Novel lesion detection aids

Several non-invasive and novel aids for the detection of (and in some cases monitoring of) caries lesions have been introduced in the field of 'caries diagnostics' over the last 15 years. This chapter focusses on those available to dentists at the time of writing; continuing research is bound to lead to further developments in the coming years. Laser fluorescence is based on measurements of back-scattered fluorescence of a 655-nm light source. It enhances occlusal and (potentially) approximal lesion detection and enables semi-quantitative caries monitoring. Systematic reviews have identified false-positive results as a limitation. Quantitative light-induced fluorescence is another sensitive method to quantitatively detect and measure mineral loss both in enamel and some dentine lesions; again, the trade-offs with lower specificity when compared with clinical visual detection must be considered. Subtraction radiography is based on the principle of digitally superimposing two radiographs with exactly the same projection geometry. This method is applicable for approximal surfaces and occlusal caries involving dentine but is not yet widely available. Electrical caries measurements gather either site-specific or surface-specific information of teeth and tooth structure. Fixed-frequency devices perform best for occlusal dentine caries but the method has also shown promise for lesions in enamel and other tooth surfaces with multi-frequency approaches. All methods require further research and further validation in well-designed clinical trials. In the future, they could have useful applications in clinical practice as part of a personalized, comprehensive caries management system.

Traditional lesion detection aids

Lesion detection aids ideally aim at increasing the sensitivity of visual caries detection without trading off too much in terms of specificity. The use of a dental probe (explorer), bitewing radiography and fibre-optic transillumination (FOTI) have long been recommended for this purpose. Today, probing of suspected lesions in the sense of checking the 'stickiness' is regarded as obsolete, since it achieves no gain of sensitivity and might cause irreversible tooth damage. Bitewing radiography helps to detect lesions that are otherwise hidden from visual examination, and it should therefore be applied to a new patient. The diagnostic performance of radiography at approximal and occlusal sites is different, as this relates to the 3-dimensional anatomy of the tooth at these sites. However, treatment decisions have to take more into account than just lesion extension. Bitewing radiography provides additional information for the decision-making process that mainly relies on the visual and clinical findings. FOTI is a quick and inexpensive method which can enhance visual examination of all tooth surfaces. Both radiography and FOTI can improve the sensitivity of caries detection, but require sufficient training and experience to interpret information correctly. Radiography also carries the burden of the risks and legislation associated with using ionizing radiation in a health setting and should be repeated at intervals guided by the individual patient's caries risk. Lesion detection aids can assist in the longitudinal monitoring of the behaviour of initial lesions.

PET-CT-guided interventions in the management of FDG-positive lesions in patients suffering from solid malignancies: initial experiences

Positron emission tomography-computed tomography (PET-CT) has gained widespread acceptance as a staging investigation in the diagnostic workup of malignant tumours and may be used to visualize metabolic changes before the evolution of morphological changes. To make histology of PET findings without distinctive structural changes available for treatment decisions, we developed a protocol for multimodal image-guided interventions using an integrated PET-CT machine. We report our first experience in 12 patients admitted for staging and restaging of breast cancer, non-small cell lung cancer, cervical cancer, soft tissue sarcoma, and osteosarcoma. Patients were repositioned according to the findings in PET-CT and intervention was planned based on a subsequent single-bed PET-CT acquisition of the region concerned. The needle was introduced under CT guidance in a step-by-step technique and correct needle position in the centre of the FDG avid lesion was assured by repetition of a single-bed PET-CT acquisition before sampling. The metabolically active part of lesions was accurately targeted in all patients and representative samples were obtained in 92%. No major adverse effects occurred. We conclude that PET-CT guidance for interventions is feasible and may be promising to optimize the diagnostic yield of CT-guided interventions and to make metabolically active lesions without morphological correlate accessible to percutaneous interventions.

Intravenous thrombolysis in stroke attributable to cervical artery dissection

BACKGROUND AND PURPOSE: Intravenous thrombolysis (IVT) for stroke seems to be beneficial independent of the underlying etiology. Whether this is also true for cervical artery dissection (CAD) is addressed in this study. METHODS: We used the Swiss IVT databank to compare outcome and complications of IVT-treated patients with CAD with IVT-treated patients with other etiologies (non-CAD patients). Main outcome and complication measures were favorable 3-month outcome, intracranial cerebral hemorrhage, and recurrent ischemic stroke. Modified Rankin Scale score

Vascular risk factors and morphometric data in cervical artery dissection: a case-control study

BACKGROUND: Limited knowledge exists on vascular risk factors, body height and weight in patients with spontaneous cervical artery dissection (sCAD). PATIENTS AND METHODS: In this case-control study, major vascular risk factors, body weight, body height and body mass index (BMI) of 239 patients obtained from a prospective hospital-based sCAD registry were compared with 516 age- and sex-matched healthy controls undergoing systematic health examinations in the Clinical and Preventive Investigations Center, Paris. Gender-specific analyses were performed. RESULTS: The mean body height was higher in sCAD patients than in controls (171.3 cm (SD 8.6) vs 167.7 cm (8.9); p<0.0001) and sCAD patients had a significantly lower mean body weight (67.5 (12.2) kg vs 69.3 (14.6) kg; p<0.001) and mean BMI (22.9 (3.3) kg/m2 vs 24.5 (4.2) kg/m2; p<0.0001) than controls. The overall frequency of hypertension, diabetes, current smoking, past smoking and hypercholesterolaemia did not differ significantly between sCAD patients and controls. The mean total plasma cholesterol level was identical in both groups (5.5 mmol/l, SD 1.1). Gender specific subgroup analyses showed similar results for men and women. CONCLUSION: Patients with sCAD had a higher body height and a lower body weight and BMI than controls, while major vascular risk factors were similar in sCAD patients and controls.

Increased prevalence of hyperhomocysteinemia in cervical artery dissection causing stroke: a case-control study

BACKGROUND: Spontaneous cervical artery dissection (sCAD) is a nonatherosclerotic vascular disease of unknown etiology. Mild elevation of total plasma homocysteine (tHcy) levels may be a risk factor for sCAD, but the precise mechanism remains unknown. On the other hand, mild hyperhomocysteinemia is also associated with ischemic stroke related to atherothrombotic or small artery disease. We undertook a case-control study to compare the prevalence of mild hyperhomocysteinemia and tHcy levels between patients with a first ischemic stroke due to sCAD and healthy volunteers, as well as patients with a first ischemic stroke due to atherothrombotic or small artery disease. METHODS: Fasting tHcy levels were determined in 346 consecutive patients with a first ischemic stroke due to sCAD (n = 86) and atherothrombotic or small artery disease (n = 260) within 24 h after the onset of symptoms, and in 100 healthy volunteers. RESULTS: Mild hyperhomocysteinemia was more prevalent in patients with sCAD causing ischemic stroke (n = 33, 38%) than in healthy volunteers (n = 23, 23%; p = 0.034), and less prevalent than in patients with ischemic stroke due to atherothrombotic or small artery disease (n = 149, 57%; p = 0.001). Mean fasting tHcy levels of patients with ischemic stroke caused by sCAD showed a trend to be higher (11.4 +/- 3.8 micromol/l) than those of healthy volunteers (10.2 +/- 3.0 micromol/l, p = 0.61), but were lower than those of patients with stroke due to atherothrombotic or small artery disease (13.6 +/- 6.6 micromol/l, p = 0.002). CONCLUSION: Our results suggest that mild hyperhomocysteinemia may be a risk factor for sCAD causing ischemic stroke, but further studies are needed to identify a possible mechanism. This study confirms the association of hyperhomocysteinemia with ischemic stroke due to atherothrombotic or small artery disease.

Non-selective cutaneous sensory neurectomy as an alternative treatment for auto-mutilation lesion following arthrodesis in three dogs

OBJECTIVE: To describe an alternative method for the treatment of non-responsive self-mutilation injuries in three dogs after carpal/tarsal arthrodesis. STUDY DESIGN: Case series ANIMALS: Two dogs with carpal injury and one dog with tarsal injury treated by arthrodesis METHODS: All dogs developed self-mutilation injuries due to licking and/or chewing of the toes within 21-52 days of surgery. Clinical signs did not resolve within one week after conservative treatment with wound debridement and protective bandages. Following general anaesthesia, a deep horseshoe-shaped skin incision, including the subdermal tissue, was performed proximal to the self-mutilation injury transecting the sensory cutaneous afferent nerves. The skin incision was closed with simple interrupted sutures. RESULTS: All wounds healed without complication. Self-mutilation resolved completely within 24 hours after surgery in all dogs. No recurrence was observed (5 months to 3 years). CONCLUSION: Non-selective cutaneous sensory neurectomy may lead to resolution of self-mutilation following arthrodesis in dogs. CLINICAL RELEVANCE: Failure of conservative treatment in self-mutilation injuries often leads to toe or limb amputation as a last resort. The technique described in this case series is a simple procedure that should be considered prior to amputation. The outcome of this procedure in dogs self-multilating due to neurological or behavioral disturbances unrelated to carpal or tarsal arthrodesis is not known.

Antiplatelets versus Anticoagulants for the Treatment of Cervical Artery Dissection: Bayesian Meta-Analysis

OBJECTIVE To compare the effects of antiplatelets and anticoagulants on stroke and death in patients with acute cervical artery dissection. DESIGN Systematic review with Bayesian meta-analysis. DATA SOURCES The reviewers searched MEDLINE and EMBASE from inception to November 2012, checked reference lists, and contacted authors. STUDY SELECTION Studies were eligible if they were randomised, quasi-randomised or observational comparisons of antiplatelets and anticoagulants in patients with cervical artery dissection. DATA EXTRACTION Data were extracted by one reviewer and checked by another. Bayesian techniques were used to appropriately account for studies with scarce event data and imbalances in the size of comparison groups. DATA SYNTHESIS Thirty-seven studies (1991 patients) were included. We found no randomised trial. The primary analysis revealed a large treatment effect in favour of antiplatelets for preventing the primary composite outcome of ischaemic stroke, intracranial haemorrhage or death within the first 3 months after treatment initiation (relative risk 0.32, 95% credibility interval 0.12 to 0.63), while the degree of between-study heterogeneity was moderate (τ(2) = 0.18). In an analysis restricted to studies of higher methodological quality, the possible advantage of antiplatelets over anticoagulants was less obvious than in the main analysis (relative risk 0.73, 95% credibility interval 0.17 to 2.30). CONCLUSION In view of these results and the safety advantages, easier usage and lower cost of antiplatelets, we conclude that antiplatelets should be given precedence over anticoagulants as a first line treatment in patients with cervical artery dissection unless results of an adequately powered randomised trial suggest the opposite.

Illusions of fusions: assessing cervical vertebral fusion on lateral cephalograms, multidetector computed tomographs, and cone-beam computed tomographs

INTRODUCTION The aims of this study were to compare lateral cephalograms with other radiologic methods for diagnosing suspected fusions of the cervical spine and to validate the assessment of congenital fusions and osteoarthritic changes against the anatomic truth. METHODS Four cadaver heads were selected with fusion of vertebrae C2 and C3 seen on a lateral cephalogram. Multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) were performed and assessed by 5 general radiologists and 5 oral radiologists, respectively. Vertebrae C2 and C3 were examined for osseous fusions, and the left and right facet joints were diagnosed for osteoarthritis. Subsequently, the C2 and C3 were macerated and appraised by a pathologist. Descriptive analysis was performed, and interrater agreements between and within the groups were computed. RESULTS All macerated specimens showed osteoarthritic findings of varying degrees, but no congenital bony fusion. All observers agreed that no fusion was found on MDCT or CBCT. They disagreed on the prevalence of osteoarthritic deformities (general radiologists/MDCT, 100%; oral radiologists/CBCT, 93.3%) and joint space assessment in the facet joints (kappa = 0.452). The agreement within the rater groups differed considerably (general radiologists/MDCT, kappa = 0.612; oral radiologists/CBCT, kappa = 0.240). CONCLUSIONS Lateral cephalograms do not provide dependable data to assess the cervical spine for fusions and cause false-positive detections. Both MDCT interpreted by general radiologists and CBCT interpreted by oral radiologists are reliable methods to exclude potential fusions. Degenerative osteoarthritic changes are diagnosed more accurately and consistently by general radiologists evaluating MDCT.

Comparison of the biomechanical properties of a ventral cervical intervertebral anchored fusion device with locking plate fixation applied to cadaveric canine cervical spines

OBJECTIVE: To evaluate fixation properties of a new intervertebral anchored fusion device and compare these with ventral locking plate fixation. STUDY DESIGN: In vitro biomechanical evaluation. ANIMALS: Cadaveric canine C4-C7 cervical spines (n = 9). METHODS: Cervical spines were nondestructively loaded with pure moments in a nonconstraining testing apparatus to induce flexion/extension while angular motion was measured. Range of motion (ROM) and neutral zone (NZ) were calculated for (1) intact specimens, (2) specimens after discectomy and fixation with a purpose-built intervertebral fusion cage with integrated ventral fixation, and (3) after removal of the device and fixation with a ventral locking plate. RESULTS: Both fixation techniques resulted in a decrease in ROM and NZ (P < .001) compared with the intact segments. There were no significant differences between the anchored spacer and locking plate fixation. CONCLUSION: An anchored spacer appears to provide similar biomechanical stability to that of locking plate fixation.

Dentin hypersensitivity: pain mechanisms and aetiology of exposed cervical dentin

OBJECTIVES The paper's aim is to review dentin hypersensitivity (DHS), discussing pain mechanisms and aetiology. MATERIALS AND METHODS Literature was reviewed using search engines with MESH terms, DH pain mechanisms and aetiology (including abrasion, erosion and periodontal disease). RESULTS The many hypotheses proposed for DHS attest to our lack of knowledge in understanding neurophysiologic mechanisms, the most widely accepted being the hydrodynamic theory. Dentin tubules must be patent from the oral environment to the pulp. Dentin exposure, usually at the cervical margin, is due to a variety of processes involving gingival recession or loss of enamel, predisposing factors being periodontal disease and treatment, limited alveolar bone, thin biotype, erosion and abrasion. CONCLUSIONS The current pain mechanism of DHS is thought to be the hydrodynamic theory. The initiation and progression of DHS are influenced by characteristics of the teeth and periodontium as well as the oral environment and external influences. Risk factors are numerous often acting synergistically and always influenced by individual susceptibility. CLINICAL RELEVANCE Whilst the pain mechanism of DHS is not well understood, clinicians need to be mindful of the aetiology and risk factors in order to manage patients' pain and expectations and prevent further dentin exposure with subsequent sensitivity.