Mandibular Morphology

A clinician should have complete knowledge of anatomic variation of macrostructure and internal and external root canal anatomy. A successful endodontic treatment includes locating the root canal orifice ,chemico mechanical cleaning and shaping of root canals before a dense root canal filling with a hermetic seal. It is known that mandibular first molar can display significant anatomical variations namely as number of roots, number of root canals and morphology.
The presence of an additional root located lingually (the radix entomolaris) or buccally (radix paramolaris) has been reported some times in mandibular molars. However, in such a case, an awareness and understanding of this unusual root and its root canal morphology can contribute to

The study carried out by Sperbergh (8) in African population showed a maximum frequency of 3%, while in Eurasian and Indian population as reported by Tratman (9) the frequency is less than 5%. Mongoloid traits (such as Chinese, Eskimo and American Indians) Curzon (10) have noted that the RE occurs with a frequency that changes from 5% to more than 30%. Ferraz (11) reported that in Caucasians the RE is not very common and with a maximum frequency of 5.4 to 4.2% is considered to be unusual and dysmorphic root

Small type: length shorter than half of the length of the distobuccal root.
2. Conical type: smaller than the small type and having no root canal within it.
Radix paramolaris (additional root located buccally)
Prevalence: Bolk reported the occurrence of radix paramolaris [13]. Radix paramolaris is very rare and occurs less frequently than radix entomolaris. Visser reported the prevalence of radix paramolaris to be 0% for mandibular first molars, 0.5% for second molars and 2% for third molars [14].
Classification: Carlsen & Alexandersen (1991) classified radix paramolaris (RP) into two different types:
1. Type A: cervical part is located on the mesial root complex.
2. Type B: cervical part is located centrally, between the mesial and distal root complexes.
Morphology: The radix paramolaris (RP) is located mesiobuccally. The dimensions of RP may vary from short conical extension to a mature root which can be separate or fuse. Few observations can be made from various studies, i.e. an increased number of cusps is not necessarily related to an increased number of roots; however, an additional root is always associated with an increased number of cusps, and with an increased number of root canals
Clinical