Development of nerve fibres in the temporomandibular joint of the human fetus
| Autor: | Guglielmo Ramieri, Giulio Preti, Giancarlo Panzica, F. Del Tetto, V. Morani, G. Bonardi, R. Arisio |
|---|---|
| Předmět: |
Adult
Embryology Pathology medicine.medical_specialty Mesenchyme Connective tissue Gestational Age Nerve Tissue Proteins Muscle Development Lateral pterygoid muscle Embryonic and Fetal Development Nerve Fibers Pregnancy Reference Values Joint capsule Medicine Humans Peripheral Nerves Muscle Skeletal Fetus Temporomandibular Joint business.industry S100 Proteins Infant Newborn Capsule Cell Biology Anatomy Immunohistochemistry Temporomandibular joint medicine.anatomical_structure Female Thiolester Hydrolases business Free nerve ending Ubiquitin Thiolesterase Developmental Biology |
| Zdroj: | Scopus-Elsevier |
| Popis: | The development of nerve fibres in the temporomandibular joint (TMJ) in relation to the development of bone, muscle and fibre components was investigated in human fetuses ranging from 9 weeks of gestation to birth. Immunohistochemistry for the glia-associated protein S-100 and for the neuro-specific marker protein gene product 9.5 (PGP 9.5) were used; specimens were compared to specimens of adult TMJ capsule and disc. At 9–10 weeks, a small number of neural elements are already present in the connective tissue around the joint and in the mesenchyme between the two articular blastemas from which the disc will differentiate. By 19 weeks many nerve fibres are clearly visible. Immunohistochemical results suggest diffuse disc innervation extending along the entire disc but not in the thin central area. More complex structures, i.e. encapsulated corpuscles, were also seen. The fetal disc appears highly innervated compared to adult tissue; already at this developmental stage morphology and distribution of nerves and corpuscles in the joint capsule are comparable to those in the adult joint. It may be concluded that the innervation of the TMJ is detectable from the end of the second month and that it develops fully between the third and the fifth month of gestation. Nerve endings in the disc are most numerous at 20 weeks, after which a progressive reduction, possibly secondary to the growth of articular tissues, is observed throughout the last trimester of fetal life and into adult life. The innervation of the lateral pterygoid muscle, on the contrary, is much less than that seen in adult muscles, even at full-term. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|