# Is There Variation in the Morphology of the Frontal Sinus in Individuals with Different Craniofacial Patterns? A Systematic Review with Meta-Analysis

## TL;DR

This study reviews whether the shape of the frontal sinus differs among people with different facial structures, finding some patterns but noting low-quality evidence.

## Contribution

The study systematically reviews and meta-analyzes frontal sinus morphology differences across craniofacial skeletal patterns for the first time.

## Key findings

- Skeletal Class II individuals have a significantly smaller frontal sinus width than Class I individuals.
- Skeletal Class III individuals show a larger frontal sinus width and area compared to Class I individuals.
- There is a suggested positive relationship between mandibular and frontal sinus size.

## Abstract

To evaluate differences in the morphology of the frontal sinus in adolescents and adults with different craniofacial patterns, searches up to April 2024 were conducted in six databases and other information sources to identify observational studies. Study selection, data extraction, and quality assessment using the NOS scale were performed independently by two reviewers. Random effects meta-analyses were conducted to estimate the difference in frontal sinus measurements between different craniofacial skeletal patterns (α = 0.05). The certainty of the evidence was evaluated according to GRADE. Fourteen studies were included in the review. All studies had methodological limitations that affected their quality. The syntheses showed that skeletal Class II subjects presented a significantly smaller width of the frontal sinus than skeletal Class I subjects (MD = 0.56; 95% CI: 0.38, 0.74; p < 0.0001; I2 = 3%). Skeletal Class III subjects showed a frontal sinus width (MD = −0.91; 95% CI: −1.35, −0.47; p < 0.0001; I2 = 36%) and area (MD = −28.13; 95% CI: −49.03, −7.23; p = 0.0084; I2 = 66%) significantly larger than those of the skeletal Class I subjects. The available evidence suggests a positive relationship between mandibular and frontal sinus size. There is limited evidence to make reliable estimates of the association of other craniofacial patterns and frontal sinus characteristics. These reported results are not conclusive and should be evaluated carefully due to the very low certainty of the evidence. The current evidence is scarce and consists of studies with methodological limitations; the results of the studies are often inconsistent, and the pooled estimates are imprecise. New high-quality research is still necessary.