Seventy-four reports of emphysematous complications in ambulatory dental patients, published in the English literature between the years 1960 and 1993, are reviewed, and an additional case of subcutaneous, retropharyngeal, and mediastinal emphysema following an impression-taking procedure for a crown preparation is presented. This rare complication occurred mainly in patients in the third and fifth decades of life, after dental procedures on the third molar, in particular during mandibular extractions and treatment on the right side. The use of an air syringe, high-speed handpieces, or their combination was reported in 71% of cases. Centripetal air dissection, with retropharyngeal and mediastinal emphysema, occurred in 35% of the patients, especially following extractions.