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From this discussion, it is clear that the timing and nature of the surgical procedure are determined at the time of the initial diagnosis, by the degree of development of the teeth concerned.

The first scenario occurs at an early stage, when a radiographic survey of a very young child may reveal pathology, such as a supernumerary tooth, an odontome, a cyst or a benign tumour, which appears likely to prevent the normal and spontaneous eruption of a neighbouring tooth. In such a case, it would be inappropriate to expose the crown of an immature tooth. One would not want to encourage the tooth to erupt before an adequate (half to two‐thirds) root length has been produced. Secondly, at that early stage of its development, the tooth cannot yet be considered to be impacted. Given time and freedom to manoeuvre, the tooth will probably erupt by itself.

Early exposure risks the possibility of damage to the crown and to the subsequent root development of the tooth. On the other hand, however, it would not be wise to ignore the situation after the discovery of the pathological condition (Figure 1.9). The potential for impaction has been revealed and leaving the condition untreated may worsen the prognosis. Accordingly, the appropriate treatment at this stage might be the removal of the pathological entity, without disturbing the adjacent permanent teeth or their follicular crypts. It may then reasonably be expected that normal development and eruption will occur in due course. However, while this is clearly the desirable course of action, access to the targeted area may be impeded by the proximity of adjacent developing structures, so that delay may still be advisable. A competent oral and maxillofacial surgeon should be consulted.

The second scenario occurs when the discovery of the pathological condition is only made when the patient is much older. In this case (Figure 1.10), the superiorly displaced central incisor has a two‐thirds root and is ready for eruption. The appropriate treatment here is to extract the deciduous and supernumerary teeth and hope that this will encourage eruption of the permanent incisor. In many scenarios, spontaneous eruption may be expected even with a closed apex, provided there is adequate space in the dental arch and little or no displacement of the impacted tooth [15, 16].

As we shall see in subsequent chapters, there are several situations and tooth types where spontaneous eruption may not occur, or may not occur in a reasonable time‐frame. This will be so in the case of severe displacement of the affected tooth. In these instances, it may be necessary to supplement the natural eruptive potential of the tooth and divert it mechanically, with the use of an orthodontic appliance.

Fig. 1.9 (a) Chance finding of mesiodens in a 4‐year‐old child. (b) Chance finding of odontoma in a 1‐year‐old infant.

Fig. 1.10 An 8‐year‐old child exhibits an unerupted maxillary left central incisor with two supernumerary teeth superimposed, pointing in opposite directions. The permanent incisor is developed adequately for eruption (retarded eruption) and the deciduous incisor is over‐retained.