A dimple is a small, natural indentation or depression in the skin, typically occurring on the cheeks, chin, or lower back of the human body, and often resulting from underlying muscle or structural variations.[1][2] These features are most prominent in the face, where cheek dimples appear as transient hollows during smiling due to an anomaly in the zygomaticus major muscle that creates a localized pull on the overlying skin.[3][4]Facial dimples, the most commonly recognized type, exhibit genetic inheritance patterns that are complex and polygenic, meaning they tend to run in families but do not follow simple dominant-recessive rules, with prevalence estimated at approximately 20-30% in the general population.[3][5][2] They can be unilateral (on one side) or bilateral (on both sides), and their appearance may fade with age as facial muscles and skin change.[5] Chin dimples, or cleft chins, arise from a similar muscular or bony variation in the mentum region.[6] Culturally, cheek dimples have long been prized as markers of attractiveness and fortune; for instance, they symbolize good luck in Chinese traditions and beauty in Arabian societies.[7]Beyond the face, sacral dimples—small pits at the base of the spine, just above the gluteal cleft—are common congenital findings present in up to 5% of newborns and usually benign, though they warrant evaluation if associated with other spinal anomalies like a tuft of hair or discharge.[8]Dimples of Venus, also known as back dimples, are bilateral symmetrical indentations on the lower back of some adults, formed by a short ligament of the posterior superior iliac spine tethering the skin to the underlying pelvis.[9] Cosmetic interest in dimples has led to dimpleplasty, a surgical procedure that artificially creates cheek dimples by suturing the skin to the muscle, with rising popularity in regions emphasizing facial aesthetics.[7]
Definition and Types
Facial Dimples
Facial dimples are small, natural indentations in the skin, most commonly appearing on the cheeks or chin, that become prominent during smiling or other facial expressions. These indentations, also known as fovea buccalis for cheek dimples, create a subtle depression in the soft tissue and are typically visible only under dynamic conditions like grinning.[3][10]Variations in facial dimples include their location, symmetry, depth, and shape. Cheek dimples can occur unilaterally on one side of the face or bilaterally on both cheeks, with studies showing a range from approximately 28% bilateral to over 70% unilateral in certain cohorts. Depth ranges from shallow surface-level dips to more pronounced hollows, while shapes may be round, vertical (longitudinal), or slightly elongated, depending on individual facial structure. Chin dimples, often referred to as cleft chins, present as a midline vertical groove that may be subtle or more defined. Chin dimples, commonly known as cleft chins, manifest as a prominent midline indentation on the chin due to the incomplete fusion of the left and right halves of the mandibular symphysis during embryonic development.[11] This results in a visible furrow or dimple that varies in depth and shape, from subtle lines to deeper clefts, and is influenced by both genetic and environmental factors.[6] The prevalence of cleft chins varies widely across populations, ranging from 4% to 71%, with examples including 9.6% in German men and up to 71% in certain Indian groups.[6]The prevalence of cheek dimples is estimated at around 20-30% in the general population, with an overall rate of 22.7% reported in meta-analyses of bifid zygomaticus major muscle variations associated with their formation. Ethnic variations exist, with higher rates observed in some groups; for instance, studies in Nigerian populations report prevalences of 31.8% to 37.7%, compared to 34% among Americans. Dimples tend to occur more frequently in families, suggesting a genetic component, though inheritance patterns are complex.[4][12][13]Historically, the term "gelasin" has been used to describe the cheek dimple that emerges with laughter, derived from the ancient Greek word gelaein meaning "to laugh," via Latin gelasinus. This nomenclature, referenced in classical texts and later works like Laurent Joubert's 1579 Treatise on Laughter, highlights the association between dimples and joyful expressions. The modern English "dimple" traces back to around 1400, from Old English roots meaning a small pit or hollow.[14][15]
Non-Facial Dimples
Non-facial dimples refer to congenital indentations occurring on various parts of the body outside the face, distinct from the dynamic dimples associated with facial expressions. These dimples arise from variations in underlying bone, muscle, or skin structure during development and are generally static in appearance.Sacral dimples, also called the dimples of Venus when appearing as paired symmetrical indentations, are small depressions located on the lower back just above the buttocks, overlying the posterior superior iliac spines where the pelvis meets the spine.[9] These dimples form due to the anatomical contours of the sacroiliac joint and are often linked to the developmental alignment of the spine and pelvis.[16] They occur in up to 5% of newborns, typically as harmless markers present from birth.[9]Rarer non-facial dimples may appear on other body areas, such as the lower back beyond the sacral region, thighs, or elbows, resulting from localized variations in soft tissue or skeletal structure.[17] Unlike facial dimples, which deepen with muscle contraction during smiling, these body dimples remain constant and unaffected by movement or expression.[17] Such occurrences are infrequently documented and considered minor morphological traits.
Anatomy and Formation
Anatomical Structure
Dimples, particularly those on the cheeks, arise from a structural variation in the zygomaticus major muscle, which is typically a single band running from the zygomatic bone to the corner of the mouth. In individuals with dimples, this muscle often presents as double or bifid, featuring an inferior bundle that inserts directly into the dermis rather than solely into the modiolus at the mouth. During facial expressions such as smiling, contraction of the bifid muscle causes the inferior bundle to pull the overlying skin inward, forming a localized fold or indentation visible as a dimple. This anatomical configuration has been documented in cadaveric dissections, with the bifid variation observed in 34% of hemifaces studied.[18]The formation involves interplay among several tissue layers. The dermis, the deeper layer of skin containing collagen and elastin fibers, serves as the primary attachment site for the inferior muscle bundle's fascial strands. These strands, composed of dense connective tissue, tether the skin to the muscle, leading to shortening and dimpling upon contraction. The subcutaneous fat layer (hypodermis), situated beneath the dermis, is displaced or compressed in the region of adhesion, contributing to the depth and visibility of the indentation without altering the muscle's primary function in elevating the oral commissure. This tethering effect is confined to the cheek's mid-region, typically 2-4 cm lateral to the oral commissure.[19][20]Chin dimples, also known as cleft chins, result from variations in the underlying mandibular structure or mentalis muscle attachments, where a midline deficiency in the chin bone or fibrous bands create a visible groove. Sacral dimples form due to a congenital short ligament or fibrous cord tethering the skin to the underlying sacral spine, often benign and present at birth. In adults, symmetrical sacral dimples are termed dimples of Venus, accentuated by pelvic structure and fat distribution.[6][8]Developmentally, cheek dimples result from an embryonic adhesion between the ectodermal skin layer and the underlying mesodermal structures, such as muscle or occasionally bone, occurring during the formation of facial tissues in the first trimester. This adhesion stems from a localized variation in subcutaneous connective tissue development, where incomplete separation leads to persistent shortening of fibrous bands. Such variations are considered benign anatomical traits rather than defects. Non-facial dimples, like sacral ones, arise from similar mesenchymal dysjunctions during spinal and pelvic development in utero.[17]Imaging studies support these findings, with high-resolution ultrasound and magnetic resonance imaging (MRI) capable of visualizing the zygomaticus major muscle's bifurcation in vivo. Ultrasound elastography, for instance, has been used to assess facial muscle properties, revealing differences in insertion patterns and tissue elasticity in dimpled versus non-dimpled individuals, while MRI provides detailed cross-sectional views of muscle splitting and dermal attachments. These modalities confirm the bifid structure without invasive dissection, aiding in preoperative planning for related procedures.[21][20]
Genetic and Developmental Factors
The inheritance of facial dimples is complex and polygenic, involving multiple genetic variants that influence muscle and skin development, with patterns that tend to run in families but do not strictly follow simple dominant-recessive rules. While often described as having dominant characteristics with incomplete penetrance—meaning not all individuals carrying the relevant variants display dimples—the trait shows variable expression and can skip generations. No single gene has been identified, and research indicates involvement of at least nine genetic variants.[3][22][23][24]Dimples form during early embryonic facial development, arising from differential growth patterns in the facial mesenchyme that affect the positioning and attachment of underlying muscles. This process occurs as part of the broader morphogenesis of the face between the 4th and 8th weeks of gestation, when neural crest-derived mesenchyme contributes to the formation of facial prominences and soft tissues. Variations in this growth lead to the bifid or shortened muscle slips characteristic of dimpled individuals. For non-facial dimples, genetic factors similarly contribute to congenital tethering or structural variations, though less studied.[25][26]From an evolutionary perspective, dimples may serve as an adaptive signal by enhancing the visibility and expressiveness of smiles, thereby facilitating social communication and emotional recognition. Some theories propose connections to neoteny, where dimples evoke youthful, childlike features that signal health and fertility, potentially influencing mate selection preferences. This could provide indirect fitness benefits through increased social attractiveness, though direct evidence remains limited.[27][24]
Cultural Significance
Beauty and Aesthetics
Dimples have long been regarded as markers of beauty across diverse cultures, often symbolizing charm and vitality. In Western traditions, particularly during the Renaissance, artists incorporated dimpled smiles into portraits to evoke a sense of approachability and liveliness; for instance, Antonello da Messina's works featured subjects with prominent cheek dimples alongside subtle smiles, reflecting ideals of natural allure and emotional expressiveness.[28] In Asian contexts, such as Chinese culture, cheek dimples are viewed as auspicious signs of good fortune and aesthetic appeal, historically linked to prosperity and enhancing the perceived harmony of facial features in physiognomy practices.[10][7]Gender plays a notable role in the desirability of cheek dimples, with research indicating a stronger preference for them in women, where they contribute to perceptions of youthfulness and fertility. This association with neotenous features—retaining childlike qualities into adulthood—further amplifies their appeal in female faces, fostering impressions of vitality and warmth.[29]In contemporary settings, dimples continue to influence beauty standards in modeling and advertising, where they are leveraged to convey friendliness and memorability. Scientific evaluations confirm that individuals with dimples are often perceived as more attractive overall, with dimpled smiles enhancing positive emotional responses in viewers during media exposure.[4]Prominent figures have exemplified how dimples can amplify public persona and fame; actor and host Mario Lopez is known for his deep cheek dimples, which contribute to his charismatic on-screen presence across decades in television. Similarly, actress Audrey Hepburn had subtle dimples that accentuated her elegant features.
Symbolism in Media and Folklore
In folklore traditions, dimples have often been interpreted as omens of prosperity and favor. For instance, in some American folklore collections rooted in European immigrant communities, a dimple on a baby's chin is believed to foretell future wealth. [30] Similarly, in Chinese cultural beliefs, cheek dimples are viewed as symbols of good luck, enhancing the bearer's fortune in life. [31]Dimples appear in literature as emblems of flirtatious allure and youthful innocence, particularly in the works of William Shakespeare. In Venus and Adonis, the poet describes Adonis's smile revealing "a pretty dimple" in each cheek, attributing the hollows to Love's own crafting as enchanting pits. [32] Likewise, in The Winter's Tale, Shakespeare praises the "pretty dimples of [the baby's] chin and cheek," evoking tenderness and beauty in a child's features. [33]In film and television, dimples frequently define character archetypes, symbolizing charm or innocence that drives narrative appeal. Child star Shirley Temple's prominent cheek dimples became iconic in 1930s Hollywood musicals like Dimples (1936), where they underscored her portrayal of plucky, endearing protagonists, captivating Depression-era audiences and embodying wholesome escapism. [34]Contemporary media amplifies dimples through viral trends and humor, often blurring celebration with satire.
Medical and Surgical Aspects
Health Implications
Facial dimples are generally considered benign cosmetic features with no associated increase in disease risk or negative health effects.[35] Similarly, chin dimples, also known as cleft chins, are typically harmless genetic variations without health implications in most cases, though they can rarely occur as part of broader craniofacial syndromes.[36]In contrast, sacral dimples warrant closer attention due to potential links to underlying spinal conditions. These dimples appear in 2-4% of newborns and are usually innocuous, but approximately 1-4% of cases may be associated with occult spinal dysraphism or tethered cord syndrome, conditions that can lead to neurological complications if undetected.[37][38] Neonatal screening is recommended to identify at-risk infants, particularly those with additional cutaneous markers like hypertrichosis or lipomas.[39]Diagnostic evaluation focuses on distinguishing simple from atypical sacral dimples. Simple dimples—defined as shallow (<5 mm deep), midline, and within 2.5 cm of the anus—rarely require imaging, with studies showing an occult spinal dysraphism rate of less than 1%.[40] Atypical features, such as depth greater than 5 mm, off-midline position, or distance more than 2.5 cm from the anus, prompt ultrasound screening to assess for spinal anomalies, as these characteristics elevate the risk to around 8-9%.[41][42] If ultrasound findings are equivocal, MRI may be pursued for definitive diagnosis.[39]
Cosmetic Procedures
As of 2024, dimpleplasty has seen increasing popularity as a sought-after cosmetic procedure, with patients facing months-long wait times.[43] Dimpleplasty, also known as dimple creationsurgery, is an elective outpatient procedure designed to artificially form cheek dimples by establishing internal adhesions between the skin and underlying buccinator muscle, mimicking the natural anatomical bifurcation that produces congenital dimples.[44] The surgery typically lasts 30 to 60 minutes and is performed under local anesthesia, often with lidocaine and epinephrine, allowing patients to return home the same day.[45] A small mucosal incision, approximately 2-3 mm, is made inside the cheek to access the target area without external scarring.[44]The most common technique is the sling method, where non-absorbable sutures such as nylon or polypropylene are used to tether the dermis to the buccinator muscle, creating a controlled indentation that becomes more dynamic with facial movement over time.[44] Variations include forming L- or T-shaped flaps for enhanced adhesion in fuller cheeks or using bolsters to maintain suture tension, which are removed after about seven days.[44] Recovery generally involves 1-2 weeks of swelling and mild discomfort, with most patients resuming normal activities within 2 days and full results visible after 2-4 weeks as initial static dimples evolve.[44][46]Potential risks and complications of dimpleplasty are uncommon but include infection (exceedingly rare with proper oral hygiene), bleeding, postoperative edema, asymmetry, hyperpigmentation, and rare instances of nerve damage or scleroma.[47][44] One study reported a 5% complication rate across 40 sites, primarily involving dimple loss or minor infection, while overall success rates exceed 95% in experienced hands, with high patient satisfaction due to the procedure's simplicity and permanence.[48][49]Non-surgical alternatives to dimpleplasty offer temporary dimple simulation, primarily through dermal fillers injected to create or accentuate cheek indentations by strategically adding volume around the desired site.[50] Techniques involve injecting 0.3-0.5 ml of biocompatible fillers like Ellansé in a ring formation within the subcutaneous layer to produce a subtle depression, lasting 6-12 months depending on the product.[51] These methods carry lower risks than surgery, such as temporary bruising, swelling, or lumpiness, but outcomes are not permanent and may require repeat treatments.[50]