A cone beam computed tomographic analysis of cervical vertebral nonsegmentation.

OBJECTIVE: Using cone beam computed tomography (CBCT), this study aimed to investigate the radiologic features of cervical vertebral nonsegmentation (CVN) in patients with no known syndromes or pathoses. STUDY DESIGN: In this retrospective study, we examined CBCT scans of patients with CVN for the following parameters: type of nonsegmentation (partial or complete); laterality of partial nonsegmentation; level of vertebrae affected in nonsegmentation; anatomic parts of the vertebrae involved; and the presence or absence of degenerative joint disease (DJD). RESULTS: From the structured reports of 13,458 CBCT scans, we found 110 CBCT scans (0.82%) with CVN. Of this total, 77.3% were partial and 22.7% were complete. Most were located at the level of the C2 and C3 vertebrae. The transverse process alone and the transverse process and body were most frequently involved in partial CVN, whereas most complete types occurred in the transverse process and body. Degenerative joint disease was present in 45.9% of partial CVN (clearly distinguishable from nonsegmentation in 36.5%) and 20% of complete CVN, with all cases clearly distinguishable. CONCLUSIONS: Cervical vertebral nonsegmentation has a low prevalence. It is mostly partial, occurs most commonly in C2-C3, and usually involves the transverse process and body. Identification of CVN on CBCT images is important because this condition can lead to DJD in older age and may increase the risk for muscle weakness, head and neck pain, limited movement, and neurologic complications.

Morphological integration in inferior alveolar canal and mandibular shapes.

OBJECTIVE: During embryogenesis of mandible, the initial ossification centre begins at the bifurcation of the inferior alveolar (IA) and the mental nerves. Additionally, in congenital anomalies like craniofacial microsomia (CFM), the IA canal is completely absent on the microsomic side. These observations led us to hypothesise that there may be a morphological integration between these structures - the IA nerve and the mandibular shapes. Therefore, the primary objective of this study was to test for morphological integration between these structures and the secondary objective was to determine if there were shape variations in these structures among skeletal Classes I, II and III subjects. SETTING AND SAMPLE POPULATION: The sample size of the study is 80 full-head cone-beam computed tomography (CBCT) scans (age 16-56 years). METHODS: We retrieved CBCT scans from our archived database using specific inclusion/exclusion criteria. In the de-identified CBCT scans, traditional coordinate landmarks and sliding semi-landmarks were placed on the mandible and the IA canal (proxy for IA nerve). Using geometric morphometric analyses, we tested integration between the IA canal and the mandibular shapes. We used Procrustes ANOVA to test for overall shape variations among the three skeletal classes (Classes I, II and III). RESULTS: The IA canal and posterior/inferior border of mandible showed strong integration (r-PLS = .845, P = .001). Similar strong integration was also observed between the IA canal and the overall shape of the mandible (r-PLS = .866, P = .001). Additionally, there was a statistically significant variation in overall shape between skeletal Class I and Class II (P = .008) and Class II and Class III (P = .001). CONCLUSIONS: The strong integration between two structures suggests that the IA nerve may play a role in establishing mandibular shape early in development. We posit this may be important in driving mandibular defects seen in CFM, which warrants further investigation.

Mucoepidermoid carcinoma mimicking a mucocele (ranula) in the floor of the mouth.

Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. The submandibular gland is rarely involved, about less than 10% of all other major salivary glands. We report a case of a 49-year-old female who presented with a mass on the left side of the floor of the mouth. She was complaining of neck pain for the last 2-3 days and had noticed the mass growing in size and becoming tender to palpation. There was no exacerbation of pain during eating, drinking, or opening of mouth. A multidetector CT scan was made. The radiographic examination revealed a mostly well-defined hypodense area suggestive of mucocele (ranula), which was thought to be corroborated by the clinical findings. The treatment of choice was the complete excision of the mucocele and the left submandibular salivary gland. The histopathological examination surprisingly revealed a low-grade MEC. No further treatment was recommended; however, a follow up was scheduled in 4 months. This atypical location of MEC in the floor of the mouth simulated the clinical and radiographic features of a mucocele. This case highlights the value and importance of using all the available diagnostic tools and modalities for optimal patient management, as the histopathological analysis played an important role to confirm the diagnosis.

Quantitative assessment of mandibular canal compression assessed by cone beam computed tomography.

OBJECTIVE: The aim of this study was to objectively quantify the topographic relation of the mandibular canals, impacted third molars, and cortical plates using cone beam computed tomography (CBCT). STUDY DESIGN: A retrospective chart review was conducted using the database of a university-based imaging service. Two calibrated reviewers examined the CBCT images of 100 cases scheduled for mandibular third molar removal. They characterized the position and condition of the mandibular canal and measured its dimensions at 3 different points relative to the third molars. RESULTS: The mandibular canal is more often located buccal to the third molars but is more likely to be compressed when in a lingual position. The vertical (cephalocaudal) dimensions of the mandibular canal change significantly as the canal progresses toward the ramus. The horizontal (buccolingual) dimensions of the mandibular canal fluctuate very little but significantly narrow in proximity to the third molars. Thinning of the lingual cortical plate is common, whereas grooving of molar roots is uncommon. CONCLUSIONS: Minor variations in the horizontal dimensions of the mandibular canal close to the third molars signify an effect on the canal. This effect may indicate an increased risk of neurovascular injury. The mandibular canal can have a direct or indirect effect on the cortical plates.

Osteoma Cutis of the Face in CBCT Images.

Osteoma cutis (OC) is a rare benign disorder where osseous nodules form in the reticular layer of normal skin. These nodules are formed by the deposition of lamellar bone and are characterized by osteocytes in the core and osteoclasts around the periphery. Interpretation of osteoma cutis cases has always been challenging especially using conventional two-dimensional (2D) radiographs, owing to difficulty in localization. Cone beam CT (CBCT), with its three-dimensional (3D) capabilities, offers a great tool to help detect and diagnose these calcific entities. We report a case of miliary type OC incidentally detected in the maxillofacial region using CBCT imaging.