The Midline Mandibular Lingual Canal: Importance in Implant Surgery

Abstract

2Running title: Implants near the midline mandibular lingual canal Abstract Purpose: To determine the position and occurrence of the midline mandibular canal (MLC) in the various age, sex, population and dentition groups. The average distances from the MLC to a planned mandibular midline implant and the inferior mandibular border were measured. Materials and methods: Cone beam computed tomography (CBCT) was used to scan 122 mandibles (31 black males; 28 black females; 32 white males and 31 white females). Midsagittal sections in the reconstructed images of edentulous mandibles or sagittal sections through the socket of the 41 tooth (FDI nomenclature) in dentate mandibles were made. A measurement of 6 mm across buccolingually (BL) was delineated with the caliper tool indicating the minimum dimensions for placement of an implant. In dentate cases where the BL distance was in excess of 6 mm, the caliper was placed across the deepest part of the socket as a marker to determine the bone dimension available below the socket for implant placement. From these markers a vertical line was dropped to the MLC to measure the available bone. Results: The MLC was a consistent finding within the anterior mandible.A statistical significant difference in bone availability amongst the sexes and with dentition pattern was found indicating that edentulous female patients were particularly at risk of injury to the vessels of the midline lingual canal during implants in that area. Conclusion: Immediate implants in the position of lower central incisors are regarded as a safe procedure as is the placement of interforaminal implants in the anterior mandible. Clinicians should however take note of the position of the midline mandibular lingual canal and approach this area with caution, especially if the alveolar ridge is to be reduced before implant placement.

Arterial blood supply variation in the anterior midline mandible: Significance to dental implantology

“…A minimum bone thickness of 6 mm would be required for successful placement of a standard-sized ±4-mm-diameter implant [11]. In the current study, the bucco-lingual thickness of the mandible at the level of the MMLF ranged from 8.00 to 12.91 mm (mean = 10.89 mm ± 1.24 SD).…”

“…The MMLF is a consistent structure through which the sublingual artery enters the mandible [8, 11]. Perforation of the lingual plate by an implant drill poses a high risk of trauma to this vessel especially when the sublingual fossa is very pronounced because this vessel courses closely to the gland and fossa [13].…”

“…Oettle et al [11] reported a distance ranging from 10.83 to 12.874 mm in a dry mandible study of both black and white South Africans. In their study, cone beam computed tomography (CBCT) was used to scan the mandibles.…”

“…This foramen is a constant finding and has an intra-osseous part, midline mandibular lingual canal (MMLC), which contains a blood vessel that is prone to transection during routine dental implant placement [7–11]. It has been found that vessels travelling horizontal to the direction of an implant drill, but perpendicular to the spin of the drill, are at the greatest risk of laceration and transection [6, 7].…”

“…A higher risk of trauma exists in some situations like where the alveolar ridge is severely resorbed, or where trimming of the ridge has to be done either to reduce excess bone or to create a flat site for drilling, because this procedure brings the MMLC closer to the superior aspect of the mandible [11]. Drilling deeper into an extraction socket to obtain primary implant stability is now an acceptable procedure which increases the risk of bleeding.…”