The Sublingual Frenulum in Breastfeeding: When Anatomy Influences the Feeding Experience

The World Health Organization (WHO) and the Italian Ministry of Health recommend exclusive breastfeeding during the first six months of life and its continuation up to two years of age and beyond, alongside complementary foods. In addition to its numerous nutritional benefits, breastfeeding plays a central role in the cognitive, emotional, and physical development of the infant.

One often overlooked aspect is the contribution of breastfeeding to the development of the craniofacial complex, as it promotes the physiological maturation of muscular and skeletal structures. A proper sucking mechanism helps prevent the onset of oral dysfunctions, such as non-nutritive sucking habits and other oral habits that may negatively affect a child’s growth. However, certain anatomical conditions can interfere with this process.

The Sublingual Frenulum: Function and Abnormalities

The sublingual frenulum is a thin fibrous membrane located beneath the tongue that connects it to the floor of the mouth, regulating its mobility. Under normal physiological conditions, the frenulum allows the tongue to move freely, facilitating sucking, swallowing, and other oral functions. However, an abnormal sublingual frenulum—commonly referred to as a tongue-tie or ankyloglossia—can restrict tongue movement and interfere with proper latch during breastfeeding. This condition is commonly observed in newborns and may significantly impair tongue function, limiting mobility and altering the suck-swallow process.

This restriction prevents the effective coordination of oral muscles, leading to feeding difficulties and, if not addressed promptly, potentially contributing to respiratory dysfunctions, sleep disturbances, and alterations in dental development. In particular, ankyloglossia may result in a range of oral and systemic issues, including postural, vocal, and speech-related disorders which, if left untreated, can negatively affect the child’s overall well-being. Although tongue-tie is not considered a disease in itself, an undiagnosed and untreated short lingual frenulum may have long-term consequences on motor development and the mother-infant relationship, significantly impacting the infant’s quality of life.

The Consequences of a Short Lingual Frenulum in Newborns

The effects of ankyloglossia extend across multiple dimensions of both infant and maternal well-being, with significant implications for feeding, growth, and development.

Among the most common issues observed in newborns are:

• Impact on Breast Milk Production: difficulty sucking due to a short lingual frenulum can compromise the effectiveness of breastfeeding, reducing breast stimulation and consequently decreasing milk production.
• Feeding Difficulties and Maternal Discomfort: poor or ineffective sucking can make breastfeeding painful and frustrating, potentially leading, in more severe cases, to the premature cessation of exclusive breastfeeding.
• Poor or Reduced Weight Gain: ineffective feeding or insufficient milk transfer may result in nutritional deficiencies, delaying or hindering the infant’s normal physical development, including healthy weight gain.
• Irregular and Restless Sleep, and Sleep-Disordered Breathing (SDB/OSA): feeding difficulties and inadequate growth may interfere with normal sleep-wake patterns, leading to restless sleep and increasing the risk of sleep-related breathing disorders, such as obstructive sleep apnea (OSA).
• Development of Mouth Breathing: the inability to use the tongue effectively during feeding may contribute to the establishment of mouth breathing, which is associated with long-term respiratory and oral health issues.
• Cranio-Mandibular Developmental Imbalance: difficulties in sucking and swallowing can impair the physiological development of oral and craniofacial structures, potentially leading to mandibular and facial growth abnormalities or dysfunctions.
• A Systematic Approach to Assessment and Management: to effectively address breastfeeding challenges and provide appropriate support, it is essential to adopt a systematic approach.