There have been many reports on the sensory threshold of mucous membrane up to the present. But the study on numerous subjects was not researched quantitatively as to the sensory threshold of mucous membrane under complete dentures.
The subjects are 99 complete dentures wearers (edentulous group), ranging from 40 to 78 in age and dentulous group (52 person) of 20 to 30 years old and 40 to 60 years old. The pain sensory threshold of mucous membrane of dentulous and edentulous are measured by the pain stimulator.
The following findings are obtained.
1. As for both of dentulous and edentulous group, the sense of pain of mucous membrane in male is more dulled than that in female, but the disparity in sex is not significantly recognized. Regarding both groups, the sense of pain on molar part is more sensitive than on midline part, furthermore, the incisal papilla part is found to be the most sensitiveness in palatal parts. In order next comes palata center, palatine foramina and palatine foveala parts.
2. In case of edentulous group, about 1/3 measuring parts on mandible are more sensitive than on maxilla, then in case of dentulous group, about 1/2 measuring parts on mandible are more sensitive than on maxilla. The disparity of jaws on several measuring parts is significant.
3. Regarding all measuring parts of both groups, the sense of pain for young subjects is more sensitive than for old subjects.
4. The sense of pain of complete denture wearers for long time have tendency of being more dull than that for short time.

View full abstract

To make clear of histological, physiological and dynamical attitudes for stress in periodontal membranes are very important in dentistry. It is especially valuable in prosthetics, periodontics and orthodontics fields. For adequately treate the tooth in prosthetics, it is important not only discuss the mobility or bitting forces of tooth which applied bucco-lingual or on axial direction loads, but also discuss stretch out or horizontally applied pulling stress to the teeth.
The author has been measured the resistance attitudes for stretching forces by using the author newly designed intra-oral pulling loads divice. The subjects were 50 male in 20 years age groupe whose were having healthy permanent dentitons, normal dental arches, normal interdesitations and normal excentric relationship. The resistance for pulling foces were measured along tooth axis direction (Vertical pulling forces), and on horizontal bucco-lingual direction (Horizontal pulling forces). From all of those findings can be summarized as follows.
1. The vertical pulling forces were aligned in orders from low to high as follows. On maxillary teeth were same on both side, Lateral incisor≅aCentral incisor<Second premolar≅First premolar≅Cuspid<Second molar≅First molar.
On the mandible teeth were same on both side, Central incisor≅Lateral incisor<First premolar≅Second premolar≅Cuspid<Second molar≅First molar.
(≅means no significant difference between two teeth, <means significant difference between two teeth.)
2. The horizontal pulling forces were aligned in orders from low to high as follows. On the maxillary teeth were same on both side, Lateral incisor≅Central incisor<Second premolar≅First premolar≅Cuspid. On the mandible teeth were also same on both side, Central incisor≅Lateral incisor<First premolar<Second premolar≅Cuspid.
3. Comparing the vertical and horizontal pulling forces on same teeth, right side teeth were slightly higher than the others. However there were no significant difference between each teeth.
4. Comparing the vertical and horizontal pullig forces on same group teeth between two arches, maxillary teeth were higher than mandible teeth. There were no significant difference except on central incisor.
5. The vertical pulling forces and horizontal pulling forces were compared on same teeth, the horizontal pulling forces were greater than the others on both arches and both side. Howerver there were no significant difference except on central and lateral incisors.

View full abstract

[in Japanese]

View full abstract