Hard palate

The hard palate is a partition between the nasal and oral cavities. Its anterior two-third is formed by the palatine processes of the maxillae and posterior one-third by the horizontal plates of the palatine bones.

Oral cavity showing Hard palate

The superior and inferior surfaces of the hard palate form the floor of the nasal cavity and the roof of the oral cavity, respectively.

• Anterolaterally, the hard palate becomes continuous with the alveolar arches and gums.
• The posterior margin of the hard palate is free and provides attachment to the soft palate.

The inferior surface of the hard palate presents the following features:

• Incisive fossa, a small pit anteriorly in the midline behind the incisor teeth, into which open the incisive canals. Each incisive canal/foramen (right and left) pierces the corresponding side and ascend into the corresponding nasal cavity. The incisive foramen transmits terminal parts of the nasopalatine nerve and greater palatine vessels.
• Greater palatine foramen, one on each side, lies in the posterolateral corner of the hard palate medial to the last molar tooth. It transmits the greater palatine nerve and vessels.
• Lesser palatine foramina (1–3 in number) on each side are in the pyramidal process of palatine bone and are located just behind the greater palatine foramen. They provide passage to lesser palatine nerve and vessels.
• Posterior nasal spine is a conical projection in the median plane on the sharp free posterior border of the hard palate.
• Palatine crest is a curved ridge near the posterior border of the hard palate.
• Masticatory mucosa is the mucous membrane lining the hard palate. In the anterior part, it is firmly united with the periosteum by multiple fibrous strands (Sharpey’s fibres), hence moving bolus of food does not displace the mucous membrane. It presents:

1. transverse masticatory ridges on either side of midline, and
2. palatine raphe, a narrow ridge of mucous membrane extending anteroposteriorly in the midline from a little papilla overlying the incisive fossa.

The hard palate is lined by keratinized stratified squamous epithelium.

Arterial Supply

This is by greater palatine arteries from the third part of the maxillary artery. Each artery emerges from greater palatine foramen and passes forwards around the palate (lateral to the nerve) to enter the incisive canal and pass up into the nose.

Venous Drainage

The veins of hard palate drain into the pterygoid venous plexus (mainly) and pharyngeal venous plexus.

Nerve Supply

The hard palate is supplied by greater palatine and nasopalatine nerves derived from pterygopalatine ganglion. The greater palatine nerve supplies whole of the palate except anterior part of palate behind incisor teeth (the area of premaxilla), which is supplied by nasopalatine nerves.

Lymphatic Drainage

The lymphatics from palate drain mostly into the upper deep cervical lymph nodes and few into retropharyngeal lymph nodes.