We read an article in the July issue entitled “Effects of magnitude of intrusive force on pulpal blood flow in maxillary molars” (Ersahan S, Sabuncuoglu FA. Am J Orthod Dentofacial Orthop 2015;148:83-9). While we were reading it, several doubts occurred to us, and we would like some explanations, if possible.
Would it not be interesting to have made the sample calculation to establish whether the sample size was sufficient to acquire a reliable result?
We noted the exclusion criteria; however, there was no eligibility criterion delimited for the participants. In view of this, it is a problem that potentially affects the validity of a study. Would it not have been better to elaborate these criteria as well?
What proportion of the patients in each subgroup were men and women? What was the most frequent age? Reduction in pulp chamber height is known to be greater in the female than male patlents, and also in the relationship between aging and secondary dentin deposition; consequently, there is a reduction in the pulp chamber. Would this not influence the result of pulp flow measurement? Knowing the diversity regarding anatomy and sizes of tooth roots and root canals, would it not be interesting to establish standardization with respect to this point?
We take the opportunity of closing these clarification questions to congratulate the authors on the study.
- 1. Wittes J.: Sample size calculations for randomized controlled trials. Epidemiol Rev 2002; 24: pp. 39-53
- 2. Rothwell P.M.: External validity of randomised controlled trials: “to whom do the results of this trial apply?”. Lancet 2005; 365: pp. 82-93
- 3. Jain R., Rai B., and Anand S.: Sexual dimorphism: dentin formation and odontoblast. Internet J Dent Sci 2007; 6: pp. 18
- 4. Star H., Thevissen P., Jacobs R., Fieuws S., Solheim T., and Willems G.: Human dental age estimation by calculation of pulp-tooth volume ratios yielded on clinically acquired cone beam computed tomography images of monoradicular teeth. J Forensic Sci 2011; 56: pp. S77-S82
- 5. Barbizam J.V., Ribeiro R.G., and Tanomaru Filho M.: Unusual anatomy of permanent maxillary molars. J Endod 2004; 30: pp. 668-671
- 6. Sharma R., Maroli K., Sinha N., and Singh B.: An unusual maxillary molar with four roots and four buccal canals confirmed with the aid of spiral computed tomography: a case report. J Int Oral Health 2014; 6: pp. 80-84
- 7. Kottoor J., Velmurugan N., Sudha R., and Hemamalathi S.: Maxillary first molar with seven root canals diagnosed with cone-beam computed tomography scanning: a case report. J Endod 2010; 36: pp. 915-921
- 8. Cleghorn B.M., Christie W.H., and Dong C.C.: Root and root canal morphology of the human permanent maxillary first molar: a literature review. J Endod 2006; 32: pp. 813-821