A study of process of growth of oral form and oral function by newly developed device

下颌运动常被用作口颌系统功能的指标。传统的划分是习惯性咀嚼运动、滑动运动和边缘运动。下颌边界的运动可能受到骨骼、下颌关节、肌肉神经传递系统、韧带或口颌系统的其他软组织的限制。这个系统在儿童中是不成熟的，因此在儿童和成人的运动之间以及在每个咬合发育阶段之间预计会有一些差异。利用笔者研制的下颌运动六自由度测量了6名男孩和6名女孩在乳牙排牙阶段、6名男孩和6名女孩在混合排牙阶段、6名男孩和6名女孩在恒牙排牙阶段的下颌切点前后、左右、上下运动范围和下颌旋转范围。比较了性别差异和排牙阶段的差异，得出以下结论：在男孩排牙阶段，乳牙和混合排牙阶段前后前后旋转范围无差异。女孩的切点运动范围在混合阶段大于乳牙排列阶段，在恒牙排列阶段大于混合阶段。

Mandibular movements are often used as indices of the functioning of the stomatognathic system. The conventional divisions are habitual chewing movement, slide movement and border movement. The mandibular border movement may be restricted by bone, mandibular articulation, the neurotransmission system for muscles, ligaments or other soft tissues of the stomatognathic system. This system is immature in children, so some difference is expected between the movements of children and adults and between each occlusal developmental stage.The ranges of back and forth, right and left and upper and lower movements of mandibular incisal points and the mandibular rotary ranges were measured in six boys and six girls in the deciduous dental arrangement stage, six boys and six girls in the mixed dental arrangement stage, and six boys and six girls in the permanent dental arrangement stage, using the six degrees of freedom for mandibular movement previously developed by the authors. Differences between sexes and between the dental arrangement stages were compared and the following conclusions made :1. In dental arrangement stages for boys, no differences were observed in the back and forth or frontal rotary ranges between the deciduous and mixed arrangement stages. For girls, the ranges of incisal point movements were greater in the mixed than in the deciduous dental arrangement stage and in the permanent than the mixed arrangement stage.