No abstract

The location and configuration of the mandibular canal are important in surgical procedures involving the mandible. Previously, we reported that bifid mandibular canals could be classified into four types: retromolar, dental, forward, and bucco-lingual canals, using cone-beam computed tomography (CBCT). Herein we report three Japanese patients with a bony canal in the mandibular ramus, which was independent of the mandibular canal, using CBCT images. A CBCT unit with a flat panel detector and exposure volume of 102 mm in diameter and 102 mm in height was used. Two-dimensional (2D) and three-dimensional (3D) images in the mandibular ramus region were reconstructed using 3D visualization and measurement software packages. Three bony canals in two patients were considered to correspond to a temporal crest canal, which was raised from the mandibular notch, and reached the antero-inferior region of the coronoid process. One bony canal in one patient, ran bucco-lingually in the mandibular ramus. It is important for variations in the mandibular and bony canals to be carefully observed, by use of CBCT images, in surgical procedures involving the mandible.

Maxillary sinus septa and exostoses could be clarified regarding their relationship with the bony palate using cone-beam CT.

Summary: Maxillary sinus septa and bony bridges were observed using dry skulls in childhood, classified based on Hellman's dental age, to clarify maxillary sinus septum formation.Eighty-eight maxillary sinuses of 44 dry skulls and a cone-beam computed tomography (CBCT) unit were used. The locations of the septum, defined as a pointed bony structure originating from the inferior wall, and bony bridge, defined as a bony structure between the maxillary sinus wall and dental germ, were antero-posteriorly recorded, and the superoinferior distance, distance from the bony palate, and angle to the median palatine suture were measured.The rate of septum presence in the maxillary sinus was high (41.7%) in IIIC, and the septa were located in the deciduous molars, premolars, and molars. Also, all bony bridges were related to the median maxillary sinus wall, and the rate of the maxillary sinus showing a bony bridge was high in IIA and IIIA.

The application of aspherical surfaces in camera lens started over twenty years ago. Many people suggested and executed many ideas regarding the application of aspherical surfaces. One of the ideas is that the application decreases the value of the F No. The example of the applications is a pick-up-lens that picks up information on a disk using the optical method. In this paper, we discuss the application of aspherical surfaces in wide angle lenses with a large back focus for reflex cameras. The application mainly corrects distortion in the lens designs. An object of the present paper is to show an inverse telescopic wide angle lens capable of simplifying the lens configuration thereby reducing the dimension of lens, correcting various aberrations in satisfactory manner, and still extending the back focus.