Практикум по переводу с английского языка на русский. Базарова Б.Б - 75 стр.

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     Case report
                                        A Maxillary Fourth Molar?
                          GARY S. HOWE, B.D.S., M.Sc, D.D.O., F.D.S., D.ORTH.
        Department of Child Dental Health, Dental School, University Hospital of Wales, Heath Park,
                                           Cardiff CF4 4XY.
     Abstract. A case is presented of misdiagnosis of a large mandibular cyst as a result of relying
solely on orthopantomography. This demonstrates a pitfall in diagnostic radiology and illustrates the
importance of clinical examination and intra-oral radiography.
     Index words: Third molar, Coronoid process, Cyst
     Introduction
     Tomographic dental radiology has come into widespread use today both in the hospital and
general dental services. In order to produce a tomogram of the jaw with its complex anatomy, the
orthopantomograph has three centres of rotation covering both the posterior and anterior regions, these
rotations being preset to average values. In common with standard intra-oral radiographs errors in
diagnosis may occur due to radiographic superimposition, but in addition, tomography gives reduced
image definition due to geometric distortion, magnification, increased object to film distance, and the
use of intensifying screens. A major, often quoted drawback of this technique is that if any structure
does not lie within the focal trough of the machine (such as a palatal supernumerary) then the structure
may not appear on the radiograph.
     Case reports
     The patient, a 13-year-old girl, was referred to the department with a minimal Class I
malocclusion and no other concerns or complaints. Radiographic examination was confined to an
orthopantomograph from which it was noted that the left mandibular third molar was congenitally
absent and a left maxillary fourth molar was present. Orthodontic treatment was to be confined to
upper labial segment alignment using a fixed appliance.
     Shortly following this initial consultation, the patient attended for full records and commence-
ment of treatment. It was then noted that the left mandibular buccal segment was markedly lingually
inclined and there was a firm non-tender swelling in the buccal sulcus extending from the first
premolar region to the coronoid process. In spite of this alveolar deformity the buccal segment
occlusion was almost ideal. There had been no history of discomfort and there was no neurological
impairment.
     Following these clinical findings and a detailed examination of the orthopantomograph a pro-
visional diagnosis of an odontogenic keratocyst was made. There was deemed to be no reason to


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