Gökhan Özkan

Validation of micro-computed tomography for occlusal caries detection: an in vitro study

Conventional methods of caries detection, including the gold standard of histological examination, have certain disadvantages that must be addressed prior to validating any other diagnostic technique-current or new. Here we evaluated the validity of micro-computed tomography (micro-CT) as an alternative gold-standard technique for caries detection. Sixty teeth with suspected occlusal caries were chosen from a pool of teeth extracted for orthodontic, periodontal, or surgical reasons. Identical reference points were marked on photographs taken for teeth and were used to evaluate each method. Dimensions of caries were assessed by two calibrated examiners using the ICDAS-II visual examination system, bitewing radiographs, and micro-CT. The teeth included in the study were selected randomly from solution before all measurements. For micro-CT, the device was set to 50 kV, 800 µA, pixel size 15 µm (at 1024 × 1024 resolution), and 1° rotation step. NRecon software (SkyScan) was used to obtain reconstructed images. For each diagnostic method, results were compared with histology results using the McNemar test. Receiver operator characteristic (ROC) analysis was also performed for each method (Z-test; p < 0.05). Besides showing a high correlation with histology results, micro-CT yielded the greatest values at the D3 threshold; moreover, accuracy and area under the ROC curve (AUC) values were greatest at the D1threshold. Our results indicate that micro-CT performs as well as or better than histological examination for the purpose of comparing methods for caries detection.

Evaluation of the factors associated with sublingual varices: a descriptive clinical study

BACKGROUND Age is considered as an important factor for the development of sublingual varices (SV). It has been suggested that some other conditions such as gender, systemic diseases, smoking, denture wearing may play a role in aetiology. However, there are a limited number of studies investigating these associations. This study was perform to evaluate association between SV and the conditions which are described as possible risk factors previously. MATERIALS AND METHODS A total of 691 patients (470 females, 221 males) who attended for comprehensive clinical examination were included in the study. Age, gender, systemic health, venous varix of the lower extremities, smoking status, denture wearing were recorded during the history taking. SV were classified into two categories: stage 0 (few or none visible) and stage 1 (moderate or severe). Tongue photographs were taken from a group of these patients. For the evalu- ation of intra-observer reliability, 60 photographs of tongue were re-evaluated by the same observer. Intra-observer reliability was evaluated using Kappa statistics. Pearson c2 test and Fishers exact test were used to assess SV in relation to each variable, and variables showing associations with p < 0.05 were selected for the multivariable analysis, then logistic regression analysis was applied. RESULTS Kappa value of intra-observer reliability was 0.91. SV were significantly associated with age (odds ratio [OR] = 1.08, p = 0.000), hypertension (OR = 2.3, p = 0.007) and denture wearing (OR = 2.17, p = 0.02). CONCLUSIONS The presence of SV is associated with hypertension and denture wearing as well as aging. More detailed studies are needed to prove causative relations between SV and systemic diseases.

Clinical evaluation of near-infrared light transillumination in approximal dentin caries detection

The objective of this clinical study was to compare conventional caries detection techniques, pen-type laser fluorescence device, and near-infrared light transillumination method in approximal dentin caries lesions. The study included 157 patients, aged 12–18, without any cavity in the posterior teeth. Two calibrated examiners carried out the assessments of selected approximal caries sites independently. After the assessments, the unopened sites were excluded and a total of 161 approximal sites were included in the study. When both the examiners arrived at a consensus regarding the presence of dentin caries, the detected lesions were opened with a conical diamond burr, the cavity extent was examined and validated (gold standard). Sensitivity, specificity, negative predictive value, positive predictive value, accuracy, and area under the ROC curve (Az) values among the caries detection methods were calculated. Bitewing radiography and near-infrared (NIR) light transillumination methods showed the highest sensitivity (0.83–0.82) and accuracy (0.82–0.80) among the methods. Visual inspection showed the lowest sensitivity (0.54). Laser fluorescence device and visual inspection showed nearly equal performance. Near-infrared light transillumination can be used as an alternative method to approximal dentin caries detection. Visual inspection and laser fluorescence device alone should not be used for approximal dentin caries.

Evaluation of Diagnostic Tests Using Information Theory for Multi-Class Diagnostic Problems and its Application for the Detection of Occlusal Caries Lesions

BACKGROUND Several methods are available to evaluate the performance of the tests when the purpose of the diagnostic test is to discriminate between two possible disease states. However multi-class diagnostic problems frequently appear in many areas of medical science. Hence, there is a need for methods which will enable us to characterize the accuracy of diagnostic tests when there are more than two possible disease states. AIMS To show that two information theory measures, information content (IC) and proportional reduction in diagnostic uncertainty (PRDU), can be used for the evaluation of the performance of diagnostic tests for multi-class diagnostic problems that may appear in different areas of medical science. STUDY DESIGN Diagnostic accuracy study. METHODS Sixty freshly extracted permanent human molar and pre-molar teeth suspected to have occlusal caries lesions were selected for the study and were assessed by two experienced examiners. Each examiner performed two evaluations. Histological examination was used as the gold standard. The scores of the histological examination were defined as sound (n=11), enamel caries (n=22) and dentin caries (n=27). Diagnostic performance of i) visual inspection, ii) radiography, iii) laser fluorescence (LF) and iv) micro-computed tomography (M-CT) caries detection methods was evaluated by calculating IC and PRDU. RESULTS Micro-computed tomography examination was the best method among the diagnostic techniques for the diagnosis of occlusal caries in terms of both IC and PRDU. M-CT examination supplied the maximum diagnostic information about the diagnosis of occlusal caries in the first (IC: 1.056; p<0.05), (PRDU: 70.5%) and second evaluation (IC: 1.105; p<0.05), (PRDU: 73.8%) for the first examiner. M-CT examination was the best method among the diagnostic techniques for the second examiner in both the first (IC:1.105; p<0.05), (PRDU:73.8%) and second evaluation (IC:1.061; p<0.05), (PRDU:70.8%). IC and PRDU were lowest for visual inspection. CONCLUSION The present study demonstrates that IC and PRDU can be used to evaluate diagnostic test performance when multiple disease states are being evaluated.

AĞIZ ORTAMINDA YAŞLANMA İLE BİRLİKTE GÖRÜLEN DEĞİŞİMLER-Changes in the Oral Cavity Due to Ageing

oz Yapilan bilimsel calismalara, hayat standartlarinin yukselmesine ve insanlarin hijyen kosullarina onem vererek yasamalarina bagli olarak son yuzyilda yasam suresinde onemli artis olmustur. Yasli bireylerde agiz ve dis sagliginin, genel saglik uzerindeki etkisi ihmal edilemeyecek kadar buyuktur. Yaslanmanin orofasiyal bolgedeki etkisinin yani sira, edinilen sistemik hastaliklar ve bunlarin tedavisinde kullanilan ilaclar agiz ortaminda istenmeyen degisikliklere yol acmaktadir. Dis kayiplari, asinmalar, Anahtar kelimeler: Yasli hasta, Orofasial degisimler periodontal hastaliklar, dis curukleri, oral mukozada meydana gelen lezyonlar vb. yasli hastalarin oral fonksiyonlari yeterince iyi yerine getirememelerine yol acar. Konusma bozukluklari, kaslarda atrofi, tat almada degisiklikler de gozlenebilir. Cigneme kabiliyeti protezlerle desteklenir ancak agiz kurulugu, protez kullanimina ve temizligine cesitli nedenlerden dolayi dikkat edilememesi mukozanin butunlugunu bozan rahatsizliklara yol acar. Boyle durumlarda ortaya cikan oral mukoza ve dislere ait komplikasyonlarin bazilari basit yollarla tedavi edilebilirken bazilari daha ciddi sorunlar dogurabilir. Yasli bireylerin, genel saglik durumunu takip eden tip hekimleri ile dis hekimlerinin birlikte hareket etmesi ve iyi bir dis tedavi planlamasi yaslinin agiz sagligini kazandirir, ancak duzenli kontrol goz ardi edilmemelidir. ABSTRACT Over the last century there has been a marked increase in life expectancy due to advances in science, improved living standards and people attaching more importance to hygiene conditions. The impact of oral and dental health on general health status of the elderly population is too big to be ignored. Besides impacts of ageing in the orofacial region, acquired systemic diseases and related medication produce unwanted changes in the oral cavity. Tooth loss, abrasions, periodontal disease, dental caries, oral mucosal lesions etc. impair satisfactory fulfillment of oral functions of elderly patients. Speech disorders, muscle atrophy, changes in taste may also occur. Dentures improve the chewing efficiency but dry mouth, denture use and cleaning deficiencies for various reasons might produce conditions disrupting integrity of oral mucosa. While some of the complications arising in the oral mucosa and teeth because of such situations might be treated with some simple measures, some might lead to serious problems. Cooperation between dentists and doctors following general health status of the elderly and a good dental treatment plan can help restore dental health of an elderly, but routine control should not be neglected. Keywords: Elderly patient, Orofacial changes