Point of View column – Edge Wala. What is it and for what?

Vol. 14 – Number 56 – 2021 Point of View column Page 19-22 Edge Wala. What is it and for what? Mauricio Brunetto1 Andre Weissheimer2 Giovani Ceron Hartmann3 Mohamad Jamal Bark4 Orlando Tanaka5 Introduction The shape of the mandibular dental arch is considered one of the main references during orthodontic treatment, since its maintenance is an important factor for treatment stability¹. The correct position of the teeth in the maxillary and mandibular occlusion line, respecting the limits of the underlying bone, is important for tooth stability after orthodontic treatment, as well as for the health of the protective periodontium². Andrews and Andrews³ suggested the use of an anatomical reference, as a parameter, with the goal of centering the roots of teeth in the basal bone, which they named WALA Edge (acronym with the initials of Will Andrews and Lawrence Andrews). The WALA border is the band of soft tissue immediately above the mucosa-gingival junction of the mandible, at or near the line that passes through the centers of rotation of the teeth, and is unique to the mandible. Clinically, when examined without stretching the jugal mucosa and lower lip, it corresponds to a whitish pink line whose lower limit usually corresponds to the mucous-gingival line or junction, i.e., the limit between the gingiva and the alveolar mucosa. The identification of the WALA border sought to meet the need to find a stable anatomical structure that would determine the ideal contour of the mandibular arch without the influence of external and internal factors4. The expansion of the dental arch is affected by the shape of the basal bone. The most common complications of orthodontic treatment, such as relapse, may have much to do with the shape of the basal bone or may come as a consequence of the shape of the basal bone5. Consequently, choosing a practical, easy and reliable method of diagnosis becomes necessary, as illustrated in the 3 clinical cases. The shape of the dental arches must be individualized to take into account individual anatomical variations6. Biomechanically, a single force, applied buccally to a tooth crown, results in tipping of the tooth near its center of resistance. Therefore, WALA edge-molded archwires conceptually bring the cusp of the teeth into a vertical position with the center of resistance remaining centered in the alveolar bone7. 1 Specialist and MSc in Orthodontics – UFSC, Professor of the Specialization Course in Orthodontics – PUCPR. 2 Adjunct Assistant Professor, Graduate Orthodontics – Herman Ostrow School of Dentistry of USC, MSc and PhD in Orthodontics – PUCRS, Specialist in Orthodontics – UFSC. 3 PhD student in Dentistry – Orthodontics – PUCPR, MSc in Dentistry – UNIOESTE. 4 Specialist in Implant Dentistry – Centro Universitário Avantis, Postgraduate in Hospital Dentistry – Instituto Israelita de Ensino Albert Einstein, Specialist in Orthodontics – PUCPR. 5 Full Professor – PPGO – PUCPR, Diplomate of the Brazilian Board of Orthodontics and Dentofacial Orthopedics.PUCPR, Diplomado pelo Board Brasileiro de Ortodontia e Ortopedia Facial. DOI: 10.24077/2021;1456-1922