Innervation of the Human Periodontal Ligament

Abstract

Istraživanje smo izvršili na materijalu izdvojenom tijekom kirurških zahvata radi sanacije malignih tumora u donjoj čeljusti i to na četiri pretkutnjaka i dva kutnjaka koje smo ispreparirali zajedno s pripadajućom alveolom i susjednim dijelovima čeljusti, te ih dekalcinirali u mravljoj kiselini. Svrha ovog rada bila je istražiti distribuciju i vrstu senzoričkih živčanih vlakana i različitih živčanih završetaka u periodontalnom ligamentu odrasla čovjeka. Ustanovili smo da živčana vlakna ulaze u periodontalni ligament prolazeći dnom alveole, dok njihov tok prate krvne žile. Periodontalni ligament je najbolje inerviran u području apikalne trećine korijena zuba, za razliku od srednje i cervikalne trećine, gdje je nazočan daleko manji broj vlakana. U periodontalnom ligamentu odrasla čovjeka nismo dokazali postojanje slobodnih živčanih završetaka odnosno grmastih završetaka koji su opisani kod različitih životinjskih vrsta. Istraživanje upućuje na prisutnost velikog broja specijaliziranih živčanih završetaka koji po svojim morfološkim karakteristikama odgovaraju Meissnerovim tjelešcima, a uklopljeni su u sustav Sharpeyevih vlakana. Najveći broj tih specijaliziranih završetaka, za koje pretpostavljamo da su pravi mehanoreceptori, smješten je u srednjoj i cervikalnoj trećini desmodonta.The aim o f this study was to analyze the distribution and forms o f nerve fibres and endings in the periodontal ligament o f the adult man. The material for this investigation was obtained at routine autopsies and consisted o f four lower premolar and two molar tooth prepared together with belonging alveola and neighbouring parts o f the mandibula. The material was decalcinated in the formic acid, embedded in paraplast, sectioned 20 micrometers thick in bucco- lingual direction and stained with modified Ungewitter’s silver nitrate method. It was found that nerve fibres enter the periodontium passing through the bottom o f the bony socket. The nerve fibres follow the course o f the blood vessels in periodontium. The richest innervation o f the periodontium was found in the apical third o f the tooth root and less fibres were present in the upper and middle third. In the periodontium o f the adult man we were not able to found free endings o f nerve fibres in the form o f bush-like terminations that were described in previous investigations in lower mammals. On the other hand, we found the presence o f the large number o f specialized nerve endings that according to their morphological characteristics could be Meissner corpuscules embedded in Sharpey’s ligaments. The largest number o f these endings may belong to real mechanoreceptors situated in the upper and middle part o f the periodontium