Study of the mandibular canal and its surrounding canals by multi-view cone-beam computed tomography

OBJECTIVES

To determine the mandibular anatomical structures by observing cone-beam computed tomography (CBCT) from multiple angles.

MATERIALS AND METHODS

This retrospective study analyzed 1593 consecutive CBCT images. Ultimately, 95 CBCTs met the inclusion criteria. The mandibular, inferior lingual, and bony canals at the tooth apex were studied by multi-angle observation CBCT. Descriptive statistics were used for statistical analysis.

RESULTS

It is beneficial to further observe the anastomosis of the mandibular, lingual, and mandibular canals when the course of the mandibular lingual canal is observed on CBCT cross-section. The frequency of the inferior lingual canal anastomosis with the mandibular canal was 43.2% (95% confidence interval (CI) 33, 53.3) in the sample. The mental foramen was located below the long axis of the tooth in a few samples, with an occurrence rate of 29.5% (95% CI 20.1, 38.8). The occurrence rate of various types of the bony canal at the apex of the tooth in canines, first premolars, second premolars, first molars, and second molars under the root apex was recorded through the multi-angle observation of the dental volume reformat (DVR) and three-dimensional (3D) levels in CBCT.

CONCLUSION

This study demonstrates the utility of CBCT imaging in examining mandibular anatomy from multiple angles, providing valuable insights into anatomical variations, and enhancing our understanding of mandibular structures. This research emphasizes the crucial role of meticulous CBCT examination in precisely identifying and understanding key anatomical structures, ultimately reducing the risk of surgical complications.

CRITICAL RELEVANCE STATEMENT

By examining cone-beam computed tomography scans from various perspectives, it is possible to determine the precise position of anatomical structures within the jaw. This allows for a more accurate assessment, reducing the risk of harm to these structures during treatment.

KEY POINTS

• It is crucial to utilize image data effectively to enhance the comprehension of human anatomy. • We captured detailed images of the mandible from different angles and orientations utilizing cone-beam computed tomography (CBCT). • This study provides essential anatomical information for procedural planning to ensure optimal outcomes and patient safety.

Vascular and neurosensory evaluation in relation to lingual canal anatomy after mandibular midline implant installation in edentulous patients

Objectives

The aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals.

Materials and methods

After performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded.

Results

Six patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes.

Conclusions

The mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height.

Clinical relevance

Despite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices.

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

OBJECTIVE

This study evaluates the mandibular lingual foramina (LF) using computed tomographic imaging data from a large Central European cohort, focusing on the most relevant anatomical parameters. We aimed to examine whether there are differences in key parameters between ethnic groups, or based on age and gender. Additionally, we analyze the potential effect of tooth loss on the LF and discuss risk management options before and during surgery.

METHODS

460 CT scans of adults (273 females and 186 males) were examined. The number, the location and the diameter of the median and lateral LF were assessed for each patient. The data was analyzed statistically, whereby a p-value lower than 0.05 was considered as significant.

RESULTS

Median and lateral LF were present in 95,9%, and 38,9% of patients, respectively. Male patients had a greater number of LF than females. While the majority of median LF (62%) was located above the mental spine, the majority of lateral LF was located below (84%). The diameter of lateral LF (1,15 mm ± 0,33) was smaller than for median LF (1,22 mm ± 0,35), as well the lateral canals (4,8 mm ± 1,28) were shorter than the median canals (5,32 mm ± 1,74). Lateral LF were equidistant to the symphysis (13,89 ± 3,63 mm) on either side. Critical diameter size >1 mm was found in about 2/3 of our cases. The distance from the foramen to the residual ridge was ∼7 mm less in edentulous patients compared to dentulous patients.

CONCLUSION

The median LF is a near-obligatory structure of the mandible, while the lateral LF is a frequently encountered structure. Age does not seem to affect the frequency of LF. Edentulous patients did not show differences regarding the presence of the LF, but their vertical osseous dimension was diminished by 7 mm and they may, therefore, be at an increased risk of adverse surgical incidents. The main findings of this study relate to the substantial variability in the anatomy and location of the LF and confirm with previous studies. As the LF can be reliably detected using CT/CBCT, the use of three-dimensional-imaging is recommended prior to conducting oral surgery. Careful pre-operative planning and accurate anatomical information may help to avoid surgical complications. To ascertain the potential significance of ethnicity on LF, more data need to be collected using standardized methodologies. A definitive conclusion on the impact of ethnicity on LF thus cannot currently be drawn based on the results of our study and those available from the published medical literature.

Cone-beam CT assessment of implant-related anatomy landmarks of the anterior mandible in a Chinese population

PURPOSE

To investigate the prevalence, location, and morphology of the mandibular lingual foramen (MLF), mandibular incisive canal (MIC), and anterior loop of the inferior alveolar canal (ALC) in a Chinese population using cone-beam CT (CBCT).

MATERIALS AND METHODS

From 2014 to 2016, CBCT images from patients with various scanning purposes were obtained from the database of the Affiliated Stomatology Hospital of Kunming Medical University, China. Imaging analyses of the MLF, MIC, and ALC were performed via the NNT viewer software. The prevalence, location, length, classification of MLF, and its distances to the alveolar crest and the lower border of mandible were investigated, and the prevalence and length of MIC and the prevalence of ALC were also studied.

RESULTS

This study examined 1008 subjects, 521 (51.7%) males, and 487 (48.3%) females. 916 (90.9%) subjects showed the medial lingual foramina (LF), a single medial LF with the supraspinous-type predominating. Lateral LF were observed in 547 (54.3%) subjects mostly located in the premolar areas. 876 (86.9%) subjects had the MIC on the left side, whereas 877 (87.0%) had the MIC on the right side. The ALC was present in 147 (14.6%) subjects.

CONCLUSIONS

This study showed a high prevalence of LF and MIC in the Southwest Chinese population. Therefore, caution should be taken during the implant treatment at the anterior mandible region.