A study on the reason of extraction, length, number and transverse morphology of the root and root canals of 100 extracted first permanent mandibular molars / 实用口腔医学杂志

To investigate the reason of extraction, length, number and transverse morphology of the root and root canals of first permanent mandibular molars. 100 extracted first permanent mandibular molars were collected. The length of mesial and distal root of the first permanent mandibular molars was 13.00 mm and 13.51 mm separately. 75% double roots and 25% three roots were observed under the stereomicroscope. Difference of root number and shape of transverse morphology in mesial root were more obvious than those in distal roots of the same first mandibular molars in this study.

A study on the reason of extraction,length,number and transverse morphology of the root and root canals of 100 extracted first permanent mandibular molars / 实用口腔医学杂志

To investigate the reason of extraction,length,number and transverse morphology of the root and root canals of first permanent mandibular molars.100 extracted first permanent mandibular molars were collected.The length of mesial and distal root of the first permanent mandibular molars was 13.00 mm and 13.51 mm separately.75% double roots and 25% three roots were observed under the stereomicroscope.Difference of root number and shape of transverse morphology in mesial root were more obvious than those in distal roots of the same first mandibular molars in this study.

Study on the length,number and transverse shape of the root canals of the first maxillary molars in vitro / 实用口腔医学杂志

Objective:To investigate the root length,number and the transverse shape of first maxillary molars using root sectioning technique. Methods:100 isolated first permanent maxillary molars from above 20 years old patients were collected. The roots were cross-sectioned in three parts(superior 1/3,middle 1/3 and apex 1/3) after measuring the length of roots. The transverse shape of root canals were observed under the stereomicroscope.The number and shape of root in three parts of roots were recorded. Results:The length of lingual root,MB and DB of the first maxillary molar is (13.82?1.51) mm;(13.06?1.12) mm and (11.64?0.85) mm respectively; complex degree of MB and DB of the first marxillar molar is very high. 51% double roots in superior 1/3 of MB were found. Above 50% dual roots in the middle 1/3and apex 1/3 in the mesiobuccal root of first maxillar molar were recorded. Conclusion:Root number and transverse configuration in MB and DB of first maxillary molar varied in different parts of roots; There may be double root canals in medium 1/3 and apex 1/3 in MB of first maxillary molar when one line type canal in superior 1/3 was found.