There is no pulp necrosis or calcific metamorphosis of pulp induced by orthodontic treatment: biological basis

ABSTRACT To biologically explain why the orthodontic treatment does not induce pulp necrosis and calcific metamorphosis of the pulp, this paper presents explanations based on pulp physiology, microscopy and pathology, and especially the cell and tissue phenomena that characterize the induced tooth movement. The final reflections are as follows: 1) the orthodontic movement does not induce pulp necrosis or calcific metamorphosis of the pulp; 2) there is no literature or experimental and clinical models to demonstrate or minimally evidence pulp alterations induced by orthodontic movement; 3) when pulp necrosis or calcific metamorphosis of the pulp is diagnosed during orthodontic treatment or soon after removal of orthodontic appliances, its etiology should be assigned to concussion dental trauma, rather than to orthodontic treatment; 4) the two pulp disorders that cause tooth discoloration in apparently healthy teeth are the aseptic pulp necrosis and calcific metamorphosis of the pulp, both only induced by dental trauma; 5) the concussion dental trauma still requires many clinical and laboratory studies with pertinent experimental models, to increasingly explain its effects on the periodontal and pulp tissues.

RESUMO Para fundamentar biologicamente por que o tratamento ortodôntico não induz necrose pulpar e metamorfose cálcica da polpa, apresentou-se explicações com base na fisiologia, microscopia e patologia pulpar, bem como, e principalmente, nos fenômenos celulares e teciduais que caracterizam a movimentação dentária induzida. As reflexões finais foram: 1) o movimento ortodôntico não induz necrose pulpar ou metamorfose cálcica da polpa; 2) não há literatura e modelos experimentais e clínicos que comprovem ou minimamente evidenciem alterações pulpares induzidas pelo movimento ortodôntico; 3) quando a necrose pulpar ou metamorfose cálcica da polpa for diagnosticada durante o tratamento ortodôntico ou logo após a remoção dos aparelhos ortodônticos, a sua etiologia deve ser atribuída ao traumatismo dentário do tipo concussão, e não ao tratamento ortodôntico; 4) as duas doenças pulpares que levam ao escurecimento coronário em dentes aparentemente hígidos são a necrose pulpar asséptica e a metamorfose cálcica da polpa, ambas induzidas exclusivamente pelo traumatismo dentário; 5) o traumatismo dentário do tipo concussão requer, ainda, muitos estudos clínicos e laboratoriais, com modelos experimentais pertinentes, para fundamentar cada vez mais os seus efeitos sobre os tecidos periodontais e pulpares.

Calcific metamorphosis with pathological root resorption in permanent teeth: morphohistometric evaluation of two cases / Metamorfosis calcificante asociada a reabsorción patológica radicular en dientes permanentes: evaluación morfohistométrica de dos casos

Calcific Metamorphosis (CM) is a pulpal response to dental trauma characterized by a deposition of hard tissue within the canal space. A tooth with CM usually presents a discoloration and a partial or total obliteration of the pulp canal space, and its vital pulp tests and symptoms are difficult. Since pulp necrosis cannot be supposed even the negative responses, the periradicular status is the only reliable criterion. Two permanent teeth diagnosed as CM and pathological root resorption, extracted from two males (22 and 53 years of age) due to severe mobility were prepared and sectioned for histological and histometrical evaluation. Images were captured, processed and measured in a total mapping of each specimen with software Pinnacle Studio 9.4® (Pinnacle Systems Inc.), Adobe® Photoshop® (CS 8.0.1, Adobe Systems Inc.) and Image J® (National Institute of Health, Bethesda, MD, USA). The images showed the simultaneous occurrence of CM and root resorption. The means of the total measurements showed that the area of radicular affection (R) was higher than the coronal affection (C), both in quantity (R: 13.75 mm2 -28.75%-/C: 4.7 mm2 -5.47%-) and quality (R: absence of CM / C: presence of CM). CM showed a fibrotic pattern, a cortical bone-like pattern and a cancellous bone-like pattern, representing a kind of reparative reaction probably initiated by the resorption process. Concurrent CM and pathological root resorption are uncommon in the same tooth, and the possibility to obtain specimens of permanent teeth to make histological and histometric evaluations of them represents a situation even more infrequent. This morphohistometric evaluation can expand the spectrum of useful variables to make clinical and therapeutic odontological decisions.

La Metamorfosis Calcificante (MC) es una respuesta pulpar a traumatismos dentales, caracterizada por un depósito de tejido duro dentro del canal pulpar. Un diente con MC usualmente presenta un cambio en el color y una obliteración parcial o total del espacio del canal pulpar, y sus respuestas a las pruebas de vitalidad y los mismos síntomas suelen ser de difícil diagnóstico. Dado que la necrosis pulpar no puede ser supuesta aún con respuestas negativas, el estado periradicular es el único criterio diagnóstico confiable. Dos dientes permanentes de dos pacientes masculinos (de 22 y 53 años) diagnosticados con MC asociada a reabsorción patológica de la raíz, extraídos por movilidad severa fueron preparados y seccionados para evaluación histológica e histométrica. Las imágenes fueron capturadas, procesadas y medidas en un mapeo total para cada espécimen utilizando software Pinnacle Studio 9.4® (Pinnacle Systems Inc.), Adobe® Photoshop® (CS 8.0.1, Adobe Systems Inc.) e Image J® (National Institute of Health, Bethesda, MD, USA). Las imágenes demostraron la concurrencia de MC y reabsorción radicular. Las medias de las mediciones totales expusieron que la superficie de afección radicular (R) fue mayor que la de afección coronaria (C), tanto en cantidad (R: 13,75 mm2 -28,75%-/C: 4,7 mm2 -5,47%-) como en calidad and (R: ausencia de MC / C: presencia de MC). La MC mostró patrones de fibrosis, de tejido similar a un hueso cortical y a un hueso esponjoso, representando una forma de reacción reparativa iniciada probablemente en el proceso de reabsorción. La concurrencia entre MC y reabsorción patológica radicular es rara en el mismo diente, y la posibilidad de obtener especímenes de dientes permanentes para evaluarlos histológica e histométricamente es aún menos frecuente. Esta evaluación histométrica permitiría expandir el espectro de variables útiles para la toma de decisiones clínicas y terapéuticas odontológicas.