Acquired Maxillary defects (1) - Minia

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

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:


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


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


- Class I Aramany's classification:

lateral defect with anterior margin approaching midline.


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


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.


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


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.


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 ????


1- Resection outline:

- Total resection of per-mailla results in :

linear arrangement of the remaining teeth

Indirect retention become impossible

Compromised retention and stability


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 )



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.



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


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.




- 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.




4- Palatal Mucosa:

- To be reflected before resection to cover medial margin


5- Soft palate:

- Remaining part should retain velopharyngeal closure.

- Otherwise removed entirely


-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,


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

- ,



- 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.



- Lateral wall of the defect

- is lined with oral mucosa (keratinized epithelium) & skin-graft, both can

tolerate pressure


Limited access of the defect Myo-cutaneous flap

Sincerely :

Dr. Hussein A. Hady Hussein

Acquired Maxillary defects (1) - Minia

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