbergloves are worn by the clinician an additional electrode is held by the patientto ensure completion of the electrical circuit. Integrity of the circuit iscontinued by illumination of an LED near the lip of the probe. The intensity ofthe stimulus increases automatically with time, the rate of increase beingpreset by the dentist. When the patient indicates that they can feel thestimulus, the probe is lifted from the tooth. The digital read-out remains for10 seconds. When the probe is applied to another tooth the instrument resets itself,hi clinical practice, this electric pulp tester is simple to use. with theadvantage that readings taken over several visits can be compared.
Nevertheless,no pulp testing method is completely reliable. A poor correlation has beenshown between the histological condition of the pulp and vitality lest results,to the extent that teeth with necrotic pulps have been known to respond toelectric pulp testers. The interpretation of such results is furthercomplicated by the fact that injured teeth, especially involving luxation,frequently show- a reduced or negative response. Also, teeth with an immatureroot anatomy (i.e. most, oro-dental injuries in children) often show little orno response whether or not they have been injured. On the other hand, teeth undergoingorthodontic movement often show a heightened response. To improve thereliability of such tests, two methods (one thermal and one electrical) areoften used.
Another,non-invasive, method which is undergoing clinical development at the time of writing,is laser Doppler flowmetry, a method which attempts to identify the presence orabsence of the flow of blood through the tooth. This will clearly be of greatbenefit in all types of assessment, but most particularly in cases where theblood How and innervation of the tooth has been interrupted (e.g. replantedteeth) and stimulation of the nerve cannot be expected to be successful formany weeks because of the slowness of re-innervation. One other method is thetest cavity. This is probably the most reliable method but more difficult tojustify as. unlike the other methods, it is invasive. One justification for itsuse may be when a tooth has been kept tinder review for many months and theresults of vitality testing and radiographic examination continue to beequivocal. In such circumstances, a test cavity will enable a firm diagnosis tobe made and appropriate treatment carried out.
RADIOGRAPHICEXAMINATION
The use ofextra-oral and intra-oral radiographs arc indispensable in the diagnosis of oro-dentaltrauma,
Extra-oralviews
The twomain views used are the panoramic tomograph and lateral soft tissue view, usingan occlusal (57 mm x 76 mm) fllm.
Panoramictomograph
Thiswell-established view provides a survey of the whole of the maxilla andmandible including parts of the zygomatic arches and both mandibular condyles.Fractures in the body of the mandible and the alveolus are easily visualized.Although the posterior teeth arc well shown, a disadvantage of the technique isthai the front of the mouth is usually unclear or distorted due to superimposilionof the spinal column.
