The four mechanisms of dental resorption initiation

ORTHODONTIC INSIGHT

The four mechanisms of dental resorption initiation

Alberto Consolaro^*

Full Professor, FOB-USP. Full Professor of the Post-graduation program, FORP-USP

^{Correspondence}

ABSTRACT

The aim of this study is to present a classification with a clinical application for root resorption, so that diagnosis will be more objective and immediately linked to the source of the problem, leading the clinician to automatically develop the likely treatment plan with a precise prognosis. With this purpose, we suggest putting together all diagnosed dental resorptions into one of these four criteria:

1) Root resorption caused by cementoblast cell death, with preservation of the Malassez epithelial rests.

2) Root resorption by cementoblasts and Malassez epithelial rests death.

3) Dental resorption by odontoblasts cell death with preservation of pulp vitality.

4) Dental resorption by direct exposure of dentin to gingival connective tissue at the cementoenamel junction gaps.

Keywords: Dental resorption. Root resorption. Tooth movement. Internal resorption. Cervical resorption.

RESUMO

O presente trabalho propõe-se a apresentar uma classificação, com aplicação clínica, para as reabsorções dentárias, para que o diagnóstico seja objetivo e imediatamente ligado à causa do problema, levando automaticamente o clínico ao provável plano de tratamento e a um prognóstico preciso. Com esse objetivo, sugerimos agrupar cada caso clínico de reabsorção dentária em um dos seguintes grupos:

1) Reabsorções radiculares pela morte dos cementoblastos, com manutenção dos restos epiteliais de Malassez.

2) Reabsorções radiculares pela morte dos cementoblastos e dos restos epiteliais de Malassez.

3) Reabsorções dentárias pela morte dos odontoblastos, com manutenção da vitalidade pulpar.

4) Reabsorções dentárias pela exposição direta da dentina ao tecido conjuntivo gengival, nos gaps da junção amelocementária.

Palavras-chave: Reabsorções dentárias. Reabsorções radiculares. Movimentação dentária. Reabsorção interna. Reabsorção cervical.

Dental resorptions are traditionally classified according with the mechanism of maintenance and evolution into:

a) Inflammatory.

b) By replacement.

Inflammatory dental resorptions¹ are maintained by inflammatory mediators that stimulate BMUs - Bone Multicellular Units - where clastic cells gradually resorb the dentin surface free of cementoblasts and odontoblasts, eliminated as a consequence of the resorption process. The therapeutic principle of these dental resorptions is based on the identification and elimination of its cause, therefore, the resorption process will evolve to the repair phase. This is how we see inflammatory resorption related to orthodontic movement in each activation period.

Dental resorptions by replacement¹ are maintained by systemic and local mediators of bone tissue which regulate the remodelling process or turnover. This resorption occurs always as a consequence of alveolodental ankylosis because of the death of Malassez epithelial rest cells - induced by dental trauma, especially by daily concussions. Since there is no way to eliminate the local mediators for bone turnover, the prognosis of dental resorption by replacement almost always involves tooth loss. It is important to highlight that orthodontic movement and occlusal trauma does not induce Malassez epithelial rests death.

To facilitate the clinical and etiological understanding of root resorptions, it was proposed a classification for each case, using as criteria its mechanism of induction and initiation of the process. Figures 1 and 2 illustrate and explain it.

Using this classification in each clinical case allows a direct and precise diagnosis, immediately linked with its cause, leading to an automatic reasoning of the likely treatment plan with an accurate prognosis.

Root resorptions are grouped as follows:

1. Root resorption by cementoblast cell death with maintenance of Malassez epithelial rests

Inflammatory root resorptions during orthodontic movement.

Apical Inflammatory root resorption in chronic periapical lesions.

Inflammatory root resorption by mild and /or contaminated trauma.

Inflammatory root resorption by occlusal trauma.

2. Root resorptions by cementoblast and Malassez epithelial rests death

Resorption by replacement in dental trauma.

Resorption by replacement in periodontal ligament atrophy of unerupted teeth - especially canines.

3. Root Resorption by odontoblast cell death with maintenance of pulp vitality

Internal Inflammatory root resorption by dental trauma.

4. Root resorption by direct exposure of dentin to the gingival connective tissue at the cementoenamel junction gaps

External cervical inflammatory resorption by accidental trauma, especially concussion.

External cervical inflammatory resorption by trans-operative dental trauma as in impacted canine traction and during intubation in general anesthetic procedures.

External cervical inflammatory resorption in association with internal whitening procedures.

FINAL CONSIDERATIONS

The application of the proposed classification for dental resorption to every clinical case will help the development of a direct diagnosis promptly linked with its cause. This will lead to a treatment plan with a precise prognosis.

Submitted: May 8, 2013

Revised and accepted: May 25, 2013

* The author reports no commercial, proprietary or financial interest in the products or companies described in this article.

• 1. Consolaro A. Reabsorções dentárias nas especialidades clínicas. 3rd ed. Maringá: Dental Press; 2012.

Publication Dates

• Publication in this collection
  31 Oct 2013
• Date of issue
  June 2013

History

• Received
  08 May 2013
• Accepted
  25 May 2013