maxillofacial prosthesis

Dr. Monia M.N. Kandil

History
Artificial facial parts found on Egyptian mummies long time ago.Ancient Chinese known to have made facial restorations.At 1953  American Academy of Maxillofacial Prosthetics was founded.

Define as: The branch of the prosthodontics concerned with the restoration and / or replacement of the stomatognathic and craniofacial structures with a prosthesis that may or may not be removed. OR The art and science of anatomic, functional, or cosmetic reconstruction by means of nonliving substitutes of those regions in the maxilla, mandible, and face that are missing or defective because of surgical intervention, trauma, pathology, or developmental or congenital malformations
Maxillofacial Prosthodontics


MFP are often needed to restore oral function such as deglutition, speech and mastication. In other instance, prosthesis may be needed for cosmetic and psychological reasons or to protect facial structures during radiotherapy of head and neck cancer patient. The over all goal of maxillofacial prosthesis treatment is to improve the quality of life by reducing the morbidity associated with treatment which benefits a particular head and neck condition . Also protect the adjacent tissue, teeth & other structures from direct injury. Improve the healing process (as stent), may or may nor carry a medication.
Objectives of Maxillofacial Prosthesis:

There are 3 types of MFD, which are: 1.Congenital: cleft palate (hard palate, soft palate or both), cleft lip, prognathism, missing ear. 2. Acquired: accident, surgery or pathology. 3. Developmental: prognathism or retrognathism. Such a classification affect prosthesis design, which become part of the total management plan. For example, prosthetic management of an adult who has experienced a maxillectomy procedure can be quite different from management of a patient with an unrepaired cleft palate.
Classification of Maxillofacial Defects

1. Acquired Defects: include those defects that are the result of trauma, or disease and its treatment. These may include a soft and/or hard palate defect resulting from removal of a squamous cell carcinoma of the region.
Classification of Maxillofacial Defects


2. Congenital defects are typically craniofacial defects that are present from birth. The most common of these include cleft defects of the palate that may include the premaxillary alveolus.
Classification of Maxillofacial Defects

3. Developmental defects are those defects that occur because of some genetic predisposition that is expressed during growth and development .
A functional jaw position developed because of a combination of tooth loss and growth discrepancy. This developmental defect is illustrated by a protruded and overclosed mandibular position.
Classification of Maxillofacial Defects

Classification of Maxillofacial Prosthesis

Maxillofacial prosthesis classified to be: Extraoral (cranial or facial replacement), Intraoral (involving the oral cavity), Combination of intra &extraoral types, or: Radiotherapy prosthesis. OR Prostheses may be interim (for short periods of time, often preoperative) or definitive (more permanent); and prostheses used as a component of management, such as a (splint or stent).


B. Mandibular Prosthesis: 1. Mandibulectomy prosthesis. 2.Marginal mandibulectomy prosthesis. 3. Mandibular guide flange prosthesis. 4.Interarch fixation prosthesis 5. Stent prosthesis.
A. Maxillary Prosthesis: 1. Obturator prosthesis. 2. Feeding aid prosthesis. 3. Speech aid Prosthesis. 4. Palatal treatment prosthesis. 5. Saliva stimulating prosthesis. 6. Palatal lift prosthesis. 7. Composite palatal treatment prosthesis. 8. Palatagmentation prosthesis.
Intraoral Prosthesis (stomatognathic):
Classification of Maxillofacial Prosthesis
C. Tongue Prosthesis.

2. Extraoral Prosthesis (craniofacial):

a. Upper facial Prosthesis. b. Middle facial prosthesis. c. Hemi facial Prosthesis. d. Nasal prosthesis. e. Orbital (eye) prosthesis. f. Auricular (ear) prosthesis.
Radiation (stent & Carrier)
4. Radiotherapy Prosthesis:
3. Combination Prosthesis:
A combination of both intra & extraoral prostheses.

Intraoral ProsthesisMaxillary Prosthesis

Cleft Palate Prosthesis

Intraoral ProsthesisMaxillary Prosthesis

Feeding Aid Prosthesis

Intraoral ProsthesisMaxillary Prosthesis

.Speech aid Prosthesis

Intraoral ProsthesisMaxillary Prosthesis

Maxillary Ramp

Maxillary Saliva Stimulating Prosthesis

Can be made with a reservoir to hold artificial saliva.
Intraoral ProsthesisMaxillary Prosthesis



Mandibular reconstruction revolutionized by microvascular and plating techniques. Prosthetics mainly restore occlusion and occlusal surface. Implants able to restore high degree of function.
Intraoral Prosthesis:Mandible Prosthesis:

Skin graft preserves alveolar ridge for denture support

Intraoral Prosthesis Mandible Prosthesis

Mandibulectomy prosthesis

Intraoral Prosthesis Mandible Prosthesis

Mandibular guide flange

Intraoral Prosthesis Mandible Prosthesis

Intraoral Prosthesis Tonque Prosthesis

Lower augmentation T.P.
Upper augmentation T.P.



Adjunctive Preprosthetic Measures
Vestibuloplasty. Lowering of Floor of Mouth. Implants.

Vestibuloplasty

Lowering the Floor of Mouth
Goal is to reposition mylohyoid muscle.

Implants

Combination exra and intra maxillofacial prosthesis

Extraoral Prostheses

General Principles: Goal is cosmetic. Retained with : 1. Adhesives. 2. Implants. 3. Skin grafting as abase & Smooth edges. 4. Glasses or exrtra equipments can help also.



Extraoral Prostheses -- Ear
Tragus hides attachment.

Extraoral Prostheses -- Orbit

Skin graft provides base for prosthesis.

Extraoral Prostheses -- Orbit

Sun glasses help to hide the defect margin.

Extraoral Prostheses -- Nose

Skin graft provides base for prosthesis.
Glasses helps for retention

Extraoral Prostheses –Orbit & Nose

Extraoral Prostheses – Orbit & Nose


Materials used mainly with the Extra-oral MFP
Acrylics Polyurethanes Silicone Elastomers.

MFP used in cases of:

After surgical intervention. After trauma. Congenital defects. Acquired defects.
* Maxillofacial Defect: Means an abnormality or missing parts of an oral and / or facial region. Both intra oral and extra oral defects caused by birth (congenital) or accident and tumor (acquired)

Indications of maxillofacial prosthesis (MFP)

1. For realignment and fixation of mandibular fragment in adequate dental occlusal relationship with the opposing jaw. 2. As obturator for the occlusion of defects of the palate and maxillary bone. 3. For maintenance of facial form and contour and prevention of contraction during healing period. 4. For restoration of facial features such as the nose, eye and auricle.

Contraindication of the MFP:

Advanced age of the patient. Poor health of the patient (contraindicated for surgical intervention). Very large deformity, that need to replaced with the help of grafts or living structures. Poor blood supply in the deformity site. Susceptibility to recurrence of malignant lesions. Operation expenses, if high.

Limitations of the MFP:

1.Economic condition of the patient. 2. Rapid color instability. 3. Movable tissue bed. 4. Difficulty in retaining the prosthesis. 5. Inadequate material available. 6. Patient acceptance. 7. Need for restoration of sinus cavities. 8. It need more accurate replication of complexities of the bone, their soft tissue coverings and attached dentition. 9. The facial prosthesis tend to deteriorate with time, changed in color, therefore it must be replaced regularly. 10. Possibility of detachment of the prosthesis especially auricular prosthesis.

Management of patient for MFP

Personal history of a patient should be obtained. Dental and medical history also should be obtained. Intra and external examination of a patient by a maxillofacial surgeon and prosthodontics should be done. Psychological & patients risk assessment should be done. A surgeon should consulate with a dentist about a surgery so that there should be a team work. All surgical alterations should be demonstrated for a dentist on a cast and MFP should be made for a day of a surgery (as much as possible).

Post surgical management.

After a surgery and even before , The team work of patient ‘s rehabilitation , should include:Maxillofacial surgeon.Prosthodontics. Orthodontist.Phyciastrist.Speech rehabilitation specialist.Oncologist.Plastic surgeon specialist

Focusing on Obturators

Forces acting on Obturators


A common feature of MFP & obturators  is that all framework design should be dictated by basic prosthodontic principles of design, that include: Broad stress distribution, Cross-arch stabilization with use of a rigid major connector.Use double retentive &/or double stabilized action clasps, to minimize the dislodging functional forces.3. Replacement tooth positions that optimize prosthesis stability and functional needs (minimum No. with great benefits). Modifications to these principles are determined on an individual basis and are greatly influenced by unique residual tissue characteristics and mandibular movement dynamics.

Postoperative Malocclusion

Deviates to surgical side.

Classification of Maxillofacial Defects

Congenital defects
(Lip and palate development) Upper lip develop by coalescence of the premaxilla and maxillary growth centers on either sides to produce the complete lip. Fusion of the of the lip developing from growth centers commences around each nostril floor and spreads downwards towards the lower border of the lip uniting the premaxilla and maxillary process in each side.

Congenital defects

Failure of this union will result in a cleft lip that varies from a notch on one side to complete bilateral cleft of the lip that may extend up to into each nostril.

Congenital defects

The Palate develops from the maxillary and premaxillary growth centers, union of the three segments commencing at the region of the nasal floor presented in full development by the nasal foramen. Union from this point proceeds backwards until both the hard and soft palates and uvula have united, and forwards along the of the future maxillary and premaxillary structures eventually.

Congenital defects

Lack of fusion of the palatal shelves either completely or partially occurs during embryonic growth side. Failure of union of palatine processes at any stage will result in a cleft palate which may be pre-alveolar ( cleft lip ) or post alveolar ( cleft palate ) . Cleft palate between 6th – 9th week of the embryonic life.

Congenital defects

Factors that influence the induction of the cleft palate: I. Hereditary factor: the incidence of clefts is greater in the children of parents with deformities than in the general population. II. Environmental factors: Endocrine factors Radiation and x-ray Nutrition inadequacies Infection and disease Stress and disturbances of fetal circulation Chemical irritation
Congenital defects

Congenital defects

Objectives of cleft palate & lip prosthesis:Speech – lack of valvopharyngeal closure leads to escape of air through the nose (nasal speech)Deglutition – greatly impede the feeding, and escape of fluids through the nose takes place .Mastication – impaired due to escape of food through the nasal cavity and due to missing teeth and malocclusion .


Congenital defects
Esthetics – is effected seriously especially in cleft palate and lip. Deterioration of the general healthPsychological trauma .Recurrent infection of the air ways and middle ear .

Congenital defects

Management of cleft lip and palate Include the following: Surgical closure It is the treatment of choice for palatal cleft closure. It superior to prosthetic closure by obturator. If cleft involves the lip, it is advisable to repair it as early as possible (6 wks. after birth) to facilitate feeding and improve appearance. Surgical closure of palatal cleft is better to be done before the end of the second year of age.

Congenital defects

Congenital defects

ACQUIRED PALATAL DEFECTS

DEFINITION:Lack of continuity of originally intact palatal structures through the whole or part of its length.ETIOLOGY: Surgical e.g. tumor removal.Traumatic, “fracture of maxilla”.Pathological conditions e.g. osteomyelitis, T. B., and syphilis .

ACQUIRED PALATAL DEFECTS

Pre-maxilla , inter dental area Preserved
During Surgical Procedure, Should be:
Cut through tooth socket
ACQUIRED PALATAL DEFECTS


Skin Grafting of Defect:
To ensure….Less pain while healing.Less contracture of scar band which obscures cancer surveillance.Better accommodation of obturator. ACQUIRED PALATAL DEFECTS

Three phases of prosthodontic treatment, includes: Surgical phace  surgical procedures + Immediate obturator. Transitional phase  Temporary obturator.Functional phase  Definitive obturator.

Immediate obturator

Temporary obturator
Definitive obturator

Obturator

Restores oro-nasal partition. At times can be added to prior dentures.
ACQUIRED PALATAL DEFECTS

ACQUIRED PALATAL DEFECTS

CONSTRUCTION:Presurgical Impression  construction of the cast models.With the help of the surgeon determine the area to be removed on the cast .The appliance is constructed as a plate to close the operation site.Prepared cast is waxed, processed using either heat or cold curing resin and wire clasps to retain the obturator.
ACQUIRED PALATAL DEFECTS

During operation eradication of the involved area, and surgical cavity is filled with surgical pack.We can say, it is simple plate with no teeth and constructed before surgery to be inserted immediately after surgery.After 5 – 7 days, the surgical obturator and packing are removed. The defect area is cleaned with mineral oil and the surgical obturator is adjusted and relined with tissue conditioner material.
ACQUIRED PALATAL DEFECTS


The patient then returns weekly for adjustment and change relining material. Finally, the relined obturator is duplicated in heat cured acrylic. resin resulting in interim obturator


Palatal screwing: The palatal bone screw can be placed through a mid palate hole predrilled through the acrylic resin base plate in the mid palate at the anterior peak of the palatal vault.

13- to 16-mm palatal bone screw, angled posteriorly for retention obturator prosthesis.
Methods for retention of Immediate (surgical) Obturator, are:


Suturing: In a previously irradiated patient, one might to use the suture technique to avoid placing a bone screw in the irradiated palate. Sutures placed at the periphery of the prosthesis can be sutured into the soft tissues of the vestibule.
Circumzygomatic wire: retention wires are passed over the zygomatic arch and threaded through two bilateral holes placed in the premolar area of the baseplate flange. This technique is the most invasive and has greatest morbidity when removing the wires in the clinical setting. It is not commonly used.
Methods for retention of Immediate (surgical) obturator are:

Clasping. Inter dental wiring. Mini-implant Adhesive. Anatomical undercuts within the confines of defect. Magnets. Osseointegrated titanium implants. Facial prosthesis connection to upper denture.
Methods for retention of Immediate (surgical) obturator are:


Use of the existing maxillary denture: Some texts suggest using the patient's existing denture for the surgical obturator and considered as interim obturator prosthesis, but there are disadvantages to using the existing denture at the surgical or interim phase. If the maxillary denture is ill-fitting preoperatively, it will be necessary to reline tl1e denture prior to surgery.


Temporary (Transitional or Interim) Obturator: Constructed few days after operation to help in restoring oro-nasal function. Those prosthesis which are placed immediately after packing removal, used until tissue contracture is minimal and prior to definitive obturator placement3weeks after maxillary resection, wound had started re-epithelizing. At this stage interim prosthesis was given Or Within 1 – 2 weeks.
ACQUIRED PALATAL DEFECTS


Carries teeth and stays 3-6 months. Making impression is complicated by presence of the wound and presence of the defect.

ACQUIRED PALATAL DEFECTS

ACQUIRED PALATAL DEFECTS
The defect is packed with gauze dipped in Vaseline to the level of the remaining tissue, then impression is taken with modified stock tray using elastic impression material. The steps of construction are the same as in immediate obturator.

Function helps in restoring: To restore deglutition and speech by restoring palatal counters. Separating nasal cavity, maxillary sinus and naso pharynx from oral cavity. Esthetics improvments. Prevent wound contamination.prevent occlusal loading in the region of resection during the early stage of healing.
ACQUIRED PALATAL DEFECTS

DEFITIVE OBTURATOR

Definitive Obturator: It is a final prosthetic management construction after complete healing of the operation site, usually wear after 3-6 months after the surgical operation. Types of Definitive obturators: Hollow bulb (Closed). Roofless (Open bulb).
ACQUIRED PALATAL DEFECTS

Different obturator bulb designs

Preparation of the mouth for obturator: Extract hopeless teeth. Periodontal therapy. Restore carious teeth.
DEFITIVE OBTURATOR
ACQUIRED PALATAL DEFECTS
Construction: Select stock tray, modified with wax according to the size and shape of the defect. Partially, pack the defect with Vaseline gauze, then do primary impression using alginate.


Under cuts are lift to help in retention. Gauze can prevent broken pieces of alginate from escaping into the defect. Construct sp. Trays and do final impression using alginate or rubber base impression material. Outline the master cast to mark the bearing area, blocking severe undercut, leaving small undercut area for obturator retention.
DEFITIVE OBTURATOR
ACQUIRED PALATAL DEFECTS

During construction of definitive obturator for better retention , support & stability the buccal border of it should articulates with scar band.
DEFITIVE OBTURATOR
ACQUIRED PALATAL DEFECTS
Scar band  healthy healed tissue (sequamous epithelial cells) Also for better retention adhesive materials or implants (such as Zycomatic implant), can used.