[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) › Frontal sinus [Skeletal system](https://durgical.com/en/anatomy/system/skeletal-system/) · [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) # Frontal sinus The frontal sinus is an air space in the frontal bone above the eyes; it lightens the skull and can fill up and hurt in sinusitis. Official name: Sinus of frontal bone [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=head_neck&select=frontal_sinus&side=r) Opens in the Durgical app, no sign-up needed. ## What it is An air space in the frontal bone above the eyes. ## What it does Lightens the skull; it can fill and hurt in sinusitis. ## Key points - Pott puffy tumour: frontal sinusitis spreads into the frontal bone, causing osteomyelitis with a subperiosteal abscess (soft forehead swelling), often with intracranial spread - Its posterior wall separates it from the dura and [frontal lobe](https://durgical.com/en/anatomy/superior-frontal-gyrus/); infection can reach the brain through valveless veins (meningitis, epidural or subdural empyema, frontal lobe abscess) - It drains through the frontal recess into the middle meatus, so ethmoid disease can block it - Its outline is unique to each person and has been used in forensic identification ## Key facts **Where** Frontal bone above the orbits; drains to the middle meatus **Blood supply** Supraorbital and anterior ethmoidal arteries **Nerve** V1 (supraorbital) **Function** Air space; absent at birth, develops ~7 years ## Relations **Behind** Anterior cranial fossa: [dura mater](https://durgical.com/en/anatomy/cranial-dura/) and the frontal lobes **Below** Roofs of the orbits and, medially, the frontal recess opening into the anterior [ethmoid cells](https://durgical.com/en/anatomy/anterior-cells-of-ethmoid-bone/) and middle meatus **In front** Anterior table of the [frontal bone](https://durgical.com/en/anatomy/frontal-bone/), the brow and the supraorbital and supratrochlear nerves **Medial** The other frontal sinus across a thin septum, usually off the midline ## How to find it It lies behind the brow, above the medial part of each orbit; tenderness over the forehead or the sinus floor at the upper inner corner of the orbit can accompany frontal sinusitis. ## Examination - Pressure or tapping on the forehead and on the sinus floor at the upper inner corner of the orbit: tenderness on one side supports frontal sinusitis, but the sign is not specific and imaging or endoscopy settles it ## On imaging CT shows its size, septa, fluid and the frontal recess; MRI with contrast is used when spread into the orbit or the cranial cavity is suspected. ## Common problems - Sinusitis: blocked nose, thick discharge, pressure in the cheeks or teeth. - Most acute sinusitis is viral; some becomes chronic. ## How it is diagnosed Symptoms and exam; nasal endoscopy and CT for chronic or complicated cases. ## Treatment - Saline rinses, nasal steroid sprays, pain relief; antibiotics only for bacterial cases. - Endoscopic sinus surgery for chronic sinusitis. ## Clinical notes - A mucocele forms when its outflow is blocked (often after trauma or surgery) and can expand into the orbit, pushing the eye down and out - Frontal sinus fractures involving the posterior table or the outflow tract carry a risk of CSF leak, meningitis and later mucocele - Endoscopic frontal sinus surgery works through the frontal recess, whose shape depends on the agger nasi and other ethmoid cells around it ## Anatomical variants - Absent on one side in a minority of people and on both sides in fewer; figures vary between studies - Size and septa vary widely, and the two sides are usually unequal ## Development It grows up from the anterior ethmoid region into the frontal bone, which is why it drains through the ethmoid area; it keeps enlarging until after puberty, so Pott puffy tumour is seen mostly in adolescents. ## Related conditions - [Acute rhinosinusitis](https://durgical.com/en/conditions/acute-rhinosinusitis/) ## Test yourself Think of the answer, then tap the question to see it. ## What is Pott puffy tumour in frontal sinusitis? Spread of frontal sinusitis into the frontal bone, causing osteomyelitis with a subperiosteal abscess (soft forehead swelling), often with intracranial spread. ## How can infection pass from the frontal sinus to the brain? Through valveless veins across the posterior wall, causing meningitis, epidural or subdural empyema or a frontal lobe abscess. ## Where does the frontal sinus drain, and why can ethmoid disease block it? Through the frontal recess into the middle meatus, a path bordered by anterior ethmoid cells. ## What can a blocked frontal sinus outflow form, and where can it expand? A mucocele, which can expand into the orbit and push the eye down and out. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/sinus-of-frontal-bone/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** sinus ossis frontalis TA2 549 **Official Spanish (DeCS)** Seno Frontal DeCS D005626 **English (TA2)** Sinus of frontal bone **Also called** bony frontal sinus · sinus frontalis ## Related - [Frontal bone](https://durgical.com/en/anatomy/frontal-bone/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=5762&filter=ths_termall&q=Frontal%20Sinus); [Anatomy, Head and Neck, Nose Paranasal Sinuses](https://www.ncbi.nlm.nih.gov/books/NBK499826/); [Anatomy, Head and Neck, Nose Sinuses](https://www.ncbi.nlm.nih.gov/books/NBK513272/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/sinus-of-frontal-bone/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/sinus-of-frontal-bone/