Anatomy and Function of the Mandibular Canal
- The mandibular canal is a canal within the mandible.
- It contains the inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein.
- The canal runs obliquely downward and forward in the ramus.
- It then runs horizontally forward in the body of the mandible, under the alveoli.
- The mandibular canal communicates with the alveoli through small openings.

Branches and Connections of the Mandibular Canal
- The mandibular canal carries branches of the inferior alveolar nerve and artery.
- It is continuous with the mental foramen, which opens in the mental region of the mandible.
- The mental foramen carries the distal fibers of the inferior alveolar nerve as the mental nerve.
- The mandibular canal is also connected to the mandibular foramen on the medial aspect of the ramus.
- The mandibular nerve enters the mandibular foramen to become the inferior alveolar nerve.

Variations of the Mandibular Canal
- The retromolar canal is a common variant (~10% of canals) that terminates in the retromolar region.
- A bifid canal is another variation (~41% of canals) that may follow the course of the main mandibular canal before re-joining it or terminate at the apex of a tooth.
- An accessory mental foramen is another variant where the canal opens as an additional mental foramen.
- A trifid mandibular canal variation has also been described.

Clinical Implications and Complications
- The mandibular canal often runs close to the apices of the third molar tooth.
- During the removal of the third molar, the inferior alveolar nerve can be damaged, causing sensory disturbance.
- Care must be taken during the removal or root canal treatment of the second or first molar teeth to prevent nerve injury or extrusion of root canal filling materials.
- Bleeding may occur during surgery in the retromolar region due to the presence of the retromolar canal.
- Variations in the mandibular canal anatomy should be considered in dental procedures to avoid complications.

Additional Images and References
- Additional images of the mandibular nerve and bone can provide visual references for better understanding.
- References from Gray's Anatomy and other scientific articles are available for further study and research.
- The prevalence and characteristics of accessory mandibular canals have been studied using cone beam computed tomography.
- Prevalence studies have also been conducted on bifid and trifid mandibular canals using cone beam computed tomography.
- The clinical relevance of bifid and trifid mandibular canals has been explored in oral and maxillofacial surgery.