Radiology Chapter 17: Craniofacial and Skull Projections

Craniofacial and Skull Projections

• Submentovertex (SMV) or Base Projection: displays the base of the skull, zygomatic arches fracture, sphenoid sinuses, hard palate, and mandible
• Waters (Occipitomental) Projection: best for viewing sinuses, displays maxillary sinuses, orbital ridges and floor, frontal and ethmoid sinuses, and nasal cavity and midfacial fractures
• Reverse Towne Projection: evaluates patients with suspected fractures of the condyle and condylar neck, shows the posterolateral wall of the maxillary antrum
• Lateral Oblique Projection: assesses presence of unerupted teeth, fractures of the mandible, and evaluation of jaw lesions
  • Mandibular ramus projection: views the ramus from the angle of the mandible to the condyl
  • Mandibular body projection: demonstrates the premolar-molar region and the inferior border of the mandible
  • Bimolar view: views both sides of the mandible in one film

Traumatic Injuries

• Oral and maxillofacial injuries: refer to injuries of the orofacial soft tissues, facial skeleton, teeth, and associated specialized soft tissues
• Can lead to orofacial deformity and malfunction, greatly diminishing quality of life and worker productivity

Traumatic Injury to Teeth

• Enamel infraction: incomplete fracture of the enamel without loss of tooth substance
• Enamel fracture: fracture with loss of enamel only
• Enamel–dentine fracture: fracture with loss of enamel and dentine, but not involving the pulp
• Complicated crown fracture: fracture involving enamel and dentine, and exposing the pulp
• Crown–root fracture: fracture involving enamel, coronal and radicular dentine, and cementum
• Root fracture: fracture involving radicular dentine cementum and the pulp

Radiographic Evaluation

• Radiographic evaluation of dentoalveolar injuries should include a panoramic radiograph and periapical radiograph of involved teeth
• Radiographic examination reveals the stage of root formation and discloses injuries affecting root portion of the tooth and periodontal structures
• Multiple periapical radiographs taken at different angles demonstrate root fractures that are minimally displaced
• Ideally, three different radiographs from different angles should be obtained for each traumatized tooth

Fractures of the Alveolar Process

• Fractures of the alveolar process are found predominantly in the anterior teeth and the premolar region
• Injuries may be isolated or may be seen in conjunction with traumatic injuries to teeth
• Radiographic Features
  • Fracture is readily identified in the intraoral periapical radiograph
  • Lateral extraoral radiographs best demonstrate the location of the fracture if some bone displacement has occurred