The position of the mental foramen in dentate and edentulous mandibles: clinical and surgical relevance

BACKGROUND

The knowledge of the exact location of the mental foramen (MF) in dentate and edentulous mandibles is clinically important when constructing complete dentures, performing anaesthetic block of the lower-anterior teeth area and intervening in the MF nearby area. In edentulous mandibles, the bone resorption after teeth loss makes the mental nerve (MN) prone to damage due to the extreme location of the MF very close to the alveolar crest (AC). Chronic compression on the MN may result in pain in the area of MN distribution (ipsilateral face and cheek area) and numbness at the lower lip. The purpose of the current study is to evaluate the exact position of the MF, calculating the distances MF-superior border of the AC and MF-inferior border of the mandible (IBM) in dentate and edentulous mandibles.

MATERIALS AND METHODS

One hundred and two (36 edentulous and 66 dentate) adult dry Greek mandibles were studied.

RESULTS

In 9 out of 36 edentulous mandibles (25%), the MF was found nearby the AC, while in 27 edentulous mandibles (75%), the MF was located at an average distance 6.4 mm from the AC and 12.6 mm from the IBM. In 38 out of 66 dentate mandibles (57.6%), the MF was located at an average distance 13.6 mm from the AC and 15.2 mm from the IBM. The dental status significantly affected (p = 0.001) the distances MF-AC and MF-IBM. Side symmetry was observed for both dentate and edentulous mandibles (p = 0.39 and p = 0.45).

CONCLUSIONS

The MF is an important landmark and its location needs to be considered prior to dental implants placement in order to avoid the MN injury and related complications. The position of MF is altered in edentulous mandibles compared with the dentate ones. The MF is a symmetric structure in Greeks.

Anatomical variation and morphology in the position of the palatine foramina in adult human skulls from Greece

OBJECTIVE

To investigate the anatomical variability of the palatine structures in Greek population.

MATERIAL AND METHODS

71 Greek adult dry human skulls were examined to detect the position of the greater palatine (GPF) and lesser palatine foramina (LPF) related to adjacent anatomical landmarks.

RESULTS

The perpendicular distance of the GPF to the midline sagittal suture was 1.53 cm and 0.3 cm from the inner border of the alveolar ridge. The mean distance from the posterior palatal border was consistent 0.46 cm on the right and 0.47 cm on the left side of the skulls. In the greater majority of the skulls (76.2%), the GPF were between proximal-distal surfaces of the 3rd maxillary molar. A single LPF was observed in 53.45% of the skulls, two LPF were observed in 31% of the skulls bilaterally and five LPF were rare (2.1%). The commonest position of LPF was at the junction of the palatine bone and the inner lamella of the pterygoid plate (71.9%).

CONCLUSION

Our results can help clinicians localize the palatine foramina in patients with and without maxillary molars and to predict the depth of a needle to anaesthetise the maxillary nerve with greater success when performing surgical procedures in the hard and soft palate.