 Hello everyone, welcome back to another session in dentistry and more so in prosthodontics today's session is about denture bearing area in maxilla so the danger bearing area basically divided into limiting structures and supporting structures and also the relief areas so this session is about These structures that is a danger bearing area in maxilla. So this will be a lengthy session will be Discussing in detail about the various structures various anatomical parts its clinical significance and what are the clinical Changes of consideration we should do while making a Maxillary denture. Okay, so let's see the details of danger bearing area and maxilla So the ultimate support for the maxillary denture are the bonds of maxilla and palatine bond and The anatomical landmarks in maxilla are the limiting structures supporting structures and relief areas So this is a somewhat Like a maxilla an idangulous maxilla. We have various anatomical structures We'll start from here, which is known as labial freedom Then the incisive papillae the palatal rugae then the buccal freedom. Here also one buccal freedom is there Then the crest of alveolar rich maxillary tuberosity the hamlur notch it's a sulcus area just behind the maxillary tuberosity and the fovea palatine and This is the post palatal C Consist of anterior and posterior vibrating lines and the buccal sulcus and the labial sulcus So each part has got importance in fabrication of upper denture So we'll start with the limiting structures limiting structures of maxilla. So we have labial freedom Then labial vestibule Then buccal freedom and buccal vestibule buccal freedom buccal vestibule then hamlur notch Then the post palatal seal and finally the fovea palatine These are the limiting structures limiting structures means These are the sites that will guide us in having an optimum extension of danger So as to engage maximum surface area without encroaching upon the muscle action So we should limit The upper denture with respect to these areas. Otherwise the muscle action will Act upon the denture and it will cause dislodgement. That is why it's known as limiting structures The boundaries should be limited or confined to these anatomical landmarks So we'll start with the labial freedom. So the first one is labial freedom It is a single or double Fibre span covered by mucus membrane which extends from the labial aspect of residual ridge So this is a labial aspect of residual ridge And it extends to the lip Okay to extends to the lip and labial aspect of residual ridge which contains no muscle fibers So what is the clinical significance of labial freedom? It limits labial flange of denture and it has to be relieved While making impression In other to prevent the dislodgement of the denture and to prevent ulceration So it is seen as a v-shaped notch in the impression V-shaped notch Okay, and the next one is labial vestibule. Okay labial vestibule It is bi-laterally present From the labial freedom to the buccal freedom. Okay So it extends from buccal freedom on one side to the other being divided into right and left by Labial freedom and it has anteriorly Orbicularis oris muscle. Okay orbicularis oris muscle anteriorly and posteriorly by the labial aspect of alveolar ridge And the clinical significance the labial flange of the denture will be in complete contact with the labial vestibule To provide a peripheral seal in the denture Next we have buccal freedom. Okay, so this is a buccal freedom We have two buccal freedom. One is on right side and one is on left side So it is a band of fibrous tissue overlying the levator Anculi oris. Okay, so levator Anculi oris and Which divides a labial vestibule from buccal vestibule? Okay So this is a buccal vestibule and this is a labial Sorry, this is a buccal vestibule and this is a labial vestibule So the clinical significance it has got Musculature muscular attachment this orbicularis oris orbicularis oris pulls this freedom Forward whereas the buccanator pulls it backward. Okay So we need to give adequate relief To prevent the dislodgement of the denture because it can move posteriorly as a result of buccanator the denture can Go posteriorly because of this buccanator muscle action and anteriorly with the action of orbicularis oris Okay, you can move anteriorly because of the action of orbicularis oris and also the buccanator Which may bring it posteriorly So it requires more clearance for its action than labial freedom. So we have learned about labial freedom So we need to give more clearance than the labial freedom for buccal freedom because It has got all these muscles. That is levator, ankle, oris buccanator And also orbicularis oris So all these muscles have action it may bring it forward Mecially backward. So we need to give more clearance than labial freedom So the next one is buccal vestibule. So buccal vestibule It extends from the buccal freedom. So this is a buccal freedom. It extends from buccal freedom to the haemular notch So this is a labial vestibule. This is buccal vestibule. It starts from the buccal freedom to the haemular notch So it bounded externally by the cheek. So here it We have the cheek muscles and internally by the residual Ridge and The size of this vestibule varies because of the contraction of buccanator muscle. Okay, so buccanator muscle Depends the size of this vestibule. So clinically why it is important because we need to keep the patient's mouth Half-open while taking the impression because opening of mouth during final impression causes the Coronoid process. So there will be coronoid process which will come forward or Antiretri which narrows the buccal vestibule. So we need to keep the patient's mouth half-open not completely open if we Kept it completely open. What happens the coronoid process come anteriorly and do the interference So we need to keep it half-open. So compared to this labial sulcus, this buccal sulcus has more got more retention because the labial flange Compared to this labial flange of the denture this buccal flange has got less interference So it can give more retention or maximum retention can be obtained from the buccal vestibule or the buccal flange of the denture So the next Structure is Hamilar notch. Okay. So Hamilar notch. So Hamilar notch forms the distal limit of the buccal vestibule Okay, so the buccal vestibule comes here and it reaches here This is the distal limit of buccal vestibule. Okay, it is behind the maxillary tuberosity So it is located between the tuberosity and Hamulus of the medial therigoid plate So there is always a muscle attached to it. That is the therigo mandibular raffae so The clinical importance is if the denture border. Okay is short of this Hamilar notch what happens is it will not have a posterior seal which result in loss of retention of the denture So if it is less than this Hamilar notch if it is coming like this It will have no retention that is the posterior seal is absent And what if it is going beyond the Hamilar notch if it is crossing this Hamilar notch What happens is the therigo mandibular raffae is pulled forward when the patient opens the mouth Which causes a dislodgement of the denture So if it is less or if it is beyond we have the denture retention problem So it should be adequate enough Which will not interfere the therigo mandibular raffae will get the good posterior seal and good retention of the maxillary denture Now we have the posterior palatal seal area or which is also known as PPS or post Damn, okay So as per GPT definition it is a soft tissue at or along the junction of hard and soft palate On which the pressure along the physiological limits of the tissues can be applied by the denture to aid in the retention of the denture Okay, so it is a Final posterior limit of the denture. Okay, when we apply a physiological limit it gives good retention So it has got two parts. The one is the post palatal seal Post palatal seal and the second is a terigo Maxillary seal, okay post palatal seal and terigo maxillary seal and It's extension and Teriorly it's extension. So this green area is a post palatal seal and teriorly it has got and T-day vibrating line posteriorly by the straight posterior vibrating line and Laterally by three to four millimeter and teriolateral to the hamilar notch and teriolateral to the amular notch Okay, so this is the post palatal seal So it has got two structures. That is a post palatal seal and terigo maxillary seal So the post palatal seal it is a part of the posterior palatal seal area that extend between the two maxillary Tuberosity, so this is the tuberosity. So these are the area which is between these two Whereas a terigo maxillary seal it is a part of the posterior palatal seal that extends across the hamilar notch So these part Across the hamilar notch. Okay, so it was extending two to four millimeter Anterior laterally, so that part is known as terigo maxillary seal. Okay, so it is extending three to four millimeter Anterior laterally to end the muco-dringival junction on the posterior part of maxillary ridge So this is the post palatal seal and these part is known as terigo maxillary seal So we need to learn The vibrating line so vibrating line is nothing but an imaginary line across the posterior part of palette palette marking The division between movable and immobile tissues of the soft palette Which can be identified when the movable tissues in moving this is based on the GPT definition Okay, so it is between the immobile and movable tissues of soft palette So dentures should always Extend one to two millimeter posterior to this vibrating lines So we have two vibrating lines and T. They're vibrating line, which is Cupid post shape and the posterior vibrating line, which is almost a straight line So and T. They're vibrating line, which is an imaginary line lying at the junction between immobile tissues over the heart palette and The slightly movable tissues of the soft palette. So it is a cupid bow shape. So it is like Cupid bow shape Because of the shape of this underlying bone So we must do Val salva manual When recording this anterior vibrating line, so in order to get a good Impression we need to Perform ask the patient to perform while salva manual. It is nothing but ask the patient to close his nostrils Firmly and gently blow through his nose Then we'll get the anterior vibrating line Whereas a posterior vibrating line this one Which is the imaginary line located at the junction of soft palette that shows limited moments and the soft palette That shows marked moment. So this is a heart palette and this is soft palette So limited moments and marked moment. So the straight line. This is a heart palette and The slightly immobile tissues of soft tissue. Okay, this is limited and marked tissues of the soft palette only and the clinical significance of this PPS is It maintains the contact with the anterior portion of the soft palette during functional moments of moments such as domestication Deglutination or phonation So therefore the primary purpose of the posterior palatal seal is a retention of maxillary denture and It reduces the tendency for gag reflex as it prevents the formation of gap between the denture base and the soft palette during these functional moments and also it prevents food accumulation between posterior part of the denture and soft palette Okay, and the last limiting structure is a fovea palataining These are the depressions or Intentations situated on the soft palette on either side of midline. So these are the fovea palataining which is present on the soft palette on either side of midline it is formed by Coalescence of the decks of several mucus glands and The position of this fovea palataining also influences the posterior border of the denture Because the secretion of the fovea spreads as a thin film on the denture therefore helps in retention So the clinically In patients with thick Rope saliva the fovea palatinate should be left uncovered Or else the thick saliva flowing between the tissue and the denture Which can increase the Hydrostatic pressure and displace the denture if it is very thin saliva it will aid in retention But if it is a very thick saliva we need to relieve the area to Help the denture to get maximum retention if it is very thick it might cause a dislodgement because of the hydrostatic pressure Now let's move on to the supporting Structures of maxilla it is primary stress bearing and the Secondary stress bearing areas okay, so primary stress bearing hard palette and The posterior lateral slope of the residual alveolar ridge posterior lateral slope of residual Ridge Whereas the secondary stress bearing area is rugae Maxillary tuberosity and alveolar tubercle So primary stress bearing area are hard palette and posterior lateral slope of residual Ridges and the secondary stress bearing areas are rugae maxillary tuberosity and alveolar tubercle So we'll start with the heart palette so it is formed by palatine shelves of the Maxillary bone and the premaxilla so premaxilla will be here the Maxillary bone will be here. So it line by keratinized epithelium and the horizontal Part of heart palette provides the stress bearing area these parts Clinical significance this trabacular pattern in the bone is perpendicular to the direction of force So it is almost perpendicular to direction of force So making it capable of withstanding any amount of force without marked Resorption, so if a Surface like this and we are applying force at 90 degree. There will not be any resorption if this Force angulation is likely tilted. It's an acute angle. There will be resorption So it can withstand Good amount of pressure without undergoing much resorption And the second structure in primary stress bearing area is a posterior lateral Slops of the residual alveolar edge so this portion Line by thick stratifies commas epithelium So it resolved rapidly following extraction and continues throughout life at a reduced rate Okay, so there'll be a continuous resorption throughout the life So still it can support the structure and where the masticatory forces so the vertical forces during Physiological activities like mastication falls on the denture and is transmitted posteriorly So these posterior lateral slopes of the rich base of force and That is why it is becoming the primary residual. I mean primary stress-bearing areas Now let's move on to the secondary stress-bearing area that is rugae. These are the mucosal folds So these are the rugae mucosal folds Located in the anterior region of the palatal mucosa. So in the area of this rugae the palette is Set at an ankle to the residual alveolar edge and is thinly covered by soft tissue Which contributes to the stress-bearing area So clinically it is important because it is associated with the sensation of taste and the function of speech They assist the tongue to absorb Why it's papillae? They also enable the tongue to form a perfect seal when it is pressed against the palate in making lingo-palatal Constant stops of speech and rugae should not be displaced Otherwise the pre-bounding may dislodge the denture And they provide anterior posterior resistance to movements Of the denture and increased surface area Which helps in retention Now the maxillary tuberosity Which is the bulbous extension. So here it is the maxillary tuberosity bulbous extension of the residual alveolar edge in the second and third molar area And it terminates in the hemilar notch And these areas are less likely to reserve so artificial teeth are not set on this tuberosity region and the tuberosity sometimes exhibit buckle undercuts if it is Unilateral it can be utilized for the retention so Those are the supporting Structures now let's move on to the Relief areas so we need to relieve few areas such as incisive papillae we need to relieve incisive papillae and mid-palatine drape mid-palatine Raffae So this is the incisive papillae mid-palatine drape then the fovea palatini We already discussed fovea palatini Then palatine torus if it is present Palatine Tori Then the rogue area these are the Relief areas so the first one is incisive papillae this midline structure situated just behind the central incisors and There will be presence of incisive foramen here, which lies immediately beneath the papillae So as resorption progresses it comes to line near to the crest of the ridge So there will be naso-palatine nerves vessels pass through it so we need to relieve it So when making final impression Pressure should not be applied on this region because there is presence of lots of nerves and other structures Then the mid-palatine raffae this is a median suture Which covered by acid mucosa so the mucosa layer is in close contact with the underlying bone For this region the soft tissue covering the median palatal tissue is non resilient in nature and may need to be relieved So if pressure is applied during impression making the denture base will cause soreness over the mid-palatine raffae Then the fovea palatini We already discussed why it is important because it consists of mucous glands And the hydrostatic pressure all those concept But it helps in determining the vibrating line then the palatine torus if palatine torae is present it should be relieved and rogue area are the irregular shaped ridges and Which is present in the anterior third of the heart palate. It should not be disturbed while taking impression So these are the structures that is the denture bearing area of maxilla So we learned limiting structures supporting structures and relieving structures. So limiting structures were seven in number The first one was the labial freedom labial freedom then the labial vestibule the buckle freedom And the buckle vestibule and the hamilar notch And the posterior palatal seal and the fovea palatini And second as a supporting structure that is the stress bearing areas primary and secondary primary we have heart palate and posterior lateral Slops of residual alveolar gys And the secondary stress bearing areas we have rugae maxillary tuberosity and alveolar Tubercal and the relieving areas the insosin papillae then the mid-palatine Raffae then the fovea palatini palatine torus and rugae areas So there can be many questions Uh, we asked from this area The limiting structure supporting structures relieving area stress bearing area The anterior vibrating line posterior vibrating line the post palatal seal the vial selva manual And all the importance or clinical significance of each structure So it is a very very important chapter in prosodontics. So I'll come up with the denture bearing area and mandible in my next session Hope you understood the concept of this Uh bearing area of maxilla Thank you