In dentistry, embrasures are a V-shaped flare surrounding the proximal contact areas of a tooth. The contact areas are relative to the that widen out from the point where two teeth in the same arch come into contact. It extends towards the cheek or lips (referred to as buccal or labial) and tongue (tae mo). If the space extend towards the area where upper and lower teeth come into contact, it is called occlusal (for molar teeth) or incisal (for incisors) embrasure. There is no cervical embrasure as this area is filled with interdental papilla.
When two teeth in the same arch are in contact,their curvatures adjacent to the contact areas form spillway spaces called embrasures. The spaces that widen out from the area of contact labially or lingually are called labial or buccal and lingual interproximal embrasures.These embrasures are continuous with the interproximal spaces between the teeth. Above the contact areas incisally and occlusally,the spaces,which are bound by marginal ridges as they join the cusps and incisal ridges are called the incisal or occlusal embrasures.Incisal or occlusal embrasures increase in size from anterior to posterior.These embrasures and the labial or buccal and lingual embrasures are continuous. The curved proximal surfaces of the contacting teeth roll away from the contact areas at all points,occlusally,labially or buccally,and lingually and cervically,and the embrasures and interproximal spaces are continuous,as they surround the areas of contact.Cervical (gingival) embrasures decrease in size from anterior to posterior. For anterior teeth, the labial embrasure and the lingual embrasure are of the same size. In posterior teeth, the buccal embrasure is narrower than the lingual one. Interproximal embrasure flaree is symmetrical between teeth, both facially and lingually.
Embrasures provide a spill way for food to escape during mastication which essentially aids in the self-cleansing process. It also reduces the pressure on teeth and allowing for proper passage. It also prevents food from being forced through the contact area. When teeth wear down to the contact area so that no embrasure remains,especially in the incisors,food is pushed into the contact area even when the teeth are not mobile. Embrasures also provide the esthetics in all teeth, especially anterior teeth (central and lateral incisors, and canines). Embrasures are usually found in between fossa of adjacent and occlusal teeth. This includes the intratemporal fossa which is deep within the TMJ fascia. However, unlike marginal embrasures, the intratemporal embrasure is located above the maxillary 3rd molar and is anterior to most of the maxillary sinus.
Wheeler's dental anatomy physiology and occlusion;9th ed ISBN 978-1-4160-6209-7