In vitro calibration and validation of a digital subtraction radiography system using scanned images

Effectiveness of digital subtraction radiography in detecting artificially created osteophytes and erosions in the temporomandibular joint

Purpose

Erosions and osteophytes are radiographic characteristics that are found in different stages of temporomandibular joint (TMJ) osteoarthritis. This study assessed the effectiveness of digital subtraction radiography (DSR) in diagnosing simulated osteophytes and erosions in the TMJ.

Materials and Methods

Five intact, dry human skulls were used to assess the effectiveness of DSR in detecting osteophytes. Four cortical bone chips of varying thicknesses (0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm) were placed at the medial, central, and lateral aspects of the condyle anterior surface. Two defects of varying depth (1.0 mm and 1.5 mm) were created on the lateral, central, and medial poles of the condyles of 2 skulls to simulate erosions. Panoramic images of the condyles were acquired before and after artificially creating the changes. Digital subtraction was performed with Emago dental image archiving software. Five observers familiar with the interpretation of TMJ radiographs evaluated the images. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic accuracy of the imaging methods.

Results

The area under the ROC curve (Az) value for the overall diagnostic accuracy of DSR in detecting osteophytic changes was 0.931. The Az value for the overall diagnostic accuracy of panoramic imaging was 0.695. The accuracy of DSR in detecting erosive changes was 0.854 and 0.696 for panoramic imaging. DSR was remarkably more accurate than panoramic imaging in detecting simulated osteophytic and erosive changes.

Conclusion

The accuracy of panoramic imaging in detecting degenerative changes was significantly lower than the accuracy of DSR (P<.05). DSR improved the accuracy of detection using panoramic images.

Adjunctive use of modified Yunu-Jian in the non-surgical treatment of male smokers with chronic periodontitis: a randomized double-blind, placebo-controlled clinical trial

Background

Yunu-Jian (YJ) is a Chinese medicine (CM) heat purging formula, which is used to reduce wei huo (stomach-heat, SH) and enrich shen yin (kidney-yin, KY). This formula is also commonly used to manage diabetes mellitus and gum/oral inflammation. The activity of YJ can be modified or refined by the addition of other CM herbs and/or minor changes to one of its five key ingredients. The aim of this study was to evaluate the adjunctive use of modified YJ (mYJ) or YJ containing additional osteoblast-stimulating and inflammation-modulating CM herbs in the non-surgical periodontal treatment of smokers with chronic periodontitis in a randomized, double-blind, prospective, placebo-controlled study.

Methods

Healthy adult male smokers with untreated chronic periodontitis who showed CM syndrome of SH and KY deficiency (KYD) whilst attending a dental teaching hospital from October to December, 2005, were invited to participate in a randomized double-blind, placebo-controlled clinical trial. The trial itself involved the once-daily oral administration of a placebo or mYJ for 3 months as an adjunct to non-surgical periodontal therapy. Several periodontal parameters, including radiographic alveolar bone density, were measured by computer-assisted densitometric image analysis (CADIA) on selected sites, and CM signs of SH and KYD were followed from their baseline values to various time points up to 12 months or the end of study.

Results

Twenty-five smokers (consumed 25.0 ± 15.3 smoking-pack years, ranged 7.5–80; aged 46.3 ± 6.8 years) with periodontitis and SH and KYD were recruited (Placebo, n = 14; mYJ, n = 11). All of the participants showed good tolerance towards the CM recipe. All of the periodontal parameters had improved after 12-month follow-up, and no statistically significant differences were detected between the control group and test group, except for the higher CADIA values observed compared with the baseline at 12 months for test sites (P = 0.025). 4/3/3 test vs 14/13/13 control participants had persisting SH and KYD at 6, 9 and 12 months (P < 0.001), respectively.

Conclusions

The adjunctive use of mYJ preserved the post-treatment increases in the radiographic alveolar bone density at the study sites and led to an overall improvement in SH and KYD compared with the controls.

Trial registration HKU Clinical Trial Register, HKCTR-1848 (www.hkuctr.com/Study/Show/3acbf983831244d29d50b543540bf6e9)

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-016-0111-z) contains supplementary material, which is available to authorized users.

Effects of nonsurgical periodontal treatment on the alveolar bone density

The aim of this study was to evaluate the effects of nonsurgical periodontal treatment on alveolar bone density (ABD) and bone height (BH) using direct digital radiography. Nineteen patients (mean age: 36 ± 7.3 years) with generalized chronic periodontitis were examined at baseline, 90 (90 AT) and 180 (180 AT) days after nonsurgical periodontal therapy. Radiographs were taken from two sites with specific characteristics: 39 sites with probing pocket depth (PPD) ≤ 3 mm and clinical attachment level (CAL) ≤ 1 mm (shallow sites); and 62 sites with PPD ≥ 5 mm and CAL ≥ 3 mm (deep sites). The ABD was assessed considering the bone regions of interest at the alveolar bone crest (ROI I) and at the medullar bone (ROI II). The BH was assessed considering the distance from the alveolar bone crest to the cementoenamel junction. Mann-Whitney test was used for the overall demographic data, Wilcoxon test was used to compare the baseline, 90 AT and 180 AT data as well as to compare the groups and subgroups within the same evaluation period. The significance level was set at 5%. The deep sites showed a significant increase of ABD in ROI I at 90 AT (p<0.007) and at 180 AT (p<0.005). ABD decrease was seen in ROI II at 180 AT (p<0.04) while BH reduced only in shallow sites at 90 AT. In conclusion, an increase in ABD was observed in deep sites of patients with generalized chronic periodontitis. However, no significant change in alveolar BH was observed in these sites.

Clinical and radiographic evaluation of regenerative potential of GTR membrane (Biomesh®) along with alloplastic bone graft (Biograft®) in the treatment of periodontal intrabony defects

BACKGROUND AND OBJECTIVES

The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of GTR membrane and alloplastc bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects.

METHODS

Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD, GTR membrane+bone graft (test) or OFD alone (control). The clinical efficacy of two treatment modalities was evaluated at 6 months postoperatively by clinical, radiographical parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD).

RESULTS

The mean reduction in PD at 0 to 6 months was 3.20±0.82 mm and CAL gain of 3.10±1.51 mm occurred in the GTR membrane+bone graft (test) group; corresponding values for OFD (control) were 2.10±0.63 mm and 1.90±0.57 mm. Similar pattern of improvement was observed when radiographically postoperative evaluation was made. All improvement in different parameters was statistically significant (p<0.01).

CONCLUSION

Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to open flap debridement alone.

Clinical evaluation of regenerative potential of type I collagen membrane along with xenogenic bone graft in the treatment of periodontal intrabony defects assessed with surgical re-entry and radiographic linear and densitometric analysis

BACKGROUND AND OBJECTIVES

The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of type I collagen (GTR membrane) and xenogenic bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects.

MATERIALS AND METHODS

Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD + collagen membrane + bone graft (Test) or OFD alone (Control). The clinical efficacy of two treatment modalities was evaluated at 9 month postoperatively by clinical, radiographical, and intrasurgical (re-entry) parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD) and intra bony component (INTRA).

RESULTS

The mean reduction in PD at 0-9 month was 3.3±0.82 mm and CAL gain of 3.40±1.51 mm occurred in the collagen membrane + bone graft (Test) group; corresponding values for OFD (Control) were 2.20±0.63 mm and 1.90±0.57 mm. Similar pattern of improvement was observed when radiographical and intra-surgical (re-entry) post operative evaluation was made. All improvement in different parameters was statistically significant (P< 0.01).

INTERPRETATION AND CONCLUSION

Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to OFD alone.

A robust generalized fuzzy operator approach to film contrast correction in digital subtraction radiography

Digital subtraction radiography requires close matching of the contrast in each pair of X-ray images to be subtracted. Previous studies have shown that nonparametric contrast/brightness correction methods using the cumulative density function (CDF) and its improvements, which are based on gray-level transformation associated with the pixel histogram, perform well in uniform contrast/brightness difference conditions. However, for radiographs with nonuniform contrast/ brightness, the CDF produces unsatisfactory results. In this paper, we propose a new approach in contrast correction based on the generalized fuzzy operator with least square method. The result shows that 50% of the contrast/brightness errors can be corrected using this approach when the contrast/brightness difference between a radiographic pair is 10 U. A comparison of our approach with that of CDF is presented, and this modified GFO method produces better contrast normalization results than the CDF approach.

Early osteotomy with delayed implant placement: a step further for immediate loading

The commonly used implantation technique involves a 2-stage surgical protocol for load-free and submerged healing to ensure predictable osseointegration. This article presents a new approach that benefits from previous bone and soft tissue protocols. It combines new surgical and insertion techniques to perform immediate loading with delayed implant placement, avoiding the problems of discomfort, inconvenience, and anxiety associated with healing periods. It maintains a similar success rate to the present common technique. After osteotomy, bone healing passes through 3 stages (i.e., inflammation, fibrous tissue, and maturation). In the new approach, implant insertion is performed 2 weeks after drilling (i.e., during the fibrous phase). The insertion timing is so selected because collagen formation and revascularization represent an acceptable implant bed configuration. Flap surgery offers the optimal osteotomy approach, but esthetic outcomes are definitely compromised. Accordingly, adopting the punch technique alleviates several postoperative problems, such as pain, tenderness, and swelling. Moreover, the punch technique avoids the sutures needed to adjust the gingiva around the abutment. It provides both cosmetic and functional properties.