the patient as to how to prevent the return by the use of dental floss and the mechanical use of tooth paste. From a scientific standpoint the healthy bone tissue, having been brought Fig. 6-A.-Maxillary gingival area 26 days after operation. in contact with the mucoperiosteum which contains all the bone building properties known as the osteogenetic layer with its odontoblasts, unite, afterall mechanical irritation and perceptible infection has been obliterated. DEPARTMENT OF DENTAL AND ORAL RADIOGRAPHY Edited By Clarence O. Simpson, M.D., D.D.S., F.A.C.D., THE TECHNIC OF ORAL RADIOGRAPHY BY DR. CLARENCE O. SIMPSON, ST. LOUIS, MO. SINUS EXAMINATIONS Lateral View (Continued from page 664.) Placement of Cassette.-With the arm of the operating chair removed, the patient is directed to turn until the side of the head is toward the head rest. The cassette in a vertical position is rested against the head rest. Retention of Cassette-Supported by the patient's shoulder and nearer hand. Immobility promoted by a tight bandage around patient's head, cassette, and head rest. Position of Head.--Sagittal plane vertical, and parallel with cassette. Verticohorizontal Angle of Projection.-Perpendicular to cassette, or horizontal. Spark Gap.-5 inches. Exposure.-80 to 120 milliampere seconds at a 40 inch target-film distance, with double coated films and intensifying screens. Anteroposterior View of Maxillary Sinuses Placement of Cassette.-Horizontal, or inclined ten degrees toward patient when there is difficulty in posing. Retention of Cassette.-Supported by a stand or table. Position of Head.-Sagittal plane vertical, forehead on cassette, and nose pressed tightly against cassette. Immobility promoted by head. clamps, or a tight bandage around patient's head and cassette. Anteroposterior Angle of Projection.-Perpendicular to cassette. Modifications. Five degrees or more above or below perpendicular as the average position of the head is changed by the facial profile, and the size and compressibility of the nose. Five or ten degrees below perpendicular for children. Lateral Angle of Projection.-Perpendicular to cassette. Cone. Centered just below the occipital protuberance. Spark Gap.-5 inches. Exposure.-80 to 120 milliampere seconds at a 30 inch target-film distance, with double coated films and intensifying screens. Fig. 1.-Position of patient, cassette, and cone for a lateral examination of the paranasal sinuses. Anteroposterior View of Frontal Sinuses Placement of Cassette.-Horizontal, or inclined ten degrees toward patient when there is difficulty in posing. Retention of Cassette.-Supported by a stand or table. Position of Head.-Sagittal plane vertical, forehead on cassette, and nose pressed tightly against cassette. Immobility promoted by head clamps, or a tight bandage around patient's head and cassette. Anteroposterior Angle of Projection.-Fifteen degrees above perpendicular to the cassette. Modifications. Ten to twenty degrees above perpendicular as the Lateral Angle of Projection.-Perpendicular to the cassette. Exposure.-100 to 140 milliampere seconds at a 30 inch target-film distance, with double coated film and intensifying screens. Special Examination of Sphenoidal Sinuses Position of Head.-Occlusal plans of maxillary teeth horizontal. Head supported by head rest. Anteroposterior Angle of Projection.-Twelve degrees posterior to vertical. Modification. Ten to twenty degrees posterior to vertical depending upon the tolerance of the patient for insertion of the cassette. Placement of Cassette.-With the tube and head in position, and the mouth open, gently insert the cassette as far posteriorly in the pharynx as it can be endured. Retention of Cassette.-Firm pressure of the teeth on cassette, immediately after placement. |
