Assessment of the configuration of the mandibular canal using cone beam computed tomography.

BACKGROUND: During dental implants placement and bone augmentation procedures, it is important to determine the presence and location of mandibular canal anatomical variation in order to avoid injuries to inferior alveolar bundle. This study aimed to describe the prevalence and configuration of mandibular canal branching in the posterior region of the mandible using cone beam computed tomography (CBCT). METHODS: The interpretation of the images was conducted according to the presence, classification and location of the mandibular canal. Horizontal and vertical distances from mandibular canal in the ramus region to the molar region was recorded. CBCT images of 751 patients, 486 women (64.7%) and 265 men (35.3%), with a mean age of 54.57 (±13.23; 14-93) years, were interpreted by one calibrated examiner. RESULTS: Out of 1502 hemi-mandibles images, mandibular canal variations were observed in 130 (8.6%). Sixty-four (49.2%) mandibular canal variations were identified on the right side and 66 (50.8%) on the left side. The mean distances between superior cortical of the mandibular canal and the base of mandible, buccal cortical of mandibular canal and buccal cortical bone, and superior cortical of mandibular canal and alveolar ridge were 12.16 mm (±2.68), 4.17 mm (±1.30), and 12.97mm (±4.01), respectively. Type I mandibular canal variation was the most frequent (68; 52.2%), followed by type III (34; 26.1%). CONCLUSIONS: Prevalence of mandibular canal variations was 8.6%, type I was the most common and its direction showed proximity with lingual surface in the second molar region.

EVALUATION OF THYROID RADIATION DOSE USING CONE BEAM COMPUTED TOMOGRAPHY.

Cone beam computed tomography (CBCT) became common in various dental specialties over the past decade. This technology is used by dental professionals regarding the investigation of maxillofacial structures. Due to the diagnostic quality and possibility of 3D view, this method has become an additional method of human exposure to ionizing radiation. This study aims to evaluate the amount of ionizing radiation absorbed by thyroid gland using CBCT. Measurements were performed by LiF dosimeters (TLD-100), positioned on a phantom for head and neck, which was irradiated by Newtom 3G-CBCT. The average of phantom surface radiation dose at the thyroid gland was 0.48 mGy. The data obtained during this study are suitable to reference values; therefore, it is important to recall that the as low as reasonably achievable principle must be applied in all procedures, thereby safeguarding the patient and also the professional.

The Radiographic Management for Surgical Planning and Implant Placement: a Case of Atypical Antral Artery Position / Avaliação Radiográfica no Planejamento Cirúrgico para Instalaçào de Implante Dentário: um Caso de Posição Atípica da Artéria Antral

O conhecimento do suprimento sanguíneo do seio maxilar, em particular da parede lateral, é de considerável importância devido à possibilidade de rompimento acidental de uma artéria durante os procedimento de elevação do assoalho do seio maxilar. Paciente do sexo feminino, 65 anos de idade, com histórico de complicação pós-operatória, após procedimento de elevação do seio maxilar realizado há três anos. Após avaliação tomográfica, foi observada a presença da artéria antral em posição atípica. Identificar e reconhecer essa estrutura anatômica pelo exame radiográfico pré-operatório, evita possíveis complicações hemorrágicas, durante e após o procedimento cirúrgico.(AU).

It is very important the knowledge of the maxillary sinus blood supply, in particular of the lateral maxillary wall, due to the possibility of accidental rupture of a vessel during the sinus floor augmentation. A case report is described of a 65-year-old female, who reported a postoperative complication after a sinus augmentation that she had had 3 years before. After radiographic evaluation, it was observed the presence of antral artery in atypical position. The identification of this anatomical structure is very important, by preoperative radiographic examination, avoiding possible bleeding complications, during and after the surgical procedures.(AU).