How do periodontal ligament fibres primarily run?

The primary orientation of periodontal ligament fibers is described as wavy. This characteristic is crucial because the wavy configuration allows for flexibility and adaptation in response to the stresses and forces applied during activities such as chewing or biting. The wavy structure is especially important as it contributes to the damping and shock-absorbing capabilities of the periodontal ligament, which helps to protect the tooth and surrounding structures from excessive force.

The other types mentioned, such as elastic, striated, and non-striated, pertain to different types of muscle or connective tissues and would not accurately describe the arrangement of periodontal ligament fibers. For instance, elastic fibers are known for their ability to stretch and recoil, which is not the primary function of the periodontal ligament. Striated muscle fibers have a banded appearance characteristic of skeletal and cardiac muscles, unlike the connective tissue of the periodontal ligament. Non-striated fibers, generally referring to smooth muscle, do not align with the specific structural characteristics of the periodontal ligament, which is designed to support teeth in their sockets effectively.