Assertion: isthmus | /r/HasProperty | 3 mm to 4 mm
Facets:
Source sentences:
text: Von Arx8 reported that, in cases requiring root-end surgery, the incidence of an isthmus 3 mm to 4 mm from the apex in the MB roots of the maxillary first molars and the M roots of the mandibular first molars was 76% and 83%, respectively.