Frankfort horizontal plane is an appropriate three-dimensinal reference in the evaluation of clinical and skeletal cant

OBJECTIVES: In three-dimensional computed tomography (3D-CT), the cant is evaluated by measuring the distance between the reference plane (or line) and the tooth. The purpose of this study was to determine the horizontal skeletal reference plane that showed the greatest correlation with clinical evaluation. MATERIALS AND METHODS: The subjects were 15 patients who closed their eyes during the CT image taking process. The menton points of all patients deviated by more than 3 mm. In the first evaluation, clinical cant was measured. The distance from the inner canthus to the ipsilateral canine tip and the distance from the eyelid to the ipsilateral first molar were obtained. The distance between the left and right sides was also measured. In the second evaluation, skeletal cant was measured. Six reference planes and one line were used for the evaluation of occlusal cant: 1) FH plane R: Or.R - Or.L - Po.R; 2) FH plane L: Or.R - Or.L - Po.L; 3) F. Ovale plane R: Rt.F.Ovale - Lt.F.Ovale - Or.R; 4) F. Ovale plane L: Rt.F.Ovale - Lt.F.Ovale - Or.L; 5) FZS plane R: Rt.FZS - Lt.FZS - Po.R; 6) FZS plane R: Rt.FZS - Lt.FZS - Po.L, and; 7) FZS line: Rt.FZS - Lt.FZS. RESULTS: The clinical and skeletal cants were compared using linear regression analysis. The FH plane R, FH plane L, and FZS line showed the highest correlation (P<0.05). CONCLUSION: The FH plane R and FH plane L are the most appropriate horizontal reference plane in evaluation of occlusal cant on 3D-CT.

Occurrence of multiple myeloma in the head and neck: a report of two cases

Multiple myeloma (MM) is a disease reported to account for 1% of all cancers and 10% of hematological malignant diseases. Unlike other malignant diseases that are transferred to the osseous tissues, MM does not show new bone formation, is associated with characteristic osteolytic lesions, and shows monoclonal protein (M-protein) on the immunohematological test, which is an important index in its diagnosis. Solitary lesions of MM are rare in the head and neck area, and, in most cases, MM of the head and neck area is related to systemic sympomts.