The Relation Between the Metopic Suture Persistence and Frontal Sinus Volume and Olfactory Fossa Depth: A Reliability Study with Semiautomatic Volume Measurement

Abstract

Objective: This study aims to investigate the relationship of the persistence of metopic suture (PMS), frontal sinus volume (FSV), and olfactory fossa depth (OFD). Methods: Tomography scans of 1,603 patients aged 18-65 years were evaluated for the presence of PMS. In the study, 74 PMS cases and 74 controls were included. The appearance of each individual’s frontal sinus was classified as aplasia, hypoplasia, or normal. Two observers independently measured the lateral lamella length (LLL), OFD, and FSV. Interobserver agreement was evaluated with the intraclass correlation coefficient (ICC) and Cohen’s kappa coefficient (κ). Results: The prevalence of PMS was found to be 4.99% [95% confidence interval (CI): 4.03-6.17]. The PMS group had five times higher hypoplasia/aplasia than the controls (52.70%, 95% CI: 41.48-63.66 and 10.81%, 95% CI: 5.58-19.91, respectively; p<0.001). An “almost perfect” agreement was detected among observers for the frontal sinus appearance classification: κ=0.807, p<0.001. The ICC of continuous measurements for OFD, LLL, and FSV, respectively, presented “excellent” reliability: 0.956, 0.958, and 0.981, with p<0.001 for each. LLL was shorter, OFD was shallower, and FSV was smaller in the PMS group than the control group (p<0.001). There was a moderate positive correlation between OFD, LLL, and FSV (r=0.306, r=0.302). Conclusions: This study interprets that the presence of PMS is related frontal sinus development and volume. With PMS, a smaller FS, shorter lateral lamella, and shallower olfactory fossa may be expected.

Metopism in adult South Africans and its relationship to frontal sinus size

“…This observation is consistent with those studies that have argued that complete metopism can affect the presence and/or size of the frontal sinus. As noted above, Guerram et al (2014), Nikolova and Toneva (2019), and Atalay and Eser (2021) recorded small sinuses to be more frequently encountered in individuals with metopism. Kumar et al (2016) reported a relationship between metopism and sinus aplasia, although none of the aplastic crania in the South African sample exhibited metopism.…”

“…At the same time, however, a number of studies have argued that full, or complete metopism can affect the presence and/or size of the frontal sinus (e.g., Rochlin & Rubaschewa, 1934; Torgersen, 1950). Thus, Guerram et al (2014) recorded small frontal sinus size to be more frequently encountered in individuals with metopism, Nikolova and Toneva (2019) described a significant relationship between the presence of a small sinus together with metopism, Atalay and Eser (2021) found metopic individuals to exhibit a 5× higher incidence of sinus hypoplasia, and Kumar et al (2016) reported a relationship between metopism and sinus aplasia. On the other hand, an almost equal number of studies have observed there to be no relationship whatsoever between metopism and frontal sinus size and/or aplasia (e.g., Bilgin et al, 2013; Hunt & Everest, 2001; Marciniak & Nizankowski, 1959; Pondé et al, 2008; Sandre et al, 2017).…”

“…For example, those that posit a relationship between metopism and sinus size include the use of dried crania and a visual assessment of metopism (e.g., Guerram et al, 2014; Kumar et al, 2016; Nikolova & Toneva, 2019) with frontal sinus size gauged by either flat plane radiographs (Guerram et al, 2014) or CT scanning (Kumar et al, 2016; Nikolova & Toneva, 2019). This group of studies includes those that employed living patients with the assessment of both metopism and sinus size by radiographic means—either through flat plane X‐rays (Rochlin & Rubaschewa, 1934; Torgersen, 1950) or via CT scanning (Atalay & Eser, 2021). Similarly, studies that found no relationship between metopism and frontal sinus size include ones that employed dried crania and a visual assessment of metopism (Hunt & Everest, 2001; Pondé et al, 2008; Sandre et al, 2017) with frontal sinus size assessed either by flat plane radiographs (Sandre et al, 2017) or from CT scans (Hunt & Everest, 2001).…”