The lambda is the posterior sutural junction where the sagittal suture meets the lambdoid suture, at the junction of the two parietal bones and the occipital bone. It corresponds to the posterior fontanelle site in infants, which closes earlier than the anterior fontanelle at approximately 6-8 weeks of age. The lambda lies approximately 7 cm above the inion on the posterior vault.
The lambdoid suture and the lambda are relevant in craniosynostosis: premature fusion of the lambdoid suture (posterior plagiocephaly from lambdoid craniosynostosis) flattens the ipsilateral occiput and produces characteristic compensatory skull changes, managed by surgical posterior vault remodelling. The lambda distinguishes true lambdoid synostosis from positional (deformational) plagiocephaly from infant head positioning, which does not require surgery. Wormian bones are frequently found in the lambdoid suture region in conditions such as osteogenesis imperfecta.
Premature fusion of the lambdoid suture causes ipsilateral occipital flattening with contralateral posterior parietal bossing and ipsilateral ear displacement forward, distinguishable from deformational plagiocephaly by the trapezoidal skull shape on vertex view CT requiring surgical vault remodelling if severe.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
