Evaluation of distracted mandibular bone using computed tomography scan and ultrasonography: technical note

Overview of Ultrasound in Dentistry for Advancing Research Methodology and Patient Care Quality with Emphasis on Periodontal/Peri-implant Applications

BACKGROUND

Ultrasound is a non-invasive, cross-sectional imaging technique emerging in dentistry. It is an adjunct tool for diagnosing pathologies in the oral cavity that overcomes some limitations of current methodologies, including direct clinical examination, 2D radiographs, and cone beam computerized tomography. Increasing demand for soft tissue imaging has led to continuous improvements on transducer miniaturization and spatial resolution. The aims of this study are (1) to create a comprehensive overview of the current literature of ultrasonic imaging relating to dentistry, and (2) to provide a view onto investigations with immediate, intermediate, and long-term impact in periodontology and implantology.

METHODS

A rapid literature review was performed using two broad searches conducted in the PubMed database, yielding 576 and 757 citations, respectively. A rating was established within a citation software (EndNote) using a 5-star classification. The broad search with 757 citations allowed for high sensitivity whereas the subsequent rating added specificity.

RESULTS

A critical review of the clinical applications of ultrasound in dentistry was provided with a focus on applications in periodontology and implantology. The role of ultrasound as a developing dental diagnostic tool was reviewed. Specific uses such as soft and hard tissue imaging, longitudinal monitoring, as well as anatomic and physiological evaluation were discussed.

CONCLUSIONS

Future efforts should be directed towards the transition of ultrasonography from a research tool to a clinical tool. Moreover, a dedicated effort is needed to introduce ultrasonic imaging to dental education and the dental community to ultimately improve the quality of patient care.

Qualitative assesement of newly formed bone after distraction osteogenesis of mandible in patients with facial asymmetry using 3 dimensional computed tomography

Introduction

Distraction osteogenesis is a surgical technique of new bone formation between the osteotomized bone segments with the help of gradual incremental traction. As distraction osteogenesis is slow biologic process, soft tissue changes gradually follow the new bone formation. Mandibular distraction is one of the accepted modalities to treat the triad of TMJ ankylosis, obstructive sleep apnoea & micrognathia and also for facial asymmetry cases like hemifacial microsomia, mandibular hypoplasia etc. After the distraction osteogenesis, some relapse has been noticed in patients. Therefore, this study was conducted to assess the quality of the newly formed bone after distraction osteogenesis of mandible using 3 dimensional computed tomography (3DCT Scan) to evaluate its relation with relapse if any.

Objectives

1) To objectively analyse the quality of bone formed after mandibular distraction osteogenesis.2) To observe the site & architecture of newly formed bone after distraction is complete.

Material and methods

Total 5 patients of facial asymmetry reported to the Department of Oral and Maxillofacial Surgery were enrolled. Distraction osteogenesis of mandible was carried out in all the patients. Radiographic analysis (CT Scan) was done after 1 year of surgery for further planning and management of deformity. The non-distracted site was considered as a control side and it was compared with newly formed bone at distraction site. The standard & universally accepted radio density measuring Hounsfield Unit (HU) in 3DCT scan was calculated in axial,coronal, sagittal sections from distraction site and it was compared with non-distraction site, as Hounsfield unit is considered as a standard tool for measuring the bone density to evaluate the quality as well as quantity of newly formed bone.

Results

The total mean Hounsfield Unit of distracted site of all three sections was 359.8 HU and non-distracted site was 545.2 HU. Statistical analysis was carried out using students paired ttest and p value was obtained which was <0.01 suggestive of statistically significant difference between the quality of bone in distracted site and non-distracted site.

Conclusion

The findings of our study concluded that the quality of bone formed after distraction osteogenesis was satisfactory but it was less mineralized with less dense trabecular pattern compared to non-distracted bone region of mandible which leads to some relapse. Therefore it was advisable to reinforce the distracted bone segment by cutting the activation arm of distractor itself or mini plate or reconstruction plate to prevent relapse.

Role of ultrasonography in oral and maxillofacial surgery: a review of literature

Maxillofacial surgery, like any other surgical specialty is greatly dependent on the discipline of radiology. This poses a greater challenge because of the complex anatomy of this region. Various investigation modalities have been applied in diagnosing various diseases which are found in the maxillofacial region, including IOPA, PET, USG, CT, MRI and panoramic radiographs. Of these, USG can easily diagnose non invasive and soft tissue diseases. It is very useful in diagnosing the diseases which are not usually evident on a conventional radiograph. However; many of the dentists are not aware of the benefits of USG in diagnosis of oral diseases. In this article, the use of ultrasound in diagnosing the various pathologies of maxillofacial region is elaborated.

Computed radiographic and ultrasonic evaluation of bone regeneration during tibial distraction osteogenesis in rabbits

Computed radiography (CR) and a combined ultrasound (US) approach involving two-dimensional (2-D) and three-dimensional (3-D) ultrasonography with ultrasonometry were employed to evaluate their respective efficacies in monitoring bone regeneration during rabbit tibial distraction osteogenesis (DO). Results demonstrated that 2-D and 3-D ultrasonography depicted bone callus growth changes during distraction while CR could not. Evaluation of callus speed of sound, acoustic reflection and attenuation showed significant linear changes over time during early DO stage (p < 0.05). However, surrogate measure of callus density by CR only showed such significant linear changes during consolidation (p < 0.05). Also, callus speed of sound and acoustic reflection during early DO stage showed strong predictions to the bone mineral density and microstructural properties (adjusted-R(2) = 0.43-0.67) of consolidated bone callus measured at the treatment end-point by microcomputed tomography. Findings of the present study indicated a preferred use of the combined US approach over CR in the early monitoring of bone regeneration during DO treatment.