Differential Healing Patterns of Odontogenic Maxillary Sinusitis Following Nonsurgical Endodontic Therapy: A Cone-Beam Computed Tomography-Based Case Series.

This case series evaluated the differential healing patterns of maxillary sinus mucosa and periapical bone following nonsurgical root canal treatment for odontogenic maxillary sinusitis to propose a prognostic perspective based on distinct radiographic features. Ten cases of odontogenic maxillary sinusitis managed by primary nonsurgical root canal treatment or retreatment were categorized into 4 radiographic patterns based on periapical and sinus lesions. Clinical symptoms were recorded, and radiographic healing was assessed using cone-beam computed tomography (CBCT) at baseline and during follow-up periods ranging from approximately 3-17 months. All cases showed clinical symptoms recovery and sinus opacities radiographic resolution. Maxillary sinus mucosal lesions, including extensive opacification and sinus floor perforations, resolved to a normal physiological thickness (<2 mm) within approximately 3 months. Conversely, periapical alveolar bone regeneration required a longer progress (approximately 3-17 months) to demonstrate radiographic healing. Cases with extensive bone destruction or periosteal displacement (periapical osteoperiostitis/halo sign) showed delayed bone healing. Within the limits of this case series, maxillary sinus mucosa appears to heal faster than periapical tissues, typically resolving within 3 months. Although periapical radiographs remain useful for evaluating sinus floor perforation and extensive bone destruction, CBCT offers superior three-dimensional assessment in anatomically complex cases or when radiographs are inconclusive. We suggest that, in selected cases, early postoperative CBCT evidence of mucosal resolution (approximately 3 months) may be considered as an adjunctive early indicator of treatment response, while acknowledging that periapical bone regeneration often lags and requires longer follow up.