Paulo Henrique Couto Souza

Applicability of Willems model for dental age estimations in Brazilian children

Several studies described tooth development as a reliable pathway for age estimations. Depending on the considered life span, the dental age indicators vary. In children, combinations of developing teeth provide the best information about age. In sub adults third molar mineralization is almost exclusively considered. The aim of this study was, firstly, to verify the Willems model in a Brazilian sample. Secondly, to observe differences between the Willems model and a new developed Brazilian model. Thirdly, the information of permanent teeth (PM) and third molar (TM), development was combined for age estimation in children. A sample of 1357 panoramic radiographs of Brazilian males (M) and females (F), with age between 5 and 23 years was collected. The technique of Gleiser and Hunt modified by Kohler (1955) [34] was applied for third molar staging in the entire sample. The Demirjian staging technique was used on the mandibular left permanent teeth (except third molars) of all individuals from 5 to 15 years. Kappa and weighted Kappa statistics were performed to verify inter- and intra-observer reliabilities. Based on the obtained Demirjian scores the Willems model was verified. Next the data were split to develop a new Brazilian model based on the Willems method and to verify the established model. The accuracy in age prediction between the Willems model and the new Brazilian model was compared. Additionally, regression models including PM, TM and PM plus TM information were compared. The Kappa and weighted Kappa statistics revealed high agreement between observers (0.88 Kappa; 0.93 weighted Kappa). The differences between predicted and chronological age for the verified Willems model were expressed in mean errors of -0.17 and -0.38 year for F and M respectively. The differences in mean error between the new developed Brazilian model and the Willems model were 0.02 (F) and 0.20 (M) year. The regression models combining PT and TM information provided only in the age range between 14 and 15.99 years a small decrease in root mean squared error (0.2 year) in females. The new developed Brazilian model provided similar age predicting performances as the Willems et al. model. Added TM was only providing more accurate age estimations in the ages of 14 and 15 year in F.

Spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst

A dentigerous cyst is the most common developmental odontogenic cyst. It is a benign and asymptomatic intraosseous lesion that affects the bones of the maxillofacial complex, interfering with tooth eruption. This article reports the spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst and extraction of the deciduous teeth. A radiograph showed a large cyst with a radiolucent area involving the mandibular left deciduous canine and first molar, and the permanent canine and first premolar. Although enucleation is the treatment of choice, marsupialization is the best option for large cysts involving an unerupted permanent tooth, as in this case. The patient was followed for 1 year, and eruption of the permanent canine and first premolar and gradual reduction of the radiolucent area were observed.

Influence of soft tissues on mandibular gray scale levels

The purpose of this study was to analyze the gray levels, expressed in pixels, of the mandibular retromolar region, with regard to the influence of muscular and fat soft tissues near this region. Fifteen dry mandibles were X-rayed with the presence of soft tissue simulators. The radiographs were digitized and evaluated by Digora software. A one cm thick layer of wax was used as a simulator of the muscular soft tissue. Animal fat samples of different thicknesses - 0.5, 1.0, 1.5 and 2.0 cm - were used as a simulator of the fat soft tissue. Results showed that the fat soft tissue simulator influenced the gray level values in pixels of the mandibular retromolar region when analyzed in different thicknesses using the Digora digitized image software.

The uniqueness of the human dentition as forensic evidence: a systematic review on the technological methodology

The uniqueness of human dentition is routinely approached as identification evidence in forensic odontology. Specifically in bitemark and human identification cases, positive identifications are obtained under the hypothesis that two individuals do not have the same dental features. The present study compiles methodological information from articles on the uniqueness of human dentition to support investigations into the mentioned hypothesis. In April 2014, three electronic library databases (SciELO®, MEDLINE®/PubMed®, and LILACS®) were systematically searched. In parallel, reference lists of relevant studies were also screened. From the obtained articles (n = 1235), 13 full-text articles were considered eligible. They were examined according to the studied parameters: the sample size, the number of examined teeth, the registration technique for data collection, the methods for data analysis, and the study outcomes. Six combinations of studied data were detected: (1) dental shape, size, angulation, and position (n = 1); (2) dental shape, size, and angulation (n = 4); (3) dental shape and size (n = 5); (4) dental angulation and position (n = 2); (5) dental shape and angulation (n = 1); and (6) dental shape (n = 1). The sample size ranged between 10 and 1099 human dentitions. Ten articles examined the six anterior teeth, while three articles examined more teeth. Four articles exclusively addressed three-dimensional (3D) data registration, while six articles used two-dimensional (2D) imaging. In three articles, both imaging registrations were combined. Most articles (n = 9) explored the data using landmark placement. The other articles (n = 4) comprised digital comparison of superimposed dental contours. Although there were large methodological variations within the investigated articles, the uniqueness of human dentition remains unproved.

Spontaneous Resolution of a Central Giant-Cell Granuloma After Incisional Biopsy: A Case Report

[Couto Souza, Paulo H.] Pontificia Univ Catolica Parana, Curso Odontol, Ctr Ciencias Biol & Saude, Sch Dent, BR-80215901 Curitiba, Parana, Brazil. [Jacobs, Reinhilde; Corpas, Livia S.] Catholic Univ Leuven, Fac Med, Oral Imaging Ctr, Louvain, Belgium. [Lambrichts, Ivo] Univ Hasselt, Dept Basic Med Sci, Fac Med, Hasselt, Belgium.

Agreement between cone beam computed tomography images and panoramic radiographs for initial orthodontic evaluation

OBJECTIVE The aim of this study was to compare the agreement between cone beam computed tomography (CBCT) and panoramic radiographs for initial orthodontic evaluation. This study was not meant to test differences between imaging modalities or to indicate superiority of one technique. STUDY DESIGN Thirty-eight subjects with both panoramic and CBCT images were retrospectively collected. Eight observers answered 14 observational questions. The observation was repeated after 4 weeks. RESULTS CBCT images yielded better agreement between 2 observer groups (orthodontic residents and radiologists) and better inter- and intraobserver agreement. The agreement between panoramic radiographs and CBCT scans was moderate. CONCLUSIONS If CBCT is a priori present in a case with justified indications, it has the potential to provide valuable diagnostic information for initial orthodontic evaluation and extra information for treatment planning. The moderate agreement between panoramic and CBCT images may indicate that the nature and amount of information gained from both imaging sources is deviant.

Three-dimensional analysis of the uniqueness of the anterior dentition in orthodontically treated patients and twins

Dental uniqueness can be proven if no perfect match in pair-wise morphological comparisons of human dentitions is detected. Establishing these comparisons in a worldwide random population is practically unfeasible due to the need for a large and representative sample size. Sample stratification is an option to reduce sample size. The present study investigated the uniqueness of the human dentition in randomly selected subjects (Group 1), orthodontically treated patients (Group 2), twins (Group 3), and orthodontically treated twins (Group 4) in comparison with a threshold control sample of identical dentitions (Group 5). The samples consisted of digital cast files (DCF) obtained through extraoral 3D scanning. A total of 2.013 pair-wise morphological comparisons were performed (Group 1 n=110, Group 2 n=1.711, Group 3 n=172, Group 4 n=10, Group 5 n=10) with Geomagic Studio® (3D Systems®, Rock Hill, SC, USA) software package. Comparisons within groups were performed quantifying the morphological differences between DCF in Euclidean distances. Comparisons between groups were established applying One-way ANOVA. To ensure fair comparisons a post-hoc Power Analysis was performed. ROC analysis was applied to distinguish unique from non-unique dentures. Identical DCF were not detected within the experimental groups (from 1 to 4). The most similar DCF had Euclidian distance of 5.19mm in Group 1, 2.06mm in Group 2, 2.03mm in Group 3, and 1.88mm in Group 4. Groups 2 and 3 were statistically different from Group 5 (p<0.05). Statistically significant difference between Group 4 and 5 revealed to be possible including more pair-wise comparisons in both groups. The ROC analysis revealed sensitivity rate of 80% and specificity between 66.7% and 81.6%. Evidence to sustain the uniqueness of the human dentition in random and stratified populations was observed in the present study. Further studies testing the influence of the quantity of tooth material on morphological difference between dentitions and its impact on uniqueness remain necessary.

Gingival Anaplastic Large-Cell Lymphoma Mimicking Hyperplastic Benignancy as the First Clinical Manifestation of AIDS: A Case Report and Review of the Literature

This paper presents an unusual case of gingival ALCL, which mimicked a benign hyperplastic lesion that occurred in a 57-year-old white man representing the first clinical manifestation of acquired immunodeficiency syndrome (AIDS). The patient was referred to the Dental Clinic of PUCPR complaining of a lobulated nodule on the gingiva of his upper central incisors. The presence of advanced chronic periodontitis and dental plaque raised suspicion for a benignancy. An excisional biopsy was performed, and large pleomorphic cells with an abundant cytoplasm, sometimes containing prominent nucleoli and “Hallmark” cells, were observed through hematoxylin and eosin staining. The tumor cells showed strong CD30 expression, EMA, Ki-67, and LCA, and negative stain for p80NPM/ALK, CKAE1/AE3, CD20, CD3, CD56, and CD15. The final diagnosis was ALCL (ALK-negative). Further laboratory tests revealed positivity for human immunodeficiency virus (HIV). The patient was submitted to chemotherapy, but four months after diagnosis, the patient died due to pneumonia and respiratory failure. Oral anaplastic large-cell lymphoma (ALCL) is a rare disorder. Only 5 cases involving the gingiva have been reported, and to our knowledge, this is the first case reported of the ALCL, which mimicked a hyperplastic benignancy as the first clinical manifestation of AIDS.

Massive Submandibular Sialolith: Complete Radiographic Registration and Biochemical Analysis through X-Ray Diffraction

Sialolithiasis is a pathologic condition that affects 60 million people per year, which is caused by the presence of calcified structures, named sialoliths, inside the salivary glands and their salivary ducts. Despite the large incidence of sialolithiasis, its etiology is still unknown. In the present case report, a 47-year-old female patient, presenting with local pain and hampered mouth opening, underwent a surgical approach for the removal of a 20 mm sialolith, which was further analyzed through X-ray diffraction. In parallel, a radiographic registration of 8 years, covering all the period for sialolith formation, is presented along the case report.

Comparison of chemical composition of packable resin composites by scanning electron microscopy

OBJECTIVES the purpose of this study was to compare the chemical composition of four different shades (incisal/extra-light, A2, A3 and B3) of two packable resin composites (SOLITAIRE®, and PRODIGY CONDENSABLE TM). METHODS AND MATERIALS the specimens measured 4mm in diameter and 4mm in thickness. Five specimens were made for each shade of the materials. They were light cured for 40 seconds at a power of 600mW/cm². Subsequently, the specimens were removed from the plates and ground to powder and then pressed into holes measuring 4mm in diameter in a Teflon matrix, using the plates of the same material as base and cover. Specimens were evaluated under SEM with an x-ray detector for the spectroscopic test by energy dispersing. RESULTS the chemical components found in both materials were practically the same, but in different proportions. Carbon, Oxygen, Aluminum, Silica, Fluoride and Barium were found. CONCLUSIONS the chemical composition of each same material varied according to each shade analyzed.