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.
