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Objective: The mandibular condylar cartilage plays significant roles in growth and articular function. This study evaluated the influence of increased joint loading on the growth of the condylar cartilage and the morphology of the mandible.
Design: Forty 7-week-old male Wistar rats were assigned to two groups: a control group and an incisal bite plane group. The condylar cartilage and subchondral bone were evaluated via histochemistry, bone histomorphometry with microcomputed tomography (micro-CT), and real-time polymerase chain reaction (PCR) at 2 and 4 weeks. The morphology of the mandible was analyzed via micro-CT.
Results: The chondrocytic cell layer became thinner in the posterosuperior region after 2 and 4 weeks of wearing the bite plane. Hypertrophied chondrocytes and calcified cartilage matrix disappeared. Subchondral bone, which runs parallel to the lower border of the chondrocytic cell layer, increased. Bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N) increased, while the amount of endochondral bone formation decreased, in the posterosuperior region of the condyle in the bite plane group, which also had reduced mRNA levels of type II collagen, type X collagen, and tartrate-resistant acid phosphatase but increased levels of osteocalcin and alkaline phosphatase. The total mandibular length and ramus height were significantly shorter in the bite plane group, although there was no significant group difference in the length of the mandibular body.
Conclusions: The biomechanical environment regulates the cellular organization of the condylar cartilage and bone formation in its subchondral region, which may eventually change mandibular morphology.
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http://dx.doi.org/10.1016/j.archoralbio.2025.106341 | DOI Listing |
J Oral Rehabil
August 2025
Department of Orthodontics, Stomatological Hospital, School of Stomatology, Southern Medical University, Guangzhou, China.
Background: Normal nasal breathing is crucial for the harmonious growth of craniofacial bones, whereas obstructed nasal breathing not only hampers craniofacial growth but also induces chronic systemic hypoxia. This study compared the effects of mandibular advancement (MA) on condylar remodelling under normal nasal breathing (NNB) and unilateral nasal obstruction (UNO).
Methods: Forty 12-week-old male C57BL/6J mice were randomly divided into NNB, UNO, NNB + MA and UNO + MA groups.
FASEB J
August 2025
Department of Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada.
Many studies have reported on the role of Proteoglycan-4 (PRG4, aka lubricin) in the reduction of friction between cartilage surfaces with a specific focus on chondroprotection within the joint. Disruption of the Prg4 gene in humans and mice leads to premature joint failure, hallmarked by synovial hyperplasia and premature articular cartilage fibrillation. Our group has published extensively using Prg4 knockout mice and has consistently noticed variable distal femoral morphology in these animals when compared to Prg4 wild-types (WT).
View Article and Find Full Text PDFThe incidence of temporomandibular joint (TMJ) degeneration has been steadily increasing, with overloading identified as a major risk factor. This condition often leads to condylar cartilage degeneration, significantly affecting patients' quality of life; however, the molecular mechanisms underlying this process remain poorly understood, and effective treatments are still lacking. We utilized single-nucleus RNA sequencing to analyze the condylar cartilage in an overloading mouse model.
View Article and Find Full Text PDFFASEB J
August 2025
Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Zhejiang Key Laboratory of Oral Biomedical, Hangzhou, China.
Cartilage degeneration and subchondral angiogenesis are key pathological features of temporomandibular joint osteoarthritis (TMJOA). This study aims to investigate the role and regulatory mechanism of SLIT3, a potent pro-angiogenic factor, in driving these processes. Male C57BL/6 mice underwent either sham surgery or unilateral anterior crossbite (UAC) surgery to induce TMJOA.
View Article and Find Full Text PDFCureus
August 2025
Department of Orthodontics, Mathrusri Ramabai Ambedkar Dental College and Hospital, Bangalore, IND.
Introduction Skeletal Class II malocclusion, commonly resulting from mandibular retrognathism, poses both functional and aesthetic challenges in growing patients. Functional orthopaedic appliances, such as the Twin Block, aim to correct this by stimulating mandibular growth through forward positioning. This biomechanical stimulus is believed to trigger adaptive remodelling at the condylar cartilage level, influencing bone formation pathways and playing a crucial role in the release of salivary biomarkers such as osteocalcin, osteonectin, and collagen type 1, which can be non-invasively detected.
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