Age-related changes in the cartilage of the temporomandibular joint.

Osteoarthritis (OA) of the knee is closely associated with aging; however, little is known about the age-related degeneration in the mandibular condylar cartilage (MCC) of the TMJ. Our objective was to examine whether a correlation exists between aging and degeneration of the MCC of the TMJ. Thirty-two male C57BL/6J wild-type mice were aged to 2, 12, 18, and 25 months old.

PTH [1-34] induced differentiation and mineralization of mandibular condylar cartilage.

Intermittent Parathyroid Hormone (I-PTH) is the only FDA approved anabolic drug therapy available for the treatment of osteoporosis in males and postmenopausal females. The effects of I-PTH on the chondrogenic lineage of the mandibular condylar cartilage (MCC) are not well understood. To investigate the role of I-PTH on the MCC and subchondral bone, we carried out our studies using 4 to 5 week old triple transgenic mice (Col1a1XCol2a1XCol10a1).

Bone Response of Loaded Periodontal Ligament.

The tooth-periodontal ligament-alveolar bone complex acts symbiotically to dissipate the mechanical loads incurred during mastication and/or orthodontic tooth movement. The periodontal ligament functions both in the tension and compression. At the molecular and celleular levels, the loads in the periodontal ligament trigger mechanobiological events in the alveolar bone, which leads to bone modeling and remodeling.

Electromyographic activity evaluation and comparison of the orbicularis oris (lower fascicle) and mentalis muscles in predominantly nose- or mouth-breathing subjects.

Introduction: The objective of this study was to evaluate and compare the electromyographic (EMG) activity of the orbicularis oris--lower fascicle (LOO) muscle and the mentalis muscle (MT)--in predominantly nose-breathing (PNB) and mouth-breathing (PMB) subjects.

Methods: Thirty-four subjects, 22 PNB and 12 PMB, with Class II Division 1 malocclusions were evaluated in 2001 (T1) and again in 2004 (T2), 2 years 5 months later. The age ranges of the sample were 11 years to 14 years 11 months at T1, and 13 years 4 months to 16 years 6 months at T2.