Gupta Kanhaiya L, Agarwal Suchi
Department of Prosthodontics and Dental Material Sciences, Institute of Dental Sciences, Bareilly, Uttar Pradesh, India.
Indian J Dent Res. 2011 Nov-Dec;22(6):883. doi: 10.4103/0970-9290.94699.
The objective of any prosthodontic service is to restore the patient to normal function, contour, esthetics, speech, and health. An optimum denture stability is difficult to achieve in conventional complete dentures. This problem is more magnified in mandibular dentures. The design of prostheses to replace lost teeth and resorbed ridges is largely determined by the position and amount of morphological change in the denture-bearing area of the jaws. A neutral zone may be defined as the space where, during function, the forces of the lips and cheeks pressing inward neutralize the forces of the tongue pressing outward. The neutral zone concept implies acquired muscle control, especially by tongue, lips, and cheeks toward the denture stability. Advocates of the neutral zone concept agree that a lack of favorable leverage is observed when teeth are positioned directly over the ridge. By employing the neutral zone concept, the dislodging muscle energy can easily become a retentive and stabilizing force.
任何口腔修复治疗的目的都是使患者恢复正常功能、外形、美观、言语及健康状态。在传统全口义齿中，要实现最佳的义齿稳定性并非易事。在下颌义齿中，这个问题更为突出。用于替代缺失牙齿和吸收牙槽嵴的修复体设计，很大程度上取决于颌骨义齿承托区形态变化的位置和程度。中性区可定义为这样一个空间，即在功能活动时，唇部和颊部向内的压力与舌部向外的压力相互抵消。中性区概念意味着后天获得的肌肉控制，尤其是舌、唇和颊对义齿稳定性的控制。中性区概念的支持者一致认为，当牙齿直接位于牙槽嵴上方时，会出现有利杠杆作用不足的情况。通过运用中性区概念，使义齿脱位的肌肉力量可轻易转变为固位和稳定力量。
