The alveolar ridge (/ˌælviˈoʊlər, ælˈviːələr, ˈælviələr/; also known as the alveolar margin) is one of the two jaw ridges, extensions of the mandible or maxilla, either on the roof of the mouth between the upper teeth and the hard palate or on the bottom of the mouth behind the lower teeth. Most of the roof of one's mouth is the hard palate and the soft palate. The alveolar ridges contain the sockets (alveoli, singular "alveolus") of the teeth. They can be felt with the tongue in the area right above the top teeth or below the bottom teeth. Its surface is covered with little ridges.
The [upper] alveolar ridge is a small protuberance just behind the upper front teeth that can easily be felt with the tongue.
Consonants whose constriction is made with the tongue tip or blade touching or reaching for the alveolar ridge are called alveolar consonants. Examples of alveolar consonants in English are, for instance, [t], [d], [s], [z], [n], [l] like in the words tight, dawn, silly, zoo, nasty and lurid. There are exceptions to this however, such as speakers of the New York accent who pronounce [t] and [d] at the back of their top teeth (dental stops). When pronouncing these sounds the tongue touches ([t], [d], [n]), or nearly touches ([s], [z]) the upper alveolar ridge, which can also be referred to as gum ridge. In many other languages, consonants transcribed with these letters are articulated slightly differently, and are often described as dental consonants. In many languages consonants are articulated with the tongue touching or close to the upper alveolar ridge. The former are called alveolar plosives (such as [t] and [d]), and the latter alveolar fricatives (such as [s] and [ʃ]).
Acrodont is a formation of the teeth whereby the teeth are consolidated with the summit of the alveolar ridge of the jaw without sockets. The term also refers to species of reptiles that have such a formation. This formation is common in the order Squamata, with the most other teeth formation in this order being pleurodont, although an extinct snake Dinilysia was thecodont. Acrodontal tooth attachment can also be seen in most rhynchocephalians including Sphenodon, as well as some lizards such as chameleons.Acrodonta (lizard)
Acrodonts are a subclade of iguanian squamates consisting entirely of Old World taxa. Extant representation include the families Chamaeleonidae (chameleons) and Agamidae (dragon lizards), with at least over 500 species described. A fossil genus though Gueragama was found in Brazil making it the only known American representative of the group.The group is eponymously named from the formation of the teeth whereby the teeth are consolidated with the summit of the alveolar ridge of the jaw without sockets. There are, however, other animals that have acrodont dentition such as tuataras..Alveolar consonant
Alveolar consonants () are articulated with the tongue against or close to the superior alveolar ridge, which is called that because it contains the alveoli (the sockets) of the superior teeth. Alveolar consonants may be articulated with the tip of the tongue (the apical consonants), as in English, or with the flat of the tongue just above the tip (the "blade" of the tongue; called laminal consonants), as in French and Spanish. The laminal alveolar articulation is often mistakenly called dental, because the tip of the tongue can be seen near to or touching the teeth. However, it is the rearmost point of contact that defines the place of articulation; this is where the oral cavity ends, and it is the resonant space of the oral cavity that gives consonants and vowels their characteristics. The International Phonetic Alphabet (IPA) does not have separate symbols for the alveolar consonants. Rather, the same symbol is used for all coronal places of articulation that are not palatalized like English palato-alveolar sh, or retroflex. To disambiguate, the bridge ([s̪, t̪, n̪, l̪], etc.) may be used for a dental consonant, or the under-bar ([s̠, t̠, n̠, l̠], etc.) may be used for the postalveolars. Note that [s̪] differs from dental [θ] in that the former is a sibilant and the latter is not. [s̠] differs from postalveolar [ʃ] in being unpalatalized. The bare letters [s, t, n, l], etc. cannot be assumed to specifically represent alveolars. The language may not make such distinctions, such that two or more coronal places of articulation are found allophonically, or the transcription may simply be too broad to distinguish dental from alveolar. If it is necessary to specify a consonant as alveolar, a diacritic from the Extended IPA may be used: [s͇, t͇, n͇, l͇], etc., though that could also mean extra-retracted. The letters ⟨s, t, n, l⟩ are frequently called 'alveolar', and the language examples below are all alveolar sounds.
(The Extended IPA diacritic was devised for speech pathology and is frequently used to mean "alveolarized", as in the labioalveolar sounds [p͇, b͇, m͇, f͇, v͇], where the lower lip contacts the alveolar ridge.)Alveolo-palatal consonant
In phonetics, alveolo-palatal (or alveopalatal) consonants, sometimes synonymous with pre-palatal consonants, are intermediate in articulation between the coronal and dorsal consonants, or which have simultaneous alveolar and palatal articulation. In the official IPA chart, alveolo-palatals would appear between the retroflex and palatal consonants but for "lack of space". Ladefoged and Maddieson characterize the alveolo-palatals as palatalized postalveolars (palato-alveolars), articulated with the blade of the tongue behind the alveolar ridge and the body of the tongue raised toward the palate, whereas Esling describes them as advanced palatals (pre-palatals), the furthest front of the dorsal consonants, articulated with the body of the tongue approaching the alveolar ridge. These descriptions are essentially equivalent, since the contact includes both the blade and body (but not the tip) of the tongue (see schematic at right). They are front enough that the fricatives and affricates are sibilants, the only sibilants among the dorsal consonants.Alveolus (disambiguation)
Alveolus (pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit.
Alveolus may refer to:
In anatomy and zoology in general
Pulmonary alveolus, an air sac in the lungs
Alveolar cell or pneumocyte
Mammary alveolus, a milk sac in the mammary glands
Dental alveolus, also known as "tooth socket", a socket in the jaw that holds the roots of teeth
Alveolar ridge, the jaw structure that contains the dental alveoli
Superior alveolar artery (disambiguation)
Anterior superior alveolar arteries
Posterior superior alveolar artery
Inferior alveolar artery
Anterior superior alveolar nerve
Middle superior alveolar nerve
Inferior alveolar nerveIn Botany, Microbiology, and related disciplines alveoli may be:
Surface cavities or pits, such as on the stem of Myrmecodia species
Pits on honeycombed surfaces such as receptacles of many angiosperms
Pits on the fruiting bodies of fungi such as Boletus or the ascocarps of fungi such as typical Ascomycetes
Pits on the valves of the tests of many diatoms
Membrane supporting vesicles of the alveolatesIn medicine
Alveolar soft part sarcomaIn linguistics
Alveolar consonant, a linguistic vocalization depending upon touching tongue to alveolar ridge
Alveolar stopBuccal exostosis
A buccal exostosis is an exostosis (bone prominence) on the buccal surface (cheek side) of the alveolar ridge of the maxilla or mandible. More commonly seen in the maxilla than the mandible, buccal exostoses are considered to be site specific. Existing as asymptomatic bony nodules , buccal exostoses don’t usually present until adult life, and some consider buccal exostoses to be a variation of normal anatomy rather than disease. Bone is thought to become hyperplastic, consisting of mature cortical and trabecular bone with a smooth outer surface. They are less common when compared with mandibular tori.Congenital epulis
Congenital epulis is a proliferation of cells most frequently occurring on the alveolar ridge of the upper jaw at birth. Less frequently the mass may arise from the mandibular alveolus. Rare cases can arise from the tongue. This lesion is more commonly found in female babies, suggesting hormonal involvement during embryonic development. The cause of this type of epulis is unknown. Also known as congenital granular cell tumor or Neumann's tumor; historically referred to as granular cell myoblastoma.
Multiple lesions occur in 10% of affected neonates. The tumor is typically pedunculated and varies in maximum size from 0.5 cm to 9 cm. The lesion is typically painless and does not increase in size after discovery. Some small lesions may regress over time. Treatment is surgical excision. Recurrence is extremely rare even after incomplete excision.Coronal–velar consonant
Coronal–velar consonants are doubly articulated at the velum and upper teeth and/or the alveolar ridge.
An example of a coronal–velar consonant is one of the coda allophones of /n/ in the Jebero language, which is realized as dentoalveolo-velar [n̪͡ŋ].Dental alveolus
Dental alveoli (singular alveolus) are sockets in the jaws in which the roots of teeth are held in the alveolar process with the periodontal ligament. The lay term for dental alveoli is tooth sockets. A joint that connects the roots of the teeth and the alveolus is called gomphosis (plural gomphoses). Alveolar bone is the bone that surrounds the roots of the teeth forming bone sockets.
In mammals, tooth sockets are found in the maxilla, the premaxilla, and the mandible.Dental and alveolar flaps
The alveolar tap or flap is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents dental, alveolar, and postalveolar flaps is [ɾ].
The terms tap and flap are usually used interchangeably. Peter Ladefoged proposed for a while that it may be useful to distinguish between them; however, his usage has been inconsistent and contradicted itself even between different editions of the same text. The last proposed distinction was that a tap strikes its point of contact directly, as a very brief stop, and a flap strikes the point of contact tangentially: "Flaps are most typically made by retracting the tongue tip behind the alveolar ridge and moving it forward so that it strikes the ridge in passing." This distinction between the alveolar tap and flap can be written in the IPA with tap [ɾ] and flap [ɽ] — the 'retroflex' symbol used for the one that starts with the tongue tip curled back behind the alveolar ridge. This distinction is noticeable in the speech of some American English speakers in distinguishing the words "potty" (tap [ɾ]), and "party" (flap [ɽ]).
For linguists who make the distinction, the coronal tap is transcribed as [ɾ], and the flap is transcribed as [ᴅ], which is not recognized by the IPA. Otherwise, alveolars and dentals are typically called taps and other articulations flaps. No language contrasts a tap and a flap at the same place of articulation.
This sound is often analyzed and thus interpreted by native English-speakers as an 'R-sound' in many foreign languages. In languages for which the segment is present but not phonemic, it is often an allophone of either an alveolar stop ([t], [d], or both) or a rhotic consonant (like the alveolar trill or the alveolar approximant).
When the alveolar tap is the only rhotic consonant in the language, it may be transcribed /r/ although that symbol technically represents the trill.
The voiced alveolar tapped fricative reported from some languages is actually a very brief voiced alveolar non-sibilant fricative.Denti-alveolar consonant
In linguistics, a denti-alveolar consonant or dento-alveolar consonant is a consonant that is articulated with a flat tongue against the alveolar ridge and upper teeth, such as /t/ and /d/ in languages such as Spanish and French. That is, a denti-alveolar consonant is one that is alveolar and laminal.
Although denti-alveolar consonants are often labeled as "dental" because only the forward contact with the teeth is visible, the point of contact of the tongue that is farthest back is most relevant, defines the maximum acoustic space of resonance and gives a characteristic sound to a consonant.In French, the contact that is farthest back is alveolar or sometimes slightly pre-alveolar. Spanish /t/ and /d/ are laminal denti-alveolar, and /l/ and /n/ are alveolar but assimilate to a following /t/ or /d/. Similarly, Italian /t/, /d/, /t͡s/, /d͡z/ are denti-alveolar, and /l/ and /n/ are alveolar.The dental clicks are also laminal denti-alveolar.Lateral release (phonetics)
In phonetics, a lateral release is the release of a plosive consonant into a lateral consonant. Such sounds are transcribed in the IPA with a superscript ⟨l⟩, for example as [tˡ] in English spotless [ˈspɒtˡlɨs]. In English words such as middle in which, historically, the tongue made separate contacts with the alveolar ridge for the /d/ and /l/, [ˈmɪdəl], many speakers today make only one tongue contact. That is, the /d/ is laterally released directly into the /l/: [ˈmɪdˡl̩]. While this is a minor phonetic detail in English (in fact, it is commonly transcribed as having no audible release: [ˈspɒt̚lɨs], [ˈmɪd̚l̩]), it may be more important in other languages.
In most languages (as in English), laterally-released plosives are straightforwardly analyzed as biphonemic clusters whose second element is /l/. In the Hmong language, however, it is sometimes claimed that laterally-released consonants are unitary phonemes. According to Peter Ladefoged and Ian Maddieson, the choice between one or another analysis is purely based on phonological convenience—there is no actual acoustic or articulatory difference between one language's "laterally-released plosive" and another language's biphonemic cluster.Le Fort fracture of skull
A Le Fort fracture of the skull is a classic transfacial fracture of the midface, involving the maxillary bone and surrounding structures in either a horizontal, pyramidal or transverse direction. The hallmark of Lefort fractures is traumatic pterygomaxillary separation, which signifies fractures between the pterygoid plates, horseshoe shaped bony protuberances which extend from the inferior margin of the maxilla, and the maxillary sinuses. Continuity of this structure is a keystone for stability of the midface, involvement of which impacts surgical management of trauma victims, as it requires fixation to a horizontal bar of the frontal bone. The pterygoid plates lie posterior to the upper dental row, or alveolar ridge, when viewing the face from an anterior view. The fractures are named after French surgeon René Le Fort (1869–1951), who discovered the fracture patterns by examining crush injuries in cadavers.Myuchelys
The Myuchelys is a genus of turtles, the Australian saw-shelled turtles, in the family Chelidae and subfamily Chelodininae. They inhabit the headwaters and tributaries of rivers within their range and this led to the name Myuchelys, which is formed from the Aboriginal word myuna meaning clear water and the Greek chelys meaning turtle. They have a short neck and the intergular scute completely separates the gular scutes. They have no alveolar ridge separating them from the snapping turtles of the genus Elseya.
The genus currently contains these cryptic small species of freshwater turtles, endemic to eastern and northern Australia:
Saw-shelled turtle, Myuchelys latisternum Gray, 1867
Bellinger River snapping turtle, Myuchelys georgesi Cann, 1997
Namoi River snapping turtle, Myuchelys bellii Gray, 1844Place of articulation
In articulatory phonetics, the place of articulation (also point of articulation) of a consonant is the point of contact where an obstruction occurs in the vocal tract between an articulatory gesture, an active articulator (typically some part of the tongue), and a passive location (typically some part of the roof of the mouth). Along with the manner of articulation and the phonation, it gives the consonant its distinctive sound.
The terminology in this article has been developed for precisely describing all the consonants in all the world's spoken languages. No known language distinguishes all of the places described here so less precision is needed to distinguish the sounds of a particular language.Retroflex consonant
A retroflex 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 consonants, especially in Indology. Other terms occasionally encountered are apico-domal and cacuminal.
The Latin-derived word retroflex means "bent back"; some retroflex consonants are pronounced with the tongue fully curled back so that articulation involves the underside of the tongue tip (subapical). These sounds are sometimes described as "true" retroflex consonants. However, retroflexes are commonly taken to include other consonants having a similar place of articulation without such extreme curling of the tongue; these may be articulated with the tongue tip (apical) or the tongue blade (laminal).Socket preservation
Socket preservation or alveolar ridge preservation (ARP) is a procedure to reduce bone loss after tooth extraction to preserve the dental alveolus (tooth socket) in the alveolar bone. A platelet rich fibrin (PRF) membrane containing bone growth enhancing elements is placed in the wound or a bone grafting material or scaffold is placed in the socket of an extracted tooth at the time of extraction. The socket is then directly closed with stitches or covered with a non-resorbable or resorbable membrane and sutured.
After extraction, jaw bone has to be preserved to keep the socket in its original shape. Without socket preservation, the bone quickly resorbs resulting in 30–60% loss in bone volume in the six months after dental extraction. The jaw bone will never revert to its original shape once bone is lost and tissue contour has changed.
The human body reduces the amount of bone that is not sufficiently used with a daily stress; without the strain stimulus, the jaw bone behaves (with or without socket preservation) as if the space occupied by the tooth and periodontal ligament was empty.Speech organ
Speech organs, or articulators, produce the sounds of language. Organs used for speech include the lips, teeth, alveolar ridge, hard palate, velum (soft palate), uvula, glottis and various parts of the tongue. They can be divided into two types: passive articulators and active articulators. Active articulators move relative to passive articulators, which remain still, to produce various speech sounds, in particular manners of articulation. The upper lip, teeth, alveolar ridge, hard palate, soft palate, uvula, and pharynx wall are passive articulators. The most important active articulator is the tongue as it is involved in the production of the majority of sounds. The lower lip is another active articulator. But glottis is not an active articulator because it is only a space between vocal folds.Voiceless alveolar affricate
A voiceless alveolar affricate is a type of affricate consonant pronounced with the tip or blade of the tongue against the alveolar ridge (gum line) just behind the teeth. This refers to a class of sounds, not a single sound. There are several types with significant perceptual differences:
The voiceless alveolar sibilant affricate [t͡s] is the most common type and has an abrupt hissing sound, as the ts in English cats.
The voiceless alveolar retracted sibilant affricate [t͡s̺], also called apico-alveolar or grave, has a weak hushing sound reminiscent of retroflex affricates. It is found e.g. in Basque, where it contrasts with a more conventional non-retracted laminal alveolar affricate.
The voiceless alveolar non-sibilant affricate [t͡θ̠] or [t͡θ͇], using the alveolar diacritic from the Extended IPA, is somewhat similar to the th in some pronunciations of English eighth. It is found as a regional realization of the sequence /tr/ in some Sicilian dialects of Standard Italian.
The voiceless alveolar lateral affricate [t͡ɬ] is found in certain languages, such as Cherokee, Icelandic and Nahuatl.