Molar tooth anatomy
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Molar Tooth Anatomy
Mandibular First Molar Root Anatomy
Root and Canal Configuration
The mandibular first molar typically presents with two roots, although variations exist. A systematic review of 18,781 teeth found that 13% of mandibular first molars had a third root, with the incidence strongly correlated to ethnicity. The mesial root commonly has two canals (94.4%) and occasionally three (2.3%), with the most frequent canal system configuration being Vertucci type IV (52.3%). The distal root predominantly exhibits a type I configuration (62.7%), followed by types II (14.5%) and IV (12.4%).
Clinical Implications
The complex root canal morphology of the mandibular first molar necessitates advanced diagnostic approaches and clinical skills to ensure successful endodontic treatment. The presence of isthmus communications, averaging 54.8% in the mesial root and 20.2% in the distal root, further complicates the treatment.
Maxillary First and Second Molar Root Anatomy
Root and Canal Configuration
Maxillary first molars typically have three roots, with 95.9% conforming to this structure, while 3.9% have two roots. The mesiobuccal root often contains two canals (56.8%), with a higher incidence observed in laboratory studies compared to clinical studies. The distobuccal and palatal roots usually have one canal each, with incidences of 98.3% and over 99%, respectively.
Fusion and C-shaped Canals
Fusion of roots occurs in approximately 5.2% of maxillary first molars, and C-shaped canals are rare, found in only 0.12% of cases. In maxillary second molars, 43% exhibit fused roots, and the prevalence of two canals in the mesiobuccal root decreases with age.
Maxillary C-shaped Molars
Prevalence and Types
C-shaped molars in the maxilla are uncommon, with a prevalence of 1.1% in first molars and 3.8% in second molars. Five distinct types of C-shaped configurations have been identified, involving various combinations of root fusions. Understanding these configurations is crucial for proper endodontic treatment.
Mandibular and Maxillary Third Molars
Anatomical Variability
Third molars exhibit significant anatomical variability. In mandibular third molars, 17% have one root, 77% have two roots, 5% have three roots, and 1% have four roots, with canal numbers ranging from one to six. Maxillary third molars show similar variability, with up to five roots and a corresponding range of canal numbers.
Clinical Considerations
The unpredictable anatomy of third molars poses challenges for endodontic treatment. Detailed imaging, such as cone-beam computed tomography (CBCT), is often necessary to accurately diagnose and treat these teeth.
Conclusion
The anatomy of molar teeth, particularly the root and canal configurations, is highly variable and complex. Successful endodontic treatment requires a thorough understanding of these anatomical variations and the use of advanced diagnostic tools. Ethnicity, age, and specific tooth type significantly influence the root and canal morphology, necessitating tailored approaches for effective clinical outcomes.
Sources and full results
Most relevant research papers on this topic