1.Positioning errors of dental implants and their associations with adjacent structures and anatomical variations: A CBCT-based study
Beatriz Ribeiro RIBAS ; Eduarda Helena LEANDRO NASCIMENTO ; Deborah Queiroz FREITAS ; Andréa dos ANJOS PONTUAL ; Maria Luiza dos ANJOS PONTUAL ; Danyel Elias CRUZ PEREZ ; Flávia Maria Moraes RAMOS-PEREZ
Imaging Science in Dentistry 2020;50(4):281-290
Purpose:
The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT).
Materials and Methods:
CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α= 0.05).
Results:
The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r= 0.232, P<0.05).
Conclusion
There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.
2.The chronology of second molar development in Brazilians and its application to forensic age estimation.
Manuella Santos Carneiro ALMEIDA ; Andrea dos Anjos PONTUAL ; Rejane Targino BELTRAO ; Ricardo Villar BELTRAO ; Maria Luiza dos Anjos PONTUAL
Imaging Science in Dentistry 2013;43(1):1-6
PURPOSE: This study investigated the possible correlation between the mineralization of the second molars and the chronological age of a sample population of the state of Paraiba, Brazil. MATERIALS AND METHODS: One thousand eight hundred fifty-four digitized panoramic images using a scanner of a private dental radiology service were obtained in six months. Of these, 457 were selected from patients aged 4.6 to 16 years who met certain criteria. The images were assessed twice by a radiologist with 5 years experience. A minimum interval of 30 days between the evaluations of the same patient was established. To analyze the relationship between chronological age, calcification level proposed by Demirjian et al in 1973, gender, and tooth, a multiple linear regression model was adjusted, taking age as the response variable (p<0.05). RESULTS: The gender and calcification level were significantly correlated with the age of the patients (p<0.05). There was a significant difference between the average age of the patients' upper teeth compared to the lower ones in both genders (p<0.05). The dental development occurred earlier in female individuals than in male ones, and there was no significant difference between the right and left second permanent molars. CONCLUSION: It was observed that ethnic variables are related to certain parameters of age and sex identification in the Brazilian population, providing important information for forensic evaluations.
Age Determination by Teeth
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Aged
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Female
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Humans
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Linear Models
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Male
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Molar
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Radiography, Panoramic
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Tooth
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Tooth Calcification
3.Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography.
Eduarda Helena Leandro DO NASCIMENTO ; Maria Luiza DOS ANJOS PONTUAL ; Andréa DOS ANJOS PONTUAL ; Danyel Elias DA CRUZ PEREZ ; José Natal FIGUEIROA ; Marco Antônio Gomes FRAZÃO ; Flávia Maria de Moraes RAMOS-PEREZ
Imaging Science in Dentistry 2016;46(2):69-75
PURPOSE: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. RESULTS: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). CONCLUSION: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.
Anatomic Variation
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Cone-Beam Computed Tomography*
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Dental Implants
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Humans
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Linear Models
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Male
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Mandible
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Prevalence
4.Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions.
Raquel Venancio Fernandes DANTAS ; Hugo Ramalho SARMENTO ; Rosangela Marques DUARTE ; Sonia Saeger MEIRELES MONTE RASO ; Ana Karina Maciel DE ANDRADE ; Maria Luiza DOS ANJOS-PONTUAL
Imaging Science in Dentistry 2013;43(3):145-151
PURPOSE: This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. MATERIALS AND METHODS: Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. RESULTS: The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. CONCLUSION: The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.
Aluminum
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Composite Resins
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Dental Enamel
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Dentin
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Humans
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Molar
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Radiographic Image Interpretation, Computer-Assisted
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Radiography, Dental, Digital
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Tooth
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X-Ray Film