New approaches to human facial morphology using automatic quantification of the relative positions of the orbital and nasal apertures

Morphological and Morphometric Analysis of the Orbital Aperture and Their Correlation With Age and Gender: A Retrospective Digital Radiographic Study

Purpose

Precise knowledge about clinically observed bony orbital aging is needed for surgical planning for acceptable cosmetic results. The effect of age and gender on the facial skeleton and orbital aperture has been appreciated earlier, but its quantification remains ignored. The purpose of this study was to evaluate age- and sex-related changes in the shape of the orbital aperture and construct a reference data set for the aging phenomenon in Indians.

Methods

Two hundred digital radiographs (Water’s/frontal view) of the skull, obtained for various reasons, were evaluated. The radiographs comprised 107 males and 93 females aged between 10 and 60 years (10-59 years). Orbital shape, height/width, and interorbital/biorbital distances were noted, and orbital indices (OIs) were calculated. Orbital parameters thus obtained were compared between right and left sides and males and females. The relation of the parameters with age and gender was analyzed.

Results

Four types of orbits, round (33.5%), elliptical (30.5%), rectangular (27.5%), and square (9.5%), were noted in the study population. The average value of height and width of the right orbit was found to be higher than that of the left (p > 0.05). Male patients had higher (p > 0.05) and wider (p > 0.05) orbits than females. The right OI (81.55 ± 5.30) was higher than the left (80.75 ± 4.80) (p > 0.05). When comparatively evaluated between gender, both orbits were found to be of the microseme type with a mere difference (p > 0.05). The average interorbital/biorbital distance was 1.27 ± 2.11 and 9.78 ± 4.40 cm, respectively, without any gender difference. No significant relation was found between the age change and the parameters defined (p > 0.05), except in one age group (10-19 years).

Conclusions

Orbital dimensions showed no association with age and gender except in one age group (10-19 years); a pubertal growth spurt in females might be causing this phenomenon. The morphometric data may be useful in forensic anthropology and better planning for reconstructive surgeries in the orbito-maxillary region.

Risk of frontal sinus anterior table fractures after craniofacial trauma and the role of anatomic variations in frontal sinus size: A retrospective case-control study

INTRODUCTION

Purpose of this study was to evaluate a probable risk of frontal sinus size for traumatic depressed anterior table fractures in patients with similar forehead trauma.

METHODS

We conducted a retrospective case-control study with a case group of consecutive treated patients with displaced frontal sinus anterior table fractures. The control group was randomly sampled from patients who presented with a blunt forehead trauma in our institution's emergency unit. In computed tomography data sets, all patients' frontal sinus size was categorized by Guerram's classification that is defined as aplasia, hypoplasia, medium-size and hyperplasia. Odds for prevalence of the sinus types as well as sinus total width and height were compared between both groups.

RESULTS

In total, 47 cases and 93 controls were identified. Hyperplasia in the case group had an odds ratio of 46:1 (p < 0.001) compared to the controls. Mean sinus width (73 mm vs. 46 mm; p < 0.001) and sinus height (30 mm vs. 15 mm; p < 0.001) were larger in the case group.

CONCLUSION

Depressed traumatic fractures of the anterior table are an injury with a high risk specific for enlarged frontal sinus sizes. Anatomy is the predictive factor for this mode of craniofacial trauma.

Frontal Sinus Morphology: A Reliable Factor for Classification of Frontal Bone Fractures?

PURPOSE

The frontal sinus shows a wide range of morphologic variations. The aim of this study was to evaluate the influence of frontal sinus size on fracture characteristics in frontal bone trauma.

MATERIALS AND METHODS

In this cross-sectional study, data from patients with traumatic fractures of the frontal bone were retrospectively collected from the institution's database. Radiometric analysis of computed tomography and cone-beam computed tomography datasets was performed. Frontal sinus size was measured as variables of height, width, and depth. The secondary predictor was morphologic sinus type according to Guerram's classification: hyperplasia, medium size, hypoplasia, or aplasia of the frontal sinus. To determine outcomes, we classified fractures into the following categories: fracture isolated to the anterior table, combined fractures of the anterior and posterior tables, fracture isolated to the posterior table, and frontal bone fracture without sinus involvement. Further study variables were patients' demographic characteristics, combined midfacial fractures, orbital rim involvement, fracture displacement, and surgical approach. For statistical analysis, fracture types were assessed for frontal sinus metric size and morphologic type using bivariate tests with P < .05 defined as significant.

RESULTS

We enrolled 53 consecutive patients with a mean age of 35 years; male patients comprised 91%. Fracture types differed significantly in sinus width and height (both P < .001), as well as depth (P = .002). Frontal sinus morphology was hyperplastic in 66%, medium in 30.2%, and hypoplastic in 3.8%. Patients with a hyperplastic frontal sinus had an increased likelihood of isolated anterior table fractures (odds ratio, 6.0; P = .007) compared with medium-sized types. Fractures without sinus involvement were more likely in hypoplastic and medium types (P < .001).

CONCLUSIONS

The morphology of the frontal sinus determines the probability of fracture types from craniofacial trauma. Thus the frontal sinus size appears to be a major factor for frontal bone resistance to traumatic force impingement.

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

OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

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%).

DISCUSSION

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.

Analysis of the human osseous nasal shape--population differences and sexual dimorphism

OBJECTIVES

In this study, the shape of the outer osseous nose in a German and a Chinese sample is analyzed using a dense set of semi-landmarks. Shape differences related to population and sex as well as directional and fluctuating asymmetry were statistically evaluated and also visualized.

MATERIALS AND METHODS

Shape differences in the bony nose were investigated between a large sample of CT scans of German (140 ♀, 127 ♂) and Chinese (135 ♀, 132 ♂) crania. We used semi-automatic methods to represent the shape of this region as a dense point-cloud, consisting of 370 three-dimensional bilateral coordinates. Both the symmetric and asymmetric modes of shape variation were addressed.

RESULTS

Strong differences in nasal shape were found between the two populations, while sex was found to play a minor role in explaining the observed shape variation. The expression of sexual dimorphism was similar in both populations. Differences attributed to population affinity and to sexual dimorphism were both found to affect the shape of the ossa nasalia and the projection of the spina nasalis. The correlation with population/sex was weak for directional asymmetry, but strong for fluctuating asymmetry. The nasal region is more asymmetric in Germans than in Chinese, with males displaying more asymmetry than females in both populations.

DISCUSSION

While the bony nose is well suited for predicting population affinity, regarding the populations under investigation, its value for sexing unknown individuals is rather moderate. The similar expression of sexual dimorphism in those otherwise very dissimilar populations indicates common factors responsible for these differences.

Importance of elliptic Fourier methods for morphometry of complex outlines: application to the distal human femur

The purpose of this technical note is to present an automatic procedure of shape characterisation using new developments in elliptical Fourier methods combined with image analysis techniques. It was applied, as an example, to the outline of the distal extremity of the distal human femur in inferior axial view. This outline was automatically extracted and characterised by an ordered series of harmonics, each harmonic being described by four new parameters called elliptical descriptors. Step by step reconstructions of outlines using an increasing number of harmonics were than performed. The simultaneous study of the elliptic descriptors and of the step by step reconstructions allowed a considerably easier geometric and morphologic interpretation of the harmonic contributions than classically. The main morphologic features of the distal femur (lateral and medial condyles, intercondylar fossa, lateral and medial borders of the articular surface, and patellar groove) were mainly described by the first seven harmonics. These new developments in elliptic Fourier methods open interesting perspectives for the study of complex outlines, providing an accurate individual morphologic characterisation, and thus the possibility of polymorphic analysis.