Deterioration of intraoral recognition of shapes after treatment of oral and pharyngeal cancer

Thirty patients with diagnosed malignant tumors of the oral cavity or phary nx were tested in regards to intraoral shape recognition at 4 test occasion s: before all treatment. after radiotherapy, 6 months after surgery, and 1 year after surgery. They were compared within groups as well as with a grou p of healthy reference individuals of the same age who underwent the same t est procedure at a 2-month interval. The tumor itself did not influence the capability of shape recognition. The reference individuals demonstrated si gnificantly better results on the second test occasion, which is known as a learning effect. Learning improvement was not seen in the patients whose s econd test occasions were after radiotherapy, implying an impediment amount ing to the magnitude of the learning effect. At 6 months after surgery the patients' capabilities of shape recognition had deteriorated significantly with no difference between the oral cancer group and the pharyngeal cancer group. No spontaneous rehabilitation had taken place 1 year after surgery. The presence or absence of surgical lingual nerve damage did not influence the results. The nonoperated side does not compensate for the operated one. It is plausible that decreased oral sensory acuity in recognizing the shap e of the bolus contributes to postoperative swallowing problems.