1 / 86

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT. dr shabeel pn. We express our deep and sincere gratitude to whom who has been our inspiration for this presentation. DEFINITION. Border molding is the shaping of an impression material by the manipulation or action of tissues adjacent to the borders of an impression tray.

alexa-ratliff
Download Presentation

ACKNOWLEDGEMENT

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ACKNOWLEDGEMENT dr shabeel pn We express our deep and sincere gratitude to whom who has been our inspiration for this presentation.

  2. DEFINITION • Border molding is the shaping of an impression material by the manipulation or action of tissues adjacent to the borders of an impression tray

  3. OBJECTIVE • To determine the contour, height and width of the borders of the complete denture

  4. ANATOMICALLANDMARKS Limiting structures:- • Labial frenum • Labial vestibule • Buccal frenum • Buccal vestibule • Vibrating line

  5. CUSTOMTRAY FABRICATION Preliminary impression is taken using stock trays Primary cast is obtained with this impression Wax spacer used, if required Custom tray is fabricated (stepped handle for maxillary arch)

  6. MATERIALS USED FOR BORDER MOLDING • GREEN STICK COMPOUND • ELASTOMERIC IMPRESSION MATERIALS (POLYETHER)

  7. BORDER MOLDING TECHNIQUE • GREEN STICK COMPOUND - SECTION WISE TECHNIQUE • POLY ETHER - SINGLE STEP TECHNIQUE

  8. FINAL PROCEDURES • FINAL ADJUSTMENTS OF REFINED TRAY • PERFORATION OF THE TRAY

  9. ANATOMICAL LANDMARKS

  10. FACIAL MUSCLES

  11. ORBICULARIS ORIS – Oral Sphincter ORIGIN Medial maxilla and mandible Deep surface of perioral skin Angle of mouth (modiolus) INSERTION Mucous membrane of lip ACTION Contraction of the muscle protrudes lip or resists distension

  12. BUCCINATOR - Cheek muscle ORIGIN • Alveolar process of maxilla and mandible • Pterygomandibular raphae INSERTION • Angle of mouth (Modiolus) • Orbicularis oris ACTION • Presses cheek against molar teeth with tongue • Helps to keep food material between occlusal surface and out of the oral vestibule • Resists distension (while blowing)

  13. LEVATOR ANGULI ORIS ORIGIN • Infraorbital maxilla (Canine Fossa) INSERTION • Angle of mouth (Modiolus) ACTION • Dilator of mouth • Elevate labial commissure - Bilaterally while smiling Unilaterally while sneering

  14. MUSCLES WITH ATTACHMENT TO THE MODIOLUS • BUCCINATOR • ZYGOMATICUS MAJOR • LEVATOR ANGULI ORIS • RISORIUS • DEPRESSOR ANGULI ORIS

  15. MUSCLE ORIGINATING FROM THE MODIOLUS ORBICULARIS ORIS SPINTURE MUSCLE OF THE ORAL FISSURE ORBICULARIS ORIS

  16. DIALATOR MUSCLES OF THE MOUTH • LEVATOR LABII SUPERIORES • LEVATOR ANGULI ORIS • ZYGIOMATICUS MAJOR • ZYGOMATICUS MINOR • DEPRESSOR LABII INFERIORIS • DEPRESSOR ANGULI ORIS • RISORIUS

  17. PALATE

  18. MUSCLES OF PALATE • LEVATOR VELI PALATINI • TENSOR VELI PALATINI • PALATOGLOSSUS • PALATOPHARYNGEUS • MUSCULUS UVULAE

  19. TENSOR VELI PALATINI SUPERIOR ATACHMENT • Scaphoid fossa of medial pterygoid plate • Spine of sphenoid bone • Cartilage of pharyngo tympanic tube INFERIOR ATACHMENT • Palatine aponeurosis ACTION • Tenses soft palate • Opens mouth of pharyngotympanic tube during swallowing and yarning

  20. LEVATOR VELI PALATINI SUPERIOR ATTACHMENT • Cartilage of pharyngotympanic tube • Petrous temporal bone INFERIOR ATTACHMENT • Palatine aponeurosis ACTION • Elevates soft palate during swallowing and yarning

  21. PALATOGLOSSUS SUPERIOR ATTACHMENT • Palatine aponeurosis INFERIOR ATTACHMENT • Side of tongue ACTION • Elevates posterior part of tongue and draws soft palate into tongue

  22. PALATOPHARYNGEUS SUPERIOR ATTACHMENT • Hard palate and palatine aponeurosis INFERIOR ATTACHMENT • Lateral wall of pharynx ACTION • Tenses soft palate and pulls walls of pharynx superiorly, anteriorly and medially during swallowing

  23. MUSCULUS UVULAE SUPERIOR ATTACHMENT • Posterior nasal spine and palatine aponeurosis INFERIOR ATTACHMENT • Mucosa of uvula ACTION • Shortens uvula and pulls it superiorly

  24. LIMITING STRUCTURES OF EDENTULOUS MAXILLARY ARCH • LABIAL FRENUM • BUCCAL FRENUM • LABIAL VESTIBULE • BUCCAL VESTIBULE • HAMULAR NOTCH • VIBRATING LINE

  25. LABIAL FRENUM • It is a fold of mucous membrane at the median line. • It starts superiorly in a fan shape and • converges as it descends to its terminal attachment on the labial side of the ridge. • It contains no muscles and has no action of its own.

  26. LABIAL NOTCH Corresponding area of labial frenum on the final impression SIGNIFICANCE The labial notch of the labial flange of denture must be wide and deep enough to allow the frenum through it without manipulation of the lip.

  27. BUCCDAL FRENUM It forms the dividing line between labial vestibule and buccal vestibule It is formed by mucous membrane Can be a single fold, double fold and even fan shaped RELATION WITH FACIAL MUSCLES Levator Anguli Oris muscle attaches beneath the frenum Orbicularis oris pulls the frenum forward Buccinator pulls the frenum backward SIGNIFICANCE It requires more clearance in the denture base for its movements than the labial frenum

  28. BUCCAL NOTCH It is the impression made by the buccal frenum on the impression It should be wide and deep enough to permit the movements of the buccal frenum SIGNIFICANCE While making impression, lips should be moved forward and backward by the dentist to allow the free movement of the buccal frenum in the buccal notch

  29. LABIAL VESTIBULE Labial vestibule is divided into left and right labial vestibule by the labial frenum Mucosa is thin and NONKERATINIZED Submucosa is thick and contains large amount of areolar tissue and elastic fibers Lamina propria is elastic in nature RELATION WTH FACIAL MUSCLES Orbicularis oris is the main muscle which forms the outer surface of the labial vestibule The fibers of this muscle runs horizontally through the lips to anastamose with the muscles of the Buccinator

  30. BUCCAL VESTIBULE It is the space distal to the buccal frenum till the hamular notch It is bound externally by the cheek and internally by the residual ridge Mucous membrane covering is similar to labial vestibule The size of the vestibule varies with contraction of the Buccinator M. position of the mandible amount of bone lost by resorption from the maxilla

  31. HAMULAR NOTCH • Region between the tuberosity of the maxilla and the hamulus of the medial pterygoid plate SIGNIFICANCE • Posterior palatal seal is placed through the centre of the deepest part of hamular notch • Forms the posterior boundary for the denture base • If the posterior border extend further in this region, the denture base will compress the pterygoid hamulus and obstruct the action of the pterygomandibular raphae

  32. VIBRATING LINE It is the imaginary line drawn across the palate that marks the beginning of motion of the soft palate when patient is asked to exhale through his/her nose with the nostrils closed Extends from one hamular notch to the other Lies distal to the junction of the hard and soft palate – lies always on the soft palate At the midline, it passes about 2mm in front of the FOVEA PALATINAE (indentations near the midline of the palate formed by a coalescence of several mucous gland ducts) It is not a well defined line – but an area Submucosa in this region contains glandular tissue

  33. SIGNIFICANCE It is an ideal guide for locating the posterior palatal seat area (the distal palatal termination of the denture) during BORDER MOLDING The distal end of the maxillary denture should extend at least to the vibrating line (in most cases 1 to 2 mm posterior to the vibrating line)

  34. FINAL IMPRESSION • After the primary impression is taken and a cast made from it, the procedure for final impression begins • A carefully made special tray is trimmed at the corners and border molding is done followed by a wash impression and pouring in the cast completes the procedure. In a nutshell, final impression involves special tray preparation and wash impression

  35. MATERIALS • Metallic Oxide Impression Paste (Ex. ZOE Impression Paste) • Elastomeric Impression Materials

  36. ZINC OXIDE EUGENOL IMPRESSION PASTE INDICATIONS • These pastes are rigid when set and can be used only when there is no bony undercuts • Used in a close fitting tray and so the overall bulk of impression is kept to a minimum. This is useful where the denture bearing area is reduced due to bone resorption CONTRAINDICATIONS • Not used in patients with dry mouths because the paste tends to adhere to the oral mucous membrane • When the patient is intolerant to Eugenol as it can cause a burning sensation in some individuals

  37. ELASTOMERIC IMPRESSION MATERIALS • These materials are used in spaced custom trays to avoid displacement the border tissues • A less viscous consistency/body of the irreversible hydrocolloid is used for making final impression compared with that used for preliminary impression.

  38. CUSTOM TRAY FABRICATION DEFINITION • A special tray is defined as a custom made device prepared for a particular patient which is used top carry, confine and control an impression material while making an impression. FUNCTION • To provide better retention of denture • To take secondary or wash impression

  39. IDEAL REQUIREMENTS • Should be rigid, well adapted and dimensionally stable on primary cast • Should be easy to manipulate and remove • Should not flow or warp • Should not react with impression material • Should be free of voids or projections • Should be at least 2 mm thick in the palatal area for adequate rigidity • Should be smooth lest it injures the soft tissue inside the mouth • Should be trimmable with bur

  40. Should be simple, taking minimum amount of time and should be prepared at a reasonable cost • Should have 2 mm relief near the sulcus so that the green stick compound can be used to do border molding • Should retain its shape while loading of impression • Should have contrasting colour to make its margins prominent when placed in mouth

  41. CONDITIONING THE PRIMARY CAST • Primary impression has overextended borders therefore special tray should be 2 to 4 mm short of the sulcus • A line is drawn across the posterior border connecting the 2 hamular notches (this line is parallel to fovea palatinus) • A line is drawn outlining the muco-buccal fold above the frenum attachments • All trays should be checked of displacement in the mouth

  42. ADAPTING THE WAX SPACER • Base plate wax, 1 mm thick approximately is placed on the cast within the outline border to provide space in the tray for the final impression material • Spacer should be cut out in 2 to 4 places so that the special tray touches the ridge in these areas. This is done to stabilize the tray during impression making. • The posterior palatal seal area on the cast is not covered with the wax spacer therefore the completed custom tray will contact the mucous membrane across the posterior palatal border

More Related