The hard palate is a thin horizontal

bony Bony may refer to: * Adjective relating to bone People * Bony Dashaco, Cameroonian businessman * Bony King, Belgian singer-songwriter * Bony Pierre (born 1991), Haitian footballer * Bony Ramirez (born 1996), Dominican-born American painter and ...

plate made up of two bones of the

facial skeleton The facial skeleton comprises the ''facial bones'' that may attach to build a portion of the skull. The remainder of the skull is the neurocranium. In human anatomy and development, the facial skeleton is sometimes called the ''membranous visc ...

, located in the roof of the mouth. The bones are the palatine process of the maxilla and the horizontal plate of palatine bone. The hard palate spans the alveolar arch formed by the

alveolar process The alveolar process () is the portion of bone containing the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The alveolar process is covered by gums within the mouth, terminating roughly along the line of the mandibu ...

that holds the upper

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

(when these are developed).

Structure

The hard palate is formed by the palatine process of the maxilla and horizontal plate of palatine bone. It forms a partition between the nasal passages and the

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

. On the anterior portion of the hard palate are the ''plicae'', irregular ridges in the mucous membrane that help hold food while the teeth are biting into it while also facilitating the movement of food backward towards the larynx once pieces have been bitten off. This partition is continued deeper into the mouth by a fleshy extension called the

soft palate The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft biological tissue, tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is ...

. On the ventral surface of the hard palate, some projections or transverse ridges are present which are called palatine

rugae In anatomy, rugae (: ruga) are a series of ridges produced by folding of the wall of an organ. In general, rugae are a biological feature found in many organisms, serving purposes such as increasing surface area, flexibility, or structural sup ...

Function

The hard palate is important for feeding and speech. Mammals with a defective hard palate may die shortly after birth due to inability to suckle. It is also involved in

mastication Chewing or mastication is the process by which food is comminution, crushed and ground by the teeth. It is the first step in the process of digestion, allowing a greater surface area for digestive enzymes to break down the foods. During the mast ...

in many species. The interaction between the

tongue The tongue is a Muscle, muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper s ...

and the hard palate is essential in the formation of certain

speech Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

sounds, notably high-front vowels,

palatal consonant Palatals are consonants articulated with the body of the tongue raised against the hard palate (the middle part of the roof of the mouth). Consonants with the tip of the tongue curled back against the palate are called retroflex. Characteris ...

s, and

retroflex consonant A retroflex () or cacuminal () consonant is a coronal consonant where the tongue has a flat, concave, or even curled shape, and is articulated between the alveolar ridge and the hard palate. They are sometimes referred to as cerebral consona ...

s such as like "see", like "yes", �(realization of /hj/ in English) like "hue", and �(/r/, only for some speakers) like "red".

Clinical significance

Cleft palate

In the

birth defect A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth de ...

called

cleft palate A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The ...

, the left and right portions of this plate are not joined, forming a gap between the mouth and nasal passage (a related defect affecting the face is

cleft lip A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nasal cavi ...

). While a cleft palate has a severe impact upon the ability to

nurse Nursing is a health care profession that "integrates the art and science of caring and focuses on the protection, promotion, and optimization of health and human functioning; prevention of illness and injury; facilitation of healing; and alle ...

and speak, it is now successfully treated through reconstructive

surgical Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery ...

procedures at an early age. This is the time where such procedures are available. Due to the complexity of this birth defect, researchers still do not know exactly what causes the cleft palate to form during foetal development. Recently, these researchers found that even though there is no exact cause, there are several factors that drastically increase the risk of a baby being born with an orofacial cleft palate. As for the environmental risk factors, maternal smoking is the most influential risk factor. Based on a recent study of 103 German patients with cleft palates, it was found that 25.2% of their mothers smoked during pregnancy, a higher proportion than for the population as a whole. While maternal smoking during pregnancy is a risk, there are also several genetic risk factors. Six

single-nucleotide polymorphisms In genetics and bioinformatics, a single-nucleotide polymorphism (SNP ; plural SNPs ) is a germline substitution of a single nucleotide at a specific position in the genome. Although certain definitions require the substitution to be present in ...

in the PAX7 gene are implicated in the development of facial features. These variations occur at six loci: 1p36, 2p21, 3p11.1, 8q21.3, 13q31.1 and 15q22. When tested in the European and Asian communities, five of the six loci had a significant association at the 95% confidence level. Besides the PAX 7 gene variants, there were also five possible mutations found in the transforming growth factor-alpha gene (''TGFA'') that could lead to the development of a cleft palate. Even though several risk factors have been linked to cleft palates, more research must be done in order to determine the true causes of the defect.

Palatal abscess

Palatal

abscess An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...

es may also occur.

Hard palate pigmentation

Long-term use of the drug

chloroquine Chloroquine is an antiparasitic medication that treats malaria. It works by increasing the levels of heme in the blood, a substance toxic to the malarial parasite. This kills the parasite and stops the infection from spreading. Certain types ...

diphosphatase, used in

malaria prophylaxis Malaria prophylaxis is the preventive treatment of malaria. Several malaria vaccines are under development. For pregnant women who are living in malaria endemic areas, routine malaria chemoprevention is recommended. It improves anemia and parasite ...

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects synovial joint, joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and h ...

and other conditions, was found to cause bluish-grey pigmentation in the hard palate.

References

{{DEFAULTSORT:Hard Palate Palate Human mouth anatomy Speech organs ja:口蓋#硬口蓋