Development of a model of soft tissue simulation using ballistic gelatin for CBCT acquisitions related to dentomaxillofacial radiology research.

OBJECTIVES: To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images. METHODS: CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA. RESULTS: The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels (p > 0.05). Higher SD values were observed in the occlusal level for both groups (p < 0.05). CONCLUSIONS: Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images.

DISPLASIA ÓSSEA FLORIDA EXPANSIVA: RELATOS DE DOIS CASOS INCOMUNS / EXPANSIVE FLORID OSSEOUS DYSPLASIA: REPORTS OF TWO UNUSUAL CASES

A displasia óssea geralmente é um achado radiográfico, por não apresentar, em sua maioria, alterações clínicas. Contudo, um novo subtipo de displasia, que afeta preferencialmente mulheres negras de meia-idade e promove expansão do osso cortical envolvido, tem sido relatada como Displasia Óssea Expansiva. O objetivo deste artigo é relatar dois casos de Displasia Óssea Florida com expressivo aspecto expansivo e perfuração das corticais ósseas envolvidas. O primeiro relata uma paciente negra, 46 anos, que compareceu à Odontoclínica Central da Marinha necessitando de restauração indireta em um dente. O exame clínico demonstrou um aumento de volume duro na face lingual do rebordo alveolar dos incisivos inferiores. Na radiografia panorâmica, foram observadas duas imagens de densidades mistas com predomínio de áreas radiopacas nas regiões apicais dos dentes anteroinferiores e do primeiro molar inferior esquerdo. A tomografia computadorizada mostrou expansão, adelgaçamento da cortical vestibular e perfuração da cortical lingual na região dos incisivos. O segundo caso apresenta uma paciente de meia idade, feoderma, que buscou atendimento para acompanhamento de lesão mista na mandíbula, nas regiões apicais dos dentes anteriores, pré-molares e na região correspondente ao terceiro molar direito. Na tomografia computadorizada por feixe cônico observaram-se expansão e adelgaçamento da cortical vestibular nos dentes anteroinferiores. Com base na literatura atual e nas características de ambas as lesões, a hipótese diagnóstica para ambos os casos foi de Displasia Óssea Florida com aspecto expansivo. As pacientes foram orientadas sobre a importância da higiene bucal adequada e da necessidade de um acompanhamento clínico imagiológico anual destas lesões.

Osseous dysplasia generally is a radiographic finding because, for the most part, it does not cause clinical changes. However, a new subtype of dysplasia that affects primarily middle-aged black women and promotes expansion of the involved cortical bone has been reported as Expansive Osseous Dysplasia. The aim of this article is to report two cases of Florida Osseous Dysplasia with expressive expansion and perforation of the osseous cortex involved. The first case reports a 46-year-old black female patient whom was attended at the Naval Dental Center requiring indirect restoration in one tooth. Clinical examination showed a hard and increased volume at lingual portion of alveolar ridge in the region of the lower incisors. In the panoramic radiography two mixed density images were observed with predominance of radiopaque areas in the apical region of the anterior inferior teeth and in the first lower left molar. The computed tomography showed the buccal cortex thinning and the expansion and perforation of the lingual cortex in the incisor region. The second case presents a middle-aged brown skin patient who sought dental care to monitor a mixed lesion in the apical region of the anterior inferior teeth, lower premolars on both sides and in the third right lower third molar. In cone beam computed tomography, expansion and thinning of the vestibular cortex in the anterior inferior teeth were observed. Based on the current literature and the characteristics of both lesions, the diagnostic hypothesis was Florida Osseous Dysplasia with expansive aspect. The patients were advised on the importance of oral hygiene and the need for an annual follow-up of these lesions