Beyond the Ligament: A Whole-Bone Periodontal View of Dentofacial Orthopedics and Falsification of Universal Alveolar Immutability

Abstract

When a theoretical basis for manifestly successful clinical outcomes cannot be fortified by traditional orthodontic tooth movement (OTM) biology that focuses solely on the periodontal ligament as the operant organ, a new hypothesis should be built on the old concepts by synthesizing new biological data with it. This article presents a modest synthesis of contemporary theories in cell biology to explain ostensible osteogenic activity and alveolar phenotype alterations by ultra-low orthopedic force from an alveolar development appliance (ADA). Histological appearance of biopsy specimens demonstrate a "reactive" woven bone pattern, dramatically illustrated under polarized light, where the alveolar development appliance puts labial forces on the palatal alveolus via acrylic panels and 300 <i>g</i> of force induced by coiled nickel titanium springs. "Internal control" biopsy specimens taken from nontreated alveoli show normal lamellar pattern in histological sections. The behavior of the bone cannot be explained totally with a periodontal pressure-tension model. Molecular biological concepts and the Utah Paradigm of Bone Physiology are recruited to explain how ultra-light forces applied to the palatal alveolus might stimulate "compensatory periosteal apposition" on the labial alveolus, thus developing a new alveolar phenotype through bony developmental "drift."