Augmented Bone Morphogenetic Protein Signaling During TMJ Development Alters Morphology in a Timepoint-Dependent...

Area of Science:

• Craniofacial development
• Endochondral ossification
• Molecular signaling pathways

Background:

• The temporomandibular joint (TMJ) possesses a unique developmental origin and functional maintenance.
• Bone morphogenic protein (BMP) signaling is crucial for endochondral ossification but its role in TMJ development is not well understood.

Purpose of the Study:

• To investigate the impact of augmented BMP signaling in cranial neural crest on postnatal TMJ development.
• To elucidate the role of BMP signaling in chondrocyte cell death and TMJ cartilage formation.

Main Methods:

• Histomorphometric analysis of TMJ in Wnt1 Cre;caBmpr1a mice.
• Assessment of cartilage length and cell death in the mandibular condyle at different postnatal timepoints (P17, P28, P42).

Main Results:

• Reduced mandibular condylar cartilage length observed before weaning (P17) in mice with augmented BMP signaling.
• Recovery of mandibular condylar cartilage length after weaning (P28 and P42).
• Alterations in chondrocyte cell death in the superficial region of the mandibular condyle correlated with changes in cartilage length.

Conclusions:

• BMP signaling influences TMJ development in a time-specific manner.
• BMP signaling affects chondrocyte cell death, thereby impacting TMJ postnatal development.
• Augmented BMP signaling in cranial neural crest leads to transient alterations in TMJ cartilage growth.