2 The mesiobuccal
cusp of mandibular first molar was deepest point of COS.
Only the mesial roots, comprising a total of 22 canals (12 mesiobuccal
and 10 mesiolingual) were used in this study.
The purpose of this study was to evaluate the effectiveness of naked eye examination and Dental-operating microscope (DOM) examination for the location of second mesiobuccal
canal (MB-2) in extracted maxillary first and second molars considering the sectioning of the tooth as gold standard for the location of MB-2.
Probing depth (PD), measured as the distance (mm) from the free gingival margin (FGM) to the bottom of the pocket; and gingival recession (GR), measured as the distance from the cementum-enamel junction (CEJ) to the FGM, were determined at 6 sites per tooth (mesiobuccal
, midbuccal, distobuccal, distolingual, midlingual, and mesiolingual sites) in all permanent teeth present, excluding third molars, using a mouth mirror (Mirror n[degrees]#5, Hu Friedy, Chicago, IL, USA) and a manual periodontal probe (PCPUNC-15, Hu Friedy, Chicago, IL, USA).
Initially four canals were located two mesials (mesiobuccal
and mesio lingual) and two distals (dis- tobuccal and distolingual).
It can also be easily seen that mesiobuccal
developmental groove of left lower anterior crown is on the distal side rather than on buccal side which confirms its horizontal rotation at 90 degrees.
The marginal flap in- cision started near the mesiobuccal
edge of the second molar to its distal surface.
Canal configuration of the mesiobuccal
root of the maxillary first molar of a Japanese sub-population.
In the present study, it was found that the highest marginal gap in the group I (PFM) was at Mesiobuccal
(MB) point i.e.
In Angle's Class I molar relation, mesiobuccal
cusp of upper first permanent molar lies in the buccal groove of lower first permanent molar.
The earliest published method of recording and classifying malocclusion on Cast was Angle's classification in 1899,5 Itis based on the correctrelationship of first permanent molar as its position remains constant following eruption and it is based when mesiobuccal
cusp of maxillary first molar occlude with the buccal grove of mandibular first molar.6 It is an easy method of assessing malocclusion on the study cast but it is the representative of only the dental classification in sagittal plane.
According to Angle's classification, Class II malocclusion is characterized by the position of the upper first molar in relation to the lower first molar in which the mesiobuccal
cusp of the upper first molar is positioned anteriorly in relation to the buccal groove of the lower first molar.