Tooth root resorption: A review

Abstract

Tooth root resorption is multifactorial, leading to progressive destruction and eventual loss of tooth root dentin and cement. There are internal and external types of root resorption, each having its variety. The etiology and pathogenesis of tooth root resorption are poorly understood, and the most significant etiological factors are trauma, pulpal infection, tooth bleaching, and orthodontic treatment. Tooth root resorption is primarily asymptomatic; thus, it is revealed accidentally by radiographic examination. Progressive clinical manifestations are pain, tooth discoloration, tooth mobility, and other conditions. Awareness of the causes and risk factors allowing tooth root resorption, and regular radiographic examination, in case of necessity, make it possible to reveal resorption at an early stage and to prevent its further development. Thus, the aim of this study is to present etiopathogenesis, a clinical course, and diagnostic peculiarities of internal and external types of tooth root resorption, enabling practicing dentists to timely diagnose root resorption and take appropriate measures to avoid further complications. Within the limitation of this review, even though the etiopathogenesis of tooth root resorption is yet not fully understood, it is suggested that the etiological factors fall into two groups (endogenic and exogenic) to enhance further understanding of the possible causes and mechanisms of root resorption and allow practitioners to monitor high-risk patients and make timely diagnoses. Moreover, radiographic examination and CBCT are indispensable for the diagnosis of root resorption.

Keywords: Root resorption; dental trauma; external resorption; internal resorption; orthodontic force; resorption classification; resorption diagnosis; resorption etiology; resorption pathogenesis.

Figure 1.

Schematic demonstration of the etiopathogenesis of internal root resorption development.

Figure 2.

‘Pink spot’ on the crown`s vestibular (A) and palatal (B) surfaces of the right central incisor.

Figure 3.

Scheme of possible explanation of the orthodontically induced root resorption due to the risk factor of allergy.

Figure 4.

Morphology classification of the root (A) Normal, (B) Shortened, (C) Pointed, (D) Blunt, (E) Eroded, (F) Bent, (G) Bottle shaped.

Figure 5.

A. Apical root resorption. The tooth has previously undergone endodontic treatment, but the root canals are insufficiently filled, which leads to periapical inflammation followed by root resorption. B. Apical replacement resorption following orthodontic treatment. In this case, resorption was caused by the incorrect application of orthodontic force. C. Tooth root internal resorption. CBCT is preferable to confirm root perforation. D. External root resorption in the lower left canine. The patient reports a jaw trauma he experienced many years ago, which caused the loss of the lower-left lateral incisor. OPG reveals the presence of generalized periodontitis.

Figure 6.

Orthodontic treatment has often been found to result in external apical root resorption across the mandibular anterior teeth and the first molars. The extent of root resorption is dependent on the duration, the type of movements carried out, and the magnitude of forces involved.

Figure 7.

Prolonged orthodontic treatment usually demonstrates external root resorption. As can be seen in the figure, the apical region of the root tends to resorb under the influence of orthodontic forces and shows a more bulbous end after an extended duration of treatment.