Prevalence and Clinical Significance of Incidental Findings in the Maxillofacial Complex of Adolescent Orthodontic Patients: A Retrospective Cone Beam Computed Tomography Analysis

Abstract

Objectives: The aim of this study was to determine the prevalence and severity of incidental findings in the maxillofacial complex of orthodontic patients imaged with cone beam computed tomography (CBCT) and assign those findings an appropriate clinical significance.

Methodology: Incidental findings (IF) were identified in 250 CBCT scans of adolescent orthodontic patients (aged 13-18 years) with a large field-of-view and categorized based on their anatomic location and placed into one of six subgroups based on anatomic region: i) sino-nasal, ii) dentoalveolar, iii) nasooropharyngeal airway, iv) temporomandibular joint, v) neck, vi) calcifications, and vi) miscellaneous findings. Additionally, findings were assigned a clinical significance score based on severity on a scale of mild, moderate and severe. Mild IF was defined as an IF that does not require any further investigation or referral. Moderate IF was defined as an IF that has the tendency to become clinically significant and should be observed periodically. IFs that warrant further investigation and/or intervention were designated as severe.

Results: The percentage of IFs in sino-nasal and dento-alveolar regions were 44.7% and 19.1% respectively. The percentage of IFs with mild, moderate, and severe clinical significance were 27%, 72%, and 1%, respectively. Out of the IFs involving calcifications, 80.8% were stylohyoid calcifications and <1% were cranial cavity IFs such as petroclinoid calcifications and falx cerebri calcifications. Among the sino-nasal findings, 1.2% were identified as severe.

Conclusion: The sino-nasal region had the highest frequency of IFs. Understanding the prevalence of incidental findings and its clinical relevance is important for clinicians to allow for appropriate monitoring and timely treatment of patients.

Keywords: 3d imaging; adolescent orthodontics; cone-beam computed tomography (cbct); incidental findings; orthodontics.

Figure 1. Frequency of incidental findings (IF) based on clinical significance of mild, moderate, and severe

Figure 2. Coronal CBCT section reveals a Haller cell (a) along the left medial orbital floor. On the right side, moderate severity polypoidal mucoperiosteal swelling is present in the sinus floor (b).

CBCT: cone beam computed tomography

Figure 3. Sagittal CBCT section shows marked pneumatization of the temporal bone component of the TMJ by mastoid air cells

CBCT: cone beam computed tomography, TMJ: temporomandibular joint

Figure 4. Various sinonasal abnormalities are shown in these CBCT sections from two different patients. A: Sagittal CBCT section shows enlarged mild to moderate mucosal thickening in frontal sinus (a), ethmoid air cells (b), and sphenoid sinuses (c). Enlarged adenoids (d) are also present. B: Coronal CBCT section shows a sino-nasal polypoid mass, a likely antrochoanal polyp (e), arising within left maxillary sinus passing through the ostium and into the left ethmoid air cells. There is associated marked enlargement of the ostium and slight elevation of the orbital floor. Mild to moderate mucosal swelling is also present in the right ethmoid air cells.

CBCT: cone beam computed tomography

Figure 5. CBCT sections show bilateral, partial calcifications of the petroclinoid ligaments in axial (5A), coronal (5B) and sagittal (5C) planes

CBCT: cone beam computed tomography