Accessory oral frenula
Page most recently updated 7 September 2026
This page focuses on accessory oral frenula as a morphologic feature of conditions that may also be associated with psychiatric manifestations, such as psychosis, mania, autism spectrum disorder, ADHD, OCD, and self-injurious behaviours. The page begins with a clinical definition of accessory oral frenula based on the standardized Elements of Morphology terminology, together with visual examples from the same source. This is followed by a list of conditions in which accessory oral frenula have been described in association with psychiatric manifestations.
Of note, to optimize clinical utility, the list does not include conditions associated with intellectual disability in the absence of other psychiatric features.
Each condition listed below is linked to a dedicated page within this resource. These pages describe the psychiatric manifestations associated with each condition, as well as other morphologic and broader clinical features, allowing the differential diagnosis to be considered from multiple perspectives.
Accessory oral frenula
These images from different patients show accessory oral frenula of the lower (A) and upper (B) lips.
Image credit: National Human Genome Research Institute (NHGRI), Elements of Morphology.
Definition
Objective: Extra folds of tissue extending from the alveolar ridge to the inner surface of the upper or lower lip.
Note: This finding is assessed by gently retracting the oral mucosa from the alveolar ridge. Typically there is a single maxillary and a single mandibular frenulum located in the midline between the two central incisors. Abnormalities of the alveolar ridges may accompany accessory frenula, but these should be assessed separately.
Synonyms: Extra oral frenula; Supernumerary oral frenula.
Conditions with potential psychiatric associations
Selected references and further reading — Morphologic lens
Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5.
Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733.
Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.
Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.