Habre-Hallage Pascale, Dricot Laurence, Jacobs Reinhilde, van Steenberghe Daniel, Reychler Hervé, Grandin Cecile B
Department of Prosthodontics, Faculty of Dentistry, Saint-Joseph University, Beirut, Lebanon.
Eur J Oral Implantol. 2012 Summer;5(2):175-90.
Our aim was to unveil the cortical neural correlates of osseoperception, i.e. the tactile sensation perceived when loading a bone-anchored implant, by taking oral implants as a model. This was performed in a cross-sectional observational study with 9 volunteering patients and 10 age-matched controls. For each patient, functional magnetic resonance imaging (fRMI) recordings were made during punctate mechanical stimulation of either teeth or osseointegrated implants in the maxillary incisor area.
During fMRI recordings, 1 Hz punctate tactile stimuli were applied either on a maxillary left central incisor, canine tooth or central incisor implant. A block design paradigm was used to stimulate, in 9 patients, maxillary left central incisor implants (I21-p) and maxillary left canines (T23-p). In 10 control subjects, maxillary left central incisors and canines (T21-c, T23-c) were stimulated. Random effect group analyses were performed for each stimulated site, and differences in cortical activity elicited when loading teeth or implants were examined using ANOVA.
As a group, patients activated somatosensory area S2 bilaterally for both I21 and T23, while controls activated S1 and S2 bilaterally for T21 and T23. At an individual level, S1 was activated by 4/9 implants, mainly on the ipsilateral side. The stimulated implants activated a larger bilateral cortical network outside the somatosensory areas: in parietal, frontal and insular lobes, the main clusters being located in the inferior frontal gyri. Stimulation of T23 in patients resulted in an activation pattern intermediate between that of the implants and that of natural teeth.
This study demonstrates that punctate mechanical stimulation of oral implants activates both primary and secondary cortical somatosensory areas. It also suggests that brain plasticity occurs when extracted teeth are replaced by endosseous implants. This cortical activation may represent the underlying mechanism of osseoperception.
我们的目标是以口腔种植体为模型，揭示骨感知的皮质神经关联，即加载骨锚式种植体时所感知到的触觉。这是在一项横断面观察性研究中进行的，研究对象包括9名志愿患者和10名年龄匹配的对照者。对每位患者，在上颌切牙区对牙齿或骨整合种植体进行点状机械刺激时，进行功能磁共振成像（fRMI）记录。
在功能磁共振成像记录期间，对上颌左侧中切牙、尖牙或中切牙种植体施加1赫兹的点状触觉刺激。采用组块设计范式，对9名患者的上颌左侧中切牙种植体（I21-p）和上颌左侧尖牙（T23-p）进行刺激。在10名对照受试者中，对上颌左侧中切牙和尖牙（T21-c、T23-c）进行刺激。对每个刺激部位进行随机效应组分析，并使用方差分析检查加载牙齿或种植体时引起的皮质活动差异。
作为一个整体，患者在I21和T23时双侧激活体感区S2，而对照者在T21和T23时双侧激活S1和S2。在个体水平上，4/9的种植体激活了S1，主要在同侧。受刺激的种植体激活了体感区以外更大的双侧皮质网络：在顶叶、额叶和岛叶，主要簇位于额下回。患者T23的刺激导致的激活模式介于种植体和天然牙之间。
本研究表明，口腔种植体的点状机械刺激激活了初级和次级皮质体感区。这也表明，当拔牙被骨内种植体替代时会发生脑可塑性。这种皮质激活可能代表了骨感知的潜在机制。
