Age and Gender Differences of the Frontal Bone: A Computed Tomographic (CT)-Based Study.

BACKGROUND: Age-related changes of the frontal bone in both males and females have received limited attention, although understanding these changes is crucial to developing the best surgical and nonsurgical treatment plans for this area. OBJECTIVES: To investigate age-related and gender-related changes of the forehead. METHODS: Cranial computed tomographic images from 157 Caucasian individuals were investigated (10 males and 10 females from each of the following decades: 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years, and of 8 males and 9 females aged 90-98 years). Frontal bone thickness and forehead distance measurements were carried out to analyze age and gender differences. RESULTS: With increasing age, the size of a male forehead reduces until no significant differences to a female forehead is present at old age (P = 0.307). The thickness of the frontal bone of the lower forehead (≤4 cm cranial to the nasal root) increased slightly in both genders with increasing age. In the upper forehead (≥4 cm cranial to the nasal root), frontal bone thickness decreased significantly (P = 0.002) in males but showed no statistically significant change in thickness in females (P = 0.165). CONCLUSIONS: The shape of the frontal bone varies in young individuals of different genders and undergoes complex changes with age because of bone remodeling. Understanding these bony changes, in addition to those in the soft tissues, helps physicians choose the best surgical and nonsurgical treatment options for the forehead.

The Relationship between Bone Remodeling and the Clockwise Rotation of the Facial Skeleton: A Computed Tomographic Imaging-Based Evaluation.

BACKGROUND: Information on the onset and gender differences of midfacial skeletal changes, including the complete understanding of the theory behind the clockwise rotational theory, remains elusive. METHODS: One hundred fifty-seven Caucasian individuals (10 men and 10 women aged 20 to 29 years, 30 to 39 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, 70 to 79 years, and 80 to 89 years, and eight men and nine women aged 90 to 98 years) were investigated. Multiplanar computed tomographic scans with standardized angle and distance measurements in all three anatomical axes and in alignment to the sella-nasion (horizontal) line were conducted. RESULTS: Both men and women displayed an increase in orbital floor angle (p < 0.001, maximum at 60 to 69 years), decrease in maxillary angle (p = 0.035, 40 to 49 years), increase in palate angle (p < 0.001, 50 to 59 years), increase in vomer angle (p = 0.022, 30 to 39 years), but a decrease in the pterygoid angle (p = 0.002, 80 to 89 years). Orbital width decreased (p < 0.001, 60 to 69 years), pyriform aperture width increased (p = 0.015, 60 to 69 years), and midfacial height decreased with aging (p < 0.001, 60 to 69 years). CONCLUSIONS: Age-related changes of the midfacial skeleton occurred independently of gender, but at various time points in different locations. The observed changes seem to be driven by a bone resorption center located in the posterior maxilla, rather than by a rotational movement of the facial skeleton.

Calvarial Volume Loss and Facial Aging: A Computed Tomographic (CT)-Based Study.

BACKGROUND: Our understanding of the aging changes involving the cranium and its impact on the overlying soft tissues is limited. OBJECTIVES: This study was designed to look at the changes that occur in the cranium with aging and to propose an additional mechanism for loss of support for overlying soft tissues. METHODS: One hundred and fifty-seven white individuals (10 males and 10 females in each decade: 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years, and 8 males and 9 females aged 90-98 years) were investigated. Computed tomographic (CT) multiplanar scans with standardized measurements of cranial thickness were performed for the frontal bone, nasion, vertex, pterion, lambda, calvarial and midfacial height, and sagittal and transverse diameter. RESULTS: Increasing age correlated with a decrease in sagittal diameter in both males (rp = -0.201) and females (rp = -0.055) but with an increase in transverse diameter in both males (rp = 0.233) and females (rp = 0.207). Frontal bone thickness decreased in males -1.57mm/-18.14%, whereas it increased slightly in females +0.26mm/+3.04%. At the pterion, bone thickness increased significantly in both genders. Calvarial volume decreased with increased age in both males and females: -70.2 ml/-5.35% and -61.4 ml/-5.10%, respectively. CONCLUSIONS: The lateral expansion of the skull may favor a skeletonized appearance of the face in elderly individuals. The computed volume of the calvaria decreased with advancing age in both genders, providing an additional element in the multifactorial model for facial soft-tissue laxity.