The lingual foramina, a potential risk in oral surgery. A retrospective analysis of location and anatomic variability

Lingual foramina of the anterior mandible in edentulous patients: CBCT analysis and surgical risk assessment

OBJECTIVE

The mandible has various unnamed accessory foramina, and surgery is often performed in the symphyseal area. The aim of this study was to analyze the anatomical characteristics of mandibular lingual foramina with the objective of preventing clinical complications during implant surgery on an edentulous mandible.

STUDY DESIGN

A total of 100 cone beam computed tomography scans of completely edentulous patients were included in this study. For each canal, nine measurements were recorded in millimeters: seven length or height measurements and two diameter measurements. The placement of a standard implant was simulated and whether the implant passed through the canal was noted. The results were analyzed by t-test and chi-squared at a significance level of 0.05. Pearson correlation analysis was used to assess the relationship between variables.

RESULTS

We identified 309 foramina: 236 medial lingual foramina and 73 lateral lingual foramina. We found no significant relationship between the number of foramina and the age of the individuals, or between diameter and the age or gender of the individuals. The mandibular canal was injured in 32.7 % of implant placement simulations.

CONCLUSION

The risk of injury to neurovascular bundles is increased in edentulous patients due to vertical bone resorption.

Frequency and anatomic variability of the mandibular lingual foramina: a cone-beam CT study

Background

To evaluate the distribution of lingual foramina (LF) and their correlation with demographic characteristics and mandible width, shape, and bone thickness in Caucasian Italian patients subjected to cone-beam CT (CBCT).

Methods

CBCTs were reviewed to assess the number of all LF, midline and lateral LF. We also assessed the relationship of the number of lateral LF with gender and mandibular width, shape, and bone thickness using the Chi Square test. A p value < 0.05 was considered statistically significant.

Results

Three-hundred patients (180 males; age range: 21–87 years) were included. The highest frequency per patient was of 2 LF (97/300, 32.3%), followed by 3 (81/300, 27%) and 4 (53/300, 17.7%). No LF were observed in 2/300 patients (0.7%), while the highest number was of 8 LF in one patient. The highest frequency of midline LF per person was of 2 LF (57.3%, 172/300), while the highest number per person was 5 LF in one patient (0.3%). The highest frequency of midline LF located above and below the genial tubercle was of 1 in 197/300 patients (65.7%) and in 169/300 patients (56.3%), respectively. Concerning lateral LF, the highest frequencies were of 0 (113/300, 37.7%) and of 1 (112/300, 37.3%). We did not observe any significant difference of the number of midline and lateral LF based on gender (P = .438 and P = .195, respectively) or mandible width (P = .069 and P = .114, respectively). The mandible shape was normal in 188 cases, with facial constriction in 42, lingual constriction in 54, and hour glass constriction in 16. The mean bone thickness was 10.76 mm in the symphysis, 10.92 mm in the right hemiarches, and 10.68 in the left hemiarches. No significant differences in the distribution of LF were observed also based on mandibular shape and bone thickness (both with P > .05).

Conclusions

We have shown the high variability of number and anatomic distribution of LF in an Italian group of patients subjected to CBCT without reporting any association with gender and mandible width, shape, and bone thickness.

Implant insertion using an orientation template and a full-guiding template - A prospective model analysis in a cohort of dentists participating in an implantology curriculum

BACKGROUND

Dental implantology has become an established option for treating tooth loss over the recent decades. Before inserting an implant in a clinical situation, theoretical and practical training is recommended. Different methods are available to give assistance in determining the correctly planned implant position. In this study, two different guiding methods were assessed considering their accuracy for implant insertion in a group of dentists.

METHODS

After three-dimensional planning of the implant positions, two surgical templates were manufactured as follows: in region 34 a stereolithographic template was used to perform a full-guided implant insertion, in region 44 a CAD/CAM milled template was used to determine the implant position and subsequently, perform a free-hand insertion. In total, 86 implants were placed in mandibular models by 43 dentists participating in a postgraduate curriculum. The differences between planned and achieved implant positions were measured and statistically analyzed.

RESULTS

The implants inserted fully-guided showed a lower deviation of the three-dimensional angulation (2.266 ± 1.443 degrees vs. 7.954 ± 4.372 degrees) and the cumulated mismatch of the implant position (0.547 ± 0.237 mm vs. 1.160 ± 0.427 mm) compared to the free-handed mode. For the angulation and the mismatch at the implant base the differences were statistically significant (p < 0.001).

CONCLUSIONS

Within the limits of the study it can be summarized that the full-guided implant insertion leads to a higher transfer accuracy compared to the free-hand method in a cohort of dentist inexperienced in dental implantology. However, the clinical effect has to be discussed as the study was performed using artificial mandibles and ideal conditions.

Ultrasound and CBCT analysis of blood flow and dimensions of the lingual vascular canal: A case control study

Objective

To assess the correlation between the diameter of the mandibular lingual vascular canal (MLVC) as determined on CBCT examination to blood flow and arterial diameter as determined by ultrasound Doppler analysis (USG) in dentate and edentulous patients.

Methods

20 subjects were equally distributed into two groups based on the status of their dentition. Group 1 included dentate subjects (DE) and Group 2 included edentulous subjects (ED).The subjects from both the groups underwent CBCT scan for the assesement of the diameter of the MLVC.Similarly, USG was done to assess the diameter of the sublingual artery anastomosis and blood flow in the anterior mandible. Data was analysed using Karl Pearson's Correlation coefficient test and Student's unpaired 't' test.

Results

Irrespective of the status of the dentition and age, a positive correlation was noted between the diameter of foramen on CBCT examination and the diameter of anastomosing artery as studied by the USG (r ​= ​0.290).Similarly, a positive correlation was observed between the diameter of foramen on CBCT and the volume of blood entering the mandible (r ​= ​0.447).A positive correlation (r ​= ​0.138) was observed between the diameter of the anastomosing artery and the volume of blood entering the mandible.

Conclusion

The anterior mandible has a rich vascular supply independent of age and status of the dentition.The dimensions and location of MVLC could be assessed on a CBCT prior to implant placement so that the operating surgeon has an idea about the vascularity of the region. Further studies with higher sample size should be undertaken to confirm these findings.