J. Makdissi

Cone beam CT in orthodontics: the current picture.

The introduction of cone beam computed tomography (CBCT) technology to dentistry and orthodontics revolutionized the diagnosis, treatment and monitoring of orthodontic patients. This review article discusses the use of CBCT in diagnosis and treatment planning in orthodontics. The steps required to install and operate a CBCT facility within the orthodontic practice as well as the challenges are highlighted. The available guidelines in relation to the clinical applications of CBCT in orthodontics are explored.

Incidence of different causes of benign obstruction of the salivary glands: retrospective analysis of 493 cases using fluoroscopy and digital subtraction sialography.

To identify the incidence of different causes of benign obstruction of the salivary glands, we retrospectively analysed 788 anonymised sialography reports of 719 patients referred to the department of dental and maxillofacial radiology between 2006 and 2012. Reports that showed evidence of benign obstruction were included (n=493). Salivary stones were identified in 151 (31%), ductal strictures in 115 (23%), and mucus plugs in 295 (60%). In 67 cases (14%) there was evidence of 2 or 3 causes of obstruction. As previously reported, mucous plugs were the most common finding, possibly because of the use of fluoroscopy or digital subtraction sialography, or both. These methods enable images to be captured during the initial filling of the main duct and are likely to prevent mucus plugs from being obscured by the contrast medium, which is the case in conventional sialography when a single image is produced after the contrast has been injected.

Effect of rituximab on a salivary gland ultrasound score in primary Sjögren’s syndrome: results of the TRACTISS randomised double-blind multicentre substudy

Objectives To compare the effects of rituximab versus placebo on salivary gland ultrasound (SGUS) in primary Sjögren’s syndrome (PSS) in a multicentre, multiobserver phase III trial substudy. Methods Subjects consenting to SGUS were randomised to rituximab or placebo given at weeks 0, 2, 24 and 26, and scanned at baseline and weeks 16 and 48. Sonographers completed a 0–11 total ultrasound score (TUS) comprising domains of echogenicity, homogeneity, glandular definition, glands involved and hypoechoic foci size. Baseline-adjusted TUS values were analysed over time, modelling change from baseline at each time point. For each TUS domain, we fitted a repeated-measures logistic regression model to model the odds of a response in the rituximab arm (≥1-point improvement) as a function of the baseline score, age category, disease duration and time point. Results 52 patients (n=26 rituximab and n=26 placebo) from nine centres completed baseline and one or more follow-up visits. Estimated between-group differences (rituximab-placebo) in baseline-adjusted TUS were −1.2 (95% CI −2.1 to −0.3; P=0.0099) and −1.2 (95% CI −2.0 to −0.5; P=0.0023) at weeks 16 and 48. Glandular definition improved in the rituximab arm with an OR of 6.8 (95% CI 1.1 to 43.0; P=0.043) at week 16 and 10.3 (95% CI 1.0 to 105.9; P=0.050) at week 48. Conclusions We demonstrated statistically significant improvement in TUS after rituximab compared with placebo. This encourages further research into both B cell depletion therapies in PSS and SGUS as an imaging biomarker. Trial registration number 65360827, 2010-021430-64; Results.

Incidental findings on MRI of the temporomandibular joint.

OBJECTIVES The aim of this study was to determine the prevalence of incidental findings in MRI of the temporomandibular joint (TMJ). METHODS MRI reports of 730 patients were assessed. The reports were analysed by one consultant and one clinical lecturer in dental and maxillofacial radiology. The prevalence of intracranial and extracranial incidental findings was recorded and categorized. RESULTS There were 53 (7.3%) incidental findings, of which 11 (1.5%) were intracranial and 42 (5.7%) were extracranial (divided into paranasal sinuses, mastoid air cells, muscle hypertrophy, lymphadenopathy and salivary glands). A total number of eight intracranial findings needed further dedicated imaging and/or specialist clinical opinion. Only one tumour (a meningioma) was found and required surgical intervention. CONCLUSIONS Incidental findings on TMJ MRI are rare but not unheard of. The clinical relevance of incidental findings can be significant, and it is therefore important to ensure that the full data set of images is inspected, including any scout slices. A close working relationship between the areas of dental and maxillofacial radiology and neuroradiology is essential in expediting a second opinion relating to intracranial findings. All incidental findings should be communicated to referring clinicians in a timely manner, based on their urgency and clinical significance.

Growth rate of salivary glands calculi: an interesting case

Salivary calculi grow by deposition, at a rate that has been estimated at approximately 1–1.5 mm per year,1 and range in size from 0.1 to 30 mm.2 The most common site is the submandibular gland where 80–90% of calculi are found. We present a case of a 63-year-old male who originally presented with a 25 × 30 mm stone (Fig. 1) in his right submandibular gland. This stone was surgically removed in April 1998 via an intraoral approach. The patient presented again in June 2003 complaining of mealtime syndrome. His radiographs revealed a new 15×20 mm stone (Fig. 2) present in the right submandibular gland. The findings suggest a calculus growth rate of up to 3.5 mm a year. This could be attributed to the change of the environment of ductal system caused by one or both of the following factors. The first is presence of a large sac produced by the presence of the previous stone, and the second is Fig. 2 Oblique lateral view of the right submandibular gland in 2003 showing stone.

Digital radiography in the dental practice: an update.

The implementation of digital imaging in dental practice should be considered. The vast number of advantages of digital imaging include time saving and image manipulation. Dose reduction is a big attraction but in practical terms this might not be fully taken advantage of, as a number of studies suggest. Challenges of images storage, back-up and exchange should be taken into account. Careful planning and integration with practice software should lead to a smooth transition. Remember, computer systems sometimes fail and contingency plans should be in place to avoid disruption to the workflow of the practice.

Is there a role for ultrasound-guided balloon sialoplasty technique in salivary gland structures

Ductal stricture is a common cause of obstructive salivary gland disease. Balloon dilatation of the parotid duct as a minimally invasive technique is currently carried out under fluoroscopic guidance or during sialendocopy. We present a case report of ultrasound-guided balloon dilatation. A 45-year-old female presented with a long history of obstructive symptoms affecting the right parotid gland. Ultrasound examination revealed a tortuous right main parotid duct with marked dilatation throughout its course and multiple sites of focal stricture formation. A sialogram was carried out to further characterize the ductal system, it showed significant dilatation of the main duct but due to overlapping of the elements of sialodochitis the visualization of the location and presence of strictures was very difficult. It was felt that ultrasound would be a better imaging modality to utilize in order to guide balloon dilatation of the strictures. Therefore, a balloon dilatation was carried out under ultrasound guidance. The main advantage of this technique is to preserve the physician and the patient from radiation exposure. In our knowledge this is the first case reported yet in the literature.