ABSTRACT
Computed tomography (CT) is a well-established aid in the preoperative assessment of the dimension of mandible and maxilla for endo-osseous implant installation. CT is a valuable tool for the measurement of the alveolar ridge and recognition of the course of the inferior alveolar nerve canal. In the present study, three different techniques were examined: normal CT images with coronal and sagittal slices, standard reconstructions based on axial slices, and multiplanar reconstruction and display (MPR/MPD), also based on axial slices. Six dissected human jaw bones were examined with these three techniques. Afterwards, these jaws were sawn, and the real values were measured. Comparing these scores with the radiological measurements, the standard reconstruction technique seemed the most reliable method in the preoperative examination of the jaw bone quality and bone proportion.
Subject(s)
Dental Implantation, Endosseous/methods , Patient Care Planning/methods , Tomography, X-Ray Computed , Humans , Image Processing, Computer-Assisted , In Vitro Techniques , Mandible/anatomy & histology , Mandible/diagnostic imaging , Maxilla/anatomy & histology , Maxilla/diagnostic imagingABSTRACT
A retrospective study of 26 patients with ethmoid adenocarcinoma is presented. CT proves to be of great diagnostic value in demonstrating the location and extension of these tumors. The only interpretation problem that may exist is the overestimation of the tumor extension due to the occurrence of retro-obstructive sinusitis.
Subject(s)
Adenocarcinoma/diagnostic imaging , Ethmoid Sinus/diagnostic imaging , Paranasal Sinus Neoplasms/diagnostic imaging , Tomography, X-Ray Computed , Adenocarcinoma/etiology , Humans , Male , Middle Aged , Occupational Diseases/diagnostic imaging , Paranasal Sinus Neoplasms/etiologySubject(s)
Hypopharyngeal Neoplasms/diagnostic imaging , Pharyngeal Neoplasms/diagnostic imaging , Rhabdomyoma/diagnostic imaging , Chronic Disease , Humans , Hypopharyngeal Neoplasms/surgery , Hypopharynx/diagnostic imaging , Hypopharynx/surgery , Male , Middle Aged , Neoplasm Recurrence, Local/diagnostic imaging , Neoplasm Recurrence, Local/surgery , Rhabdomyoma/surgery , Tomography, X-Ray ComputedABSTRACT
Computed tomography of the maxillary alveolar arch was performed in three children with delayed eruption of one or both maxillary cuspids. Computed tomography demonstrated close contact between the ectopically localized and nonerupted canine and the lateral incisor. The lesion was unilateral in two patients and bilateral in one. In two patients resorption of the lateral incisor root was demonstrated. Moreover, CT permitted exact determination of the extent of the lesion by differentiating between superficial cementodentine resorption limited to the cementodentine (superficial resorption) and resorption extending into the pulpal canal (pulpal canal involvement).
Subject(s)
Cuspid/diagnostic imaging , Incisor/diagnostic imaging , Root Resorption/diagnostic imaging , Tomography, X-Ray Computed , Tooth Eruption, Ectopic/diagnostic imaging , Tooth, Unerupted/diagnostic imaging , Adolescent , Child , Cuspid/abnormalities , Female , Humans , Male , Maxilla , Radiography, Panoramic , Root Resorption/etiology , Tooth Eruption, Ectopic/complications , Tooth, Unerupted/complicationsABSTRACT
Computed tomography can assist the surgeon in planning the exact three-dimensional positioning of endosseous implants in the jaw bone. This study examined the reliability of three CT techniques: direct imaging (normal coronal and sagittal slices), standard reconstruction (based on axial slices), and multiplanar reconstruction and display (also based on axial slices). The three imaging techniques were used to estimate the bone height, bone width, and maximal implant length in six dissected human jaw bones. These jaws were then sawed perpendicular to their axis to enable measurement of real values for comparison. The sagittal and coronal slices frequently were overestimated, especially in the canine and premolar regions. The mean absolute deviation was 1.4 mm. Standard reconstruction offered the most reliable cross-sectional images, with a mean absolute deviation of 0.5 mm. The multiplanar reconstruction and display technique frequently demonstrated underestimations (mean absolute deviation was 2.3 mm). The standard reconstruction technique seems to be the method of choice in preoperative radiographic examination of patients before implant placement.
