This paper describes the treatment of a patient diagnosed clinically and based on cone beam computed tomography images with excessive gingival display caused by altered passive eruption Type 1B. A digitally computer designed and 3-D printed surgical guide was fabricated for crown lengthening to provide periodontal esthetics. The combination of intraoral scanners and cone-beam computerized tomography images, and use of planning software, provides a very precise representation of the real conditions of the hard and soft tissues. The design and fabrication of computer surgical guides can improve precision and predictability for surgical procedures and can be superior to conventional free-handed surgery in terms of efficiency and treatment outcomes. Surgical experience and general understanding of computer assisted systems and thorough knowledge of conventional protocols is mandatory to make routine use of these systems. To select a treatment modality, the etiology must be clearly identified and the patient has to be informed of his options for treatment which for this condition are a gingivectomy or an apically positioned flap with or without osseous reduction determined by the type of altered passive eruption.

There are multiple etiologies for facial subcutaneous emphysema, including facial trauma, dissection of air along facial planes from a pneumomediastinum, infection, and entry of air through defects in teeth due to decay, trauma, or dental procedure. In addition, air can be forced through lacerations of the oral or pharyngeal mucosa by increased intraoral pressure. An infrequently reported cause of subcutaneous emphysema is autoinsufflation of the parotid duct with extravasation of air into the surrounding tissue. In this report, the authors present a 14-year-old patient treated at the Department of Oral and Maxillofacial Surgery of the Hospital Escuela Universitario due to an increase in size in the buccal region and left masseterine space of 2 months of evolution. Presenting with a sudden evolution, without any possible explanation, which caused displacement of adjacent structures without damage to the bone or surrounding tissues. After a series of echographic and tomographic studies, it showed that inside the submandibular gland there was a hypodense image with gas density (-1100 UH) expanding the gland and its respective excretory duct.