116 males were examined. Of these, 52 belonged to a control group, whereas 40 had severe obstructive sleep apnoea (apnoea index > 20 + clinical symptoms) and 24 mild obstructive sleep apnoea (apnoea index 5-20 + clinical symptoms) (in the following, OSA signifies obstructive sleep apnoea). Cephalometry and planimetric examinations of the pharynx were performed in recumbent position with the head in neutral position and with shallow respiration. The narrowest passage of the pharynx was measured; other measured sites were the areas of the nasopharynx, oropharynx (at the level of the tip of the palatine uvula) and of the hypopharynx (at the level of the base of the tongue). The sum of all the measured cross-sections was obtained. The cephalogram was evaluated to obtain the length and thickness of the soft palate, the distance between the mandible and hyoid bone, the posterior airspace (PAS), the nuchal subcutaneous fatty tissue at the level of the spine of the second cervical vertebra (also known as axis), the thickness of the posterior pharyngeal wall at the level of the second cervical vertebra, or axis, and the angles between the sella, nasion and superior maxilla and between the sella, nasion and mandible (SNA and SNB, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)