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Acquired Maxillary defects (1)
Lecturer of prosthetic dentistry and implantology
Faculty of dentistry – Minia University
Acquired defect definition :
Lack of continuity of originally
intact palatal structures through the
whole or part of its length
Acquired defects can occur
anywhere in palate, while congenital
defects are confined to the lines of
fusion between embryonic processes.
Etiology and Consequences
1- Trauma
a. Sharp instrument
b. Gun shot
c. Comminuted fracture of the maxilla
d. Vehicle accident
e. Suicide attempt
f. Suction cups
2- Diseases :
- T.B , Syphilis , osteomyelitis , Fungal infection and Cancer .
3- Surgical excision :
Etiology of Acquired defects
Mucoepidermoid carcinoma Pleomorphic Adenoma
Most of them has late metastasis
Usually no contralateral lymphatic spread
Midline acts as a barrier for local extension so serves as medial surgical
margin
Can spread to base of the skull through foramina
Tend to expand when reach spaces
Characteristics of Neoplasms of the palate and paranasal sinuses
Disabilities associated with acquired defects
Disabilities associated with acquired defects
Disabilities
Speech
Appearance
Psychological trauma
Swallowing
1-Functional :
a) Speech: will be nasal (hyper-nasality)
b)Swallowing: will be difficult
2- Appearance: depends on size of the resected part, the surgery may extend to
the inferior orbital margin, lowered eye level (diplopia), face disfigurement.
3- Psychological trauma:
Disabilities associated with acquired defects
Classifications of acquired defects
A- According to location:
- Anterior - Posterior - Median - Lateral
B- According to size and area of involvement :
- Unilateral total maxillectomy (hemi-maxillectomy)
- Unilateral partial ( sub-total ) maxillectomy
- Bilateral total maxillectomy
- Bilateral partial ( sub-total ) maxillectomy
Classifications of acquired defects
C- Armany’s Classification:
According to the Defect location and its Relation to the Remaining teeth
- Class I: Lateral defect do reaches the midline
- Class II: Lateral defect doesn’t reaches the midline
- Class III: Midian defect
- Class IV: Lateral defect that crosses the midline
- Class V: Posterior defect that anterior teeth remaining
- Class VI: Anterior defect the posterior teeth remaining
- Class VII: Small lateral defect
Classifications of acquired defects
- Class I Aramany's classification:
lateral defect with anterior margin approaching midline.
Classifications of acquired defects
Class II Aramany's
classification:
Lateral defect with
anterior margin away
from midline.
Class III Aramany's
classification:
Middle defect surrounded
by remaining teeth
Class IV Aramany's
classification:
Lateral defect with
anterior margin crossing
midline
Classifications of acquired defects
Class V Aramany's classification:
Defect with anterior teeth remaining
(posterior defect)
Class VI Aramany's classification:
Defect with posterior teeth remaining
(anterior defect)
Rehabilitation of acquired maxillary defects
Rehabilitation of acquired maxillary defects
Prosthetic rehabilitation Surgical rehabilitation
Etiology and size is the primary consideration
- Traumatic defects Immediate surgical closure
- Benign tumors Surgery , no fear of recurrence, small defect
- Malignant tumors prosthodontics
- Midline granuloma Surgery is not indicated poor blood supply
Surgery Versus Prosthodontics
- Small hard palate and alveolar ridge defects surgically
- Medium size defects require obturator.
- Large soft palatal defects are difficult to restore to normal function
surgically
Surgery Versus Prosthodontics
Surgical modifications that enhance prosthetic prognosis
Indications for surgical modifications
- Defect results from Trauma
- Defect size is small
- No susceptibility to recurrence
- Indication of prosthetic rehabilitation:
- Recurrence is possible.
- Defect size is Large.
Surgical modifications that enhance prosthetic prognosis
General principles:
1- Resection outline: Saving as much of the maxilla specially premaxilla
2- Skin grafting
3- Retention of key teeth
4- Palatal mucosa
5- Soft palate
6- Access to the defect
Surgical modifications that enhance prosthetic prognosis
1- Resection outline: Saving as much of the maxilla specially premaxilla
- Preservation as much as oral structure as possible without jeopardizing the
concept proper safety margin removal of the tumor to prevent recurrences.
- Exact evaluation of tumor size and extension using the new imaging
techniques ( CBCT, CT and MRI)
- Hard palate margin of the defect: act as a a fulcrum around which the
prosthesis rotate during function especially in edentulous patients.
Surgical modifications that enhance prosthetic prognosis
1- Resection outline:
Soft palate: it is important that the remaining portion retain the ability to affect
velo-pharyngeal closure.
- Stability and support enhanced if the per-maxilla of the defect side have been
retained.
- Very valuable specially in edentulous patients with tapering arches
- Total resection of permailla ????
Surgical modifications that enhance prosthetic prognosis
1- Resection outline:
- Total resection of per-mailla results in :
linear arrangement of the remaining teeth
Indirect retention become impossible
Compromised retention and stability
Surgical modifications that enhance prosthetic prognosis
2- Skin grafting of the Lateral margin
- The surgeon improves the retention of the obturator if the reflected cheek
flap is lined with Split thickness skin graft.
- Advantages of Split thickness skin graft :
a) More resistance to abrasion than respiratory mucosa.
b) More suitable denture bearing area.
c) Limits the scar contraction
d) Increase flexibility of the cheek
e) Form Skin graft mucosal junction ( Scar Band )
Surgical modifications that enhance prosthetic prognosis
2- Skin grafting of the Lateral margin
Skin graft mucosal junction
- It is the junction between the skin graft and the lining mucosa of the cheek
and lip.
- It is highly sensitive at the beginning.
- Healing --- tough fibrous tissue termed scar band.
Surgical modifications that enhance prosthetic prognosis
2- Skin grafting of the Lateral margin
Scar band :
- Contract longitudinally during healing --- does so like purse string creating
lateral undercut superior to the scar band.
- Engagement the scar band superiorly and inferiorly serve to enhance stability,
support and retention.
- After complete healing a scar band is formed at this site creating a shelf
which can be used for retaining the obturator
Surgical modifications that enhance prosthetic prognosis
3- Retention of the key teeth:
- Cuspid teeth is important because of its great bony support.
- Exact evaluation of tumor size and extension using the new imaging
techniques ( CBCT, CT and MRI)
- The trans-alveolar resection should be made in a distance from the tooth
adjacent to the resection.
- The next distal tooth to the tumor should be extracted and the trans-alveolar
cut made through the distal portion of the socket.
Surgical modifications that enhance prosthetic prognosis
Surgical modifications that enhance prosthetic prognosis
3- Retention of the key teeth:
- This will result in the retention of more bony support and improve the
clinical usefulness of the tooth adjacent to the resection.
- The tooth adjacent to the resection will soon be lost if the resection is made
through transeptal bone approximating the tooth border.
- The tooth become mobile or asymptomatic , need endodontic treatment,
amputation at the gingival margin or extraction.
Surgical modifications that enhance prosthetic prognosis
3- Retention of the key teeth:
Surgical modifications that enhance prosthetic prognosis
4- Palatal Mucosa:
- To be reflected before resection to cover medial margin
Surgical modifications that enhance prosthetic prognosis
5- Soft palate:
- Remaining part should retain velopharyngeal closure.
- Otherwise removed entirely
Surgical modifications that enhance prosthetic prognosis
-The obturator will enhance the speech, and
swallowing
-An exception is edentulous patients where
remnants help retention
5- Soft palate:
- Remaining portion of the soft palate is non-functional and contracted
superiorly , blocking the access to the lateral posterior pharyngeal wall
movement
- In edentulous patients it increase retention of complete maxillary denture by
extending its base superiorly over the nasal surface of residual soft palate,
Surgical modifications that enhance prosthetic prognosis
6- Access to the defecte:
- Access to superior and lateral aspect is important.
- Structures interfering with obturator placement and function are to be
remove.
- Residual turbinates restrict access to the defect
- ,
Surgical modifications that enhance prosthetic prognosis
6- Access to the defecte:
- Medial wall of the defect:
- Related to nasal cavity. - Have a bony undercuts.
- Lined with respiratory epithelium which is sensitive & can’t withstand
pressure or friction.
Surgical modifications that enhance prosthetic prognosis
6- Access to the defecte:
- Lateral wall of the defect
- is lined with oral mucosa (keratinized epithelium) & skin-graft, both can
tolerate pressure
Surgical modifications that enhance prosthetic prognosis
Limited access of the defect Myo-cutaneous flap
Sincerely :
Dr. Hussein A. Hady Hussein