Dental findings on face and neck imaging

Abstract

When it is necessary to evaluate dental structures, the typical method is to obtain intraoral or panoramic X-rays at specialized dental clinics. However, in the daily practice of head and neck radiology, or even general radiology, it is common to encounter clinical situations or examination findings related to dental problems that should not be ignored. Because such problems can often be responsible for the clinical complaints of patients, this review aims to assist radiologists in identifying and describing common dental conditions on computed tomography of paranasal sinuses, face, and neck. It is important for radiologists to have knowledge of dental arch anatomy and its relationships with facial structures, as well as of major dental pathologies, including periapical sclerotic lesions, odontogenic cysts, fistulas, and abscesses, together with knowledge of incidental findings without clinical repercussions, which should be easily identified and stressed by the radiologist when necessary. The imaging methods most commonly used in evaluation of paranasal sinuses and face are computed tomography and magnetic resonance imaging. Those methods allow radiologists to recognize and become familiar with the main dental findings. The description of such findings by a radiologist can lead to a change in treatment strategy.

Keywords: Dental arch/pathology; Magnetic resonance imaging; Periodontal diseases/diagnosis; Tomography, X-ray computed.

Figure 1

Tooth count and anatomical relationships between teeth. A: With adjacent cervical spaces. B: With the floor of the mouth. CS, carotid space; MS, masticatory space; PS, parotid space; PpS, parapharyngeal space; PvS, prevertebral space; RS, retropharyngeal space; GG, genioglossos muscle; JM, jugal mucosa; MM, mylohyoid muscle; SS, sublingual space; SM, submandibular space; LS, lingual septum.

Figure 2

Tooth anatomy. A: Schematic drawing. B: Dental surfaces.

Figure 3

Axial (A) and coronal in maximum intensity projection (B) CT scans showing dental supernumerary element impacted in the midline of the maxila between two central incisors-a mesiodens (red arrow)-which differs from the single central incisor (blue arrow).

Figure 4

Axial CT of the paranasal sinuses showing lower left third molar (tooth 38) partially unerupted, impacted at the distal root of the second molar, showing cariogenic lesions (red arrows) together with signs of periodontitis (yellow arrow).

Figure 5

Sagittal CT of the paranasal sinuses showing the relationship between the maxillary dental arch and the floor of the maxillary sinus (red arrow), as well as the relationship between an impacted third molar (in the mandibular dental arch) and the mandibular canal where the inferior alveolar nerve passes (blue arrow).

Figure 6

Coronal CT of the paranasal sinuses showing periapical disease with the formation of a periapical cyst at the upper right canine (red arrow), which presents signs of endodontic treatment (blue arrow).

Figure 7

Coronal CT of the paranasal sinuses showing a bone defect in the floor of the left maxillary sinus (red arrow), which corresponds to an oroantral fistula causing odontogenic sinusitis. Note also the radicular amputation of the adjacent tooth (blue arrow).

Figure 8

Axial CT of the face showing a periosteal reaction in the right branch of the mandible, together with bone sclerosis (red arrow). Note the areas of erosion areas throughout the lingual cortex on the right (yellow arrow). Taken together, these findings are suggestive of osteomyelitis.

Figure 9

Axial and sagittal CT scans of the face and neck (A and B, respectively) of a patient submitted to extraction of lower right third molar who evolved to the formation of an odontogenic abscess (red arrow). The fluid collection extended to the masticatory space (blue arrow) and, subsequently, to the remaining deep cervical spaces (yellow arrows), to the level of the mediastinum, causing mediastinitis. These findings are compatible with Ludwig's angina.

Figure 10

Contrast-enhanced axial T1-weighted MRI sequence of the face (A) and apparent diffusion coefficient map (B) showing extraction (A) of the lower right second molar (yellow arrow) with granulation tissue and signs of alveolar inflammation accompanied by a heterogeneous fluid collection showing restricted diffusion (B), delineating the planes of the floor of the mouth, and extending to the base of the tongue, causing narrowing of the oropharyngeal air column (red arrows).

Figure 11

Axial CT of the face showing a longitudinal fracture of the upper right first molar (red arrow) with signs of endodontic treatment (yellow arrows) in some teeth. Note also the periapical disease in the upper left first molar (blue arrow).

Figure 12

Sagittal and axial CT scans of the face (A and B, respectively) showing partial loss of the crown with root intrusion in the upper left lateral incisor (A) and a hypodense halo around the root of the upper left central incisor (B), with anterior dislocation of that tooth, suggestive of dislocation (yellow arrow), together with traces of fractures in the alveolar process in the maxila between the central incisor and the upper left lateral incisor (blue arrow).