Hidenori Katada

A Newly Proposed Method to Predict Optimum Occlusal Vertical Dimension.

PURPOSE Establishing the optimum occlusal vertical dimension (OVD) in prosthetic treatment is an important clinical procedure. No methods are considered to be scientifically accurate in determining the reduced OVD in patients with missing posterior teeth. The purpose of this study was to derive a new formula to predict the lower facial height (LFH) using cephalometric analysis. MATERIALS AND METHODS Fifty-eight lateral cephalometric radiographs of Japanese clinical residents (mean age, 28.6 years) with complete natural dentition were used for this study. Conventional skeletal landmarks were traced. Not only the LFH, but six angular parameters and four linear parameters, which did not vary with reduced OVD, were selected. Multiple linear regression analysis with a stepwise forward approach was used to develop a prediction formula for the LFH using other measured parameters as independent variables. RESULTS The LFH was significantly correlated with Gonial angle, SNA, N-S, Go-Me, Nasal floor to FH, Nasal floor to SN, and FH to SN. By stepwise multiple linear regression analysis, the following formula was obtained: LFH (degree) = 65.38 + 0.30* (Gonial angle; degree) - 0.49* (SNA; degree) - 0.41* (N-S; mm) + 0.21* (Go-Me; mm) - 15.45* (Nasal floor to FH; degree) + 15.22* (Nasal floor to SN; degree) - 15.40* (FH to SN; degree). CONCLUSIONS Within the limitations of this study for one racial group, our prediction formula is valid in every LFH range (37 to 59°), and it may also be applicable to patients in whom the LFH deviated greatly from the average.

Case of Severe Maxillary Protrusion Accompanied by Crowding and Scissor Bite.

This case involved a 30-year-old woman who visited our hospital with the main complaint of protrusion of the maxillary incisors and upper and lower lips. She had difficulty closing her lips, and a chin button was observed when the lips were closed. The skeletal pattern showed maxillary protrusion and mandibular retrusion, and the mandible showed severe high angle. Labial inclination of both the maxillary and mandibular incisors was found, as well as crowding. In addition, the maxillary left second molar showed buccal displacement, and scissor bite was evident in the left second molar region. The bilateral molar relationship was cusp-to-cusp class II malocclusion. Angle class II maxillary protrusion accompanied by crowding and left second molar scissor bite was diagnosed. Surgical orthodontic treatment was judged as the best approach to treat the jaw deformities. However, in line with the wishes of the patient, treatment was undertaken using implant anchors instead. Straight-wire brackets with a 0.022-inch slot were fitted. A lingual arch was placed in the mandible and plate-type implant anchors in the first molar region of the maxilla. Almost no change was observed in skeletal pattern as no surgery was performed. The maxillary incisors moved back 10 mm, however, and the mandibular incisors showed an improvement of 4 mm from L1 to APo. The upper and lower lips consequently moved back 7 mm with respect to the E-line. Active treatment required 3 years and 6 months. Esthetic and functional improvements were achieved.

Occlusal status and craniofacial morphology in Down syndrome patients

1 Division of Orthodontics and Dentofacial Orthopedics, Ohu University Graduate School of Dentistry, Japan 2 Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, Ohu University School of Dentistry, Japan 3 Division of Oral Physiology, Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Japan Orthod Waves–Jpn Ed 2013;72(1):1–9