Development of difficulty index for management of impacted maxillary canine: A CBCT-based study

Maxillary Canine Impaction: Assessing the Influence of Maxillary Anatomy Using Cone Beam Computed Tomography

BACKGROUND The purpose of this study was to evaluate the anatomical characteristics of patients with unilateral impacted canine teeth compared to a control group. Cone beam computed tomography (CBCT) records were retrospectively analyzed. MATERIAL AND METHODS CBCT records of 64 patients with unilateral impacted canine teeth (57.8% female and 42.2% male) and 64 controls (59.4% female and 40.6% male) were retrospectively analyzed. On the CBCT images, intermolar width, arch length, arch perimeter, palatal width in the molar region at cementoenamel junction, palatal width in the molar region at the crest, palatal width in the molar region measured from mid-root level, nasal cavity width, and palatal depth were evaluated. RESULTS In the palatal width measurement from the mid-root variable, the measurement of labially positioned canines was significantly lower than the control group (P<0.05). In terms of intermolar width, the labial positioned impacted canines' values were lower than in the control group. There was a significant difference in terms of the perimeter variable and both palatinally and labially positioned impacted canines were significantly lower than in the control group (P<0.05). All parameters were compared according to sex, and measurements of male patients were significantly higher than in female patients (P<0.05). CONCLUSIONS A labially impacted canine was strongly linked to a decrease in mid-root palatal and intermolar widths. Additionally, impacted canines positioned both palatally and labially were found to result in a reduced arch perimeter. Moreover, male patients with impacted canines exhibited notably greater anatomical measurements compared to female patients.

Assessment of clinical validity of KPG index for 3D classification of impacted maxillary canines by cone beam computed tomography in patients

OBJECTIVES

The primary objective of this study was to assess the validity of the KPG index in predicting the difficulty of treatment involving impacted maxillary canines. The secondary objective was to assess the reliability and reproducibility of the index.

MATERIALS AND METHODS

A retrospective study was conducted on 96 maxillary impacted canines (MIC) in 60 patients aged 13-35 years. Cone-beam computed tomography (CBCT) scans were used to predict the treatment difficulty of MIC using the KPG index. Patient case files were assessed for the actual difficulty encountered in treating MIC. Cohen's kappa correlation coefficient was used for intra-observer reliability and Kendell's W test was used for inter-observer reliability. Spearman's correlation coefficient test was used to assess the correlation between predicted and actual treatment.

RESULTS

Easy and moderately difficult cases exhibited a moderate correlation between actual and predicted treatment outcomes, whereas difficult cases displayed a weak correlation. The perfect correlation was observed exclusively in extremely difficult cases. The intra-observer reliability for assessing CBCT scans using the KPG guide was found to be 0.88, and the inter-rater reliability was 0.94.

CONCLUSION

The KPG index displayed 87%, 71%, 50% and 100% validity in easy, moderately difficult, difficult, and extremely difficult cases, respectively. This index showed good reliability and reproducibility. However, it is imperative to consider a multitude of other factors, including the patient's age, presence of associated root resorption in adjacent teeth, and duration of treatment, to make an informed decision between surgical exposure and extraction.

Comparison of 3D Easy Box cone-beam computed tomography analysis with 2D Modified Easy Box on OPG as a prognostic tool for impacted maxillary canines: A pilot study

OBJECTIVE

To assess and compare the validity of 2D modified Easy Box and measurement of the Beta angle on standard conventional orthopantomogram (OPG) versus 3D cone-beam computed tomography (CBCT) OPG-constructed view.

DESIGN

A retrospective agreement study.

METHODS

The aim of this study was to construct an Easy Box on a standard conventional OPG and to validate this novel method by comparing it with the Easy Box method on 3D CBCT. After approval from the Ethics Committee, OPG and CBCT radiographs were obtained for the study from departmental records and five private practices in the same location (Indore, India). The radiographs were selected based on record availability and with written consent from the participants before the commencement of the study. The records were analysed to enable a comparison and to assess the accuracy of Easy Box construction on both 3D CBCT and standard conventional OPG radiographs. The location of the impacted canine within the Easy Box boundaries and the measurement of the Beta angle were determined on both views.

RESULTS

A perfect agreement was obtained for the comparison of 3D Easy Box CBCT analysis with 2D modified Easy Box on OPG for impacted maxillary canines (Kappa = 1.0). A Bland-Altman (LoA) analysis showed no proportional bias in the comparison of the Beta angle on 3D and 2D OPG radiographs.

CONCLUSION

Beta angle and 2D modified Easy Box on a conventional OPG yield similar results when compared to Easy Box on 3D CBCT OPG-constructed view. The standard OPG was valuable and cost-effective, particularly in the early stages of diagnosis and treatment planning, either as a substitute or when CBCT was unavailable.

Diagnostic accuracy of conventional orthodontic radiographic modalities and cone-beam computed tomography for localization of impacted maxillary canine teeth

BACKGROUND

Orthodontic treatment planning for an impacted canine tooth requires accurate information about its position. The aim of this study was to compare the diagnostic accuracy of two conventional orthodontic radiographic modalities with cone-beam computed tomography (CBCT) for localization of impacted maxillary canine teeth.

MATERIALS AND METHODS

Panoramic radiographs, lateral cephalograms, and CBCT scans of 30 patients with unilaterally impacted maxillary canine teeth were retrieved from the archives. Eight expert orthodontists evaluated the parameters related to the location of impacted canine teeth by using panoramic radiographs and lateral cephalograms of patients. After 4 weeks, the same parameters were evaluated on CBCT scans of patients. The diagnostic accuracy of conventional modalities and CBCT was compared with each other and also with the gold standard.

RESULTS

The conventional radiographic modalities and CBCT had similar accuracy for assessment of the overall inclination (p = 0.11), apex morphology (p = 0.18), and mesiodistal position of the apex (p = 0.12). CBCT had significantly higher accuracy for determination of incisal tip location (p = 0.001), labiopalatal (p = 0.001) and vertical (p = 0.01) position of the crown tip, minimum bone thickness covering the crown (p = 0.001), and root resorption of the adjacent tooth (p = 0.001).

CONCLUSION

The combination of panoramic radiographs and lateral cephalograms was sufficiently accurate to assess some diagnostic parameters such as overall inclination, apex morphology, and mesiodistal apex location of impacted canine teeth.

Three-dimensional decision support system for treatment of canine impaction

INTRODUCTION

This study aimed to develop a 3-dimensional (3D) characterization of the severity of maxillary impacted canines and to test the clinical performance of this characterization as a treatment decision support tool.

METHODS

Cone-beam computed tomography images obtained from 83 patients with 120 impacted maxillary canines were included. Quantitative information on the canine 3D position and qualitative assessment of root damage of adjacent teeth were evaluated. A severity index was constructed on the basis of the quantitative findings. Clinical applicability was tested by comparing clinical diagnosis and treatment planning for conventional records vs the 3D characterization via a 2-part survey.

RESULTS

The average quantitative assessments of impacted maxillary canine position were 6.4 ± 3.6 mm from the midsagittal plane, 11.6 ± 3.1 mm in height relative to the occlusal plane, 31.5° ± 18° of roll, and 48.8° ± 14.3° of pitch. The severity index ranged from 0-13 with a mean score of 4.5 ± 2.2. Overlap with adjacent teeth was the greatest contributor (33%) to the index. Bicortically impacted canines caused the most severe root damage. Cone-beam computed tomography was preferred for assessing root damage and overall severity, whereas conventional imaging was sufficient for height and angulation assessment. The 3D report was very important or important for evaluating root damage, canine position, overall severity, and overlap. The 3D report changed most of the decisions relating to biomechanics, patient education, and treatment time estimate. The decision of exposure and traction vs extraction was changed 22% of the time after the presentation of the 3D report.

CONCLUSIONS

The overlap with adjacent teeth frequently contributes the most to the severity index. The 3D report provided relevant clinical information regarding the canine position, damage to adjacent teeth, and the severity index, with a profound impact on the decisions of the clinicians regarding biomechanics, patient education, and treatment time estimate.

Development and validation of a new prognostic tool for impacted maxillary canines, 'Easy box': A cone-beam computed tomographic study

OBJECTIVE

To develop a tool to facilitate simple, easy and rapid assessment of the level of difficulty in disimpaction of an impacted canine using cone-beam computed tomography (CBCT).

DESIGN

A cross-sectional study.

METHODS

A panel of four experienced orthodontists formulated a questionnaire capable of portraying the limits of a three-dimensional (3D) area around impacted maxillary canines on CBCT images, which would determine the disimpaction difficulty level. In total, 14 experienced orthodontists graded each item in the questionnaire and assigned scores in the range of 0-5. Average scores obtained outlined the limits of a 3D area, within which an impaction was deemed favourable. This area was termed 'Easy box'. The disimpaction difficulty level of 170 impacted maxillary canines was then assessed using 'Easy box' and the existing tool KPG index for convergent validation.

RESULTS

Perfect inter-examiner agreement was obtained as evidenced by Fleiss kappa value of 0.984 for the tool 'Easy box' and 0.948 for the KPG index. There was also perfect agreement between the two methods of assessment (Cohen weighted kappa, k>0.86). The average time taken for assessment using 'Easy box' was 3.3 min compared to 8.8 min for the KPG index.

CONCLUSION

'Easy box' proves to be a simple, accurate and rapid assessment tool for the prognostic evaluation of impacted canines, using CBCT images. Impacted maxillary canines with cusp tips that lie beyond the limits of the 3D 'Easy box' area with a beta angle greater than 45°, were rated to be more difficult to align.

Application of a Cone-Beam Computed Tomography-Based Index for Evaluating Surgical Sites Prior to Sinus Lift Procedures-A Pilot Study

OBJECTIVES

Radiography-based indices can help surgeons perform detailed examinations of the surgical site and predict the surgical difficulty of cases. We aimed to develop and validate a novel CBCT-based index that can predict the surgical difficulty of sinus-augmentation procedures.

MATERIALS AND METHODS

In the first stage, five experienced dental specialists performed a review of the literature and closed group discussions and designed the novel index. In the next stage, the index was validated. CBCT scans of 30 patients scheduled for sinus-augmentation procedures were evaluated and assigned presurgical CBCT evaluation scores (PSCESs) by five examiners. Subsequently, one oral surgeon performed sinus augmentation using the lateral antrostomy technique and assigned surgical difficulty scores (SDSs) to each of the 30 cases along with 2 observers. The PSCESs and SDSs were statistically analysed to determine the interrater reliability and validity of the index.

RESULTS

The interrater agreement of the PSCES among the five presurgical evaluators was 0.85. The PSCES of the five evaluators had highly significant correlation (P < 0.001, r = 0.68 to 0.76) with the SDS. Regression analysis revealed that for every unit increase in the PSCES, there is 0.46 to 0.57 increase in the SDS value.

CONCLUSION

The results of this pilot study revealed that a novel CBCT-based index can be used as a reliable tool for predicting the surgical difficulty of sinus-augmentation procedures. However, the novel index needs to be tested on a larger sample of patients and evaluators for a more concrete validity and reliability.