Are mucous retention cysts and pseudocysts in the maxillary sinus a risk factor for dental implants? A systematic review

Abstract

Background Mucous retention cysts and pseudocysts of the maxillary sinus are benign lesions present in up to 13% of adult patients. Different surgical approaches for sinus lift and dental implant placement in the presence of these lesions have been proposed. Material and Methods A systematic review was performed following the PRISMA statement recommendations to answer the PICO question: Does the aspiration or removal of mucous retention cysts/pseudocysts before or during sinus lifting and dental implant placing, affect the survival of the implants? The study was pre-registered in PROSPERO (CRD42020185528). Included articles quality was assessed using the “NIH quality assessment tool” and “The Newcastle-Ottawa scale”. Results Previous literature in this field is scarce and with a low level of evidence. There are no randomized prospective studies. Only 19 studies were identified, being composed of 2 cohort studies and 17 case series/reports. These studies involved 182 patients with a previous history of mucous retention cyst or pseudocyst in 195 maxillary sinuses where 233 implants were placed. The mean age of the patients was 45.5 (range: 12-80 years); 122 (67%) were male patients and 60 (33%) were female patients. The mean follow-up of the patients was 17.6 (range: 4-90 months). Only two fail was reported. No differences were identified in relation to the surgical approach or in relation to the removal/aspiration of the sinus lesion (prior to or simultaneous to sinus grafting) or not. Conclusions The level of evidence was grade 4 according to the CEBM and further studies are needed to confirm this observations, but with the available data, dental implants placement after sinus lift procedure in patients with mucous retention cysts and pseudocysts seems to be safe and present high survival regardless on the removal of the lesion or not. Key words: Dental implants, maxillary sinus, sinus lift, mucous retention cyst, pseudocyst.

Sinus lifts in the presence of pseudoantral and mucous retention cysts

“…Since most of the recommended approaches are based on case reports, there is no research-based consensus. Anitua et al 8 reported a systemic review examining whether cysts should be removed before or during a sinus lift. This study included 182 people with previous mucous retention cysts or pseudoantral cysts in 195 maxillary sinuses where 233 implants were installed.…”

“…No statistical differences in implant survival were observed in relation to age, sex, surgical approach, implant surgery, or grafting material. They concluded that the presence of mucous retention cysts or pseudoantral cysts had not been considered a contraindication for sinus lift and implant placement and that removal of the cysts did not affect implant survival 8 .…”

“…Mucoceles are destructive, causing bony expansion, bony perforation, and displacement of adjacent structures. In contrast, mucous retention cysts and pseudoantral cysts are noninvasive and asymptomatic 8 , 11 . Mucous retention cysts and pseudoantral cysts can be distinguished from mucoceles on radiographic examination.…”

“…As a result, a characteristic solitary dome-shaped structure is formed within the floor of the sinus 3 , 7 . Mucous retention cysts result from ductal obstructions of the seromucous glands located within the lamina propria 3 , 8 . Blockage of the duct of a seromucous gland by a mucus plug can result in dilatation of the duct.…”

“…Cloudy radiopacity, bony expansion, bony perforation, and structural displacement are observed in mucoceles, while, mucous retention cysts and pseudoantral cysts are dome-shaped, nondestructive, and non-expansive and have a smooth margin 12 . However, mucous retention cysts and pseudoantral cysts of the maxillary sinus are difficult to distinguish based on radiologic features alone 7 , 8 .…”