RT Journal Article
T1 Mentalis nerve branches supplying the lower lip revisited: a study of human fetuses and donated elderly cadavers
A1 Cho, Kwang Ho
A1 Sugiyama, Yuki
A1 Watanabe, Genji
A1 Hirouchi, Hidetomo
A1 Murakami, Gen
A1 Rodríguez Vázquez, José Francisco
A1 Abe, Shinichi
AB PurposeLittle information is known about the mentalis nerve course from the lower lip approximation margin (free margin) to the upper lip. Likewise, no difference in nerve distribution has been observed between the cutaneous and mucosal parts of the lip. Therefore, this study reexamined mentalis nerve morphology.MethodsFor macroscopic observations, three fresh cadavers were dissected (one male and two females; aged 78–93). We also evaluated histological sections obtained from five donated elderly cadavers (two males and three females, aged 82–96 years) and 15 human fetuses (11–40 weeks or crown–rump length 80–372 mm). Immunohistochemical analysis for S100 protein and tyrosine hydroxylase was performed.ResultsIn both fetuses and adult cadavers, one to three nerve branches ran upward in the submucosal tissue from the mental foramen. Near the free margin of the lip, some branches passed through the orbicularis oris muscle layer toward the lip skin, whereas others followed a reversed J-shaped course along the free margin. Nerve twigs ran in parallel beneath the mucosa, whereas wavy nerve twigs attached to the basal lamina of the lip epidermis. The difference in nerve endings abruptly occurred at the skin–mucosal junction. Tyrosine hydroxylase-positive sympathetic nerve twigs surrounded arteries and formed a branch composed of S100-negative unmyelinated fibers.ConclusionThe lower lip skin was innervated by a perforating branch passing through the orbicularis oris muscle, that was different from the lip mucosa. A sudden change in the nerve ending configuration at the mucocutaneous junction seemed to develop postnatally.
PB Springer
SN 0930-1038
YR 2024
FD 2024-04-29
LK https://hdl.handle.net/20.500.14352/108859
UL https://hdl.handle.net/20.500.14352/108859
LA eng
DS Docta Complutense
RD 6 abr 2025