Preprosthetic Surgery

Alex Isom

Preprosthetic Surgery

 Review from the previous week:  Cross-section of the Mandible  With age, loss of teeth, the bone melts away yet the muscle attachments remain in place

Preprosthetic Surgery

  To reposition the muscle attachments in order to place a denture on the mandible, a split thickness skin graft (STSG) is performed A supraperiosteal dissection is another way Dr. G. described it

Preprosthetic Surgery

  In order to prevent relapse of the muscles and vestibule, the harvested skin grafts are placed into a splint and placed onto the ridge An awl is inserted under the chin and pushed upwards through the floor of the mouth

Preprosthetic Surgery

   The suture is passed through the tip of the awl, like threading a needle Somehow (probably magic) the awl is used to pass the suture thread under the mandible and bring it up on the other side, making a “sling” You must understand this concept in order to graduate

Preprosthetic Surgery

  The suture wraps around the mandible to hold the graft onto the ridge This is usually known as a submandibular stitch or a circummandibular sling suture

Preprosthetic Surgery

   Use the graft together with the splint for 10-14 days The graft should “take” and gain a blood supply This only works if you have adequate bone

Absolute Heightening Procedure      Indicated when there is extreme of the body of the mandible resorption There is less than 2cm at the mid-body Osteotomy and bone grafting are indicated to augment the height of the ridge, actually increasing the bone height Subsequent muscle repositioning may be necessary to achieve desired results a.k.a. Bone Graft!

Relative Heightening Procedure      Indicated for a flat ridge with moderate resorption of the alveolar bone There is 2cm or more at the mid-body of the mandible Muscle insertions can be repositioned apically Height will be increased in the symphysis and the mid-body regions a.k.a. Vestibuloplasty

NBDE II

 The two main reasons that STSG in the mandible fail:   The graft was placed upside down You didn’t do an actual supraperiosteal dissection therefore there was no blood supply to the graft

Soft Tissue Abnormalities

  Frena   Undermine the wound to prevent scar formation You can carve out the denture, but then it will become too thin and break (do a frenectomy) High Muscle attachments   Similar to frena attachments They become more prominent as the bone melts away

Hypertrophy of the Tuberosity     The maxillary tuberosity may occlude with the retromolar pad NBDE II Generally the tuberosity is FIBROUS NOT BONY Obtain a panorex to get an accurate view of the sinus to bone to tissue discrepancy It is common to miss the occlusion of the tuberosity on an oral exam so have MODELS

Inflammatory Papillary Hyperplasia   PAPILLARY HYPERPLASIA: the body attempts to make the denture more stable  1. Epulis Fissuratum  2. Papillary Hyperplasia As patients wear dentures for a long time  the bone wears away become loose resorbs more   with granulation tissue  the denture it wobbles  the bone the body fills up the space

Flabby Ridge

  This occurs when you have natural teeth occluding against denture teeth Bone disappears and the body fills the space with flabby tissue

Epulis Fissuratum

   Forms around the periphery of the denture  Soft, movable, poor base for denture Epulis fissuratum appears as a single or multiple fold of tissue that grows in excess around the alveolar vestibule Usually, the edge of the denture rests in between two of the folds. The excess tissue is firm and fibrous, and ulcerations may be present

Epulis Fissuratum

Papillary Hyperplasia

   The great majority of cases are seen beneath ill-fitting dentures of long use and in persons who do not take their dentures out overnight. The lesion seems to result from a combination of chronic, mild trauma and low-grade infection by bacteria or candida yeast. It is occasionally seen in patients without dentures but with high palatal vaults or with the habit of breathing through their mouths.

Papillary Hyperplasia

Hard Tissue Abnormality

    Excessive bone in the tuberosity  Get a panorex, it’s usually fibrous Sharp mylohyoid ridge  Discomfort Prominent genial tubercles  As the alveolar ridge resorbs, the flange can rub against it Tori   Maxillary- sometimes we can work around it Mandibular- painful, too hard to work around

The Atrophic Maxilla

   Submucous Resection Note: I couldn’t find anything on this that related to the maxilla, what I did find was the pre-prosthetic surgery named “submucous vestibuloplasty” Submucous resection generally refers to a nasal septum reconstruction procedure

Submucous Vestibuloplasty

 Does not require hospitalization   Can be done on sick patients Does not require GA  “Incision between 8 and 9,  Make two tunnels next to gingiva all the way back to the tuberosity – get rid of all of the adherences to give the denture more room” as per Dr. G.

Submucous Vestibuloplasty

   Can be used for improvement of the maxillary vestibule The alveolar ridge resorption is not severe but mucosal and muscular attachments exist near the crest of the ridge Through a midline incision, submucosal and subperiosteal dissections are performed Oral and Maxillofacial Surgery Secrets, A. Omar Abubaker, DMD, PhD, Kenneth J. Benson, DDS

Submucous Vestibuloplasty

  The tissue between these two tunnels is cut and allowed to retract A splint is relined and secured in place for 7-10 days Oral and Maxillofacial Surgery Secrets, A. Omar Abubaker, DMD, PhD, Kenneth J. Benson, DDS

The Atrophic Mandible

    Vestibuloplasty with Secondary Epithelization Generally we need something to cover that tissue You would do this if there is no need to skin graft, just let the area re epithelialize Not a situation where we have to use a hospital

Vestibuloplasty with Skin Grafting   If extensive, you’ll need a skin graft and you’ll need to be in a hospital This is when you need the skin from the thigh

Mandibular Vestibuloplasty (From Module)   This is a technique which increases the relative height of the alveolar process by apically repositioning the alveolar mucosa and the buccinator, mentalis, and mylohyoid muscles as they insert into the mandible Following vestibuloplasty, the periosteum is uncovered

Mandibular Vestibuloplasty (From Module)    Occasionally this wound is allowed to granulate but this usually results in relapse, especially on the labial surface To prevent this, a skin or mucosal graft is usually placed over the periosteum The skin is removed from the outer surface of the thigh, while the mucosa can be taken from either the cheek or the palate

Mandibular Vestibuloplasty (From Module)  There are advantages and disadvantages to both, but most oral and maxillofacial surgeons and prosthodontists currently favor the use of mucosal grafts

Mandibular Vestibuloplasty (From Module)   Vestibuloplasty can be limited to the buccal and labial surfaces, but it usually includes the lingual surface of the mandible as well When performing a mandibular vestibuloplasty the surgeon must be careful not to injure the mental nerve, which exits through the mental foramina

Mandibular Vestibuloplasty (From Module)   In advanced resorption the foramina may be seen to exit from the ridge crest The mental foramen originates in the body of the mandible which clinically may become the ridge crest when alveolar bone has resorbed

Mandibular Vestibuloplasty (From Module)

Implants

   Subperiosteal Transosseous Endosseous  most popular today  many variations on a common theme

Hydroxyapatite

      Hydroxyapatite migrates all over the place If you use it today, it has to be controlled You’ll need a splint, and do a very minimal dissection to place it in It can migrate all over the mouth So now very minimal dissections and a splint takes care of holding things down The hydroxyapatite is placed sub periosteally

Immediate Dentures

  Prosthetics/surgery done by GP Surgery to be done by OMFS depending on certain factors:  Complexity  Length of case  The older the patient, the more dense the bone, the longer it takes to get the teeth out.

 Anxiety level  To many women, this is a sign of aging which will cause them to become more anxious, thus requiring i.v. sedation

Immediate Dentures

   Preoperative stage   Mounted models are not required anymore They should be required in order to see undercuts, tuberosity occluding with retromandibular pad etc.

Operative stage  Two phases   1. Posterior extractions 2. Anterior extractions Postoperative stage  Adjustments   More adjustments on an immediate denture The bone will remodel itself

Immediate Dentures

  Remove the teeth in two phases:  Remove the posteriors first  Allow the tissue to heal  Remove the anteriors secondly The following case pictures were donated by Chris Nelson

Immediate Dentures

 The posterior teeth are removed first and the ridge is permitted to heal

Immediate Dentures

Immediate Dentures

 The anterior teeth are removed and the immediate denture is delivered

Alveoplasty

  The most superficial surface of bone that is removed Bone removed with bone file or bur

Alveolectomy

 When you’re removing buccal bone during a surgical extraction

Radical Alveolectomy

  When you remove the whole alveolus on the buccal This occurs less frequently and involves going all the way to the root apex