Frequency and anatomical features of the mandibular lingual foramina: systematic review and meta-analysis

Lingual mandibular foramina are peculiar anatomical variations often present on the bone surface of the inferior jaw. These structures host vascular and nervous anastomosis deriving from the branches of the submental artery, lingual artery, and the mylohyoid nerve. Reports pointed out intra-operative massive bleeding accidents during implant interventions occurred in this area. The aim of this systematic review and meta-analysis was to summarize quantitatively the features of the lingual foramina on the midline of the inferior jaw. We performed a systematic review and meta-analysis complying the PRISMA statement and registering it in PROSPERO database. The frequency rate of the foramina resulted to have a point estimate of 0.965. The means of the diameters showed to have a point estimate of 0.840 with a standard error of 0.06. The results showed a significant high frequency reported in the literature of this variation, with a quite important diameter, sign of significant caliber of the related vessels. Even if this variation is underreported in modern textbooks of oral anatomy, we suggest an accurate screening via CT scan pre-operatively. In addition, a proper risk management is necessary to minimize injure hazard and properly managing the vascular plexus of the anterior floor of oral cavity.