Treatment of ectopic first permanent molar teeth

The eruption of teeth is a complex process and can be disturbed by genetic, cellular, molecular or tissue causes.1 Ectopic eruption describes the eruption of a tooth into an atypical position.2 The incidence of ectopic eruption of maxillary first molars varies between 2% and 6%.3 It affects both sexes equally.1 It occurs 25 times more often in the maxilla than mandible.4 The aetiology is not completely understood. Local factors have been suggested.5 A strong genetic element, including a higher incidence in patients with cleft lip and palate, has also been reported.6^,7 Ectopic eruption is classified according to its effect on the primary second molar tooth1 (Table 1 and Figure 1). Ectopic molars can be further differentiated into reversible (permanent molar spontaneously self corrects and erupts in a normal position) or irreversible (permanent molar remains blocked by the primary molar). The aims of treatment of an irreversible ectopic first molar tooth are movement of the tooth distally to regain space and correction of the mesial angulation to allow normal eruption.8 Spontaneous correction can occur, but in the majority of cases this will have occurred before seven years of age.9 This paper will describe the management of ectopic first permanent molars, using clinical examples to illustrate the available treatment options.