the present invention is advantageously applied in lower dentures as shown in fig1 . the present denture as a whole is designated reference numeral 1 , and includes an upper section 2 including ranged sections , hinging areas 3 , and flange extensions 4 . upper section 2 incorporates analogous elements of conventional dentures . in fig1 upper section 2 includes teeth such as incisors 6 and molars 7 . the present invention may be used to secure and stabilize appliances across any underlying substantially straight section of an intraoral bone ridge , and is particularly advantageous when used across the mylohyoid ridge 5 , as shown in fig2 . preferably , two devices according to the present invention are advantageously positioned over both mylohyoid ridges 5 , with the flange extensions 4 applying slight pressure to the tissue of the submandibular fossae under the mylohyoid ridge , as seen in fig3 . the interior of a ranged denture useful in the present invention , which contacts the tissue of the mouth , is shaped to conform to the individual user , being the complimentary shape of substantially all features of the user &# 39 ; s intraoral tissue that the denture will overlay . this may be accomplished by making a cast of the user &# 39 ; s mouth . the cast preparation may be accomplished with readily available materials and techniques with the stipulation that the tissue over which flange extensions 4 will be positioned must be included in the casting . preferred materials for making the cast include gypsum , resin , silicone , and rubber . preferred techniques for making the cast include forming a dental impression , using these materials to create a mold , which is then poured with a thermal setting modeling composition . the resultant model of the user &# 39 ; s mouth is then prepared before creating the appropriate flanged appliance . areas on the model that correspond to the tissue over which flange extensions 4 will be positioned is relieved or shaved . preferably , from 0 . 2 to 1 mm is relieved from these areas . most preferably , from 0 . 25 to 0 . 50 mm is relieved . for example , in appliances such as lower dentures where the bone ridges used are the mylohyoid ridges , the area relieved corresponds to the tissue overlying the submandibular fossae . the appropriate flanged appliance of the present invention is then manufactured on the model . preferably , hard denture base is use to create the foundation of the appliance . preferred materials for the denture base include hard acrylics , such as methyl methacrylate with a low water content , vinyl , and silicone . the hard denture base may be textured or detailed to simulate gums and like tissue where appropriate . in lower dentures 1 , upper section 2 and flanges 4 are most preferably created unitarily from hard acrylic , and teeth 6 and 7 are inserted or rendered on upper section 2 . the hinging section 3 may then be created . the considerations important in the creation of the hinging section include : 1 ) sufficient freedom of movement such that the attached flange extension may in one state be positioned to apply pressure against the tissue overlying a target fossa , and in a second state be unrestricted by any bone ridge ; 2 ) positional memory for at least the above first state , such that once installed , the attached flange extensions will reposition to exert the necessary pressure in cooperation with the appliance as a whole , and will distribute forces across the height of contour over which the hinging section rests ; and 3 ) the hinging section should remain smooth to the tissue , having no fissures or sharp protrusions to irritate and / or lacerate tissue . disparate elements may be used to provide the necessary functionalities . a biasing mechanism can be used to urge the flange extension to pivot about the hinging area in a direction towards the fossae proximate to the bone ridge , having a stop when the flange extension reaches the first state , and flexible materials incorporated into the hinging ares to cover the biasing mechanism . alternatively , the necessary functionalities may be met by the inherent resilience in the materials incorporated into the hinging areas or by a combination of both . as can be seen best in fig9 - 11 , a portion of upper section 2 corresponding to the interior part of a flange which lies along the gums of the mouth , and the flange extension 4 , in the first state meet at a line which is substantially over and parallel to the line demarcated by a substantially linear bone ridge . this configuration may be achieved by forming 2 and 4 unitarily , then cutting a groove or grooves through the unitary piece to form the separate parts . alternatively , 2 and 4 may be formed separately , having angled edges . the angle defined by the cut sides of the groove , or the angled edges of 2 and 4 , is preferably between 30 degrees and 100 degrees , being preferably about 35 degrees - 50 degrees when a single groove is cut , as shown in fig9 and about 35 degrees - 90 degrees when two grooves are cut , as shown in fig1 . preferred constructions of the hinged section utilize semi - rigid materials in a wedge or wedges 10 filled in between upper section 2 and flange extension 4 . further , to enhance the positional memory across the hinged section , an additional liner of semi - rigid material 9 may be applied to the inside surface around the hinged area to provide biasing . liner 9 may run along the full height of the appliance , as shown in fig6 and 7 , or be substantially located only in the hinged section . the denture base material of 2 and 4 may be relieved to accommodate liner 9 , or the liner may be cast prior to 2 and 4 upon the model of the users mouth . the passive , semi - rigid materials used in wedge 10 and liner 9 include any intraorally acceptable polymeric material which preferably has sufficient elasticity that a user may flex the hinged section to the second state , yet have sufficient rigidity to maintain the first state under typical loads for the appliance . a device such as disclosed by eckland , u . s . pat . no . 5 , 055 , 041 may be used to determine the necessary characteristics of the material . preferably , the material is an acrylic . most preferably , the material is a methyl methacrylate , with higher water content than used in a hard denture base . the use of methyl methacrylate is desirable , since its rigidity and elasticity may be altered by the level of hydration in curing . when both the wedge material 10 and liner 9 is used in the hinged area , the wedge material is preferably less rigid than the liner material . as the denture base may also be made from methyl methacrylate with a low water content , the materials necessary for the instant invention are readily available in this most preferred embodiment . optionally , further mechanisms 11 may be used to enhance the positional memory of the hinging section . these may be used in conjunction with liner 9 , as shown in fig9 or without a liner , as shown in fig1 . the mechanism 11 may be of the spring loaded biasing type having hinge 12 , spring 13 , and biasing members as shown in fig5 . this type of mechanism when utilized should be made from biocompatible materials , such as surgical steel , and have an axis of hinging action substantially along the line demarcated by the underlying bone ridge . preferably , these mechanisms are embedded into the denture base material of 2 and 4 prior to hardening of the base material . other mechanisms 11 may be used including living hinges , such as a rigid sheet of polypropylene or like crystalline plastic which is scored along the hinging axis . this type of mechanism may be embedded in the denture base material of 2 and 4 , in substantially the same manner as the spring loaded biasing type . holes may be provided on both sides of the score line such that the denture base material , as it cures , fixes the position of the mechanism . when mechanisms 11 are used to provide the positional memory and / or hinging action , the requirements on materials filling wedges 10 and liner 9 may be relaxed , as they no longer need to supply the transferred functionality . accordingly , a wider range of materials may be used , the important consideration being the ability to provide a smooth surface for contacting tissue throughout the motion of the embedded mechanism . an alginate impression of a patient &# 39 ; s mouth was made in the dentist chair which extended into the lingual sulcus . a custom tray was then fabricated in the lab , extending 3 mm from the sulcus in the lingual area . the custom tray was then fitted to the alveolar ridge , being trimmed and boarder molded as needed . while the impression making and fitting were performed , the patient was instructed to open his / her mouth to its fullest extent , and to place their tongue against the palate . any displacement caused by this is corrected . the impression is then corrected with the modified custom tray . the resultant corrected impression was then poured in the lab to form a model of the patient &# 39 ; s mouth in dental stone , and allowed to set . one to two millimeters was relieved from the area representing both the submandibular fossae in equal amounts . a mandibular denture was created on the model from methyl methacrylate denture base . 45 ° v shaped grooves were cut along both of the mylohyoid ridges , separating the denture into an upper section , and two flange extensions . methyl methacrylate having a higher water content was filled into the grooves , and along the surface around the groove on the tissue contacting side of the denture . a mixture of 4 : 8 liquid to methyl methacrylate powder was used in the groove , and 4 : 10 liquid to powder was used along the contacting surface . a ninety - five year old woman upon losing her conventional lower denture was fitted with a mandibular denture according to example 1 . the patient had worn dentures for over fifty years , and the anterior portion of her mandibular alveolar ridge had resorbed to the point of almost being flat , leading to the instability and loss of her conventional dentures . despite this , the improved stability of the dentures prepared according to the present invention allowed the patient to continue to wear lower dentures . a sixty year old man with an edentulous mandibular ridge had previously been unable to tolerate conventional lower dentures . after fitting the patient with mandibular dentures according to example 1 , the patient was able to immediately eat an apple without causing dislodgement of the dentures . it is to be understood that the present invention is not limited to the embodiments described above , but encompasses any and all embodiments within the scope of the following claims .