Feature Selection of the Combination of Porous Trabecular with Anthropometric Features for Osteoporosis Screening

This study aims to select the important features from the combination of porous trabecular pattern with anthropometric features for osteoporosis screening. The study sample has their bone mineral density (BMD) measured at the proximal femur/lumbar spine using dual-energy X-ray absorptiometry (DXA). Morphological porous features such as porosity, the size of porous, and the orientation of porous are obtained from each dental radiograph using digital image processing. The anthropometric features considered are age, height, weight, and body mass index (BMI). Decision tree (J.48 method) is used to evaluate the accuracy of morphological porous and anthropometric features for selection data. The study shows that the most important feature is age and the considered features for osteoporosis screening are porosity, vertical pore, and oblique pore. The decision tree has considerably high accuracy, sensitivity, and specificity

Familial adenomatous polyposis : new insights into the craniofacial radiograph features

Tese (doutorado) — Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Saúde Animal, 2020.A Polipose Adenomatosa Familial (FAP) é uma doença com padrão de herança autossômico dominante predisponente ao câncer colorretal. No Brasil, o câncer colorretal está entre as quatro neoplasias malignas mais frequentes e é o terceiro em mortalidade em ambos os sexos. Os pacientes com FAP, além de apresentarem manifestações intestinais, apresentam alterações dento-ósseas. Dentre essas, são relatados presença de osteomas, odontomas, dentes supranumerários, escleroses ósseas no complexo maxilomandibular que podem se manifestar precocemente - antes do aparecimento dos pólipos intestinais. Uma revisão sistemática da literatura demonstrou a importância da investigação de doenças sistêmicas por meio de alterações ósseas presentes em radiografias panorâmicas - rotineiramente requisitadas por cirurgiões-dentistas. Baseando em artigos incluídos na revisão, regiões de interesse foram mapeadas como pontos de referência para uma futura área de análise de índices radiomorfométricos. Alterações ósseas foram detectadas quando condiçōes sistêmicas acometiam os pacientes. Um segundo projeto demonstrou que o trabeculado ósseo mandibular de pacientes FAP, quando comparados com controles pareados, apresentou alterações micro estruturais no osso trabecular mandibular quando submetidos a análise de dimensão fractal. Numa tentativa de englobar pacientes pediátricos e adultos em países diferentes, um estudo multicêntrico foi elaborado em parceria com a Universidade de Brasília e o Mercy’s Children Hospital nos Estados Unidos. Pacientes pediátricos FAP mostraram alterações ósseas similares aos adultos. Quando esses pacientes foram comparados aos controles, os pacientes FAP apresentaram alterações no padrão trabeculado ósseo, além de alterações dentais. Esse último estudo têm como objetivo recomendar o acompanhamento odontológico periódico através de radiografia panorâmica convencional anual em pacientes FAP e nas famílias em risco. Além de enfatizar a necessidade de participação do dentista nas equipes médicas multiprofissionais que acompanham essas famílias. Assim, esse trabalho alerta e conscientiza de forma crítica, baseada em evidências, nas equipes de saúde bucal sobre a importância de investigar doenças sistêmicas, alterações ósseas e FAP nos exames radiográficos rotineiros.Familial Adenomatous Polyposis (FAP) is an autosomal dominant disorder caused by mutations in the Adenomatous Polyposis Coli gene (APC). Worldwide, colorectal cancer (CRC) is within the third most frequent malignant neoplasm. CRC ranked as the third modality associated-death with females and males. The FAP patients, in addition to present extraintestinal manifestations, also show dento-osseous alterations. These alterations are mostly associated with odontomas, osteomas, supernumerary teeth, and idiopathic osteosclerosis. These last could precede the clinical evidence of intestinal polyps. A systemic review of the literature demonstrated the importance of the systemic disease investigation through mandibular trabecular bone alterations using conventional panoramic radiographs – which are routinely prescribed by dentists in general practice. Based on the articles included in this systematic review, regions of interest were mapped and used as reference-points to investigate radiomorphometric indexes. Besides, trabecular and cortical bone alterations were possibly associated with systemic conditions. A second project demonstrated that the mandibular trabecular bone pattern in FAP patients when compared to healthy individuals, showed texture discrepancies and narrow bone alterations via the fractal dimension analysis. In an attempt to radiographically assess FAP children and adults in different locations, we developed a multicentric study in partnership with the Children’s Mercy Hospital in Kansas City, United States. Pediatric FAP demonstrated osseous alterations that were similar to the adults affected by the same disease. Compared to the healthy controls, the FAP patients, presented alterations in the trabecular bone texture of the mandible. These studies aim to recommend the annual dental follow-up on the FAP patients and families at risk using the panoramic radiograph. In addition to emphasizing the importance of a dentist collaborating in the FAP multispecialty team. Thus, our objective is to alert and create critical thinking, based on scientific evidence, in the dental health teams about the importance of the opportunistic surveillance and screening of systemic diseases and FAP extraintestinal manifestations on the routinely taken dental radiographs

Cone Beam Computed Tomography and Impacted Maxillary Canines : Dose, Optimisation, and Justification

Retinerte hjørnetenner i overkjeven som er sperret av andre tenner for å vokse ut, er den vanligste grunnen til bruk av Cone Beam Computed Tomography (CBCT) hos barn og unge. Hvis diagnostisering av de retinerte hjørnetenner mangler eller kommer sent, kan rotresorpsjon forekomme på de permanente nabo tennene. Resorpsjonene kan senere føre til behov for kjeveortopedisk behandling, kirurgiske ekstraksjoner og i noen tilfeller implantat eller andre proteseløsninger. Retinerte hjørnetenner oppdages vanligvis hos barn ved klinisk undersøkelse i kombinasjon med intraorale og panorama røntgenbilder. Når mer informasjon er nødvendig for diagnostikk og planlegging, er CBCT-undersøkelse berettiget. På grunn av råd om strålevern er det enighet om at CBCT ikke bør brukes ved førstehånds undersøkelse, men det er fortsatt ingen konsensus om hvorvidt CBCT påvirker terapiplanlegging blant klinikere. Den ideelle radiografiske modaliteten og eksponering varierer, avhengig av den klinisk situasjonen. Når ioniserende stråling benyttes for å undersøke pasienter, må man være oppmerksom på balansen mellom fordelene for pasienten og klinikeren og risikoen ved stråling. Denne doktorgradsavhandlingen hadde som mål å vurdere belastningen ved strålingsdose for barn der retinerte hjørnetenner ble undersøkt. Avhandlingen ser også på metoder for å begrense doseeksponering ved å bruke protokoller for å optimaliserte en lav dose og begrense CBCT-undersøkelsene. Første artikkel i avhandlingen hadde som mål å se effektiv dose ved å sammenligne todimensjonale (2D) undersøkelser (panorama og periapikale røntgenbilder) og tredimensjonale (3D) CBCT. Dosen fra 2D-undersøkelse og CBC fra to enheter (Promax3D og NewTom 5G) ble sammenlignet etter måling av doser på et antropomorft barnefantom. Dosen fra CBCT-undersøkelsen var fra 15 til 140 ganger høyere enn for de konvensjonelle 2D-undersøkelsene, avhengig av CBCT-enhet og type 2D-undersøkelse. Andre artikkel evaluerte bildekvalitet og synlighet av anatomiske strukturer på lavdose CBCT-skanning og effekten av et støyreduksjonsfilter for vurdering av overkjevens front. Flere CBCT-protokoller (Promax3D), blant annet fire lavdoseprotokoller, ble testet på skallefantomer for å sammenligne bildekvalitet og synlighet av anatomiske strukturer som er relevante for vurdering av retinerte hjørnetenner. Tre av lavdoseprotokollene gav akseptabel diagnostisk bildekvalitet, selv om dosen ble redusert med 61 % – 77 %. I tredje artikkel ble det undersøkt hvordan CBCT påvirker behandlingsplanen til pasienter med retinerte hjørnetenner, samt mulige kliniske og 2D-bilde markører for planlagt CBCT-bruk. For å avgjøre om CBCT var berettiget for planlegging av behandling, evaluerte og planlagt en tverrfaglig gruppe 89 kasus med retinerte hjørnetenner. Mer enn halvparten av CBCT-undersøkelsene ble vurdert som uberettiget. Planlagt behandling ble endret i 9,8 % av tilfellene. Variable målt før CBCT som predikerte behovet for ytterligere CBCT, var horisontalt plasserte hjørnetenner, strategi for ekstraksjon på permanente tenner, og bukkalt posisjonerte hjørnetenner. Denne avhandlingen viser at, CBCT medfør høyere effektiv dose for pasienter sammenlignet med konvensjonell 2D røntgenbilder. Dosene pasienter får ved undersøkelse av retinerte hjørnetenner kan minimeres ved å 1) optimalisere protokoller for lavdose CBCT og 2) begrense bruk av CBCT til tilfeller der ytterligere 3D-informasjon er viktig for videre terapeutisk behandling.Impacted maxillary canines are the most common reason for Cone Beam Computed Tomography (CBCT) examinations of the anterior maxilla in children and adolescents today. If impacted canines are missed or diagnosed late, root resorptions may occur on permanent adjacent incisors. In turn, these resorptions may lead to the need for further orthodontic treatment, surgical extractions, and even implants or other prosthetic solutions. Impacted canines are usually discovered in children via clinical examinations in combination with intraoral periapical radiographs and panoramic images. When more diagnostic information is needed, the next step is a CBCT examination. While regulating authorities in radiation protection agree that CBCT should not be used first-hand, there is still no consensus over whether CBCT alters therapy planning amongst clinicians. The ideal radiographic modality and exposure parameters vary, depending on each individual clinical task. When using ionizing radiation to examine patients, attention must be paid to the balance between the benefit to the patient and clinician contra the radiation risk. This thesis aimed to assess the radiation dose burden to children examined for impacted canines and explore methods of limiting dose exposure by applying optimised low-dose protocols and by limiting CBCT examinations through a justification process performed at the therapeutic thinking level. The first paper aimed to measure the effective dose using two-dimensional (2D) examinations (panoramic and periapical radiographs) and three-dimensional (3D) CBCT devices. 2D examination doses and CBCT doses from two devices (Promax3D and NewTom 5G) were compared after measuring organ doses on an anthropomorphic child phantom. The dose from CBCT examinations ranged from 15 to 140 times higher than conventional 2D examinations, depending on the CBCT unit and the type of 2D examination. The second paper evaluated overall image quality and visibility of anatomic structures on low-dose CBCT scans and the effect of a noise reduction filter for assessment of the anterior maxilla. Multiple CBCT protocols (Promax3D), including four low-dose protocols, were tested on dry skull phantoms to compare overall image quality and visibility of anatomic structures pertinent to impacted canine assessment. Of the low-dose protocols, three provided acceptable diagnostic image quality while reducing the dose by 61% – 77%. The third paper investigated how CBCT affects the treatment plan of patients with impacted canines, as well as identified possible clinical and 2D imaging markers for the justified CBCT examination at the therapeutic thinking level. To decide whether CBCT was justified for therapy planning, an interdisciplinary therapy-planning group evaluated impacted canine cases and decided treatment alternatives, first without and later in addition to diagnostic information from CBCT examinations. More than half of the CBCT examinations were considered unjustified, and the therapy plan changed in 9.8% of the cases. Variables measured prior to CBCT that predict the need for further CBCT examinations were horizontally positioned canines (OR= 10.9, p = 0.013 when compared to vertically positioned canines), when extraction strategy was involved (OR = 6.7, p = 0.006), and buccally positioned canines when compared to palatal (OR = 5.3, p = 0.047), central (OR = 25.0, p = 0.001), and distal or uncertain positions (OR =7.7, p = 0.005). Even when optimised, CBCT examinations come at the cost of a higher radiation dose than conventional 2D images. Based on the papers comprising this thesis, patient dose burdens can be minimized when assessing impacted maxillary canines in radiosensitive paediatric patient populations by 1) optimising low-dose CBCT protocols and 2) limiting CBCT exposures to cases where additional 3D information is important for therapeutic thinking and planning.Doktorgradsavhandlin

Quantitative assessment of buccal cortical bone thickness in South Indian population for miniscrew implant placement using computed tomography: An in vitro study

The results of the study revealed that, buccal cortical bone is thinnest in the anterior maxilla and increases gradually towards the posterior maxilla. There is a gradual increase in thickness till the 2nd molar level beyond which the CBT decreases bilaterally. An interesting finding in the study was the decrease in CBT at the level of 4mm from the alveolar crest in the posterior maxilla on both right and left sides. This variation was different from the usual pattern seen in the anterior maxilla, where the CBT increases as the distance from alveolar bone to basal bone increased. Comparison between sexes revealed that, there was a male predominance with greater CBT than female population. The comparison between age groups revealed that the adult age group had a greater CBT than the adolescent age group. The clinical implications of the study are: • In the anterior maxilla, the thickest region is at 8 mm level vertically and between central incisors and lateral incisors anteroposteriorly. • In the posterior maxilla, the thickest region is at 8 mm level vertically and between 2nd bicuspid and 1st molar anteroposteriorly in both the sexes. • In the anterior maxilla, the thinnest region is at 2 mm level vertically and between the central incisors anteroposteriorly in both the sexes. • In the posterior maxilla, the thinnest region is at 4 mm level vertically and between 2nd molar and 3rd molar anteroposteriorly in both the sexes

Management of bone defects with Bio-oss

Introduction: The defects in the alveolar bone might appear as a result of congenital malformations, traumatic injuries, periodontal disease, surgical traumas, chronic periapical changes and tumors from benign or malignant origin. The aim of this study was to provide solid and healthy area with application of Bio-Oss in the defect. Materials and methods: Based on the clinical diagnosisestablished by previously taken history, clinical examination and radiographic images oral-surgery interventions was made. To realize the aim of this work, augmentative material was implicated in the bone defects made in the patients after removal of follicular cyst, chronic periapical lesion, and parodontopathia. During the first and seventh day of the interventions, the patients have been followed through from aspect of possible development of local and general complications after the oral-surgery intervention. After period of one, three and six mount control x-ray was made. Results: Obtained results confirmed that: volume of the socket and defect of the bone was kept, fast revascularization was achieved, bone formation and slow resorption of the augmentative material was achieved, and period of normal healing without infection was also achieved. Conclusions: The augmentative materials used for treatment of bone defects besides their basic chemical and physical characteristics referring to their solubility in the body fluids, the transformation, modulation and resorption must be completely safe or secure, i.e. not to bring any risk of infection, immunological risk, physiological intolerance or inhibition of the process of restitutio ad integrum. In our study Bio-Oss was confirmed as augmentative material who had this characteristics. Keywords: bone defect, resorption of the bone, augmentative material, Bio-Os

CT Scanning

Since its introduction in 1972, X-ray computed tomography (CT) has evolved into an essential diagnostic imaging tool for a continually increasing variety of clinical applications. The goal of this book was not simply to summarize currently available CT imaging techniques but also to provide clinical perspectives, advances in hybrid technologies, new applications other than medicine and an outlook on future developments. Major experts in this growing field contributed to this book, which is geared to radiologists, orthopedic surgeons, engineers, and clinical and basic researchers. We believe that CT scanning is an effective and essential tools in treatment planning, basic understanding of physiology, and and tackling the ever-increasing challenge of diagnosis in our society

The Effects of Aging and Tooth Loss to the Microstructure of the Mandible in South Africans

Thesis (PhD (Anatomy))--University of Pretoria, 2022.The mandible plays a crucial role in many biological functions (especially mastication, swallowing and speech) and its efficiency to perform these functions depends on its intactness. Aging and tooth loss are biological processes that may compromise the normal functioning of the mandible by changing its morphology. While many studies address the macroscopic mandibular variations, there is a paucity regarding its microstructure. The aim was to investigate microstructural mandibular changes, with reference to the macrostructure, with advancing age and across various tooth loss patterns in South Africans. As the reasons why individuals are differently affected (extent, rate) by senescence or tooth loss are unclear, the influence of other biological factors (sex, ancestry) was also considered. Using micro-focus X-ray Computed Tomography (micro-CT) scans of 333 mandibles, external dimensions, and inner parameters, namely the cortical thickness (CtTh) and cortical density (approximated by histomorphometric parameters, BV/TV) were measured. To assess whether the mandible ages in the same way and rate as the rest of the skeleton, a comparison of mandibular and femoral cortical BV/TV, using a micro-CT subsample of 68 individuals, was included. A comprehensive assessment of the mandibular morphology and cortical microstructure of fully dentate individuals highlighted that the smaller the alveolar height is, the thicker and denser the cortical bone. An inner cortical asymmetry between basal, buccal, and lingual areas was described for CtTh, but was absent for BV/TV. Sexual dimorphism and ancestral variations were confirmed for the external distances and CtTh, but not for BV/TV. With tooth loss, a general decrease in external distances (aggravated by edentulism), CtTh and BV/TV was observed, except at the midline where the lingual CtTh increased with edentulism. Sexual dimorphism and ancestral variations of the external dimensions and CtTh were emphasised in edentulous mandibles. The cortical density decreased with aging, corroborating the general decline in bone mass of the skeleton, as noted in the femur. By contrasting the effects of tooth loss and aging, it was concluded that both external distances and CtTh were mainly influenced by tooth loss and not age, whereas the cortical bone density displayed an age-related decrease independent of tooth loss. To ascertain the applicability of the findings in a dental setting, where Cone-Beam Computed Tomography (CBCT) is commonly used, measurements were performed on 24 mandibles scanned by both CBCT and micro-CT (considered as the reference). The accuracy and repeatability of CBCT was confirmed for large-scale measurements, and CtTh in a lesser manner, whereas results were uncertain for BV/TV, revealing a distinct lack of reliability. In conclusion, this thesis inferred the precise role of aging and tooth loss, but also sex and ancestry, on the variations of the mandibular macro- and microstructure. Not only does knowledge and understanding of these changes have implications in dentistry fields, as cortical thickness and density are essential for many dental procedures; but also in biological anthropology, in which the microstructure of extant human mandibles gives valuable insights into intra- and interspecific variations (e.g., sexual dimorphism), or functional considerations (mastication, diet) of archaeological/fossil specimens.AnatomyPhD (Anatomy)Unrestricte

Segmentation of the Oral and Facial Regions from Imaging Modalities with Reduced or No Ionizing Radiation

Ph.DDOCTOR OF PHILOSOPH

Forensic Odontology: Application in the Mediterranean Area

The use of dentition for identification and age estimation has been well established in the field of forensics, however, the accuracy and validity of various methods has not been systematically investigated in a variety of ethnic groups. Dental analysis has been widely employed for personal identification and age estimation due to teeth durability and being resilient to change. The aim of this thesis is to evaluate the applicability and reliability of three major dental methods for age estimation, focusing on Libyan population. Three principal dental approaches (dental wear and on shading, third molar maturity index (I3M), and linear regression formula) are explored. Furthermore, cervical vertebrae analysis, which concomitantly used with I3M for age estimation of young people, is also applied in this study. In the study of age estimation, dental wear and shading are two separate indicators that have to be combined together for best results. Herein, the score and shading data of 412 participants of known age and sex from North Africa (majority from Libya) and England were studied. The participants were classified into 14 age groups of 5-year intervals. A new table has been made for age estimation using shading wear. The results show a good agreement with real age of most participants with minimal errors associated with data analysis. The results also indicate the superiority of tooth wear level investigation over shading method in actual age estimation; 71% of the estimated ages are in agreement with the real age of the participants. New samples were gathered for the purpose of validation of age estimates; a sample of 918 healthy living Libyan subjects (521 females and 397 males), aged between 14 and 23, was used to analyse the third molar development by assessment of the I3M. The obtained results highlighted the significance of the I3M-based approach to adult age estimation, as 86.4% of the females and 89% of the males were correctly classified. It was also shown that, by using an I3M cut-off value of 0.09 instead of 0.08, an increase of around 3% was achieved in the numbers of individuals correctly identified using the method of Cameriere et al. (2006), when estimating the age of children by measurements of open apices in their teeth. The authors provided a first formula for the Italian population and in 2007, a formula for the European population. In this study, a new formula has been produced for the Libyan populations. According to the results, Libyan formula is the most accurate method compared with two methods tested in the present study, i.e. Italian and European formulae in Libyan population. The performance of the age estimation formula developed in thesis for the Libyan population has been compared against two other formulae previously presented in literature for the Italian and the European populations. No statistically significant difference was found between the European and Libyan formula proposed in this thesis, however, a difference was found between when compared with the Italian formula. Nevertheless, the linear regression formula developed in this thesis performed exceptionally well in estimating the age of Libyan population