SA2 - A Novel Analysis of Randomized Controlled Trials in Oral and Maxillofacial Surgical Procedures: Comparing the Fragility Indices Between BSSO and IVRO

Oral Abstract Presenter(s)

• 

  Michael Baron, DMD, MD

  Oral and Maxillofacial Surgery Resident
  Icahn School of Medicine at Mount Sinai
  New York, New York

  Handouts

Co-Author(s)

• SS

  Shiven Sharma, JD

  Medical Student
  Icahn School of Medicine at Mount Sinai
  New York, New York
• RG

  Rahul Guda, AB

  Medical Student
  Icahn School of Medicine at Mount Sinai
  New York, New York
• GC

  Gregory Cooke, DDS, MD

  Resident
  Mount Sinai Health System
  New York, New York
• 

  Michael D. Turner, DDS, MD, MSc

  Chief of Oral and Maxillofacial Surgery
  Mount Sinai Hospital
  New York, New York

Abstract:

Purpose: This study introduces fragility analysis as a methodological tool for evaluating the statistical robustness of RCT outcomes in oral and maxillofacial surgery. Using the comparison between bilateral sagittal split osteotomies (BSSO) and intraoral vertical ramus osteotomies (IVRO) solely as an illustrative example, we demonstrate how fragility metrics – namely the Fragility Index (FI), reverse Fragility Index (rFI), and Fragility Quotient (FQ) – provide deeper insight into the stability of reported findings without drawing clinical conclusions.¹
Materials and

Methods: A systematic review was conducted following PRISMA guidelines. Of 85 identified RCTs published between January 1, 1998, and April 1, 2024, 58 studies were screened in full text, and 10 studies met the inclusion criteria for fragility analysis. Dichotomous outcomes were extracted and analyzed using a two-tailed Fisher’s exact test (P < .05 threshold). The FI quantifies the minimum number of event reversals required to change significance, while the rFI does so for non-significant outcomes; the FQ normalizes these indices by the sample size.² Figure 1 demonstrates the statistical significance reversal using a 2 × 2 contingency table.
Results
Across 21 outcomes, the overall mean FI was 5.75 (SD = 3.09), indicating that on average, six event reversals could alter statistical significance. The median FQ was 0.060 (SD = .048), meaning that an event reversal in approximately 6% of patients would shift outcome significance. Among the statistically significant outcomes, the median FI was 7.00 (SD = 3.16) with a mean FQ of 0.086 (SD = .078); non-significant outcomes had a mean FI of 5.33 (SD = 3.09) and an FQ of 0.051 (SD = .035). Detailed study characteristics and fragility data are provided in Table 1 and Table 2, respectively.

Conclusions: Fragility analysis offers a valuable complement to traditional statistical measures by revealing the sensitivity of RCT outcomes to minor data changes. The BSSO versus IVRO example serves purely as a methodological demonstration, with no clinical recommendations drawn. Incorporating fragility metrics alongside conventional P values may enhance the appraisal of evidence quality in oral and maxillofacial surgery research.

1. Tignanelli CJ, Napolitano LM. The Fragility Index in Randomized Clinical Trials as a Means of Optimizing Patient Care. JAMA Surg. 2019;154(1):74–79.
2. Ahmed W, Fowler RA, McCredie VA. Does Sample Size Matter When Interpreting the Fragility Index? Crit Care Med. 2016;44(11):e1142–e1143.
Figure 1 Table 1 Table 2