Ultrasonographically locating the mental foramen and its soft tissue relations

Evaluation of the validity of mental foramen USG measurements by comparison with CBCT and determination of blood flow

OBJECTIVES

To examine mental foramen (MF) morphology and morphometry in comparison with ultrasonography (USG) and cone-beam computed tomography (CBCT), and to determine the relationship between mental artery blood flow parameters and age, gender, dental status, alveolar crest height, mandibular cortical index (MCI) with USG.

METHODS

A total of 120 MF and mental arteries of 60 patients (21 males and 39 females), including 20 patients in each group, aged 18-39, 40-59, and 60 years and above, were evaluated. The horizontal and vertical diameter of the MF and the distance between it and the alveolar crest were evaluated with USG and CBCT. In addition, mental artery blood flow parameters were examined by USG.

RESULTS

When the horizontal diameter values of MF were compared in USG and CBCT measurements; the diameter was significantly lower in the measurements obtained by USG (p < 0.05). It was observed that there were no mental arteries whose blood flow could not be recorded, 31 (25.8%) had strong blood flow and 89 (74.2%) had weak blood flow. No significant correlation was observed between gender and blood flow parameters (p > 0.05).

CONCLUSIONS

Considering that CBCT images are used as gold standard in our study, it may be said that USG is not as reliable as CBCT in evaluating the MF dimensions in the maxillofacial region. Nevertheless, USG is a suitable technique for determining the visualizing and blood flow of the MF.

Periodontal evaluation using a non-invasive imaging method (ultrasonography)

The periodontal disease and gingival bleeding are highly prevalent in the adult population worldwide. The World Health Organization (WHO) data shows that 90–100% of the 34-year-old adults present gingival inflammation. Therefore, an investigation method is required to allow the assessment of the periodontal disease as well as the monitoring of the evolution of the gingival inflammation after periodontal treatments. Non-invasive and operator-independent methods for periodontal examination are necessary for diagnosing and monitoring the periodontal disease. The periodontal ultrasonography is a reliable technique for visualizing the anatomical elements which are necessary to diagnose the periodontal status. Using this imaging technique the dentino-enamel junction, the cortical bone, the radicular surface from the crown to the alveolar bone, the gingival tissue can be seen without interfering with those elements during the examination. Also, calculus visualization is possible before and after scaling in order to evaluate the quality of the treatment.

Using 2D ultrasonography is not feasible in dental practice as it requires extensive experience and is also time consuming. The reproducibility of the 2D slices is very difficult in order to have the possibility to compare different investigations efficiently. 3D reconstructions of the periodontal tissue can be a very good alternative to eliminate the operator dependence.

Ultrasonography allows the practitioner to visualize the anatomic elements involved in making a periodontal diagnosis. It also allows tracking of subsequent changes. This method is not commonly used for periodontal examination and further studies are required. Previous studies show that ultrasonography can be a reliable non-invasive method to diagnose and monitor the periodontal disease.

Transoral Thyroidectomy Using A Flexible Robotic System: A Preclinical Cadaver Feasibility Study

OBJECTIVES/HYPOTHESIS

Traditionally, most thyroid surgery utilizes a curvilinear cervical incision with a resulting permanent scar. Minimally invasive and remote access thyroid surgery techniques continue to evolve. Transoral approaches through a vestibular incision have been developed at several centers throughout the world, obviating the need for a cutaneous incision and optimizing aesthetics. To date this technique has been performed using rigid endoscopes or a linear robotic platform. The goal of this study was to test the feasibility of a novel flexible robotic system to perform a transvestibular thyroidectomy in a preclinical cadaver model.

STUDY DESIGN

Preclinical feasibility study.

METHODS

Right and left thyroid lobectomies were successfully performed via a transvestibular approach in four cadavers.

RESULTS

A single vestibular incision between bilateral mental nerves allowed entrance of the flexible robot in a subplatysmal plane in both male and female cadavers. The recurrent laryngeal nerves and parathyroids were identified and preserved. The flexible three-dimensional camera allowed excellent visualization and could be easily repositioned for optimal visualization of right and left structures. The flexible and wristed instruments enabled an atraumatic approach and allowed for precise surgical technique.

CONCLUSIONS

The transoral vestibular approach to the central neck is a promising technique for thyroidectomy with optimal cosmesis and can be successfully accomplished using this novel flexible robotic system. Improvements in visualization and access offered by this system may improve application of this technique.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:1482-1487, 2019.

Locating the mental foramen at the bedside with point of care ultrasound imaging

Introduction

Ultrasound guided neuro-anaesthesia is a developing field of interest to clinicians from various disciplines. The objective of this proof of concept study was to explore the ability, ease and rapidity of ultrasonography in locating the mental foramen.

Methods

A convenience sample of 100 patients aged 18 years or older, with no known pathology to the mandibular region, that presented to a single urban ED were enrolled. All patients underwent an ultrasound examination on both sides of the face to locate the mental foramina.

Results

A total of 100 patients' mental foramina were studied. Mean age was 35.7 years (SD 9.1 years), 50% were black and 25% each were asian and white. The mental foramina were ultrasonographically identified in all (100%) of the subjects in the study group. Although requiring a larger quantity of ultrasound gel, the mental foramina were also visualized in all twelve subjects with facial hair. Three out of the 100 subjects were noted to have accessory mental foramina. The overall mean time taken to locate the first mental foramen in each patient was 16.1 seconds (SD 12.9 seconds). For the first 25 subjects studied, the mean time taken was 34.7 seconds (SD 13.4 seconds), whereas for the next 75 subjects studied, the mean time taken was 9.9 seconds (SD 3.0 seconds).

Conclusion

Bedside ultrasound imaging is a potentially reliable method to identify and locate the mental foramen. With practice and experience, the mental foramen can be more easily identified.