# Anthropometric vs. Dental Variables of the Ageing Face: A Clinical Study
## 1 Introduction  
Ageing is a dynamic and continuous process that alters the harmony and symmetry of the face, affecting smooth facial contours and thus each individual's physical attractiveness, self-esteem and social interaction [1; 2; 3]. A broad spectrum of changes occurs in facial anatomy with age. Extrinsic factors such as lifestyle or environmental influences and intrinsic factors such as development and innate soft and bony changes may vary; facial skeleton remodelling, fat pad repositioning, volume increase or atrophy, skin weakening and the thinning and loss of muscle tone result in a flabby or drooping appearance known as the \"ageing face\" [3; 4]. The first signs of facial ageing typically appear between 20 and 30 years old. These signs appear earlier in females than males [4; 5; 6; 7]. Specifically, discrepancies in facial and dental anatomy are clinically noted from the age of 25 [5; 6]. The face is divided into the upper, middle, and lower thirds for extra-oral examination. In the upper third of the face, a dominant ageing element is the formation of wrinkles, which is attributed to muscle activation and fat loss [4; 8; 9]. Another substantial alteration is the observed elongation of the upper third that is caused by the upward movement of the hairline [10]. In the middle third, nasal tip ptosis is noted, along with dorsal irregularities and nose lengthening [10], while the maxillary height is reduced, and alveolarbone resorption occurs [11]. In the lower third of the face, the lips may lose their fullness over time, and their contour may lose its shape and distinction from the period skin [12]. In addition, bone alterations in dentate individuals indicate that the mandible changes shape and continues to grow with time [13; 14; 15]. These progressive changes may affect the appearance of the lower face, making it appear older and affecting facial aesthetics. The analysis of facial aesthetics through anthropometric measurements constitutes an integral part of diagnosing and planning extraoral and intraoral interventions. Lately, there has been a growing interest in assessing the thickness of facial soft tissue through different methods. This is because it provides vital data for estimating the facial features of the skull [16; 17]. Moreover, a recent study reported that the thickness of facial soft tissue, which affects facial aesthetics, is influenced by sex. Males tend to have greater soft tissue thickness in the mouth region, while females have greater thickness in the zygomatic and eye regions [18]. However, [PERSON] et al. stated that there is still a need to improve technical recommendations for soft facial tissues, particularly in the provision of better underlying data structures and standardisation [19]. Anthropometric parameters differ among ethnic groups and can be influenced by age, sex, environmental factors and intraoral conditions such as partial or total tooth loss [20]. At present, aesthetic standards have shifted through the immense usage of Botox, hyaluronic acid and other fillers [21; 22]. There is also an increased emphasis on aesthetic standards for older individuals [1]. This has resulted in more people opting for multiple plastic surgeries, injectables or full-arch-implant-supported dental restorations to meet these demands. The analysis of anthropometric parameters is of key importance for scientific fields such as dentistry to achieve the best design of dental restorations in the case of missing teeth or cosmetic surgery and to restore aged facial structures accurately. Scientific data based on anthropometric parameters assessed during an extra-oral examination indicate a correlation with aesthetic outcomes. This information can be useful when planning full-arch dental restorations, extractions of wisdom teeth, intraoral bone regeneration techniques, sinus lift augmentations and reconstructive surgery after trauma or oncological resections to achieve an aesthetically harmonious appearance [23; 24; 25].