[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/) › Lower right first premolar [Digestive system](https://durgical.com/en/anatomy/system/digestive-system/) · [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) # Lower right first premolar The lower right first premolar (tooth 44) is the tooth just behind the canine; it helps crush and grind food. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=head_neck&select=teeth_44&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A transition tooth between the canine and the molars, with two cusps (cheek side and tongue side). ## What it does Crushes and tears food. ## Key points - Its buccal cusp is large and pointed while the lingual cusp is small and barely reaches the bite, so it looks like a step between canine and premolar - The [mental foramen](https://durgical.com/en/anatomy/mental-foramen/) usually lies below the space between the two lower premolars or below the second premolar - One of the first premolars commonly removed to gain room when crowding is treated orthodontically ## Key facts **Joints with** Alveolar socket of the [mandible](https://durgical.com/en/anatomy/mandible/) (gomphosis held by the periodontal ligament); bites against the opposing teeth **Landmarks** FDI 44, lower right first premolar: 1 root; two cusps; often removed for orthodontic space; erupts at about 10–12 years; nerve: [inferior alveolar nerve](https://durgical.com/en/anatomy/inferior-alveolar-nerve/) (V3) ## Relations **In front** The [lower right canine](https://durgical.com/en/anatomy/lower-right-canine/) **Behind** The [lower right second premolar](https://durgical.com/en/anatomy/lower-right-second-premolar/) **Above** Meets the [upper right canine](https://durgical.com/en/anatomy/upper-right-canine/) and the [upper right first premolar](https://durgical.com/en/anatomy/upper-right-first-premolar/) **Medial** [Tongue](https://durgical.com/en/anatomy/tongue/) and floor of the mouth; its root tip lies above the [mylohyoid](https://durgical.com/en/anatomy/mylohyoid-muscle/) line ## How to find it Fourth from the midline on the lower right, behind the canine; the mental nerve leaves the bone below the area between it and the second premolar. ## On imaging A panoramic film shows the mental foramen as a round dark spot below the premolar roots, useful to mark before implants or flaps; bitewings show decay at its contacts. ## Common problems - Often the tooth removed to make space in orthodontic treatment. ## Clinical notes - Supplied by the inferior alveolar nerve (V3); an inferior alveolar nerve block or a mental (incisive) block numbs it - Infection from its apex, above the attachment of the mylohyoid, spreads into the sublingual space and raises the floor of the mouth on that side ## Anatomical variants - A small extra cusp-like tubercle in the middle of its biting surface (dens evaginatus) occurs mainly on lower premolars and can fracture and open the pulp ## Development Replaces the primary [lower right first molar](https://durgical.com/en/anatomy/lower-right-first-molar/) (FDI 84). The primary molars are wider than their successors, and in the lower arch this spare room (leeway space) is larger than in the upper. ## Related conditions - [Dental caries](https://durgical.com/en/conditions/dental-caries/) ## Test yourself Think of the answer, then tap the question to see it. ## Where does the mental foramen usually lie in relation to the lower right first premolar? Below the space between the two lower premolars or below the second premolar. ## Where does infection from the apex of the lower right first premolar spread? Into the sublingual space, because the apex lies above the mylohyoid attachment; the floor of the mouth rises on that side. ## Which primary tooth does the lower right first premolar replace? The primary lower right first molar (FDI 84). ## On a panoramic film, where does the mental foramen appear in relation to the lower right first premolar? As a round dark spot below the premolar roots, usually between the two premolars or under the second. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/lower-right-first-premolar/) Educational information, not medical advice. For any symptom, see a health professional. ## Related - [Mandible](https://durgical.com/en/anatomy/mandible/) Sources: [Anatomy, Head and Neck, Teeth](https://www.ncbi.nlm.nih.gov/books/NBK557543/); [Anatomy, Permanent Dentition](https://www.ncbi.nlm.nih.gov/books/NBK570590/); [Anatomy, Head and Neck, Tooth Eruption](https://www.ncbi.nlm.nih.gov/books/NBK549878/); [Anatomy, Head and Neck: Alveolar Nerve](https://www.ncbi.nlm.nih.gov/books/NBK546712/); [23.3 The Mouth, Pharynx, and Esophagus](https://openstax.org/books/anatomy-and-physiology-2e/pages/23-3-the-mouth-pharynx-and-esophagus) (OpenStax (Rice University), 2022) · adapted, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). ## **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/lower-right-first-premolar/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/lower-right-first-premolar/