Self-revascularization Following Horizontal Root Fracture with Lateral Luxation Injury in a Permanent Maxillary Central Incisor

Abstract

Repair or regeneration of the pulp, following trauma, is a part of the wound healing process. However, pulp necrosis or root resorption, whether partial or complete, might obstruct this process. Because of the neurovascular bundle at the apical foramen and the periodontal ligament, the pulp in this fragment generally remains normal when the apical fragment is not moved. We describe a mature upper left central incisor with a horizontal root fracture in the mid-third of the root and lateral luxation that healed on its own after undergoing a procedure called self-revascularization. The fracture was detected during a routine dental checkup on a tooth that was asymptomatic. Two tooth pieces with trabecular bone between them were discovered using periapical radiography and cone-beam computed tomography (CBCT). Therefore, the endodontic intervention was not needed. Regular follow-up after trauma is mandatory to evaluate any signs of pulp necrosis. CBCT can help assess healing and identify resorption.

INTRODUCTION

Root fractures are the consequence of horizontal or frontal impact on the teeth causing direct dental damage.[1,2] In children between the ages of 11 and 20 years, root fractures are most common in the maxillary central incisors, the largest permanent teeth.[2,3,4] Root fractures are relatively rare, and their prevalence varies from 1.2% to 7.0%.[1,5] Following acute dental trauma, the dental hard tissues, pulp, and periodontium may be damaged; the neurovascular supply to the tooth may be affected in luxation injuries at the apical foramen and the level of the fracture line in root fracture. However, partial or total pulp necrosis or root resorption often leads to failure of the healing process. When the apical fragment is not displaced, the neurovascular bundle of the pulp at the apical foramen remains unharmed, and the pulp in the tooth fragment remains normal.[6,7] Moreover, the periodontal ligament (PDL) surrounding the apical fragment also remains intact.[8]

CASE REPORT

A 24-year-old male visited the Department of Endodontics. Majmaah University, complaining of stained maxillary anterior teeth. Although the patient's medical records indicated that he was in good condition, his dental records revealed that he had suffered oral injuries in a violent conflict when he was just 20 years old. The patient admitted that he had not sought professional dental treatment at the time and that no splints or antibiotics had been applied to the wound. No abnormalities were found during the extraoral examination. However, the intraoral examination revealed a slightly mesially misplaced tooth and discoloration of the maxillary left central incisor [Figure 1]. There was no intraoral sinus tract, movement, or pain on touch or percussion, and the probing depth surrounding the tooth was within normal range. During the sensitivity testing, both maxillary and mandibular anterior teeth responded positively to Endo Ice (1,1,1,2-tetrafluoroethane) and an electric pulp tester (Courtesy SybronEndo, Orange, California, USA). A routine periapical radiograph revealed a horizontal fracture in the maxillary left central incisor root's middle third with lateral luxation [Figure 2]. A typical trabecular pattern separated the pieces, and the PDL space in both coronal and apical fragments seemed normal. Apical fragments had their pulp canals completely destroyed, while the coronal portions did not. The pulp and apical tissue of the maxillary left central incisor were both found to be normal in this case. According to the Andreasen et al. categorization, the healing type following a horizontal root fracture, in this case, was “healing by the interposition of bone and connective tissue.”[1] Further evaluation was performed using cone-beam computed tomography (CBCT) [Figure 3]. A Planmeca ProMax three-dimensional (3D) CBCT machine (Planmeca Inc., Roselle, IL, USA) was used, and the scanning parameters were as follows: Large field of view, voxel size of <200 μm, exposure time <15 s, and 0.2-mm thick cross-section and were viewed from the coronal to the apical direction. It was necessary to make adjustments to the photos' contrast and brightness so that they could be seen clearly by the program. Radiology scans indicated horizontal root fracture of the maxillary left central incisor on axial view, however on coronal view, a horizontal root fracture in the middle third of the root was seen with lateral luxation, and the tooth tilted to the left. The apical part was obliterated. The images showed a healed fracture, an absence of periradicular pathology, and cervical/internal absorption. Direct composite veneering was planned to improve the esthetic appearance of the maxillary anterior teeth [Figure 4].

Figure 1.

Clinical photograph showing the discoloration of maxillary anterior teeth

Figure 2.

Intraoral periapical radiograph examination of maxillary left central incisor showing the healing of horizontal root fracture. No lesion was present between the two fragments and the apical part of the root. The radiography was performed 4 years after the trauma

Figure 3.

Cone-beam computed tomography of the maxillary teeth showing fragments separated by a bone with normal trabecular pattern with periodontal ligament space of the coronal and apical part. (a) The coronal plane, (b) the axial plane

Figure 4.

Postoperative photograph showing direct composite veneering of the maxillary anterior teeth

DISCUSSION

The patient complained of discoloration of the upper and lower anterior teeth. His dental history revealed trauma 4 years previously. A research that included histology, histobacteriology, and radiography[9] showed only pain on percussion during the diagnostic of pulp necrosis may be linked to an infected, necrotic pulp. Recently, Estrela et al.[10] have reported that CBCT can detect inflammatory root resorption at earlier stages more accurately than intraoral periapical radiographic images because of the potential of the 3D images. Periapical radiographs may underestimate the extent of inflammatory root resorption. We recommend using CBCT to identify possible cervical or internal or external resorption. Thus, in the present case, the choice of diagnostic imaging techniques was in accordance with the ALARA principle.[11,12] According to Andreasen et al., the first long-term research on permanent teeth was published in 1989 after a 10-year follow-up of 95 individuals.[4] The researchers discovered that the position of a tooth's root fracture is a good indicator of how long a tooth would last. In the apical third of the root, survival rates were greatest (89%) followed by mid-root (78%), cervical mid-root (67%), and cervix root fractures (45%) (33%). However, pulp canal obliteration and complications during pulp and periodontal healing were detected during the follow-up. Usually, no immediate treatment is necessary for root fractures at the apical and middle thirds. However, due to the possibility of pathological changes occurring several years after the injury, a long-term follow-up of patients with traumatic injuries is mandatory.[13,14,15] The use of antibiotics in root fractures has a slight negative effect and does not help healing, as mentioned in two previous studies.[4,16] Therefore, antibiotics should not be prescribed for a root fracture unless the injury requires this type of medication. As discussed above, root fractures and teeth with trauma should be examined regularly. Soft tissues, such as the pulp, PDL, and gingiva, require a longer duration of observation. Therefore, regular check-ups should be performed at 4-5-year intervals once healing is documented. A follow-up routine for collection of clinical information regarding sensibility testing should be implemented. Careful clinical and radiographic analyses are required to monitor the pulp.[17]

CONCLUSION

Self-revascularization can occur after horizontal root fracture with lateral luxation in a closed apex. Regular follow-up after trauma is mandatory to evaluate any signs of pulp necrosis. CBCT should be performed to observe the type of healing or detect any type of resorption. Antibiotics or splinting may not affect the healing type of root fracture. Further clinical studies on horizontal root fracture with a closed apex are needed to observe self-revascularization in a large number of cases.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.