CLINICAL EXAMINATION AND DIAGNOSTIC IMAGING OF THE NOSE AND NASOPHARYNX
This depends on the dilating of the nostril anteriorly with some form of speculum (in the UK a Thudichum speculum, as illustrated in Figure 40, is used). This enables the examiner, who has a headlight or head mirror attached to his head, to direct light into the nasal cavity. It is impossible to dilate the nose sufficiently far back to obtain a view of more than the front half at best of the nasal cavity, because of sensitivity and poor access. Anterior speculum examination, although the mainstay for many years, is therefore extremely limited in the information which it can produce. Conventional examination is completed by inspecting the post-nasal space with a small, round, plane mirror on a long stem (Figure 40). This is introduced into the mouth while the tongue is held down with a tongue depressor, and slid backwards behind the free margin of the soft palate so as to reflect the post-nasal space. The examination is, intrinsically, extremely difficult. If the patient is unable to relax the throat while there is pressure on the tongue, the palate is drawn backwards and no view can be obtained at all. The use of a local anaesthetic spray to the pharynx may improve the situation, but even with a relaxed patient who is entirely cooperative in both the voluntary and the involuntary senses, the experienced examiner will not obtain a diagnostic view in every case. In practice, even the most skilled practitioners will only achieve a meaningful inspection of the post-nasal space by the mirror technique in perhaps 30% of cases.