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![(a) 2D X-ray image of a human mandible, with differentiation between regions of purely cortical bone and of mixed cortical/trabecular bone; (b) typical shape of mandibular cross section as encountered in plane A-A, this plane appearing as line in (a); after radiograph of Angelopoulos [2]](profile/Lars-Bonitz/publication/280866929/figure/fig5/AS:281004595007546@1444008124784/a-2D-X-ray-image-of-a-human-mandible-with-differentiation-between-regions-of-purely.png)
(a) 2D X-ray image of a human mandible, with differentiation between regions of purely cortical bone and of mixed cortical/trabecular bone; (b) typical shape of mandibular cross section as encountered in plane A-A, this plane appearing as line in (a); after radiograph of Angelopoulos [2]
Source publication
In dentistry, clinical radiographs (also called X-ray images) reflect the intensity loss of an X-ray when being transmitted through the mandibular objects, and this loss is quantified in terms of grey values. While such images are standardly used for pathology detection by the experienced dentist, we here present a new method for getting more quant...
Citations
... However, panoramic radiographs commonly used in oral and maxillofacial regions can also be used to obtain quantitative information about cortical and trabecular bones. [9] Several methods including mental index (MI), panoramic mandibular index (PMI), mandibular cortical index (MCI), gonial index (GI), antegonial index (AI), and fractal dimension analysis (FDA) are often used to measure bone quality and density in panoramic radiographs. ...
Objectives
Maxillary impacted canines have an important place in orthodontics for the reason of being a common anomaly and its treatment is time consuming and difficult. The aim of this study was to investigate the mandibular indexes and cephalometric parameters in adolescents with impacted maxillary canines.
Materials and Methods
The radiographs of 4026 patients aged 12–19 years old were scanned and a total of 155 patients were included in the study. Subjects were divided into three groups according to the permanent maxillary canines: Bilateral impacted canine (BIC) (52 subjects; mean age 15.02 ± 1.74 years), unilaterally impacted canine (UIC) (51 subjects; mean age 14.89 ± 1.39 years), and the control (52 subjects; mean age 14.84 ± 1.65 years) groups. Skeletal, soft tissue and dental measurements were performed on cephalometric radiographs. Mandibular index analyzes including the panoramic mandibular index (PMI), mental index (MI), antegonial index (AI), and gonial index (GI) measurements and also angular measurements of impacted maxillary canines were performed on panoramic radiographs. Data were analyzed statistically and P < 0.05 was considered significant.
Results
Maxillary skeletal and dental measurements showed retrusive positioned maxillary dental arch in the sagittal direction in the impacted canine groups ( P < 0.05). PMI and MI values were greater in the BIC and UIC groups than in control group ( P < 0.05). There was no statistically significant difference in AI value among groups ( P < 0.05). GI value of BIC group was found statistically lower than other groups ( P < 0.05).
Conclusion
Individuals with impacted maxillary canines have more retrusive maxillary dental arch and soft-tissue components. Furthermore, mandibular cortex was thicker in subjects with impacted maxillary canine than individuals with not and clinicians should keep in mind this when examine the panoramic radiographs in terms of early diagnosis of impacted maxillary canine teeth.
... Bone status at different skeletal sites can be assessed using conventional radiographs, quantitative computed tomography (QCT), dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), and cone-beam computed tomography (CBCT). Panoramicradiograph,anextensivelyutilizedimagingmodalityin oral and maxillofacial region,canbe used forobtaining more quantitative information of cortical and trabecular bone based on different methods [14]. Although many methods have been proposed, mental index (MI) and panoramic mandibular index (PMI) are commonly used to evaluate mandibular morphological changes and amount of bone on panoramic radiographs [15][16][17]. ...
Objective
The objective of this study is to evaluate the mental index (MI) and panoramic mandibular index (PMI) of a group of adolescent patients in different body mass index (BMI) percentile.
Material and methods
Subjects were divided into three different groups in accordance to their BMI percentile status: normal weight (35 subjects; mean age, 14.81 ± 2.12 years), overweight (32 subjects; mean age, 14.77 ± 2.56 years), and obese (33 subjects; mean age, 14.06 ± 2.59 years) groups. Mental index (MI) and panoramic mandibular index (PMI) were assessed on panoramic radiographs.
Results
There were statistically significant differences in PMI and MI that were observed among groups (p < 0.0001 and p < 0.001, respectivel). MI and PMI are higher in overweight and obese individuals than in normal-weight.
Conclusions
Mandibular cortex was found thicker in patients who are obese and overweight compared to normal weight patients. We can suggest that young obese individuals’ bone structure can be take in consideration in orthodontic or dental surgical treatment planning.
Clinical relevance
Dense cortical bone may cause some difficulties in orthodontic and surgical treatment. Clinicians should understand obesity and overweight-related jaw bone changes and consider these factors to treat their patients.
... Panoramic radiograph is an extensively utilized imaging modality in oral and maxillofacial surgical practices [5]. Furthermore, dental panoramic radiographs (DPRs) can be extended into the third dimension for obtaining more quantitative information of cortical and trabecular bone geometry based on x-ray physics transformation method [6]. Bone changes may be detected early on dental radiographs because bone formation rate is high during the mandibular alveolar process. ...
It is important to investigate the irregularities in aging-associated changes in bone, between men and women for bone strength and osteoporosis. The purpose of this study was to characterize the changes and associations of mandibular cortical and trabecular bone measures of men and women based on age and to the evaluation of cortical shape categories, in a large Korean population. Panoramic radiographs of 1047 subjects (603 women and 444 men) aged between 15 to 90 years were used. Mandibular cortical width (MCW), mandibular cortical index (MCI), and fractal dimensions (FD) of the molar, premolar, and anterior regions of the mandibular trabecular bone were measured. Study subjects were grouped into six 10-years age groups. A local linear regression smoothing with bootstrap resampling for robust fitting of data was used to estimate the relationship between radiographic mandibular variables and age groups as well as genders. The mean age of women (49.56 ± 19.5 years) was significantly higher than that of men (45.57 ± 19.6 years). The MCW of men and women (3.17mm and 2.91mm, respectively, p < 0.0001) was strongly associated with age and MCI. Indeed, trabecular measures also correlated with age in men (r > −0.140, p = 0.003), though not as strongly as in women (r > −0.210, p < 0.0001). In men aged over 55 years, only MCW was significantly associated (r = −0.412, p < 0.0001). Furthermore, by comparison of mandibular variables from different age groups and MCI categories, the results suggest that MCW was detected to be strongly associated in both men and women for the detection of bone strength and osteoporosis. The FD measures revealed relatively higher association with age among women than men, but not as strong as MCW.
The use of contrast media on CT scans needs to be done to see the urinary tract clearly. Contrast media itself has side effects that can harm patients if they have allergies. The purpose of this study was to determine if black tea can be used as a natural contrast medium to replace iodine contrast media in CT urography. This study used a case study method by observing a patient diagnosed with hydronephrosis who underwent CT urography. Prior to the examination, the patient had drunk 600 ml of black tea. Examination using CT Scan GE Revolution ACT 32 slices with axial, coronal and sagittal images. The results of the image are then taken to a radiologist and a radiographer to assess the image quality and anatomical clarity in the form of an interview. The results showed that the patient drank 600 ml of plain black tea on a CT-Scan urography examination in cases of Hydronephrosis could open or clarify the ureteral tract, making it easier for doctors to read out radiographs. The use of tea was able to reveal the ureteral groove and facilitate tracking. Black tea with natural ingredients has the opportunity to be a substitute for iodine contrast media which uses chemicals in CT Urography so as to reduce the potential for allergies and side effects to patients and is inexpensive. Studies related to the ratio of black tea and water can be carried out to obtain an optimal density value.
Transparent and removable aligners represent an effective solution to correct various orthodontic malocclusions through minimally invasive procedures. An aligner‐based treatment requires patients to sequentially wear dentition‐mating shells obtained by thermoforming polymeric disks on reference dental models. An aligner is shaped introducing a geometrical mismatch with respect to the actual tooth positions to induce a loading system, which moves the target teeth toward the correct positions. The common practice is based on selecting the aligner features (material, thickness, and auxiliary elements) by only considering clinician's subjective assessments.
In this article, a computational design and engineering methodology has been developed to reconstruct anatomical tissues, to model parametric aligner shapes, to simulate orthodontic movements, and to enhance the aligner design. The proposed approach integrates computer‐aided technologies, from tomographic imaging to optical scanning, from parametric modeling to finite element analyses, within a 3‐dimensional digital framework.
The anatomical modeling provides anatomies, including teeth (roots and crowns), jaw bones, and periodontal ligaments, which are the references for the down streaming parametric aligner shaping. The biomechanical interactions between anatomical models and aligner geometries are virtually reproduced using a finite element analysis software. The methodology allows numerical simulations of patient‐specific conditions and the comparative analyses of different aligner configurations.
In this article, the digital framework has been used to study the influence of various auxiliary elements on the loading system delivered to a maxillary and a mandibular central incisor during an orthodontic tipping movement. Numerical simulations have shown a high dependency of the orthodontic tooth movement on the auxiliary element configuration, which should then be accurately selected to maximize the aligner's effectiveness.
