Frontal sinus ontogeny and covariation with bone structures in a modern human population

Abstract

In humans, the frontal sinus (FS) is located in the medial part of the supraorbital region, sometimes expanded throughout the frontal squama. It exhibits high morphological variability, but its general form appears to be constrained by surrounding structures. The goal of this study is to analyze FS growth and test for covariation between FS volume and the glabellar region, upper nasal region, bone thickness and endocranial size in a human sample from Argentina. The sample comprises 149 reconstructions derived from computed tomography images of individuals aged 0–31 years. Volume of the FS and measurements of the surrounding structures were recorded. The FS growth trajectory was assessed by parametric and nonparametric methods, and covariation was determined using correlations and partial correlations. The FS volume could be measured at an age of about 6 years and older; adults had no aplasia but hyperplasia was found in some cases. Since the most conspicuous characteristic found was variation among individuals, the nonparametric smoothing spline produced very poor fitting. The modified logistic function was the only parametric method providing significant parameters. Sexes differed in the age at which FS growth began and ended, with FS developing earlier but at a slower rate in females than in males. The FS volume did not correlate with either upper nasal width or endocranial volume, but it correlated with bone thickness measurements (mainly from the glabellar region), even when age was held constant. Expansion of the FS at the frontal poles also correlated with frontal bone thickness. Despite the difficulty in modeling and predicting the trajectory and morphology of FS, our results suggest that it is affected by its surrounding bony environment.

The Effects of Cranial Orientation on Forensic Frontal Sinus Identification as Assessed by Outline Analyses

“…Thus, this methodological study is able to assess effects of deviations on a broad range of individual sinus morphologies, as appropriate for our question. Although some studies have documented patterns in frontal sinus morphology between population, sex, or age groups or with variables such as body size and craniofacial morphology, these relationships are relatively weak [ 34 , 35 , 36 ], and the underlying factors contributing to such a high degree of frontal sinus variation, whether within or across groups, are unknown. These variations are described as differences in sinus appearance, size, and shape— all variables included in the present study.…”

Ontogenetic patterns in human frontal sinus shape: A longitudinal study using elliptical Fourier analysis

“…First, as with any ontogenetic variable, there is individual variation in the age at which final frontal sinus morphology is attained. In fact, studies already point to inherent noise in frontal sinus ontogenetic data (see Prossinger, 2004; Prossinger & Bookstein, 2003; Sardi et al, 2018). Radiographs were not available at every age for every individual in this study, and toward the older ages (20 yoa and above), sample sizes are greatly reduced—thus, there are some inherent gaps in the data.…”

“…Further, Sardi et al (2018) highlight a complicated ontogenetic relationship between frontal bone morphology and frontal sinus dimensions. Specifically, the cranial and sinus dimensions analyzed in their study showed drastically different ontogenetic trajectories across their sample.…”

“…Although the frontal sinus may appear above the orbits earlier in some individuals, most literature agrees that an observable frontal sinus is generally present on radiographs by 8 yoa. Given that previous studies have suggested the frontal sinus may attain its adult size in the mid‐teens (e.g., Brown et al, 1984; Gagliardi et al, 2004; Sardi et al, 2018), requiring individuals to have at least one radiograph at 18 yoa or older should provide a final, or near‐final, adult morphology for comparison. Radiographs of individuals 30 yoa or older were not included in the study given their small sample sizes in the AAOF Legacy Collection.…”

“…As mentioned above, noted discrepancies in the ontogenetic literature are likely due to a multitude of reasons, including sample composition, imaging modality (e.g., traditional radiographs versus CT scans), imaging orientation, variables of interest, and overall research design. The use of cross‐sectional samples (e.g., Bargouth et al, 2002; Buyuk et al, 2017; Fatu et al, 2006; Mahmood et al, 2016; Moore & Ross, 2017; Park et al, 2010; Patil & Revankar, 2013; Prossinger, 2004; Sardi et al, 2018; Spaeth et al, 1997; Tehranchi et al, 2017; Weiglein et al, 1992; Yun et al, 2011), particularly those with limited sample sizes at each group, may also impact results. Both factors limit the amount of ontogenetic variation captured and can contribute to reported discrepancies.…”