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Year : 2014  |  Volume : 25  |  Issue : 3  |  Page : 311-315
Evaluating intrusive injuries in primary dentition from computed tomographic scans: A preliminary report

1 Department of Pediatric Dentistry, Sri Ramakrishna Dental College and Hospital, Lucknow, Uttar Pradesh, India
2 Department of Pedodontics with Preventive Dentistry, Faculty of Dental Sciences, C.S.M. Medical University, Lucknow, Uttar Pradesh, India
3 Department of Pediatric Dentistry, Uttar Pradesh Dental College, Lucknow, Uttar Pradesh, India
4 Director, The Dentale Study Group, Coimbatore, Tamil Nadu, India

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Date of Submission29-Jan-2013
Date of Decision31-Mar-2014
Date of Acceptance20-May-2014
Date of Web Publication7-Aug-2014


Context: Children sustaining maxillofacial trauma may undergo computed tomographic (CT) examination to exclude potential complications, which pave way for spread of infection into the meningeal region. Following treatment, these children report for management of their dental injuries as out-patients for which a separate conventional radiographic examination is usually done. The usefulness of the initial maxillofacial CT scan in evaluating dental injuries needs to be assessed so as to possibly avoid children from being subjected to a separate radiographic examination.
Aims: The objective of this study was to evaluate the ability of pediatric dentists to assess intrusive injuries in primary dentition from preexisting maxillofacial CT scans of children.
Settings and Design: Hospital based cross-sectional study.
Subjects and Methods: Among 70 pediatric patients who were admitted following maxillofacial injuries, 10 children underwent CT examination. CT segments displaying the tooth bearing portions of the jaw were reformatted using the Dentascan software and three precalibrated pediatric dentists clinically examined the selected children and with the use of Dentascan based CT sections assessed the relative position of the intruded teeth in relation to the permanent successor and planned treatment for each individual intruded tooth.
Statistical Analysis: Fleiss Kappa statistics.
Results: There was perfect agreement between the interpretations of all participants (κ = 1.0000, 95% confidence interval = 0.6861-1.3139) and the interpretations of each participant with the "gold standard" evaluator (κ = 1.000).
Conclusion: Maxillofacial CT scans made to assess maxillofacial injuries in children can also be reliably used for assessing intrusive injuries in primary dentition.

Keywords: Maxillofacial injuries, radiography, tomography, tooth injuries

How to cite this article:
Padmanabhan MY, Pandey RK, Tewari N, Aparna R. Evaluating intrusive injuries in primary dentition from computed tomographic scans: A preliminary report. Indian J Dent Res 2014;25:311-5

How to cite this URL:
Padmanabhan MY, Pandey RK, Tewari N, Aparna R. Evaluating intrusive injuries in primary dentition from computed tomographic scans: A preliminary report. Indian J Dent Res [serial online] 2014 [cited 2023 Mar 26];25:311-5. Available from:
Intrusive injuries are the most common type of traumatic injuries in primary dentition, [1] which require careful examination of not only the involved tooth, but also the potential impact of these injuries on developing permanent tooth germs. Radiographic examination of these intrusive injuries serve as an important adjunct to clinical examination as it helps in assessing the relationship between the roots of intruded primary incisors, their permanent successors and the adjacent cortical bone. The decision to immediately extract or observe (for spontaneous re-eruption) the intruded primary anterior teeth depends chiefly on the relationship of its roots in relation to the permanent successor or adjacent buccal cortical plate. [2]

The International Association for Dental Traumatology recommends the following radiographic examinations to assess intruded primary anteriors: (1) An anterior occlusal radiograph and (2) a lateral extraoral radiograph (using a size 2 periapical film). [3] However, recent studies have found no additional advantage in obtaining lateral extraoral radiographs in intrusive injuries involving primary teeth in children. [4] Conventionally, foreshortening or elongation of intruded tooth (when compared to the noninjured antimere) in the anterior occlusal radiograph was used to establish intrusions towards the labial bone or permanent successor, respectively. [2] A major requisite in this technique is that the central beam of X-rays must be oriented exactly through the midline between the two incisors (between the injured and noninjured teeth) to be compared, in order to correctly diagnose the relationship between the roots of intruded tooth and its permanent successor, which may be difficult to obtain in all cases. Another major drawback of this technique is that it relies on comparative assessment of the intruded teeth with the adjacent teeth to determine the nature of intrusion, which may be difficult in-patients with a noninjured antimere as in the case of multiple intrusive injuries or in-patients with multiple dental injuries, wherein crown fractures of the antimere or intruded tooth may deter accurate comparisons. Moreover, intrusions of maxillary primary canines and lateral incisors (during some instances), which are usually present at zones of maximal curvature in the arch are not ideal candidates for conventional radiographic evaluation, due to problems associated with superimposition.

In pediatric in-patients who have sustained intrusive injuries along with severe maxillofacial trauma, positioning intra-oral films or making an orthopantomography may be a difficult task. However, a small proportion of these patients might have underwent a computed tomographic (CT) examination already to assess the severity and potential complications associated with their maxillofacial injuries. The objective of this pilot study was to check if pediatric dentists can assess and plan treatment for intrusive injuries in primary dentition from maxillofacial CT images of pediatric patients who were subjected to a CT scan for assessment of maxillofacial trauma.

   Subjects and methods Top

We followed the ethical guidelines provided by the Department of Pedodontics with Preventive Dentistry, CSM Medical University, Lucknow, India, which clearly stated that no children were to be intentionally subjected to a CT scan only for diagnosing dental injuries. Only children who were indicated for a CT scan for assessment of their maxillofacial injuries were to be included in this study.

Three pediatric dentists of similar qualification and work experience who routinely evaluate traumatic injuries at the study center were selected for the study. They underwent a tutorial on Dentascan based CT imaging and assessing intrusive injuries in primary anterior teeth from CT scans as a part of calibration exercise. To assess inter- and intra-rater reliability, these pediatric dentists were asked to evaluate 10 Dentascan images of intruded primary teeth and classify them as being intruded towards- or intruded away- from the permanent successor. The same test was conducted again with the images being given in a different order. The interpretations of each pediatric dentist was compared with-his own interpretations during the second test, the other pediatric dentists' interpretations and with the interpretations of a 'gold standard' evaluator, who was an expert in pediatric dental traumatology and three-dimensional imaging. The images used during calibration exercise were collected from patients who had reported to the center before this study was begun and were not included in this study.

We decided to include pediatric patients who (i) reported following maxillofacial trauma, (ii) were indicated for a maxillofacial CT scan and (iii) presented with intrusive injuries in the primary dentition. The protocol followed at the study center involved subjecting pediatric patients to CT scan only when the benefits outweigh the radiation associated risks. A total of 10 pediatric in-patients who reported following road accidents with maxillofacial injuries and who were indicated for a maxillofacial CT scan (in order to assess the severity of maxillofacial injury or potential fatal complications) were selected for the study. All patients had sustained maxillofacial injuries following road traffic accidents. These patients were subjected to a maxillofacial CT scan in order to assess the extent of bone fracture and other complications, which were performed using the same spiral CT scanner (CT/e, GE Medical Systems, Milwaukee, WI, USA), using a 13.7 cm field of view, 512 × 512 matrix, with the operating parameters set at 80 kV and 100 mA. From the maxillofacial CT scans sagittal section of primary teeth and its surrounding structures, were reconstructed using the  Dentascan software (GE Medical Systems, Milwaukee, WI, USA).

Each precalibrated pediatric dentist was asked to examine the selected 10 pediatric patients and their Dentascan based CT sections of the primary maxillary anterior region. Based on clinical and radiographic examination, the participants were asked to:

  • To classify the intruded teeth as being (1) intruded towards- or (2) intruded away, from the permanent successor; or (3) unclear
  • Treatment plan for each intruded tooth: (1) Observation for spontaneous re-eruption, (2) extraction or (3) not sure.

Following assessment of these patients, the pediatric dentists answered a questionnaire, which enquired about: (1) Ease of assessment of intruded teeth and (2) ease of treatment planning using Dentascan based CT examination; when compared to conventional film based two-dimensional radiographic examination. While answering these questions the participating pediatric dentists were asked to provide a comparative assessment keeping in mind their previous experiences related to conventional radiographic examination of pediatric patients with multiple intrusive injuries.

Statistical analysis

During the calibration exercise, Kappa statistics was used to calculate the agreement between the scores of each pediatric dentist and the "gold standard" evaluator, and intra-rater reliability. Similarly, Fleiss's kappa was used to calculate the inter-rater reliability between the three pediatric dentists. The agreement between the three pediatric dentists in assessing the type of intrusion and devising the treatment plan was also assessed through multi-rater kappa statistics.

   Results Top

Calibration exercise

The interpretations of all participating pediatric dentists agreed perfectly with the "gold standard" evaluator (κ = 1.000) during the calibration exercise. Similarly, the inter-rater reliability between the three raters (Fleiss Kappa for 3 raters = 1.0000, standard error [SE] = 0.1826, 95% confidence interval [CI] = 0.6422 ± 1.3578) and their intra-rater reliability (κ = 1.000) was excellent due to complete agreement between the interpretations of the Dentascan images.

Patient characteristics

The mean age of the children whose records were included for the study was 37 months (±3.162 months). All children had sustained intrusive injuries to two or more teeth, with a total of 28 intruded primary anterior teeth being examined [Table 1]. In all the patients, intrusive injuries were associated with other types of dental injuries to adjacent primary teeth and soft tissue injuries. All three pediatric dentists provided their interpretation pertaining to the type of intrusive injury from the Dentascan based CT images and the treatment plan for the 28 intruded primary anterior teeth.
Table 1: Number of intruded primary anterior teeth observed in this study

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Assessment of intrusion and treatment planning

There was no disagreement between the interpretations and treatment plan of the three participants (Fleiss Kappa for 3 raters = 1.0000, SE = 0.1601, 95% CI = 0.6861-1.3139) in the study. The responses to the questionnaire revealed that all participants experienced greater ease during assessment and treatment planning (100%) for intrusive injuries in these patients due to the presence of Dentascan based CT images.

   Discussion Top

Evidence-based clinical decision making during pediatric dental trauma involves choosing the right modality of treatment with appropriate utilization of investigations which are safe, efficient and effective. These challenges are magnified by the trends and policies involved in utilizing radiographic services during dental trauma in children. The justification for a radiographic examination is based on the assumption that the benefits outweigh the risks. The clinical decision to extract or observe an intruded primary tooth in a pediatric out-patient presenting with dental injury is conventionally made based on clinical examination and the findings of anterior occlusal radiographs.

However, in patients with severe maxillofacial injuries numerous factors may hinder appropriate anterior occlusal radiographic examination. Concomitant presence of injuries in oro-facial soft tissues, adjacent teeth and jaws, which hinder placement of radiographic films, medical status of the patient, level of consciousness, etc., may significantly influence intra-oral placement of films in these patients or performing an orthopantomographic examination. Moreover, pediatric patients with maxillofacial trauma may have multiple dental injuries which may not be sufficiently assessed with a single conventional film radiograph. This study was done to assess if the information required from a radiographic investigation in case of intrusive injuries can be provided by reconstruction of maxillary CT axial sections using Dentascan software.

The efficacy of a new diagnostic device can be proved by comparing with an established valid and reliable gold standard diagnostic modality. In order to comparatively assess the diagnostic efficacy of CT in intrusive injuries in primary maxillary anterior teeth, directly visualizing the relationship between the intruded teeth and permanent successor (anatomic truth) by surgical exploration (gold standard) or subjecting pediatric patients to another radiographic investigation cannot be done. Studies were carried out to compare the accuracy in replicating linear and angular measurements of two-dimensional conventional radiographs and three-dimensional imaging systems, have shown that these measures are comparable or more accurate in case of three-dimensional imaging modalities. [5],[6] Moreover, it has also been shown that the measurements made between anatomical landmarks following computerized reconstruction both in case of cone beam computed tomography and conventional CTs can be reliably used for three-dimensional assessment. [7],[8] Based on the results of these studies and due to the benefit of the presence of sagittal and axial sections [Figure 1] and [Figure 2], which provide better view of the relationship between intruded teeth and permanent successors it can be inferred that three-dimensional imaging modalities may have an edge over conventional anterior occlusal radiographs in assessment of intrusive injuries in primary dentition. Moreover, assessment of intrusions in the lateral incisors and canines can also be done with ease without any superimpositions. Planning the treatment for intruded teeth using the initial maxillofacial CT in a child reporting with maxillofacial trauma allows the management of the intruded teeth to take place along with other surgical procedures, which may be performed under general anesthesia or sedation. This in turn prevents the patient from being subjected to a separate radiographic examination or clinical session for assessment and management of the intruded teeth.
Figure 1: Frontal view of primary anterior teeth (a) after healing of maxillofacial injuries. Axial (b) and sagittal reconstruction (c) of computed tomographic sections showing primary central incisor intruded toward the permanent successor and lateral incisor not intruded towards the permanent successor. The central incisor was extracted and lateral incisor allowed to re-erupt

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Figure 2: Frontal view of primary anterior teeth (a) along with axial (b) and sagittal reconstruction (c) of computed tomographic sections showing primary central incisor intruded away from the permanent successor

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Although cone beam CTs are more preferred than conventional CTs by virtue of the low radiation exposure associated with it, conventional CTs were used as the selected children were under analgo-sedation prior to the radiographic exposure and had to be scanned in the supine position; and CT scans of other portions of the body also had to be made. Moreover, a low dose protocol was adopted, while performing CT scans in the pediatric patients selected for the study in order to minimize radiation exposure. [9],[10] The authors recommend using Dentascan assisted evaluation of dental injuries only in those pediatric patients who have already been indicated for a CT examination (in order to assess maxillofacial injuries) and this reconstruction of the maxillary axial sections can be performed when the patients are undergoing a maxillofacial CT scan.

The relatively lower number of participants in the present study is due to the strict inclusion criterion, which requires patients reporting with - maxillofacial trauma, concomitant intrusive injuries in primary dentition, and an indication for maxillofacial CT scan; a rare combination of conditions, which can justify the significance of the inferences drawn from this study. In pediatric patients requiring maxillofacial CT scan following facial trauma, Dentascan based reformatting of CT sections can enable better assessment and treatment planning in case of accompanying intrusive injuries in primary dentition.

   Conclusion Top

Intrusive injuries can be reliably assessed from maxillofacial CT scans of pediatric patients, thereby preventing them from being subjected to another radiographic exam for assessing dental injuries. Subjecting a pediatric patient to a CT scan solely for the purpose of assessing dental injuries cannot be accepted due to the high radiation risk associated with this procedure. However, if children with maxillofacial injuries have already undergone a CT examination, then the axial CT sections of dentoalveolar portion of the jaw bones can be reformatted using appropriate software to reliably assess dental injuries.

   References Top Espírito Santo Jácomo DR, Campos V. Prevalence of sequelae in the permanent anterior teeth after trauma in their predecessors: A longitudinal study of 8 years. Dent Traumatol 2009;25:300-4.  Back to cited text no. 1
2.Flores MT, Holan G, Borum M, Andreasen JO. Injuries to the primary dentition. In: Andreasen JO, Andreasen FM, Andersson L, editors. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 4 th ed. Oxford: Blackwell Munksgaard; 2007. p. 516-41.  Back to cited text no. 2
3.Malmgren B, Andreasen JO, Flores MT, Robertson A, DiAngelis AJ, Andersson L, et al. International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition. Dent Traumatol 2012;28:174-82.  Back to cited text no. 3
4.Holan G, Ram D, Fuks AB. The diagnostic value of lateral extraoral radiography for intruded maxillary primary incisors. Pediatr Dent 2002;24:38-42.  Back to cited text no. 4
5.Moshiri M, Scarfe WC, Hilgers ML, Scheetz JP, Silveira AM, Farman AG. Accuracy of linear measurements from imaging plate and lateral cephalometric images derived from cone-beam computed tomography. Am J Orthod Dentofacial Orthop 2007;132:550-60.  Back to cited text no. 5
6.Oz U, Orhan K, Abe N. Comparison of linear and angular measurements using two-dimensional conventional methods and three-dimensional cone beam CT images reconstructed from a volumetric rendering program in vivo. Dentomaxillofac Radiol 2011;40:492-500.  Back to cited text no. 6
7.Kim M, Huh KH, Yi WJ, Heo MS, Lee SS, Choi SC. Evaluation of accuracy of 3D reconstruction images using multi-detector CT and cone-beam CT. Imaging Sci Dent 2012;42:25-33.  Back to cited text no. 7
8.Medelnik J, Hertrich K, Steinhäuser-Andresen S, Hirschfelder U, Hofmann E. Accuracy of anatomical landmark identification using different CBCT-and MSCT-based 3D images: An in vitro study. J Orofac Orthop 2011;72:261-78.  Back to cited text no. 8
9.Sun Z, Ng KH, Sarji SA. Is utilisation of computed tomography justified in clinical practice? Part IV: Applications of paediatric computed tomography. Singapore Med J 2010;51:457-63.  Back to cited text no. 9
10.Mahesh M. Advances in CT technology and application to pediatric imaging. Pediatr Radiol 2011;41 Suppl 2:493-7.  Back to cited text no. 10

Correspondence Address:
Makkada Yuvaraj Padmanabhan
Department of Pediatric Dentistry, Sri Ramakrishna Dental College and Hospital, Lucknow, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0970-9290.138322

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