distinguished, but a distinct division generally disappears by physical maturity.

The median palatine suture forms a slightly irregular midline. Posteriorly the midline projects, as the ends of each concave palatine posterior border meet and form the posterior nasal spine (8) . Often, the bones bordering the suture are raised slightly where they meet. This elevation — the palatine torus may follow the entire midline, or only part of it, and often is of variable height and width in the same individual.

The intermaxillary suture can usually be distinguished in occlusal radiographs of young patients, and frequently in older ones as well. The dense cortical bone facing the juncture appears as two thin white lines separated by a dark seam. However, the structure may be obscured by the shadow of the nasal septum. A normal suture is generally of equal width in the same individual, but it may appear to be discontinuous.

Because most implant candidates are older, the suture will probably be totally or partially fused. However, even an older patient may have an open or partially unfused suture. A radio-graph alone is not reliable in determining the state of the suture, although radiographic indications substantiated by clinical observations are usually fairly indicative of health or disease. Assuming that there is no evidence of disease or that an open suture is not giving rise to a cleft palate condition, there is no reason why the palatal portion of the intermaxillary suture should hinder implant procedures. However, in many cases, the midline juncture of the premaxillae should be avoided when placing endosseous implants in the dental arch. The incisive foramen's proximity to a resorbed ridge makes it preferable to place endosseous implants on each side of the midline rather than to span it with a single implant.

The incisive foramen — also called the incisive fossa, incisal foramen, or anterior palatine foramen — lies in the midline immediately behind the incisors at the juncture of the apex of the premaxillae with the maxillary processes. The foramen usually appears as a single opening (9), as the bilateral incisive canals (10) join into a common pathway shortly before surfacing on the palate. The nasopalatine nerve descends through the canal to supply the palatal surface of the premaxillae, and the greater palatine artery ascends through it to anastomose with the spheno (naso)-palatine artery on the nasal septum. The foramen (canal) also contains vestiges of Stensen's organs, or the epithelial nasopalatine ducts.

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