Murase Itsuki
Department of Maxillofacial Prosthetics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Nihon Hotetsu Shika Gakkai Zasshi. 2008 Apr;52(2):150-9. doi: 10.2186/jjps.52.150.
The purpose of this study was to apply in vivo modal analysis to the maxillary dentition of the maxillectomy patient using obturator prostheses which were different in lateral wall height of the bulb: specifically a high type (H type), middle type (M type), and low type (L type).
The left central incisor was struck with an impact hammer, and the response at each measurement point was detected using a Laser-Doppler vibrometer. The transfer function was then obtained from each measurement point using a fast Fourier transform analyzer. Finally, a computer analysis and simulation were performed based on the measured transfer functions to obtain the natural frequency, modal shape decay rate (DR), and maximum displacement (MDP).
The results showed that the natural frequency was different between with and without obturator prostheses, that the modal shapes with M and L type obturator prostheses are more suitable than that with H type. The DR of the maxillary dentition with the L type was significantly higher than that with the H or M types, and the MDP of the maxillary dentition with an obturator prosthesis was significantly lower than without an obturator prosthesis.
From the standpoint of vibratory characteristics, the L type obturator prosthesis is the most suitable bulb design for the patient of the three types obturator prostheses. This is the first report to apply in-vivo modal analysis to the maxillary dentition of the maxillectomy patient using obturator prostheses and clarify the vibratory characteristics of the dentition.
本研究旨在对使用不同球部侧壁高度的阻塞器假体的上颌骨切除患者的上颌牙列进行体内模态分析，具体为高型（H型）、中型（M型）和低型（L型）。
用冲击锤敲击左中切牙，使用激光多普勒振动计检测每个测量点的响应。然后使用快速傅里叶变换分析仪从每个测量点获得传递函数。最后，基于测量的传递函数进行计算机分析和模拟，以获得固有频率、模态形状衰减率（DR）和最大位移（MDP）。
结果表明，有无阻塞器假体时固有频率不同，M型和L型阻塞器假体的模态形状比H型更合适。L型上颌牙列的DR显著高于H型或M型，有阻塞器假体时上颌牙列的MDP显著低于无阻塞器假体时。
从振动特性的角度来看，在三种类型的阻塞器假体中，L型阻塞器假体是最适合该患者的球部设计。这是首次将体内模态分析应用于上颌骨切除患者使用阻塞器假体的上颌牙列并阐明牙列振动特性的报告。
