A rare case of unerupted second deciduous molar located inferior to the second premolar: case report.

Tooth eruption is defined as the movement of a tooth from its site of development within the alveolar process to its functional position in the oral cavity [Massler et al., 1941]. The process of tooth eruption can be divided into different phases: pre-eruptive bone stage, alveolar bone stage, mucosal stage, preocclusal stage, occlusal stage and maturation stage [Andreasen et al., 1997]. Any disturbance in these phases can lead to eruptive anomalies. The incidence of unerupted teeth is usually higher among permanent teeth than among deciduous ones [Walker et al., 2004; Otsuka et al., 2001; Amir et al., 1982; Broadway, 1976; Pinborg et al., 1970]. Of the primary teeth reported as unerupted, second primary molars are the teeth most frequently involved [Walker et al., 2004; Otsuka et al., 2001; Bianchi et al., 1991; Ranta et al., 1988; Tsukamoto et al., 1986; Amir et al., 1982], followed by primary central incisors [Otsuka et al., 2001].This paper presents a case of inversion of the intraosseous position of a second unerupted deciduous molar and the succedaneous second premolar.