Panoramic screening for dental anomalies assessed by professionals with identical and different backgrounds

The aim of the present study was to evaluate how dental professionals with identical and different backgrounds assess dental anomalies viewed on panoramic radiographs. 101 panoramic radiographs performed of 9-to-10-yr-old children were examined independently by three orthodontists and two radiologists. All observers agreed on the recording of number and identification of congenitally missing permanent teeth. The observers' assessments of malpositioned teeth, teeth in infraocclusion, and primary teeth with atypical/non root resorption varied, however, to a great extent. Two of the orthodontists seemed to report only major deviations from normality (in 38 and 51 of the children respectively) while one reported several more findings (in 85 children). The radiologists reported abnormal findings in 80 and 88 children respectively. In only three children were no dental anomalies reported by any observer. The inconsistent reporting of the majority of dental anomalies (except for agenesis) in children, even among members of subgroups with a similar educational background (e.g. orthodontists), substantiates the need for an evaluation of the expedience of panoramic screening.     

Comparisons of dental maturity between the rural community of Kuhmo in northeastern Finland and the city of Helsinki

Abstract The aim of the study was to check whether dental maturity charts made in southern Finland can be used without modifications in other parts of the country. For this reason the dental maturity of 90 children living in the sparsely populated areas of Kuhmo in northeastern Finland was compared with that of a larger sample of Helsinki children. Most of the Kuhmo children were 7.0–8.5 and 10.5–12.5 yr of age. The method of Demirjian and associates was used to estimate dental maturity. The means of dental maturity scores were greater in Kuhmo in most half-year groups in both sexes. The median dental maturity scores of Kuhmo children were between the 50th and 84th percentile curves of Helsinki children. A referent of the same age and sex was chosen for each Kuhmo child from the Helsinki children. The paired r-test was based on the difference in dental age. The dental age of the Kuhmo children was higher (P<0.05). These findings suggest differences in dental maturity within a fairly homogeneous population, which should be considered when national charts are used.     

Triage screening for osteoporosis in dental clinics using panoramic radiographs

Oral Diseases (2010) 16 , 316–327 Many patients with osteoporosis go undiagnosed because typically no symptoms are present before a fracture. Triage screening to refer patients to appropriate medical professionals for further investigation would be useful to address the increase in the incidence of osteoporotic fractures. Dental clinics may offer a new triage screening pathway because dentists frequently take radiographs of bones in the course of dental treatment. A major premise for such triage screening in dental clinics is that dentists can readily use a screening tool in their dental practice. For example, cortical width and shape of the mandible detected on panoramic radiographs may be appropriate indices for triaging individuals with osteoporosis. To date, several investigators have demonstrated significant associations between cortical indices on panoramic radiographs and bone mineral density of the skeleton generally, such as the spine and femur, biochemical markers of bone turnover and risk of osteoporotic fractures. Further, in two recent Japanese clinical trials, approximately 95% of women who were identified by trained dentists in their clinics using cortical shape findings did have osteopenia or osteoporosis. These findings support the possibility that dental clinics may offer a new triage platform to identify individuals with otherwise undetected osteoporosis.     

The impacted maxillary canine. Further observations on aetiology, radiographic localization, prevention/interception of impaction, and when to suspect impaction

A bstract — Adjacent anomalous or missing maxillary lateral incisors have been implicated in the aetiology of palatally displaced canines by not providing proper guidance to the canine during its eruption. However, a recent review of the literature suggests that the aetiology of palatally displaced canines is genetic in origin. The aetiology of labially impacted canines differs, being due to inadequate arch space. Vertex occlusal radiographs have been recommended for localization but have limitations, and a case is illustrated where this radiograph is deceptive. The prevention/interception of a palatally displaced canine by the extraction of the deciduous canine is best carried out as early as the displacement is detected, mostly soon after 10 years of age. Usually, prevention/interception will avoid the surgical and orthodontic treatment needed to align a palatally impacted canine and may help prevent resorption of the adjacent incisor root. Suspicions that an impaction could occur or has occurred arise a) before the age of 10 years if there is a familial history and/or the maxillary lateral incisors are anomalous or missing; b) after the age of 10 years if there is asymmetry in palpation or a pronounced difference in eruption of canines between the left and right side; or, the canines cannot be palpated and occlusal development is advanced; or, the lateral incisor is proclined and tipped distally; and, on a panoramic radiograph of the late mixed dentition if the incisal tip of the canine overlaps the root of the lateral incisor.     

Panoramic findings in 34-year-old subjects with facial pain and pain-free controls

The aim of this study was to compare panoramic radiographic findings between subjects with reported facial pain and pain-free controls in a population-based sample of 34-year olds. The study was a part of a comprehensive medical survey including subjects born in the year 1966 in Northern Finland. A sub-sample of the cohort was formed based on the question concerning facial pain. A panoramic radiograph was taken of 48 subjects with facial pain and 47 pain-free controls. Pathological findings in the dentition, jaws, maxillary sinuses and temporomandibular joints (TMJs) were compared between the groups. The majority of the subjects in both groups did not have pathological findings. Compared with controls, the subjects with facial pain did not show significantly more pathological findings in the teeth, periodontium, maxillary sinuses, TMJs or in the other areas. Radiographic panoramic findings had no association with reported facial pain in the population-based sample of young adults, and have little impact on the diagnosis of facial pain.     

颞下领关节的曲面断层域测量摆位研究与应用

目的：针对解决颌面部畸形及体位受限者,双侧下颌骨升支及颞下颌关节曲面断层检查与颈椎影像重叠问题。方法：将患者颏部置于颏托上,矢状面与地面垂直,咬合平面与地面平行。观察断层域深度标志线,由前向后用尺子直线测量9cm至外耳孔,再由颏托平面起至外耳孔高度小于10cm,进行投照,并与传统摆位方法进行对比。结果：现传统摆位下颌骨升支及髁状突与颈椎影像重叠者,选层测量摆位新技术获取影像均能避开重叠。结论：新的曲面断层域选层测量摆位法,可解决因颌面骨畸形及体位受限者,致下颌骨升支和髁状突与颈椎影像重叠现象,为临床提供高质量的曲面断层影像。     

Personal computer equipment for dental digital subtraction radiography vs. industrial computer equipment and conventional radiography

A "low-cost" personal computer (PC) system used to digitize dental radiographs was tested by assessing the accuracy of its subtraction images versus those of "high-cost" industrial equipment and conventional radiography. Subtraction images were made of artificial lesions in human femur bone and subsequently evaluated by students and teachers. The observations were analyzed in terms of true positive and false positive reports. "Low-cost" and "high-cost" subtraction images revealed only small differences in diagnostic accuracy. Compared to conventional radiography, the diagnostic accuracy of the subtraction images with the "low-cost" PC system was significantly higher for all observers. The interexaminer variance was similar for the subtraction and the conventional images for both students and teachers, except for a significantly reduced interexaminer variance for the teachers concerning the true positive reports with the "low-cost" PC subtraction technique.     

Reduction of body doses in rotational panoramic radiography by means of reduced beam width in combination with rare earth intensifying screens

Abstract – The absorbed doses in the body of a Rando-Alderson phantom were measured in rotational panoramic radiography (OP-5) with LiF-700 crystals using conventional intensifying screens and standard collimator, as well as rare earth intensifying screens and a collimator slit of reduced width. The reduction of the absorbed doses obtained by using the latter combination was calculated. The reduction range in different regions was 0–50%. The greatest reduction was obtained in the cranial part of the phantom. In the caudal part little or no reduction was observed, probably because leakage radiation contributes substantially to the absorbed doses in this area. The average dose equivalent was calculated for organs in which measurements were made in several locations. The reduction was about 50% for these organs except for the gonads (8%). Compared to the estimated average annual dose equivalent originating from the natural background radiation sources, the dose equivalent resulting from this X-ray examination was very small except in the thyroid gland. In this organ the dose equivalent from one exposure corresponded to 36 days of natural background radiation, but it could be reduced to 18 days by using rare earth intensifying screens in combination with reduced beam width.     

Analysis of C-shaped Canals by Panoramic Radiography and Cone-beam Computed Tomography: Root-type Specificity by Longitudinal Distribution

Introduction

The purpose of this study was to document the characteristics of C-shaped canal systems in permanent mandibular second molars using a combination of orthopantomogram (OPT) and cross-sectional cone-beam computed tomographic (CBCT) imaging.

Methods

Two hundred participants (94 men and 106 women, mean age = 35 years) who underwent both routine CBCT and OPT examinations were enrolled. One endodontist and 1 oral radiologist examined the images of 339 mandibular second molars and described the radiographic features of C-shaped canals from OPT images as confirmed by CBCT imaging. Root morphology was classified as nonfused (NFRI–II) or fused (FRI–III) based on OPT images. Cross-sectional root canal configurations (C1–C5) were identified from CBCT imaging at 3 different levels (coronal, middle, and apical). Frequency distributions of root morphology and root canal configurations were compared at each level, and interobserver reliability was tested using the Cohen kappa test.

Results

Of the 339 teeth, 29 (8.6 %) had C-shaped root canal systems. Most of the root canals were NFR type (86%); only 2% had C-shaped root canals (all NFRII). In the FR category, 23 teeth with C-shaped canals were equally distributed between the FRI and FRII subtypes. Interobserver agreement was almost perfect (κ = 0.89 and κ = 0.91; right and left second molars, respectively). Per CBCT imaging, the most common configuration was C3 at all levels; no C5 case was detected.

Conclusions

OPT usage can assist in recognizing and diagnosing C-shaped root canal systems. Radicular fusion or proximity is a characteristic feature of C-shaped canal systems. However, nonfused root appearances should also be considered suspicious.     

Comparison of panoramic and intraoral radiography and pocket probing for the measurement of the marginal bone level

Panoramic, bitewing and periapical radiography and probing for measurement of the marginal bone level were compared. Altogether 237 sites of 23 patients were examined. Radiographs were taken with a splint containing steel balls to allow calculation of the enlargement of the radiographs. Probing was done before and during flap surgery using the same splint. The open bone measurement represented the true value. All radiographs were assessed by 5 observers. The mean enlargement of panoramic radiography was 27% in the upper and 26% in the lower arch. For bitewing and periapical radiography, it was 8% in the upper and 4-5% in the lower arch. All methods underestimated the bone loss. Probing bone level before surgery was most accurate, deviating at most 5% from the true value. Periapical radiography was more accurate than panoramic and bitewing radiography (p less than 0.001). Panoramic radiography presented a slightly lower mean accuracy than bitewing radiography (p less than 0.05). The underestimation of the bone loss ranged from 13 to 32% in orthopantomograms, 11-23% in bitewing and 9-20% in periapical radiographs. The interobserver variation of the radiographic methods was substantial.     

Age estimation based on tooth development: a test of reliability and validity

Abstract— The precision and accuracy of three commonly used methods for age determination by teeth were studied in 541 children aged 5.5-14.5 yr. These methods rely on estimation of tooth development as seen in radiographs compared with compiled dental charts. It was found that charts made from Scandinavian populations gave a rather good precision, while one from a Canadian population gave a consistent overestimate. Dependent on the method used, sex, and age, the 95% confidence interval for an individual prediction could be more than ±2 yr.     

不同分辨率锥形束CT和全景片在根尖吸收诊断中的对比研究

目的 比较不同分辨率锥形束CT（CBCT）和全景片在根尖吸收诊断中的差异。方法 选取160颗单根前磨牙,用以模拟4种不同程度的根尖吸收：无（完整的牙根）、轻度（根尖区近中、远中、颊面、舌面1.0 mm直径和深度的洞形）、中度（0.4、0.8、1.2、1.6 mm根尖缩短）、重度（2.4、2.8、3.2、3.6 mm根尖缩短）。模拟完成后,对所有牙齿拍摄CBCT（0.2和0.3 mm分辨率）和全景片获取3组X线图像。经校正后,3名正畸临床医师通过对图像资料的分析对所有样本的根尖吸收程度进行诊断。采用McNemar检验对比分析采用不同成像技术诊断不同程度根尖吸收的正确率。结果 采用全景片诊断全部根尖吸收样本的正确率为57.5%,而采用0.2和0.3 mm分辨率CBCT的正确率分别为85%和81.3%。对全部样本的诊断,0.2 mm分辨率CBCT和全景片以及0.3 mm分辨率CBCT和全景片的差异均有统计学意义（P〈0.01）。然而,对无、轻度、重度和全部根尖吸收样本的诊断,0.2和0.3 mm分辨率CBCT间差异无统计学意义（P〉0.05）。结论 相比于全景片,CBCT对根尖吸收具有更高的检出率。在根尖吸收的诊断中,0.2和0.3 mm分辨率CBCT诊断效能无明显差异,但0.3 mm分辨率CBCT对患者的辐射水平更低。     

Influence of contrast enhancement and pseudocolor transformation on the diagnosis with digital subtraction images (DSI)

This study evaluated the influence of the image processing step of digital subtraction images on inter- and intraexaminer agreement in the interpretation of alveolar bone changes. 52 pairs of standardized radiographs from various clinical trails were included. Six dentists were invited to interpret the images projected as slides in random order. Display one demonstrated the slide of the digitized baseline radiograph and the follow-up image. Display two showed the regular digital subtraction image. Display three represented a grey level contrast enhanced version and displays four and five were pseudo/color enhanced subtraction images. Applying κ-statistics and multiple regression analysis it was demonstrated that better agreements were obtained when the two color coded displays of subtraction images were shown to the interpreters. The image interpretation was performed in two series. For the first evaluation the interpreters were not informed about the therapy provided nor the time elapsed between taking the pairs of standardized radiographs. In the second series this information was provided. It could be demonstrated that the agreement in the diagnosis of bone change was less influenzed by the knowledge about the clinical information if the two color-converted versions of subtracted images were evaluated. Thus, it was concluded that image processing of subtraction images using color enhancement might improve agreement in the diagnostic task. The color coded images were less influenced by the bias in the interpretation of an expected change. The decision making process might be more objective when using color enhanced subtraction images.     

Relation between sucking habits and dental characteristics in preschoolchildren with unilateral cross-bite

Abstract – The relationship between sucking habits and dental characteristics of unilateral cross-bite in 4-yr-old children ( n = 76) was studied. The cross-bites were classified on the variables "number of teeth involved", incisor "overjet" and "overbite", "terminal plane shift", "midline shift", "asymmetric maxillary dental arch" and "max./mand. arch width difference". Type of sucking habit (dummy, finger) and its duration and intensity were analyzed from a questionnaire answered by the parents. The "max./mand. arch width difference" in the canine region was found to be negatively related to the intensity and duration of the sucking habit, and also negatively related to sucking a dummy compared to finger sucking. The study indicates that the "duration" and "intensity" of the sucking habit have a negative influence by reducing the transverse width of the maxillary arch in children with a unilateral cross-bite. Dummy sucking was more detrimental to the transverse dimension in the canine region than finger sucking.     

Nursing caries in Head Start children, St. Thomas U.S. Virgin Islands: assessed by examiners with different dental backgrounds.

The purposes of this study were to determine the prevalence of nursing caries in 3- to 5-year-old Head Start (HS) children on St. Thomas, U.S. Virgin Islands and to assess the reliability of examiners with different dental backgrounds. A dentist, hygienist, and nondental HS personnel participated in a 1/2 day training session (lecture and workshop) and then independently conducted visual examinations for caries of the maxillary anterior teeth including nursing caries. Twenty-three HS personnel examined a total of 375 children; the dentist and hygienist examined a random sample of 74 and 73 children, respectively. Seventy-one children received all three independent examinations. Reliability was assessed by percent agreement, sensitivity, specificity, and kappa value. The dentist found 41% of the children had caries of the maxillary incisors, which included nursing caries. The percentage of children with nursing caries was 12%. There was strong-to-good diagnostic agreement between the dentist and hygienist. The HS personnel also found that 12% of the children had nursing caries, but the diagnostic agreement between the dentist and HS personnel was only good-to-fair.     

Radiographic screening examination: frequency, equipment, and film in general dental practice in Denmark

The aim of the present study was to evaluate types and frequencies of radiographic screening examinations, and radiographic equipment and film used in general dental practice in Denmark. A questionnaire was mailed to 400 randomly selected dental practitioners. A total of 258 questionnaires were returned, out of which 249 were analyzed. Two-thirds of the respondents performed radiographic screening examinations, of which bitewing-screening was the one most frequently used for first-visit and regular patients. The more recent their graduation year, the more apt were dentists to perform radiographic screening examinations. More than 40% of the dentists had radiographic units operating at a voltage capacity of 60–70 kV, and more than 50% had facilities for automatic or semiautomatic processing. Only one-quarter of the respondents used the Kodak Ektaspeed film (E-speed film). The results show that radiographic procedures and film used in general dental practice are not always in accordance with guidelines and recommendations.     

Predictors of postretention stability of mandibular dental arch dimensions in patients treated with a lip bumper during mixed dentition followed by fixed appliances

Objective:To identify which dental and/or cephalometric variables were predictors of postretention mandibular dental arch stability in patients who underwent treatment with transpalatal arch and lip bumper during mixed dentition followed by full fixed appliances in the permanent dentition.Materials and Methods:Thirty-one patients were divided into stable and relapse groups based on the postretention presence or absence of relapse. Intercuspid, interpremolar, and intermolar widths; arch length and perimeter; crowding; and lower incisor proclination were evaluated before treatment (T0), after lip bumper treatment (T1), after fixed appliance treatment (T2), and a minimum of 3 years after removal of the full fixed appliance (T3). Logistic regression analyses were performed to evaluate the effect of changes between T0 and T1, as predictive variables, on the occurrence of relapse at T3.Results:The model explained 53.5 % of the variance in treatment stability and correctly classified 80.6 % of the sample. Of the seven prediction variables, intermolar and interpremolar changes between T0 and T1 (P = .024 and P = .034, respectively) were statistically significant. For every millimeter of increase in intermolar and interpremolar widths there was a 1.52 and 2.70 times increase, respectively, in the odds of having stability. There was also weak evidence for the effect of sex (P = .047).Conclusions:The best predictors of an average 4-year postretention mandibular dental arch stability after treatment with a lip bumper followed by full fixed appliances were intermolar and interpremolar width increases during lip bumper therapy. The amount of relapse in this crowding could be considered clinically irrelevant.