[Growth and development of the alveolar ridge after extraction of deciduous teeth and its clinical application].

This paper is a description of the growth and development of the alveolar ridge after extraction of deciduous teeth for the purpose of handling the appliance for denture guidance and its clinical application. The regions observed were regions of the maxillary and mandibular deciduous molars and maxillary deciduous incisors, frequently causing premature loss of deciduous teeth. Changes of the alveolar ridge width after extraction in all regions can be divided into the following three phases; decreasing, stable, increasing. The decreasing phase finished about four months after the extraction. The increasing phase began from about eight months prior to the emergence of the succedaneous teeth. The period of the stable phase differed according to the time of the extraction of the deciduous teeth, in other words, the earlier the deciduous teeth were extracted, the longer the stable phase was. The decrease of the alveolar ridge width in the regions of the maxillary incisor and maxillary molar were caused mainly by resorption of the labial or buccal alveolar ridge, although resorption of the palatal alveolar ridge scarcely occurred. On the other hand, the decrease of the alveolar ridge in the region of the mandibular deciduous molars was caused by resorption of both the buccal and lingual alveolar ridges. The alveolar ridge began to expand about eight months prior to the emergence of the succedaneous teeth. In regions of the maxillary deciduous molars and maxillary deciduous incisors, mainly the buccal or labial alveolar ridges began to expand. In the region of the mandibular deciduous molars, both the buccal and lingual alveolar ridges began to expand.+2