Ultrasound in Dentistry: Toward a Future of Radiation-Free Imaging

Ultrasonography as an additional tool to localize impacted canines

Canine impaction is a common dental anomaly that requires a multidisciplinary approach, from diagnosis to treatment. The regular two-dimensional (2D) radiographs are able to visualize if the tooth is impacted, but unable to specifically localize it, and determine if there are any root resorptions associated to it. The cone-beam computed tomography (CBCT) is able to three-dimensionally determine its location, aiding to the diagnosis and treatment plan. The major disadvantage is the amount of radiation that is added to the patient and can be even more significant in pediatric patients. The intra-oral ultrasound (io-US) is a new non-invasive and non-radiating real-time chairside imaging method that has the potential to aid in locating the impacted tooth. This paper presents 4 cases that required a CBCT for the location and treatment planning of impacted maxillary canines and were also scanned with intra-oral ultrasound. The images were then compared to the CBCT exam for validation of the new method. Through these cases, we highlight the capability of the io-US to locate the impacted canines. Other advantages of io-US might include evaluation of soft tissue thickness and vasculature that are important for surgical planning and execution.

Ex vivo human teeth imaging with various photoacoustic imaging systems

Dental caries cause pain and if not diagnosed, it may lead to the loss of teeth in extreme cases. Dental X-ray imaging is the gold standard for caries detection; however, it cannot detect hidden caries. In addition, the ionizing nature of X-ray radiation is another concern. Hence, other alternate imaging modalities like photoacoustic (PA) imaging are being explored for dental imaging. Here, we demonstrate the feasibility of acoustic resolution photoacoustic microscopy (ARPAM) to image a tooth with metal filling, circular photoacoustic computed tomography (cPACT) to acquire images of teeth with caries and pigmentation, and linear array-based photoacoustic imaging (lPACT) of teeth with caries and pigmentation. The cavity measured with lPACT imaging is compared with the X-ray computed tomography image. The metal filling and its boundaries are clearly seen in the ARPAM image. cPACT images at 1064 nm were a better representative of the tooth surface compared to the images acquired at 532 nm. It was possible to detect the cavities present in the dentine when lPACT imaging was used. The PA signal from the pigmented caries on the lateral surface (occlusion view) of the tooth was high when imaged using the lPACT system.

The usefulness of ultrasonography as a dynamic measurement system for visualizing root canal working length: an in vivo study

OBJECTIVE

Although apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length.

MATERIALS AND METHODS

Forty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot.

RESULTS

The mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques.

CONCLUSION

Ultrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons.

Radiographic diagnosis of periodontal diseases - Current evidence versus innovations

Accurate diagnosis of periodontal and peri-implant diseases relies significantly on radiographic examination, especially for assessing alveolar bone levels, bone defect morphology, and bone quality. This narrative review aimed to comprehensively outline the current state-of-the-art in radiographic diagnosis of alveolar bone diseases, covering both two-dimensional (2D) and three-dimensional (3D) modalities. Additionally, this review explores recent technological advances in periodontal imaging diagnosis, focusing on their potential integration into clinical practice. Clinical probing and intraoral radiography, while crucial, encounter limitations in effectively assessing complex periodontal bone defects. Recognizing these challenges, 3D imaging modalities, such as cone beam computed tomography (CBCT), have been explored for a more comprehensive understanding of periodontal structures. The significance of the radiographic assessment approach is evidenced by its ability to offer an objective and standardized means of evaluating hard tissues, reducing variability associated with manual clinical measurements and contributing to a more precise diagnosis of periodontal health. However, clinicians should be aware of challenges related to CBCT imaging assessment, including beam-hardening artifacts generated by the high-density materials present in the field of view, which might affect image quality. Integration of digital technologies, such as artificial intelligence-based tools in intraoral radiography software, the enhances the diagnostic process. The overarching recommendation is a judicious combination of CBCT and digital intraoral radiography for enhanced periodontal bone assessment. Therefore, it is crucial for clinicians to weigh the benefits against the risks associated with higher radiation exposure on a case-by-case basis, prioritizing patient safety and treatment outcomes.

Diagnostic measures for monitoring and follow-up in periodontology and implant dentistry

This review discusses the role of diagnostic measures in the lifelong management of periodontal disease and peri-implant complications. After active treatment, these conditions require regular monitoring of the supporting structures of teeth and dental implants to assess bone and soft tissue health over time. Several clinical measures have been developed for the routine assessment of periodontal and peri-implant tissues, including periodontal and peri-implant probing, bleeding on probing, intraoral radiography, biomarker analysis, and microbiological testing. This review highlights the evolution of diagnostic practices, integrating traditional methods with emerging technologies such as resonance frequency analysis and ultrasound imaging to provide a holistic view of peri-implant health assessment. In addition to objective measurements, patient risk factors are considered. The goals of periodontal and peri-implant maintenance are to control disease activity and stabilize tissues through supportive care, which includes diagnostic measures at follow-up visits. This enables clinicians to monitor treatment outcomes, assess health status, and detect recurrence or progression early through routine evaluation, allowing additional interventions, including adjustment of supportive therapy intervals, to further improve and maintain periodontal and peri-implant stability over time.

The feasibility of ultrasonography for the measurement of periodontal and peri-implant phenotype: A systematic review and meta-analysis

BACKGROUND

Screening ultrasonography was proposed for monitoring periodontal soft tissues in the early 1960s, owing to its nonionizing, real-time, and cost-effective properties. Studies have provided convincing preliminary evidence for the use of ultrasound (US) in implant dentistry.

PURPOSE

To assess the feasibility of ultrasonography (US) for measuring the buccal thickness of periodontal and peri-implant tissues. The secondary objective was to evaluate the reliability of US measurements compared to classic techniques, such as CBCT and directly measurements.

MATERIALS AND METHODS

An electronic literature search was conducted by three independent reviewers through February 2023. The inclusion criteria were articles investigating at least five patients/cadavers with US measurements in periodontal or peri-implant buccal tissues. Compliance with methodological reporting standards and risk of bias was assessed using EULAR and QUADAS-C tools, respectively. Random-effects meta-analysis was conducted, using Bland-Altman analysis. Certainty of the evidence was assessed using GRADE.

RESULTS

The final selection included 12 studies examining 458 patients and 13 cadavers, with a total of 226 implants, 1958 teeth and 60 edentulous sites. The body of evidence was assessed as partially compliant with methodological reporting standards for US studies and had an unclear to high risk of bias. Meta-analysis of five comparative studies showed no evidence of clinically significant bias between US and direct measurements (very low certainty), and between US and CBCT (very low certainty) for soft-tissue thickness. Likewise, for bone thickness, there is no evidence of clinically significant bias between US and CBCT (low certainty).

CONCLUSIONS

Compared to the CBCT and direct measurements, ultrasonography might be a reliable approach for monitoring on periodontal and peri-implant phenotype. However, there is uncertainty about estimates of the actual effect, so further standardized and larger sample size of clinical research is needed.

Recent development of photoacoustic imaging in dentistry: A review on studies over the last decade

Background

This work performs a literature review of photoacoustic imaging (PAI) in dentistry and discusses the development of PAI in relation to oral health.

Methods

A search method was used to locate papers published between 2011 and 2023 in Google Scholar and PubMed databases, and 25 studies were selected. Reports on PAI in dentistry were included. Articles not written in English or whose full text could not be accessed were excluded. The remaining publications were checked and evaluated to determine whether they contain supportive materials for PAI in dentistry.

Results

The majority of articles about PAI in dentistry are associated with caries studies. Photoacoustic microscopy is the most commonly utilized PAI system. PAI studies generally focus on ex-vivo investigations using extracted human teeth. The acoustic signal obtained from carious teeth is greater than that obtained from normal teeth. In addition to imaging oral soft tissues from animal models and the periodontal pocket depth in human volunteers, PAI is applied to evaluate dental implants and oral biofilms.

Conclusion

There have been numerous investigation on PAI in dentistry, but it is not yet applicable in dental practice. In the future, PAI studies are expected to contribute to the invention of an alternative non-ionizing imaging technology that is comfortable for patients, user friendly, and capable of providing reliable information at a reasonable cost.

Ultrasonographic evaluation of edentulous crestal bone topography: A proof-of-principle retrospective study

OBJECTIVE

Edentulous crestal bone ridge assessment, an essential task for planning of implant and bone regenerative procedures, is performed through radiographs. Ultrasonography, providing point of care and cross-sectional images without radiation, could be an adjunct for this purpose. The aim was to investigate the feasibility of ultrasound (US) in assessing bone ridge width (BRW) and crestal bone surface quality (CBSQ) compared with cone beam computed tomography (CBCT).

STUDY DESIGN

Records of patients who were planned for implant placement in at least 1 healed edentulous ridge space with available CBCT and US images were included. The BRWs at 1, 2, and 3 mm from the crest were measured and compared. The CBSQ agreement evaluated using a 3-tier grading system was calculated.

RESULTS

A total of 45 sites were included. The mean correlation of BRW was 0.97. The mean BRW differences ranged from 0.048 mm (95% confidence interval, -0.69 to 0.78 mm) at the 1-mm level to 0.18 mm (95% confidence interval, -0.92 to 1.3 mm) at the 3-mm level. There was a 91% agreement in CBSQ between the 2 methods.

CONCLUSIONS

Preliminary data with a limited clinical sample size suggested that US is feasible in evaluating crestal BRW and surface quality assessment compared with CBCT.

Ultrasound Imaging in Dentistry: A Literature Overview

(1) Background: the frequency with which diagnostic tests are prescribed with exposure to ionizing radiation, a cause of biological damage, has been studied, and with much more attention, patients are subjected to these diagnostic tests for diagnosis and follow-up. This review aimed, given the recent developments of this technology, to evaluate the possible use of ultrasound in different branches of dentistry. The possibility of applying ionizing-radiation-free diagnostic exams in dentistry, overcoming the limits of this application, has led scientific research in this area to obtain interesting results that bode well for the future. (2) Methods: a search for articles on the application of ultrasounds in dentistry was performed using the PubMed electronic database. (3) Results: only 32 studies were included, and these clearly stated that this examination is widely usable and in great progress. (4) Conclusions: regarding the modern application techniques of this diagnostic test, it is essential to consider technological evolution as an objective to reduce the damage and side effects of necessary diagnostic tests. The use of ultrasound in dentistry can represent a valid radiation-free alternative, in certain contexts, to the other most used exams.

Recommendations, Practices and Infrastructural Model for the Dental Radiology Set-up in Clinical and Academic Institutions in the COVID-19 Era

The pandemic of Coronavirus disease (COVID-19) has emerged as a global catastrophe that is plaguing mankind. In the past eight months since the world discovered about COVID-19, we learned a lot about server acute respiratory syndrome coronavirus 2 (SARS CoV-2) and perhaps there is much more to discover and understand about the virus. With the current understanding of the disease, we assume it will remain in an active state of transmission and progression among the community for a long time. Thus, it is advisable to adopt the disease's prevention protocol in our daily and work routine. During this pandemic patient requiring dental treatment cannot be neglected and the role of dental imaging is crucial in delivering treatment. Hence, this article attempts to provide an evidence-based compilation about the mode of transmission and clinical features of COVID-19. It also throws light on the potential source of disease transmission in the dental radiology setting. In addition, it suggests preventive measures to curb the infection and infrastructural model of the clinical setting that will assist in achieving control over the disease transmission. This article intends to project a strategy about protocols, infrastructure, and daily activities in a dental radiology office that institutions can adopt with modifications according to their local scenario.

Ultrasound-guided arthrocentesis using single-puncture, double-lumen, single-barrel needle for patients with temporomandibular joint acute closed lock internal derangement

PURPOSE

Temporomandibular joint (TMJ) disc derangement is defined as a malpositioning of the articular disc relative to the condyle and eminence. Arthrocentesis of the TMJ is considered by many as the first-line surgical treatment for patients who do not respond to conservative treatment. The aim of this study is to assist needle insertion for temporomandibular joint arthrocentesis using ultrasonography.

MATERIALS AND METHOD

Twenty patients who required arthrocentesis of the TMJ were randomly assigned to two groups A and B undergoing single-puncture arthrocentesis with modified double-lumen single-barrel needle and ultrasound-guided single-puncture arthrocentesis using modified double-lumen single-barrel needle (n = 10 in each group). The number of attempts of needle manipulation, duration of the operative procedural time, and visual analog (VAS) scale score for pain to assess surgical discomfort were the main outcome variables.

RESULTS

None of the patients in either group developed any complication with no significant difference in VAS score for pain between the two study groups. The number of attempts for needle manipulation (mean ± SD) for group A was 2.20 ± 0.789, and for group B, it was 1.10 ± 0.316 (p value, 0.0007); operative procedural time (mean ± SD) for group A was 18.5 ± 3.171 min, and for group B, it was 13.1 ± 1.663 (p value, 0.0002) which was significantly lesser in group A than in group B. The sentence signifies that the number of attempts that was required to re-insert the needle to enter the joint space in Ultrasound guided and conventional method of arthrocentesis.

CONCLUSION

Ultrasound-guided single-puncture arthrocentesis using a customized needle is a promising method to perform joint lavage with minimal trauma and in a precise manner.

Feasibility of a combination of intraoral UHFUS and CBCT in the study of peri-implantitis

OBJECTIVES

The aim of this study was to investigate the combination of intraoral ultra-high-frequency ultrasonography (UHFUS) and cone beam computed tomography (CBCT) in the evaluation of hard and soft tissues in a case of peri-implantitis.

STUDY DESIGN

A 57-year-old patient was referred for pain and numbness of the chin after implant placement and the subsequent guided bone regeneration (GBR) procedure. Clinical examination revealed hard tumefaction of the mandibular mucosa, with mild mobility of the implants. Assessment with UHFUS was undertaken for the study of the width, degree of tissue alteration, and vascularity of the swollen mucosa, and CBCT was used to evaluate the bone surrounding the implants and the possible impingement of the inferior alveolar nerve.

RESULTS

A combination of CBCT and UHFUS was effective in the evaluation of GBR complications in peri-implantitis, revealing alterations in the periosteum secondary to suboptimal GBR treatment. This was the first study to use UHFUS to evaluate the characteristics of oral soft tissues.

CONCLUSIONS

UHFUS is a promising tool for the diagnosis of complicated soft tissue diseases. When used with CBCT, it can provide useful information on oral and maxillofacial diseases involving hard and soft tissue in a noninvasive way, with reduced radiation dose exposure.