Frontal Sinus Development Research Articles

Frontal sinus size in South African Later Stone Age Holocene Khoe-San.

Frontal size variation is comparatively poorly sampled among sub-Saharan African populations. This study assessed frontal sinus size in a sample of Khoe-San skeletal remains from South African Later Stone Age contexts. Volumes were determined from CT scans of 102 adult crania; individual sex could be estimated in 82 cases. Sinus volume is not sexually dimorphic in this sample. The lack of frontal sinus aplasia is concordant with the low incidences recorded for other sub-Saharan African and most other global populations save those that inhabit high latitudes. There is considerable variation in frontal sinus size among global populations, and the Khoe-San possess among the smallest. The Khoe-San have rather diminutive sinuses compared to sub-Saharan Bantu-speaking populations but resemble a northern African (Sudanese) population. Genetic studies indicate the earliest population divergence within Homo sapiens to have been between the Khoe-San and all other living groups, and that this likely occurred in Africa during the span of Marine Isotope Stages 8-6. There is scant information on frontal sinus development among Late Quaternary African fossils that are likely either closely related or attributable to Homo sapiens. Among these, the MIS 3 cranium from Hofmeyr, South Africa, exhibits distinct Khoe-San cranial affinities and despite its large size has a very small frontal sinus. This raises the possibility that the small frontal sinuses of the Holocene South African Khoe-San might be a feature retained from an earlier MIS 3 population.

CT analysis of frontal recess air cell and fluid dynamics simulation of frontal sinus in people with different frontal sinus development after Draf1–3 surgery

ObjectiveTo explore the effects of Draf1–3 on frontal sinus airflow and frontal sinus irrigation in people with different frontal sinus developmentMethodsThe development of the frontal sinus and the distribution of the frontal recess cells were evaluated by CT scan in 150 adults (300 sides). The airflow changes into the frontal sinus and frontal recess after Draf were analyzed by Fluent software under a steady state and quiet inspiratory state. Nasal irrigation after Draf in adults with well-developed frontal sinus was simulated using 120 mL saline at a rate of 12 mL/s in a position at 45° to observe the changes in transient flow distribution.ResultsThe moderately developed type of the frontal sinus was the most common. The airflow patterns in the frontal sinus and frontal recess in the moderate development group were laminar, while several large vortexes were formed between the frontal sinus and frontal recess in the well-development group. The Draf exerted more significant effects on the patterns, pressure, and velocity of the airflow in the frontal sinus and frontal recess in the well development group than in the moderate development group. The volume fraction of saline in the frontal sinus increased significantly from Draf1 to Draf3, and the time required for a complete infiltration of saline in the frontal sinus mucosa was significantly reduced.ConclusionsDraf1–3 has different effects on the airflow field of the frontal sinus with different developmental types; and Draf1–3 can significantly improve the postoperative flushing of the frontal sinus.

Common Drainage Pathway From Bilateral Frontal Sinuses: Lessons From 2 Cases

Primary pneumatization of the frontal bone occurs in the first year of life, but further pneumatization continues until 18 years of age. Elongation of the ethmoidal infundibulum and frontal recess, or upwards migration of the anterior ethmoidal cells has been proposed as a mechanism of frontal sinus development. The frontal sinus drainage pathway is displaced in the anterior or posterior direction depending on the pneumatization pattern of the frontoethmoidal cells. Also, frontal sinuses can be connected to the infundibulum or directly to the middle meatus depending on the superior attachment pattern of the uncinate process. Bilateral frontal sinuses are separated by their bony septum, and thus have their own drainage pathways. Contrary to this general rule, we experienced two cases of frontal sinuses that were connected to each other, showing a single drainage pathway from both frontal sinuses. We report these two cases along with a literature review.

First digital study of the frontal sinus of stem-Canini (Canidae, Carnivora): evolutionary and ecological insights throughout advanced diagnostic in paleobiology

IntroductionThe phylogenetic and ecological importance of paranasal sinuses in carnivorans was highlighted by several previous authors, mostly in extant species. Nevertheless, no specific study on this feature on extant canids, and no one on fossil representatives of the family, has been published up to now. Here, we analyze for the first time the paranasal sinus of extant and fossil canids through computed tomographic techniques to characterize them morphologically and morphometrically, making ecological inferences.MethodsTo do so, we applied for the first time an innovative deformation-based morphometric approach.ResultsThe results obtained for extant species highlight a remarkable correlation between morphology and ecomorphotypes previously defined by some scholars (namely hypercarnivorous group-hunters; small-prey hypercarnivores, mesocarnivores, hypocarnivores). Our results thus support the direct relationship between diet preferences and the development of frontal sinus in canids. Regarding fossil specimens, we reconstructed for the first time the frontal sinus of three Eucyon species and compared it to those of living forms.DiscussionThe best-preserved specimen, the only known cranium of Eucyon adoxus dated to the Late Pliocene of Saint-Estève (France), displayed similarities with hypercarnivorous group-hunter canids by the large sinus prominences. Given that the overall craniodental morphology of E. adoxus suggests that it acted as a small prey hypercarnivore—similar to extant Canis simensis—the aforementioned affinities might have evolved independently, in relation to high stresses during feeding. Overall, our study demonstrates that morphological inspection and deformation-based geometric morphometrics complement each other and allow a thorough investigation of sinus shape variability, thus enabling the study of sinus morphology in other fossil carnivorans with the ultimate goal of inferring their ecological preferences.

Incidental Paranasal Sinus Findings on Computed Tomography Images of Pediatric Patients: A Cross-sectional Prevalence Study.

The study was conducted to assess the prevalence of incidental paranasal sinus pathologies in children on computed tomography (CT) scans. A nonrandomized retrospective study was done on CT scans of 232 pediatric patients taken in the past 6 months duration. These scans were evaluated in different age groups from 0-13 years who had visited or were admitted to the hospital for various other head and neck-related problems. Each scan was examined for incidental pathologic findings in all the paranasal sinuses. The data were analyzed using descriptive statistics and Fisher's exact test to determine non-random associations between variables. A total of 232 subjects were examined, amongst which 72 (31.03%) had incidental sinus pathologies. Multiple sinus pathologies were found in 36 subjects, 28 had single sinus involvement, and four showed no development of frontal sinus at the age of 11 years. Four subjects had pathology in multiple sinuses as well as no development of frontal sinus at the age of 6-7 years age range. Sinus pathologies are not unusual in the asymptomatic children population, and the incidence is almost equivalent to that of the adult population. Early identification can aid in diagnosing orofacial pain of unknown origin and also if children are susceptible to upper respiratory tract infections and their secondary effects like sleep apnea, mouth breathers, etc. Talwade P, Deshpande PS, Pene S, et al. Incidental Paranasal Sinus Findings on Computed Tomography Images of Pediatric Patients: A Cross-sectional Prevalence Study. Int J Clin Pediatr Dent 2023;16(2):292-294.

Orthodontic Treatment Does Not Affect Frontal Sinus Development in Female Adults: A Clinical Study.

Frontal sinus growth is gradual and lasts until post-puberty. However, the influence of biomechanical stimuli, such as orthodontic treatment, on frontal sinus development after the growth period has ended remains unclear. This study was designed to elucidate the impact of orthodontic treatment on the frontal sinus morphology of adult females. Sixty women were included and divided into three groups, based on the Frankfort mandibular plane angle. All participants underwent computed tomography and lateral cephalometry before and after treatment. Although two participants exhibited frontal sinus agenesis, most exhibited a bilaterally symmetric frontal sinus without fusion. The frontal sinus width and height were almost similar, irrespective of the vertical skeletal pattern, where the frontal sinus depth was significantly larger in the average mandibular plane angle group than in the low- and high-angle groups. Furthermore, the sinus volume in the low-angle group was likely smaller than that in the average and high-angle groups. On comparing pre-treatment and post-treatment measurements, minimal or no changes to the frontal sinus dimension were detected after treatment. In conclusion, orthodontic treatment did not affect frontal sinus development after the end of growth.

3D CT stereoscopic imaging: observations of the frontal and anterior ethmoid sinuses development from birth to early adulthood

Objective: Our objective is to provide observations demonstrated with 3Dimensional Computed x-ray Stereoscopic Imaging (3DCTSI) in the evaluation of the anterior ethmoid and frontal sinus development from birth to age 18. Methods: This is a retrospective evaluation of patient’s CT studies performed over a fifteen-year period, reported as normal studies, and included 53 patients (142 sides) from birth to age 18. Results: At birth, there are two spaces covered by folds, the uncinate and bulla lamellae. The spaces communicate with the Middle Meatus (MM) through the emerging ethmoid infundibulum (EI) and the retrobulbar recess space (RBRS). In the first month after birth, an expansile and breakdown developmental phase blend and continue throughout the growth into the teenage years. The 3D images reveal dark lamellar structures, on the surface of the medial lamina papyracea as well as bridging the broken spatial outlines. The dark lamellae represent the mucosal lamina propria, in unossified lamellae and are the origin of permanent spatial walls. From ages 4 to 18 years, initially, the frontal recess (FR) and later the MM penetrate into the cancellous frontal bone creating the frontal Sinus (FS), the frontal septum (FS), Inter-Frontal Sinus Septal Cell (IFSSC), as well as the Fronto-Ethmoidal and Frontal Bulla Spaces. Conclusion: 3DCTSI is the first intuitive imaging modality to reveal the microanatomical development of the anterior ethmoid and frontal sinus anatomy.

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

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.

Radiographic assessment of the influence of metopism in frontal sinus morphology – a systematic review

Objective: This systematic literature reviews aimed to revisit radiographic observational studies the find out the potential influence of metopism in frontal sinus (FS) development. Methodology: Medline, Scopus, SciELO, LILACS and Web of Science databases were searched. Only cross-sectional and case-control original studies were eligible. Two reviewers independently participated in each phase of this review. General, methodological and outcome-related information of each study were extracted. Risk of bias was assessed with the Joanna Briggs Institute (JBI) Critical Appraisal tool for observational studies. Based on the limitations of each study, recommendations were made following EQUATOR/STROBE guidelines. Results: Depicted in an adapted PRISMA flowchart, three-hundred and sixty-five studies were identified and seven (published between 1959-2019) remained for qualitative analysis. Without considering studies with overlapping samples, five-hundred and nine skulls with metopism were detected. FS aplasia reached a prevalence of nearly 13%. Four studies (three with overlapping samples) observed a tendency of FS underdevelopment in skulls with metopism, while three studies suggested the opposite. Higher risk of bias was found in the latter. Conclusion: The available and most recent scientific literature points toward an eventual influence of metopism in FS underdevelopment. Due to the study of overlapping samples and the lack of standardized reporting protocols of methods and outcomes, however, the evidence extracted in the present systematic literature review does not confirm the association of FS underdevelopment and metopism.

Morphometric Analysis of Frontal Sinus Dimensions Using Digital Radiographs

The present study was aimed to evaluate the importance of combined use of frontal sinus dimensions and evaluating possible implications.The study was retrospective and intended to measure dimensions on 60 digital radiographs (PA Caldwell's View)of age group 20 to 50 years. The Institutional Ethical Committee approved the research protocol. Inclusion Criteria was taken as radiographs with good image quality and absence of any artefact. Radiographs of individuals with bilateral complete frontal sinus development were included while radiographs are exhibiting pathology like, e.g. mucous retention within the frontal sinus, aplasia(unilateral and bilateral) or rudimentary frontal sinus excluded from the study. Parameters measured were maximum height, width on both sides and symmetry of frontal sinus.Out of 60 radiographs five were excluded from the study (2 frontal sinus aplasia and 3 unilateral frontal sinuses). The final study involved 55 radiographs(N=55) which constituted 28 males and 27 females. The mean values of maximum height and width were obtained. Symmetry was calculated using width. There were significant differences in average width and height of frontal sinus of males and females.The results of the study favour the radiographic evaluation and frontal sinus dimensions for identification in forensics and also it is useful for the management of sinus-related ailments.

The Effect of Fronto-Orbital Advancement on Frontal Sinus Development and Function in Non-Syndromic and Syndromic Craniosynostosis.

The impact of fronto-orbital advancement (FOA) on frontal sinus development and function is anecdotally variable. The aim of this study was to assess the impact of FOA on development of frontal sinuses, and additionally to identify the complications that might arise out of such procedures. This was a retrospective case-control study. Non-syndromic and syndromic craniosynostosis patients (n = 58) who underwent FOA at an early age and also had a skull radiograph or CT scan after the age of 12 were selected. Age matched trauma patients with CT scans done beyond 12 years of age were used as controls. Age at first FOA surgery, total number of procedures and age at imaging was noted. Presence or absence of frontal sinuses was assessed using imaging studies initially. Patients with a formed frontal sinus and a CT scan were further chosen for volumetric studies. Complications related to frontal sinus and secondary surgeries were recorded. One of 27 non-syndromic patients had absent frontal sinuses. Seven of 31 syndromic patients had absent sinuses. Among 20 controls, only 1 patient did not develop frontal sinuses. The mean age at first FOA was 11.81 months and 18.25 months for non-syndromic and syndromic groups, respectively. The average number of procedures before 12 years of age was 1.25 and 1.51 for non-syndromic and syndromic patients, respectively. The mean age at imaging was 17.74, 20.96, and 20.25 years for non-syndromic, syndromic and control groups, respectively. The mean frontal sinus volumes were 13050.36, 15039.02, and 8459.48 mm for non-syndromic, syndromic and control groups, respectively. In conclusion, FOA does not seem to have an impact on rate of pneumatization in the background of similar rates in the non-syndromic and control groups. The low pneumatization rate in syndromic group might be a virtue of the disease itself. There were significant frontal sinus complications that occurred after fronto orbital advancement and this should be borne in mind during the surgical consenting process.

Frontal sinus development with preserved metopic suture

Frontal sinus development with preserved metopic suture

Digital radiomorphometric analysis of the frontal sinus and assessment of the relation between persistent metopic suture and frontal sinus development.

This study aimed to establish the frequency of the frontal sinus (FS) aplasia, to compare metopic and nonmetopic series and thus to assess the relationship between the preservation of metopic suture and FS development. FSs were investigated in 230 dry skulls of adult males distributed into control (137) and metopic (93) series. They were visualized through industrial digital radiography. In the control series, the FS aplasia was observed in 12.41% of the skulls, and it was mostly unilateral (8.76%) than bilateral (3.65%). The left-sided aplasia (5.11%) slightly prevailed over the right-sided one (3.65%). In the metopic series, the aplasia was observed with a frequency of 19.35%, and the bilateral aplasia (7.53%) was rarer that the unilateral one (11.83%), while the right-sided aplasia was clearly predominant (9.68%) compared to the left-sided one (2.15%). The significant differences between both series showed a tendency for the persistence of metopic suture to be frequently related with FS underdevelopment in the vertical plate of the frontal bone, but in cases of pneumatization, it was preferentially on the left side. Taking into account that the cranial hypertension leads to suture diastasis and hinders development of the FS, it could be suggested that persistence of the metopic suture along with underdevelopment of the FS in nonsyndromic adults could be an expression of an elevated intracranial pressure during early development as an after-effect of certain condition.

How Do Le Fort–Type Fractures Present in a Pediatric Cohort?

Le Fort-type fractures are very rare in children, and there is a paucity of literature presenting their frequency and characteristics. The purpose of this study was to determine the etiology, frequency, and fracture patterns of children with severe facial trauma associated with pterygoid plate fractures in a pediatric cohort. We performed a retrospective cohort study of all children aged younger than 16years with pterygoid plate and facial fractures who presented to our institute between 1990 and 2010. Patient charts and radiologic records were reviewed for demographic and fracture characteristics. Patients were categorized into 2 groups as per facial fracture pattern: non-Le Fort-type fractures (groupA) and Le Fort-type fractures (group B). Other variables including dentition age, frontal sinus development, mechanism of injury, injury severity, and concomitant injuries were recorded. Univariate methods were used to compare groups. We identified 24 children; 25% were girls, and 20.8% were of nonwhite race.Most presented with Le Fort-type fracture patterns (group B, 66.7%). Age was significantly different between group A and group B (mean, 5.9years and 9.9years, respectively; P=.009).No significant differences in Injury Severity Score, rate of operative repair, and length of stay were found between groups. Most children with severe facial fractures and pterygoid plate fractures presented with Le Fort-type fracture patterns in our cohort. The mean age of children with Le Fort-type fractures was greater than in those with non-Le Fort-type patterns. However, Le Fort-type fractures did occur in younger children with deciduous and mixed dentition.

Frontal Sinus Volume and Frontal Bar Position Are Associated in Unicoronal Craniosynostosis.

Frontal sinus pneumatization plays an important role in brow protrusion, and absence of frontal sinus development may be associated with brow retrusion. Using unicoronal craniosynostosis as a model, the authors studied the relationship among frontal sinus volume, supraorbital retrusion, and brow position. The authors conducted a retrospective review of unicoronal craniosynostosis patients with head computed tomographic scans and photographs taken from ages 5 to 18 years. Frontal sinus volume and supraorbital retrusion were calculated using three-dimensional computed tomographic reconstructions. A "brow score" from 0 to 3 was assigned to each patient's photographs by a consensus of two craniofacial surgeons; sinus morphology and brow scores were compared. The study included 20 unicoronal craniosynostosis patients. The affected side demonstrated increased retrusion (7.1 ± 3.7 mm versus 3.0 ± 3.1 mm; p < 0.001) and decreased frontal sinus volume (0.8 ± 0.9 cc versus 2.6 ± 1.8 cc; p < 0.001). Qualitative brow retrusion scores differed between affected and unaffected sides (score of 0, 17 percent affected versus 78 percent unaffected; score of 1, 28 percent versus 22 percent; score of 2, 39 percent versus 0 percent; and score of 3, 17 percent versus 0 percent; p < 0.001). Brow scores trended with retrusion measurements (score of 0, 2.7 ± 2.9 mm retrusion; score of 1, 6.1 ± 3.5 mm; score of 2, 8.9 ± 3.2 mm; and score of 3, 9.7 ± 2.8 mm; p < 0.001). Subjects with brow scores of 0 or 1 had larger frontal sinus volumes than subjects with brow scores of 2 or 3 (p = 0.018). Qualitative brow retrusion correlates strongly with both quantitative supraorbital retrusion and frontal sinus volume. Although this retrospective study cannot prove causality, which is likely multifactorial, its strong correlation with frontal sinus pneumatization highlights the importance of the frontal sinus in brow position in unicoronal craniosynostosis. Therapeutic, III.

Impact of Fronto-Orbital Advancement on Frontal Sinus Volume, Morphology, and Disease in Nonsyndromic Craniosynostosis.

Fronto-orbital advancement for nonsyndromic craniosynostosis has been thought to injure frontal sinus buds, lead to chronic sinus disease, and influence final forehead shape. This study investigates the effect of fronto-orbital advancement in infancy on subsequent frontal sinus volume, morphology, and disease. The authors conducted a retrospective review of nonsyndromic craniosynostosis patients treated with fronto-orbital advancement in infancy with a head computed tomographic scan obtained at age 7 to 18 years. Facial trauma patients served as age-matched controls. Frontal sinus characteristics were determined using three-dimensional reconstructions. The study included 33 nonsyndromic craniosynostosis patients who underwent fronto-orbital advancement (n = 20 unicoronal; n = 13 metopic) and 20 control patients. The incidence of at least unilateral pneumatization was 94 percent for fronto-orbital advancement subjects and 95 percent for control subjects. Mean frontal sinus volumes for unicoronal synostosis, metopic synostosis, and control groups were 3427 ± 2294, 4576 ± 3510, and 4157 ± 3963 mm, respectively (p = 0.598). Asymmetry scores were as follows: unicoronal synostosis, 56 ± 35 percent; metopic synostosis, 36 ± 33 percent; and control, 23 ± 24 percent (p = 0.010). Unicoronal subjects displayed prominent asymmetry, with increased pneumatization on the unaffected side. Frontal sinus volume correlated with age at computed tomography but not with age at fronto-orbital advancement. Interrater reliability was 0.997. One fronto-orbital advancement subject and zero control subjects demonstrated computed tomographic evidence of frontal sinus disease. Frontal sinus volume, morphology, and disease do not differ significantly between control subjects and nonsyndromic craniosynostosis subjects following fronto-orbital advancement, but subtle differences such as increased asymmetry in the unicoronal synostosis group can be appreciated. Further research with syndromic craniosynostosis patients undergoing multiple procedures may help elucidate the association between surgical disruption and frontal sinus development. Therapeutic, III.

A roentgen-anatomic study of association between persistant inter-frontal Suture with varied presence of frontal sinus

Introduction: The suture that persist between frontal bones beyond 8 years of life is termed as “Metopism”. This metopic suture has been shown to exhibit ethnic variability in its incidence with an Asian incidence of up to 5.5%. Previous studies had morphologically classified metopism into complete and incomplete types. The presence of this inter-frontal suture is claimed to alter the development of frontal sinus from asymmetry to complete absence. Methodology: Occurrence of metopic suture among180 adult skulls was studied. The observed suture was further classified morphologically into complete and incomplete types. The skulls with either of the types were further studied radiologically for the presence and symmetry of the frontal sinus. Result: Complete and incomplete metopism was observed in 3.88% and 46.66% of the skulls studied respectively. On radiological examination, absence of frontal sinus was seen more with complete metopism while asymmetry of frontal sinus was noted mainly with incomplete type. Conclusion: The presence of inter-frontal suture in adults with its associated variation in the development of frontal sinuses is of interest for anatomist and significant for radiologist, neurosurgeon and forensic pathologist while examining, operating and reporting of frontal fractures. Keywords: Metopism, Frontal sinus, Inter frontal suture, Metopic suture

The Effect of Nasal Septal Deviation on Frontal and Maxillary Sinus Volumes and Development of Sinusitis.

The purpose of this study was to determine the possible role of nasal septal deviation on volume of maxillary and frontal sinuses. Between February 2011 and October 2013, paranasal sinus computed tomography (CT) findings of 732 patients (410 males, 322 females) who were admitted to Ear Nose and Throat Department of Kayseri Research and Training Hospital were retrospectively analyzed. By excluding the other coexistent sinonasal pathologies, 83 consecutive patients with nasal septal deviations were included in the study. The volume of each maxillary and frontal sinus (ipsi- and contralateral to the deviation side) was also calculated using the computer program. There was no statistically significant difference between ipsilateral and contralateral maxillary sinus volumes in group 1 and group 3 (P > 0.05). There was a statistically significant difference between ipsilateral and contralateral maxillary sinus volumes in group 2 (P < 0.05). There was no statistically significant difference between ipsilateral and contralateral frontal sinus volumes in group 1, group 2, and group 3 (P > 0.05). Moderate septal deviation significantly affects the volume of maxillary sinus. Mild and severe septal deviation does not significantly affect the volume of maxillary sinus. Effect of septal deviation on frontal sinus volume was not detected. The probability to encounter maxillary and frontal sinusitis ipsilateral to the all septum deviation groups was significantly increased in both right- and left-sided subjects.

Association between frontal sinus development and persistent metopic suture

Frontal sinuses are 2 irregular cavities, placed between 2 lamina of frontal bone. Expansion continues during childhood and reaches full size after puberty. Persistent metopic suture is one of the factors that are related to abnormal frontal sinus development. In this study, we want to discuss about the coexistence of persistent metopic suture and abnormal frontal sinus development using radiological techniques. In this retrospectively planned study, images of 631 patients were examined, 217 (34.4%) of them were men and 414 (65.6%) of them were women. Brain computed tomography and magnetic resonance images were retrieved from the electronic archive for analysis. In this study, frontal sinus development is categorised as right side atrophy, left side atrophy, bilateral atrophy and bilaterally developed sinuses. The presence of metopic suture was accepted as persistent metopic suture. Frontal sinus atrophy was found in 22.7% and persistent metopic sutures were found in 9.7% of overall. In this study, no significant results were detected that were relatedto the frontal sinus agenesis or dismorphism associated with persistent metopicsuture. We conclude that, although publications propounding metopism thatleads to abnormal frontal sinus development are present in the literature, noreasonable explanation has been mentioned in these articles; and we believe thatthese findings are all incidental.

Study on the development of frontal sinuses by morphometric analysis of the skull

The frontal sinuses are cranial areas of clinical, forensic and pathology importance whose development mechanisms are still poorly defined. Nasal airflow and brain development are two of the main theories. Current analysis debates whether they are the real determinants of frontal sinuses growth, which may be proved by the skull's morphometric analysis. Four groups of measures related to the external cranial architecture, the pyriform aperture, orbital cavities and frontal sinuses were defined. Thirty-three skulls of individuals, mean age 68 years, from the Laboratory of Anatomy of the Academic Centre of Victoria - UFPE - Brazil, were used. Statistical analysis showed total agenesis of the frontal sinus in 18.2% of the skulls. There was significant correlation between the development of the right frontal sinus and the pyriform aperture, and between the left frontal sinus and two cranial measurements (p ≤ 0.05). Significant differences between mean of pyriform aperture areas of the skulls with or without sinuses were also reported (p ≤ 0.01). Results supported the fact that there was a modulation activity by nasal aeration and brain formation in the development of frontal sinuses.