The clinical significance of the retromolar canal and foramen in dentistry

Abstract

The mandibular canal is nowadays acknowledged as a major trunk with multiple smaller branches running roughly parallel to it. Most of these accessory canals contain branches of the inferior alveolar neurovascular bundle that supplies the dentition, jawbone, and soft tissue around the gingiva and lower lip. This article reviews the prevalence, classification and morphometric measurements of the retromolar canal and its aperture. A retromolar canal is a bifid variation of the mandibular canal that divides from above this main canal, and travels anterosuperiorly within the bone to exit via a single foramen or multiple foramina into the retromolar fossa. This foramen, termed the retromolar foramen, allows accessory branches of the inferior alveolar neurovascular bundles to supply tissues at the retromolar trigone. Clinically, it is of the utmost importance to determine the exact location of the mandibular canal and to identify its retromolar accessory branches when surgery in the posterior mandible is to be performed.

Mandibular canal vs. inferior alveolar canal: Evidence‐based terminology analysis

“…The articles that were included in the IAC/IANC group were excluded from this group. The most recent, consecutive 50 articles containing “mandibular canal” but neither “inferior alveolar canal” nor “inferior alveolar nerve canal” were included (defined as the MC group) (Abd Fattah, Hariri, Nambiar, Abu Bakar, & Abdul Rahman, 2019; Al‐Shayyab, Qabba'ah, Alsoleihat, & Baqain, 2019; Alves, Dias, Mansa, & Machado, 2020; Arias et al, 2019; Bosykh, Turkina, Franco, Franco, & Makeeva, 2019; Bozkurt & Görürgöz, 2019; Burian et al, 2019; Cârstocea, Săndulescu, Hostiuc, & Rusu, 2020; M. H. Chen et al, 2019; Costa et al, 2019; Esposito et al, 2019; Felice et al, 2019; Felice, Barausse, Pistilli, Ippolito, & Esposito, 2019; Fistarol, De Stavola, Fincato, & Bressan, 2019; Freire, Nascimento, Vasconcelos, Freitas, & Haiter‐Neto, 2019; Friedrich, Matschke, & Wilczak, 2019; Iwanaga et al, 2020, 2020; Iwanaga, Wong, Kikuta, & Tubbs, 2019; Kalabalik & Aytuğar, 2019; Koç, Eroğlu, & Bilgili, 2019; Komal, Bedi, Wadhwani, Aurora, & Chauhan, 2020; K. C. Lee, Yoon, Philipone, & Peters, 2019; Liye et al, 2019; Matsuda, Yoshimura, & Sano, 2019; Matzen, Petersen, Schropp, & Wenzel, 2019; Matzen, Villefrance, Nørholt, Bak, & Wenzel, 2020; Munhoz, Arita, Nishimura, & Watanabe, 2019; Na et al, 2019; Ngeow & Chai, 2020a, 2020b; Nicol, Loncle, Pasquet, & Vacher, 2019; Okumuş & Dumlu, 2019; Oliveira et al, 2019; Ozdede, 2020; Pedersen, Matzen, Hermann, & Nørholt, 2019; Predoiu, Rusu, & Chiriţă, 2019; Puciło, Lipski, Sroczyk‐Jaszczyńska, Puciło, & Nowicka, 2020; Raju et al, 2019; Sahl, Alqahtani, Alqahtani, & Gallez, 2018; Satir, 2019; Sholapurkar & Davies, 2019; Sinha et al, 2019; Sun et al, 2019; Tereshchuk & Sukharev, 2019; Uğur Ay...…”

“False” foramina and fissures of the skull: a narrative review with clinical implications

“…Additional named passageways include the internal acoustic meatus, jugular foramen, and hypoglossal canal, which are passages for CN VII-XII and important vasculature, including the internal jugular vein [45]. Variant skull foramina include the orbitomeningeal, retromolar, and sphenoidal emissary foramina (28,31,36).…”

Prevalence and morphometric analysis of the retromolar canal in a Spanish population sample: a helical CT scan study

“…RMC prevalence very much changes in previous studies and might stem from the different exploration methods followed, from varying RMC concepts, and is considered a relevant anatomical independent variation or a BMC subtype given the differences in the sample well by number, composition or genetic factors ( 9 ). The works that have studied its prevalence by analysing panoramic radiographs have detected minor prevalences than those obtained by cone-beam computed tomography (CBCT) ( 3 , 10 ). Differences in prevalences have also been observed in some studies according to the population groups that formed the sample: Asia (between 8.5% and 75.4%) ( 5 , 11 ) and Europe (from 16.12% to 71.9%) ( 12 , 13 ).…”