GPT Terms – S

sad·dle n, obs: see DENTURE BASE

saddle pontic obs: a pontic with a broad concave facio-lingual area of contact with the residual ridge. It is also know as a ridge lap pontic. This type of pontic is known to be uncleanseable and result in tissue irritation at the area of contact with the ridge mucosa

sag·it·tal : situated in the plane of the cranial sagittal suture or parallel to that plane—usage: see SAGITTAL PLANE

sagittal axis : an imaginary anteroposterior line around which the mandible may rotate when viewed in the frontal plane

sagittal axis of the mandible: see SAGITTAL AXIS

sagittal plane : any vertical plane or section parallel to the median plane of the body that divides a body into right and left portions

sanitary bridge obs: see HYGIENIC PONTIC

sanitary pontic obs: a trade name originally designed as a manufactured convex blank with a slotted back. The name was used occasionaly as a synonym for a hygienic pontic, wherein the pontic does not contact the residual ridge

sat·u·ra·tion : the attribute of color perception that expresses the degree of departure from gray of the same lightness. All grays have zero saturation

scaf·fold : a supporting surface, either natural or prosthetic, that maintains the contour of tissue; a supporting framework

lscal·lop : one of a continuous series of circles

2scal·lop : to shape, cut, or finish in scallops; segments or angular projections forming a border

scanning electron micrograph: a micrograph resulting from use of electron microscopy in which specimens are coated with heavy metal and scanned by an electron beam. The image is built up on a monitor screen (in the same way as the raster builds a conventional television image). The resolution is less than transmission electron microscopy, but preparation is easier (often by fixation followed by critical point drying), the depth of focus is relatively large allowing significant magnification and observation of the specimen surface

scattered radiation : radiation that, during passage through a substance, has been deviated in direction. It may also have been modified by an increase in wavelengths. It is one form of secondary radiation

scat·ter·ing : diffusion or redirection of radiant energy encountering particles of different refractive index; scattering occurs at any such interface, at the surface, or inside a medium containing particles

scattering coefficient : single scattering coefficient of a particle in a medium of different refractive index, expressed as a ratio between scattering cross section and geometric cross section of the particle. It should properly be called scattering efficiency, but in popular use, called scattering coefficient

scotopic vision : vision that occurs in faint light or dark adaptation and is attributable to the retinal rods. The maximum of the relative spectral visual sensitivity is shifted to 510 nm and the spectrum is seen uncolored

screw endosteal dental implant 1: any dental implant whose configuration resembles a screw 2: any screw-shaped dental implant; it may be hollow or solid, and usually consists of the dental implant abutment and the dental implant

scribe ; scrib·ed ; scrib·ing : to write, trace, or mark by making a line or lines with a pointed instrument

second stage dental implant surgery \ 1: for eposteal dental implant surgery, the term refers to the procedure involving placement of the eposteal framework fabricated after the first stage implant surgery 2: for endosteal dental implant surgery, after surgical reflection, the occlusal aspect of the dental implant is exposed, the cover screw is removed, and either the interim or definitive dental implant abutment is placed. After this, the investing tissues are (when needed) sutured

secondary bonds : weak inter-atomic bonds arising from dipoles within atoms or molecules

secondary crown: see TELESCOPIC CROWN

secondary dentition: see PERMANENT DENTITION

secondary fracture : a fracture occurring as a consequence of infection, necrosis or some other disease of the bone

secondary occlusal trauma : the effects induced by occlusal force (normal or abnormal) acting on teeth with decreased periodontal support

secondary pain : heterotopic pain and/or secondary hyperalgesia induced by deep somatic pain as a central excitatory effect

sec·tion . the portion of a maxillofacial prosthesis that serves to fill a defect as a part of the prosthesis.

sectional facial moulage impression: a procedure used to record the soft tissue contours of a portion of the face. Occasionally several separate sectional impressions are made, and then reassembled to provide a full facial contour cast. The impression is utilized to create a partial facial moulage and generally is not reusable

sectional impression : a negative likeness that is made in sections

seg·ment: any of the parts into which a body naturally separates or is divided either actually or by an imaginary line or plane

Seibert classification: the classification of residual alveolar ridge form into three categories identified as class I, II and III. Class I defects—faciolingual loss of tissue width with normal ridge height; class II defects—loss of ridge height with normal ridge width; class III defects—a combination of loss in both dimensions

Seibert JS Reconstruction of deformed, partially edentulous ridges, using full thickness onlay grafts. Part I. Technique and wound healing. Compend Contin Educ Dent 1983;4: 437-53

selective grinding: see OCCLUSAL RESHAPING

self-curing resin: see AUTOPOLYMERIZING RESIN

self-separating plaster: an impression plaster that disintegrates in hot water (GPT-4)

self-threading pin : a pin screwed into a hole prepared in dentin to enhance retention

sella turcica : a cephalometric landmark in the geometric center of the pituitary fossa of the spheroid bone; a bony anatomic landmark

semi-adjustable articulator : an articulator that allows adjustment to replicate average mandibular movements—called also Class III articulator

semiprecious metal alloy : an alloy composed of precious and base metals. There is no distinct ratio of components separating semiprecious alloys from another group

semiprecision attachment: a laboratory fabricated rigid metallic extension (patrix) of a fixed or removable dental prosthesis that fits into a slot-type keyway (matrix) in a cast restoration, allowing some movement between the components—comp PRECISION ATTACHMENT

semiprecision rest : a rigid metallic extension of a fixed or removable dental prosthesis that fits into an intracoronal preparation in a cast restoration

senile atrophy: see AGE ATROPHY

separating medium 1: a coating applied to a surface and serving to prevent a second surface from adhering to the first2: a material, usually applied on an impression, to facilitate removal of the cast

sep·tum , sep·ta : a dividing wall or membrane, especially between bodily spaces or masses

sequestrum: a portion of devitalized bone entirely separated from the adjacent vital bone

sequestrectomy: surgical removal of a sequestrum

setting expansion : the dimensional increase that occurs concurrent with the hardening of various materials, such as plaster of paris, dental stone, die stone, and dental casting investment

setup v, obs: see TOOTH ARRANGEMENT

sex·tant :n New Latin sextant-, sextans, from Latin, sixth part of anything, from sextus sixth +-ant-,-ans -ant: 1: the sixth part of a circle 2: an instrument for measuring altitudes of celestial bodies from a moving ship or airplane with a maximum angle of 60 degrees between its reflecting mirrors 3: in dentistry, a subdivision of the dental arch by adjacent tooth grouping. The maxillary and mandibular arches may be divided into a total of 6 areas termed sextants. In the maxilla, the right posterior sextant extends from tooth # 1-5, the anterior maxillary sextant extends from tooth #6-11, and the left posterior maxillary sextant extends from #12-16. The mandibular arch may be divided into three similar sextants: teeth # 17-21, # 22-27 and #28-32–comp OCTANT

shade 1: a term used to describe a particular hue, or variation of a primary hue, such as a greenish shade of yellow 2: a term used to describe a mixture with black (or gray) as opposed to a tint that is a mixture with white—see TOOTH COLOR SELECTION

shade selection: see TOOTH COLOR SELECTION

shearing stress : the internal induced force that opposes the sliding of one plane on an adjacent plane or the force that resists a twisting action

shellac base : a record base constructed using a shellac-based wafer that has been adapted to the cast with heat (GPT-4)

shell crown 1: an artificial full-veneer crown swaged from metal plate 2: an artificial crown that is adapted like a shell or cap over the remaining clinical crown of a tooth; the space between the crown and the shell is filled with cement—called also cap crown

shim·stock n: a thin (8-12 micrometer) strip of polyester film used to identify the presence or absence of occlusal or proximal contacts

shoulder finish line : a finish line design for tooth preparation in which the gingival floor meets the external axial surfaces at approximately a right angle

shrink-spot porosity : an area of porosity in cast metal that is caused by shrinkage of a portion of the metal as it solidifies from the molten state without flow of additional molten metal from surrounding areas

side shift: see MANDIBULAR TRANSLATION

si·li·ca : silicon dioxide occurring in crystalline, amorphous, and usually impure forms (as quartz, opal, and sand, respectively)

silica-bonded investment: a casting investment with ethyl silicate or a silica gel as a binder, the latter reverting to silica upon heating. This is combined with cristobalite or quartz as the refractory material. Such investments exhibit considerable thermal expansion and can be used when casting higher fusing chromium alloys

silent period : a momentary electromyographic decrease in elevator muscle activity on initial tooth contact presumably due to the inhibitory effect of stimulated periodontal membrane receptors

simple fracture : a linear bony fracture that is not in communication with the exterior

simple joint: a joint in which only two bones articulate

simulation film : radiographs made with the same field size, source-to-skin distance, and orientation as a therapy beam to mimic the beam and for visualization of the treated volume on a radiograph

single crystal sapphire : a material composed of a single crystalline alpha aluminum oxide that is identical in crystalline structure to a gem sapphire

single denture construction : the making of a maxillary or mandibular denture as distinguished from a set of complete dentures (GPT-1)

1sinter : a deposit formed by evaporation of lake or spring water

2sinter : to cause to become a coherent mass by heating without melting

sinus tract: an abnormal passage from a pathological process to an external surface

sialorrhea: excessive flow of saliva

skia·graph 1: a figure formed by shading in the outline of a shadow 2: a radiograph—called also skiagram (GPT-1)

sleeper : slang for any dental implant body not used for support and stabilization of a dental prosthesis

sliding movement: see TRANSLATION

slotted attachment: see PRECISION ATTACHMENT

1sluice : an artificial passage for water fitted with a valve or gate for stopping or regulating the flow

2sluice ; sluic·ed; sluic·ing 1: to draw off by or via a sluice 2: to wash with or in water through or from a sluice 3: to drench with a sudden flow

SNA angle: acronym for Sella-Nasion-A point—in cephalometrics, an angle measuring the anteroposterior relationship of the maxillary basal arch to the anterior cranial base; it shows the degree of maxillary prognathism

snap impression obs: see PRELIMINARY IMPRESSION

SNB angle: acronym for Sella-Nasion-B point—in cephalometrics, an angle showing the anterior limit of the mandibular basal arch in relation to the anterior cranial base

sock·et : any opening or hollow that forms a holder for something, e.g., a tooth

soft palate : the movable part of the palatal anatomy posterior to the hard palate

soft palate obturator: see SPEECH AID PROSTHESIS

soft splint : a resilient device covering either the maxillary or the mandibular teeth for the purpose of preventing trauma to the dentition or acting as a deprogrammer

1sol·der : a fusible metal alloy used to unite the edges or surfaces of two pieces of metal; something that unites or cements

2sol·der , sol·der·ed ; sol·der·ing sol·der·a·bil·i·ty : to unite, bring into, or restore to a firm union; the act of uniting two pieces of metal by the proper alloy of metals

soldering antiflux: a material, such as iron oxide (rouge) dissolved in a suitable solvent such as turpentine placed on a metal surface to confine the flow of molten solder

soldering flux: a material such as borax glass (Na2B4O7) applied to a metal surface to remove oxides or prevent their formation in order to facilitate the flow of solder

soldering index: 1: a mold used to record the relative position of multiple cast restorations prior to investing for a soldering procedure. 2: a rigid resin connection between multiple cast restorations fixing their relative position prior to a soldering procedure

solidification porosity : a porosity that may be produced by improper spruing or improper heating of either the metal or the investment

so·ma·to·pros·thet·ics : the art and science of prosthetic replacement of external parts of the body that are missing or deformed

son·i·cate –cat·ed -cat·ing : to disrupt (i.e. bacteria) by means of application of high frequency sound waves — son·i·ca·tion \so?n?i?-k??shun\ n

space : a delimited, three-dimensional region; physical space independent of what occupies it—see DENTURE S., INTERPROXIMAL S., INTERRADICULAR S., RETROMYLOHYOID S.

space of Donders [F.C. Donders]: eponym for the space that lies above the dorsum of the tongue and below the hard and soft palates when the mandible and tongue are in the rest position

span length : the length of a beam between two supports

spat·u·la : a flat-bladed instrument used for mixing or spreading materials

1spat·u·late : shaped like a spatula

2spat·u·late –ed/-ing/-s: to work or treat with a spatula

spat·u·la·tion : the manipulation of material with a spatula to produce a homogenous mass

speaking space : the space that occurs between the incisal or/and occlusal surfaces of the maxillary and mandibular teeth during speech

spectral curve: see SPECTROPHOTOMETRIC CURVE

spectral reflection : reflection in which the angle of reflection is equal to the angle of incidence. Associated with objects having optically smooth (glossy) surfaces—called also mirrored reflection

spec·tro·pho·tom·e·ter : a photometry device for the measurement of spectral transmissions, reflectance, or relative emissions. Spectrophotometers are normally equipped with dispersion optics (prism or grating) to give a continuous spectral curve

spectrophotometric curve : a curve measured on a spectrophotometer hence, a graph of relative reflectance or transmittance (or absorption) as the ordinate, plotted versus wavelengths or frequency as the abscissa. The most common curves in the visible region use wavelength units of a nanometer, with the short wavelength to the left of the scale. The word spectral is frequently used in place of the longer spectrophotometric, but they are not necessarily synonymous

spec·trum 1: band of colors produced when sunlight is passed through a prism 2: spatial arrangements of components of radiant energy in order of their wavelengths, wave numbers, or frequency ___ spec·tral adj

speech aid : any therapy or any instrument, apparatus, or device used to improve speech quality

speech aid prosthesis : a removable maxillofacial prosthesis used to restore an acquired or congenital defect of the soft palate with a portion extending into the pharynx to separate the oropharynx and nasopharynx during phonation and deglutition, thereby completing the palatopharyngeal sphincter—syn ADULT S.A.P., PEDIATRIC S.A.P.—called also pharyngeal s.a.p, cleft palate prosthesis

speech aid prosthesis modification: any revision of a pediatric or adult speech aid prosthesis not necessitating its replacement

speech articulation 1: the production of individual sounds in connected discourse 2: the movement and placement during speech of the organs that serve to interrupt or modify the voiced or unvoiced air stream into meaningful sounds 3: the speech function performed largely through the movements of the lower jaw, lips, tongue, and soft palate

speech bulb: see SPEECH AID PROSTHESIS

speech prosthesis: see SPEECH AID PROSTHESIS

spherical form of occlusion : an arrangement of teeth that places their occlusal surfaces on the surface of an imaginary sphere (usually 8 inches in diameter) with its center above the level of the teeth (GPT-4)

sphinc·ter : a ringlike band of muscle fibers that constricts to close an orifice or passage

spider partial : a unilateral partial removable dental prosthesis

1splint 1: a rigid or flexible device that maintains in position a displaced or movable part; also used to keep in place and protect an injured part 2: a rigid or flexible material used to protect, immobilize, or restrict motion in a part—see ANDERSON S., CAP S., ESSIG S., FUNCTIONAL OCCLUSAL S., GUNNING’S S., INTERDENTAL S., KINGSLEY S., LABIAL S., LINGUAL S., PROVISIONAL S., RESIN-BONDED S., SOFT S., SURGICAL S., WIRE S.

2splint : to immobilize, support, or brace

splint·ing 1: in dentistry, the joining of two or more teeth into a rigid unit by means of fixed or removable restorations or devices 2:in physiology, prolonged muscle spasms that inhibit or prevent movement

split-cast method 1: a procedure for placing indexed casts on an articulator to facilitate their removal and replacement on the instrument 2: the procedure of checking the ability of an articulator to receive or be adjusted to a maxillomandibular relation record (GPT-4)

split-cast mounting : a method of mounting casts wherein the dental cast’s base is sharply grooved and keyed to the mounting ring’s base. The procedure allows verifying the accuracy of the mounting, ease of removal and replacement of the casts

split-dowel crown : an artificial crown supported and retained by a dowel that was split longitudinally in an attempt to use spring retention in an undersized dowel space

split-thickness graft : a transplant of skin or mucous membrane consisting of epithelium and a portion of the dermis

spontaneous anterior dislocation: see MANDIBULAR DISLOCATION

spontaneous fracture : a fracture occurring without any external injury trauma-also called pathologic fracture

spoon denture : a maxillary provisional removable dental prosthesis, without clasps, whose palatal resin base resembles the shape of a spoon. The resin base does not contact the lingual surfaces of the teeth and is confined to the central portion of the palate. It was often used during periodontal treatment because the resin base extension did not promote plaque accumulation around the teeth and permitted surgical procedures to be performed

sports dentistry : all aspects of dentistry, either preventive or therapeutic, directly or indirectly involved with sports and recreation

spot grinding: see OCCLUSAL RESHAPING

spring plate : according to James Harrison Prothero, DDS, Emeritus Professor of Prosthetic Dentistry and Metallurgy at Northwestern University Dental School, Chicago, IL, “a spring plate was a denture molded over the cast of a mouth with teeth bearing the relation to each other as stated (ed. note: providing lingual undercuts), which would spring as it passes over the points of nearest approach of the teeth involved and resume its normal width without undue lateral pressure when firmly seated on the oral tissues”—called also spring lock bridge

sprue 1: the channel or hole through which plastic or metal is poured or cast into a gate or reservoir and then into a mold 2: the cast metal or plastic that connects a casting to the residual sprue button

sprue button : the material remaining in the reservoir of the mold after a dental casting

sprue former: a wax, plastic, or metal pattern used to form the channel or channels allowing molten metal to flow into a mold to make a casting

sprue pin: see SPRUE FORMER

stab·il·ize vb –liz·ed; –liz·ing vt, stabilization v (1861) 1: to make firm, steadfast, stable 2: to hold steady, as to maintain the stability of any object by means of a stabilizer

sta·bil·i·ty 1: that quality of maintaining a constant character or position in the presence of forces that threaten to disturb it; the quality of being stable; to stand or endure 2: the quality of a removable dental prosthesis to be firm, steady, or constant, to resist displacement by functional horizontal or rotational stresses 3. resistance to horizontal displacement of a prosthesis—see DENTURE S., DIMENSIONAL S., OCCLUSAL S.

sta·b·i·li·za·tion : the seating of a fixed or removable denture so that it will not tilt or be displaced under pressure (GPT-1)

stab·il·ize –liz·ed –liz·ing ; stabilization 1: to make firm, steadfast, stable 2: to hold steady, as to maintain the stability of any object by means of a stabilizer

stabilized base plate: see STABILIZED RECORD BASE

stabilized record base : a record base lined with a material to improve its fit and adaptation to the underlying supporting tissues

stabilizing circumferential clasp arm : a circumferential clasp arm that is relatively rigid and contacts the height of contour of the tooth

1stain 1: a soiled or discolored spot; a spot of color in contrast to the surrounding area 2: a preparation used in staining 3: in dentistry, the discoloration of a tooth surface or surfaces as a result of ingested materials, bacterial action, tobacco, and/or other substances. This may be intrinsic, extrinsic, acquired, or developmental

2stain 1: to suffuse with color 2: to color by processes affecting chemically or otherwise the material itself 3: in dentistry, to intentionally alter restorations through the application of intrinsic or extrinsic colorants to achieve a desired effect, best termed characterization or to characterize a restoration

stanch 1: to check or stop the flow of; also: to stop the flow of blood from (a wound) 2 a: to stop or check in its course 2b: to make watertight: stop up

standard illuminant : the illuminants A, B. C, D (and others) defined by the CIE in terms of their relative power distribution curves. “A” is an illuminant with a Planckion temperature of approximately 2854°K. It is intended to represent a common tungsten filament source. “B” approximates solar radiation—4870°K—and is obsolete. “C” is average daylight, 6740°K. “D” is daylight with the near ultraviolet source included

standard light source : a reference light source whose spectral power distribution is known

standard observer : a hypothetical observer with a visual response mechanism possessing the calorimetric properties defined by the CIE in 1931 as representative of the human population having normal color vision

standard of care: the level of care that reasonably prudent healthcare providers in the same or a similar locality would provide under similar circumstances

stat·ic : related to bodies at rest or forces in equilibrium

static fatigue : the delayed failure of glass and ceramic materials resulting from stress enhanced chemical reactions aided by water vapor acting on surface cracks. Analogous to stress corrosion occurring in metals

static relation : the relationship between two parts that are not in motion

stay plate n obj: see INTERIM DENTAL PROSTHESIS

Steinmann’s pin [Fritz Steinmann, Swiss surgeon, 1872-1932]: eponym for a firm metal pin that is sharpened on one end; used for the internal fixation of fractures

steam cleaning: the process of debris removal from a restoration, framework or dental prosthesis through use of pressurized steam

sten·o·sis ;-no·ses (ca. 1860): a narrowing or constriction in the diameter of a passage or orifice—ste·not·ic

stent [Charles R. Stent, English dentist, 18??-1901]: eponym for any supplementary prosthesis used in conjunction with a surgical procedure to keep a skin graft in place; often modified with acrylic resin or dental modeling impression compound that was previously termedStent’s mass; also refers to any device or mold used to hold a skin graft in place or provide support for anastomosed structures— see NASAL S., SURGICAL S.

ste·reo·graph : an instrument that records mandibular movement in three planes. Engraving, milling, or burnishing the recording medium by means of styli, teeth, abrasive rims, or rotary instruments thus obtains the registrations

stereographic record : an intra or extraoral recording of mandibular movement as viewed in three planes in which the registrations are obtained by engraving, milling, or burnishing the recording medium by means of studs, rotary instruments, styli, teeth, or abrasive rims

ster·ile : free from living microorganisms; aseptic

sterile technique : a standard surgical technique in which an aseptic area is established and maintained, including proper sterilization of instruments, drapes, gowns, gloves, and the surgical area. With respect to dental implant placement, the systematic maintenance of asepsis with special emphasis on non-contamination of instruments and implant elements throughout an implant placement procedure

ster·il·i·za·tion : the process of completely eliminating microbial viability

stip·ple ; stip·pled ;stip·pling 1: to engrave by means of dots or/and flicks 2: to make small short touches that together produce an even or softly graded shadow 3: to speckle or fleck—stip·pler

stock tray : a metal prefabricated impression tray typically available in various sizes and used principally for preliminary impressions—compCUSTOM TRAY

sto·ma ,  sto·ma·ta ,  sto·mas 1: any simple bodily opening 2: an artificial permanent opening usually made surgically

sto·mat·o·gnath·ic : denoting the jaws and mouth collectively

stomatognathic system : the combination of structures involved in speech, receiving, mastication, and deglutition as well as parafunctional actions

sto·ma·tol·o·gy : the study of the structures, functions, and diseases of the mouth

stone n : see DENTAL STONE

stone die: see MODEL, REPLICA

stop clasp : as described by James Harrison Prothero, DDS, “the stop clasp was an early forerunner to the conventional clasp assembly by the addition of a lug (occlusal rest) to the retentive and reciprocal clasp assembly”

Prothero JH. Prosthetic dentistry. 2nd ed. Chicago: Medico-Dental Publishing Co., 1916:332.

strain : change in length per unit length when stress is applied; the change in length/original length

stress : force per unit area; a force exerted on one body that presses on, pulls on, pushes against, or tends to invest or compress another body; the deformation caused in a body by such a force; an internal force that resists an externally applied load or force. It is normally defined in terms of mechanical stress, which is the force divided by the perpendicular cross sectional area over which the force is applied—see COMPRESSIVE S., SHEARING S., TENSILE S.

stress-bearing area: see STRESS-BEARING REGION

stress-bearing region 1. the surfaces of oral structures that resist forces, strains, or pressures brought on them during function2: the portion of the mouth capable of providing support for a denture—see also DENTURE FOUNDATION AREA

stress breaker: see STRESS DIRECTOR

stress concentration: an area or point of significantly higher stress associated with a structural discontinuity such as a crack or pore; a marked change in dimension of a structure

stress director : a device or system that relieves specific dental structures of part or all of the occlusal forces and redirects those forces to other bearing structures or regions

stress-strain curve: the graphic representation of the tensile or compressive stress and associated strain of a material

study cast obs: see DIAGNOSTIC CAST

stylus tracing : a planar tracing that resembles an arrowhead or gothic arch made by means of a device attached to the opposing arches. The shape of the tracing depends on the location of the marking point relative to the tracing table, i.e., in the incisal region as opposed to posteriorly. The apex of a properly made anterior tracing is considered to indicate the centric relation position, called also arrow-point tracing,gothic arch tracing, needlepoint tracing—see CENTRAL BEARING TRACING DEVICE

sub antral augmentation : augmentation of the antral floor with autologous bone or bone substitutes to provide a host site for dental implants – called also, SINUS LIFT, ANTHROPLASTY

subcondylar fracture : a fracture beneath the condylar head and within the condylar neck

subdermal implant: see MUCOSAL INSERT

subgingival margin: the restoration margin or tooth preparation finish line that is located apical to the free gingival tissue

sub·lin·gual : pertaining to the region or structures located beneath the tongue

sublingual crescent : the crescent shaped area on the anterior floor of the mouth formed by the lingual wall of the mandible and the adjacent sublingual fold. It is the area of the anterior alveolingual sulcus

sublingual fold : the crescent-shaped area on the floor of the mouth following the inner wall of the mandible and tapering toward the molar region. The sublingual gland and submaxillary duct form it

sublingual fossa : a smooth depression on the lingual surface of the body of the mandible near the midline, above the mylohyoid line and below the alveolus. This fossa accommodates part of the sublingual gland

sub·lux·a·tion : an incomplete or partial dislocation that is self-reducing— see CONDYLAR SUBLUXATION

submersible endosteal implant obj: see ENDOSTEAL DENTAL IMPLANT

submersible implant obj: see ENDOSTEAL DENTAL IMPLANT

submucosal inserts: see MUCOSAL INSERT

submucous cleft palate: see OCCULT CLEFT PALATE

subocclusal connector : an interproximal nonrigid connector positioned apical to and not in communication with the occlusal plane

subocclusal surface : a portion of the occlusal surface of a tooth that is below the level of the occluding portion of the tooth (GPT-1)

subperiosteal dental implant : an eposteal dental implant that is placed beneath the periosteum while overlying the bony cortex – first attributed to Swedish Dentist, G.S. Dahl

subperiosteal dental implant abutment : that portion of the implant that protrudes through the mucosa into the oral cavity for the retention or support of a crown or a fixed removable denture (GPT-4)—see ABUTMENT

subperiosteal dental implant substructure : a cast metal framework that fits on the residual ridge beneath the periosteum and provides support for a dental prosthesis by means of posts or other mechanisms protruding through the mucosa; the implant body

subperiosteal dental implant superstructure : the metal framework, usually within a removable dental prosthesis, that fits onto the dental implant abutment(s) and provides retention for artificial teeth and the denture base material of the prosthesis. It is a structural component of the fixed or removable dental prosthesis

subperiosteal fracture : a bony fracture occurring beneath the periosteum, without displacement

subtractive color system : the system whereby light is removed by filtration or absorption from a white source. The primary colors of the subtractive system are magenta, cyan, and yellow—called also pigment mixture color system

subtractive primary colors : the primary colorant substances for pigment and filtering mixtures typically evoking responses of cyan (blue-green), magenta (red-blue), and yellow (red-green). The complementary colors of the subtractive primary colors are red, green, and blue. Magenta is a mixture of red and blue and is the complement of green. Cyan is a mixture of blue and green and is the complement of red. Yellow is a mixture of red and green and is the complement of blue

suck-back porosity : a shrinkage void in a solidified casting opposite the location of the sprue attachment, resulting from a heat swell and localized lingering of molten metal after the casting, as a whole, has solidified

suction chamber : relief provided in the midline palatal area of a maxillary denture in an attempt to obtain additional retention by means of the theoretical vacuum created (GPT-4)

suction cup : a thin rubber disk, usually with a hole in its center, which fits over a button that is larger in diameter than the hole. This causes the disk to assume a cup shape. When applied to the tissue surface of a denture, the cup attaches itself to the mucous membrane by suction (GPT-1)

sulcular epithelium: see CREVICULAR EPITHELIUM

sul·cus n: see GINGIVAL CREVICE

superimposed prosthesis: see OVERDENTURE

superjacent : lying above or upon; overlying

su·per·struc·ture : the superior part of a fixed or removable dental prosthesis that includes the replacement teeth and associated gingival/alveolar structures

1sup·port : the foundation area on which a dental prosthesis rests. With respect to dental prostheses, the resistance to displacement away from the basal tissue or underlying structures

2sup·port: to hold up, serve as a foundation, or prop for

supporting area 1: the surface of the mouth available for support of a denture (GPT-1) 2: those areas of the maxillary and mandibular edentulous ridges that are considered best suited to carry the forces of mastication when the dentures are in function (GPT-1)

supporting cusps : those cusps or incisal edges of teeth that contact in and support maximum intercuspation. Usually facial cusps of the mandibular posterior teeth, the maxillary palatal cusps, and the incisal edges of the mandibular anterior teeth

su·pra·bulge : that portion of a tooth or crown that converges toward the occlusal surface, i.e., above the height of contour

suprabulge clasp : any partial removable dental prosthesis retentive clasp that approaches the retentive undercut from an occlusal or suprabulge direction

su·pra·erup·tion : movement of a tooth or teeth above the normal occlusal plane

su·pra·gin·gi·val 1: located above the gingiva 2: that portion of a natural or artificial tooth that is coronal to the gingival crest

su·pra·men·tal·e : a landmark representing the deepest point of the symphyseal cavity between infradentale and pogonion

su·pra·oc·clus·ion : malocclusion in which the occluding surfaces of teeth extend beyond the normal occlusal plane—called also overeruption

surface tension : a property of liquids in which the exposed surface tends to contract to the smallest possible area, as in the spherical formation of drops. This is a phenomenon attributed to the attractive forces, or cohesion, between the molecules of the liquid

sur·fac·tant n: a surface active substance (as a detergent) applied to a substrate to facilitate its wetting by another material

surgical baseplate: see SURGICAL OBTURATOR

surgical guide: see SURGICAL PROSTHESIS, SURGICAL TEMPLATE

surgical maxillomandibular relation : the establishing and recording of the correct vertical dimension and centric relation between a surgically exposed bone surface and opposite arch at the time of making a surgical bone impression

surgical obturator : a temporary maxillofacial prosthesis inserted during or immediately following surgical or traumatic loss of a portion or all of one or both maxillary bones and contiguous alveolar structures (i.e. gingival tissue, teeth). Frequent revisions of surgical obturators are necessary during the ensuing healing phase (approximately six months). Some dentists prefer to replace many or all teeth removed by the surgical procedure with the surgical obturator, while others do not replace any teeth. Further surgical revisions may require fabrication of another surgical obturator (i.e., an initially planned small defect may be revised and greatly enlarged after the final pathologic report indicates margins are not free of tumor)—see INTERIM OBTURATOR

surgical occlusion rim : an occlusion rim used in recording surgical maxillomandibular relations

surgical prosthesis : any ancillary prosthesis prepared for insertion during a surgical procedure and intended for short-term use

surgical splint : any ancillary prosthesis designed to utilize existing teeth and/or alveolar processes as points of anchorage to assist in stabilization and immobilization of broken bones during healing. It is used to re-establish, as much as possible, normal occlusal relationships, during the process of immobilization. Frequently, an existing prosthesis (i.e. a patient’s complete removable dental prosthesis) can be modified to serve as a surgical splint. Frequently surgical splints have arch bars added to facilitate intermaxillary fixation. Rubber elastics may be used to assist in this process. Circummandibular eyelet hooks can be utilized for enhanced stabilization with wiring to adjacent bone— synCAST METAL SPLINT, FENESTRATED SPLINT, GUNNING SPLINT, KINGSLEY SPLINT, LABIOLINGUAL SPLINT, MODIFIED GUNNING SPLINT

surgical stay plate: see SURGICAL OBTURATOR

surgical stent : named for the dentist who first described their use, Charles R. Stent, such ancillary prostheses are used to apply pressure to soft tissues to facilitate healing and prevent cicatrization or collapse—syn COLUMELLAR STENT, PERIODONTAL STENT, SKIN GRAFT STENT

surgical template 1: a thin, transparent form duplicating the tissue surface of a dental prosthesis and used as a guide for surgically shaping the alveolar process 2: a guide used to assist in proper surgical placement and angulation of dental implants 3: a guide used to assist in establishing the desired occlusion during orthognathic surgery

surface tension : a property of liquids in which the exposed surface tends to contract to the smallest possible area, as in the spherical formation of drops; this is a phenomenon attributed to the attractive forces, or cohesion, between the molecules of the liquid

sur·vey 1: to examine as to condition, value, or situation; to appraise 2: to determine the form and position of a given entity by means of taking linear and angular measurements 3: to inspect or scrutinize 4: the procedure of locating and delineating the contour and position of the abutment teeth and associated structures before designing a removable partial denture (GPT-1) sur·vey·ed, sur·vey·ing

survey line : a line produced on a cast by a surveyor marking the greatest prominence of contour in relation to the planned path of placement of a restoration

sur·vey·ing : an analysis and comparison of the prominence of intraoral contours associated with the fabrication of a dental prosthesis

sur·vey·or : a paralleling instrument used in construction of a dental prosthesis to locate and delineate the contours and relative positions of abutment teeth and associated structures

sut·ur·ing : the process of uniting the tissues separated by either a traumatic or a surgical wound in a specific manner using an appropriate material

1swage : any tool used for shaping metal by striking with a hammer or sledgehammer

2swage ; swaged ; swag·ing : to shape a material by hammering or adapting it onto a die with a swage instrument

swallowing threshold : the critical moment of reflex action initiated by sufficient stimulation before the act of deglutition

sympathetic nervous system : the part of the autonomic nervous system that responds to dangerous or threatening situations by preparing a person physiologically for “fight or flight”— see PARASYMPATHETIC NERVOUS SYSTEM

symphysis –physes 1: a type of cartilaginous joint in which the opposed bony surfaces are firmly united by a plate of fibrocartilage 2: the immovable dense midline articulation of the right and left halves of the adult mandible

symp·tom : subjective evidence of disease or physical disturbance; something that indicates the presence of a bodily disorder

syn·chro·ny : the simultaneous appearance of two separate events

syn·drome : a group of symptoms that occur together

synovial fluid : a viscid fluid contained in joint cavities and secreted by the synovial membrane

synovial membrane: the articular membrane composed of specialized endothelial cells capable of producing synovial fluid filling the joint cavity surrounded by the membrane

systemic etiologic factors : generalized biologic factors that are implicated in the causation, modification, and/or perpetuation of a disease entity