MANDIBULAR CONDYLAR PROCESS REMODELING IN RATS WITH DIFFERENT BITE-ALTERING DEVICES

The objective was to compare different dental splint models and materials for inducing abnormal loading on the gross morphology and histological appearance of the mandibular condylar processes of Sprague Dawley rats. Three different types of dental splints (resin molar, aluminum incisor, stainless-steel incisor) were placed unilaterally to induce occlusal perturbation for 4 weeks. At that time, mandibular condylar processes were assessed by gross appearance and histology. Quantitative measurements were also conducted on the hematoxylin & eosin images for condyle shape. The results showed that although the condylar cartilage was affected by all splint types, the resin molar splint was associated with the most extensive mandibular condylar process remodeling, which was primarily a slant (skewness) of the lateral aspect of the condylar process. Additionally, quantitative measurements on the histological specimens demonstrated that the split and tilt angle of the left (ipsilateral) condylar processes in the resin molar group (124.8 +/- 12.7 degrees and 104.1 +/- 12.7 degrees, respectively) increased significantly (p < 0.05) when compared to right (contralateral) condylar processes (104.7 +/- 5.8 degrees and 91.6 +/- 4.4 degrees, respectively). However, no changes were noted on the thickness of the fibrocartilage layer at medial, central, and lateral regions of the condylar process. Another major finding is the high variability of morphology of the naive animals. Future studies will assess the impact of longer durations of splinting, age, and sex on the remodeling of the mandibular condylar process, allowing for the development of diagnostics and therapies.

Automated summary

The study compared different dental splint models and materials for inducing abnormal loading on the mandibular condylar processes in rats. The results showed that the resin molar splint caused the most extensive remodeling of the condylar process. Future studies will assess the impact of duration, age, and sex on the remodeling process.