Aim To investigate the root and canal morphology of Burmese maxillary molar
s using a canal staining and tooth clearing technique.
Methodology Maxillary molars (239) were collected from indigenous Burmese p
atients and designated; first (90), second (77), third (72) molars. Followi
ng pulp tissue removal and canal system staining with Indian ink, the teeth
were decalcified with 10%. nitric acid, dehydrated and cleared with methyl
salicylate. The following features were evaluated: (i) number of roots and
morphology; (ii) number of canals per root: (iii) root canal configuration
(Vertucci's classification): (iv) number of apical foramina per root; (v)
number and location of lateral canals; and (vi) the presence of intercanal
communications.
Results All first and second molars had three separate roots. whilst third
molars had one of five different root forms, of which three separate (25%)
or fused (31%) roots were most prevalent. The majority of palatal (100%) an
d disto-buccal (96%) roots possessed one canal (type I). The prevalence of
mesio-buccal roots with two canals decreased from first to third molars (68
%, 49%, 39%, respectively); type II (two orifices, one apical foramen) and
IV (two orifices, two apical foramina) configurations were the most common.
Single/fused rooted third molars had a range of number and type of canals.
Most roots in all molars had one apical foramen, those with four apical fo
ramina were confined to third molars. Intercanal communications were most p
revalent in mesio-buccal roots and two/three fused rooted third molars. Lat
eral canals were most prevalent in the apical third of the roots of all mol
ars.
Conclusions The mesio-buccal roots of Burmese maxillary molars possessed a
variety of canal system types. Over 50% of the first and second molars had
a second mesio-buccal canal, of which over 20% had intercanal communication
s. The palatal and disto-buccal canals mainly had type I canals. Lateral ca
nals were equally prevalent in all tooth types but were most common in the
apical third.