The Incidence of Radiographic Lesions of Endodontic Origin Associated With Uncomplicated Crown Fractures of the Maxillary Fourth Premolar in Canine Patients.

Fractured maxillary fourth premolar teeth are commonly diagnosed in canine patients. These fractures are subdivided into uncomplicated and complicated, depending on absence or presence of pulp exposure, respectively. Pulp injury associated with fractures can lead to pulpitis, pulp necrosis, and "lesions of endodontic origin" (LEO) on intraoral radiographs. The incidence of LEO associated with uncomplicated crown fractures (UCFs) of the maxillary fourth premolar in canine patients is currently unknown. We hypothesized that a significant number of UCFs of the maxillary fourth premolar would have LEO evident on intraoral radiographs. The purpose of this article was to identify this incidence and to illustrate the importance of radiographing these teeth. This was a retrospective study of 111 UCFs and 500 nonfractured (control) maxillary fourth premolars in domestic canine patients. The frequency of LEO was 24.3% (27/111) in the UCF population and 0% (0/500) in the control population (P < .0001). These findings are important because UCFs are sometimes ignored or considered insignificant, when in fact a large proportion of them have LEO, indicating periapical pathology. These results suggest that all UCFs be radiographed, even if there are no other abnormalities noted on clinical oral examination.