Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / @xirurgi_2025 / @xirurgi_2025 - 257 - файл
.pdf
Casts enable determination of maximal intercuspation:
centric occlusion
Casts facilitate fabrication of occlusal splint to guide
positioning following osteotomy
For “two-piece” Le Fort I cases (ie, maxillary arch
must be widened with sagittal osteotomy), a splint
is required to maintain desired palatal width
For “two-jaw” or “double-jaw” cases (ie, maxillary
and mandibular osteotomies), two splints are
required: intermediate and final
In “double-jaw” cases, facebow transfer is required to
establish the relationship of the maxilla to the skull
base
Bite registration needed to then relate mandibular
cast to maxillary cast on articulator
Maxillary cast osteotomy (model surgery)
performed on articulator to fashion intermediate
splint
Final splint fabricated on separate models
mounted on Galetti articulator
Arch bars or braces with brackets required
GENERAL MANAGEMENT
CONSIDERATIONS
*Vertical Maxillary Excess
Examination findings
Long face/“gummy smile” with excess gingival
show
Greater than 4-mm incisor show
Mentalis strain
Flattened midface
Class II malocclusion most common but can have
any occlusion
SNA and SNB are decreased; ANB increased
https://t.me/medicina_free
Etiology: open-mouthed breathing-nasal airway
obstruction, myotonic dystrophy, adenoid hypertrophy, and
familial
Treatment: Le Fort I impaction, possible mandibular
advancement. With maxillary impaction, mandible will
autorotate into occlusion with maxillary dentition
This will improve SNB angle without mandibular
osteotomy
Concomitant genioplasty sometimes needed to correct
relative chin retrusion or midline menton discrepancy
Vertical Maxillary Deficiency
Examination findings
Short face: see very little maxillary dentition in repose
and with smiling
No incisor show
Aged, edentulous appearance, prominent chin with
jowling
Class II malocclusion
Increased SNA and SNB angles
Treatment: downfracture Le Fort I with bone grafting,
possible mandibular advancement
Orthodontics: curve of Spee (vertical wave in occlusal
plane) is corrected postsurgically
Maxillary Retrusion/Midface Hypoplasia
Examination findings
Flat or dish face
Depressed nasal tip and wide alar base
Negative overjet
Short upper lip
Class III malocclusion
Decreased SNA; normal to larger SNB; negative ANB
Etiology: often history of cleft lip ± palate, CPAP
(continuous positive airway pressure) during childhood
Treatment: maxillary advancement
High-winged Le Fort I
Improves malar position with one operation
Obviates need for implants or bone grafts
https://t.me/medicina_free
Le Fort I via distraction osteogenesis
Used in large advancements (>10 mm)
Requires halo mounted to cranium during
initiation, activation, and consolidation phases
Unable to precisely establish final occlusion
*Le Fort I advancement changes the nasal
appearance
Widened alar base
Increased tip projection
Increased nasolabial angled
Narrowing of upper lip show (smaller
vermillion)
Soft tissue of upper lip moves 0.5-0.9 compared with
the bone
Retrognathia
Examination findings
Decreased mandibular projection
Obtuse cervicomental angle, redundant submental soft
tissue
May have excessive eversion of lower lip
Positive overjet
Class II malocclusion
Decreased SNB angle
Orthodontic presurgical management seeks to eliminate
crowding (limits the amount by which the mandible can be
advanced)
Etiology: may have history of Pierre-Robin sequence
Treatment: bilateral sagittal split osteotomy (BSSO),
possible genioplasty
Prognathia
Examination findings
Prominence mandible with apparent midface retrusion
Mandibular over-rotation
Negative overjet
Class III malocclusion
Increased SNB angle
Treatment
https://t.me/medicina_free
Consider maxillary advancement only
Setback mandible only in severe cases
BSSO
Intraoral vertical ramus osteotomy (IVRO)
If setback is >10 mm
Requires postoperative maxillomandibular
fixation (MMF)
Obstructive sleep apnea (OSA)
With severe OSA not amenable to CPAP, “bi-max”
advancement, also known as maxillomandibular
advancement (MMA), is considered.
Advancement of maxillomandibular skeleton improves
airway patency and relieves upper airway obstruction.
OPERATIVE TECHNIQUES
Anesthetic Considerations
Hypotensive anesthesia
Reverse Trendelenburg positioning (head up) reduces
bleeding intraoperatively
Le Fort I osteotomy (Fig. 18-3)
https://t.me/medicina_free
Figure 18-3 Versatility of the Le Fort I
osteotomy. The Le Fort osteotomy can be
varied to position portions of the maxilla in
various ways. A. Inferior displacement
https://t.me/medicina_free
(with bone graft) to increase vertical
length. B. Impaction to reduce maxillary
height. C. Anterior movement of the
maxilla is possible. D. The surgeon may
adjust the width of the maxilla as needed.
E. Posterior movement of the maxilla is
possible as well. (From Thorne CH, ed.
Grabb and Smith’s Plastic Surgery. 7th ed.
Lippincott Williams & Wilkins; 2014. Figure
25.5.)
Upper buccal sulcus incision.
Leave 2- to 3-mm cuff of tissue on gingiva for closure.
Avoid parotid papilla.
Identify infraorbital nerve in midpupillary line.
Dissect along buttresses in subperiosteal plane.
Elevate mucosa from nasal floor, septum, and sidewalls.
Buttress osteotomies
Nasomaxillary: reciprocating saw from piriform aperture
medial to lateral in horizontal plane.
Zygomaticomaxillary: reciprocating saw directed from
lateral to medial in horizontal plane.
Pterygomaxillary: curved osteotome behind maxillary
tuberosity into pterygomaxillary fissure.
Nasal septum divided using double-ball, guarded
osteotome.
Check lip-tooth relationship with acrylic splint in place.
Plate fixation at piriform ± maxillary buttress.
V-Y vestibular closure: prevent nasal widening, thinning
of upper lip, and commissure downturn.
Check occlusion and revise hardware if incorrect.
Bilateral Sagittal Split Osteotomy (BSSO) (Fig. 18-4)
https://t.me/medicina_free
Figure 18-4 The sagittal split
osteotomy. It may be used to move the
anterior mandible into a more anterior
position (A) or, more rarely, into a more
posterior position (B). (From Thorne CH,
ed. Grabb and Smith’s Plastic Surgery. 7th
ed. Lippincott Williams & Wilkins; 2014.
Figure 25.4.)
Requires removal of third molars ~6 months preoperatively.
Intraoral incision over ascending ramus and external
oblique ridge.
Subperiosteal dissection on medial surface of ramus
Above the level of occlusal plane at lingula
https://t.me/medicina_free
Point where inferior alveolar nerve enters the mandible
Step-wise osteotomy in sagittal plane.
Segments mandible into three segments
Proximal (two segments, bilateral): contains ramus and
condyle
Distal (one segment, central): contains body, both
branches of inferior alveolar nerve
Acrylic splint guides the distal segment into occlusion.
Transbuccal trocar is used to assist in bicortical screw
fixation of both mandibular segments.
Seat condyles in glenoid fossa (centric relation) during
fixation.
Check occlusion on release of MMF and revise hardware if
incorrect.
Intraoral Vertical Ramus Osteotomy (IVRO)
Intraoral incision over ascending ramus and external
oblique ridge
Subperiosteal dissection on lateral surface of ramus
Posterior to entrance of inferior alveolar nerve
Splits mandible in coronal plane between condyle and
coronoid (sigmoid notch)
Internal maxillary artery traverses this bony interval
Less favored technique of mandibular osteotomy
Used when large mandibular setback is required (ie, class
III malocclusion)
No osseous fixation employed; requires MMF
postoperatively
Genioplasty
Lower buccal sulcus incision.
Leave the cuff of mucosa and mentalis muscle for two-layer
closure.
Subperiosteal dissection centrally and along inferior
mandibular border to reveal mental nerves
Located between first and second premolars
*May course ~2 mm beneath the mental foramen
before exiting
Transverse osteotomy with sagittal saw.
https://t.me/medicina_free
Measured step plates may be used to achieve fixation at
desired location.
“Double-Jaw” Surgery
Le Fort I
BSSO or IVRO
Performed in series, beginning with Le Fort I osteotomy
Intermediate and final occlusal splints used to establish
occlusion
POSTOPERATIVE CONSIDERATIONS
POSTOPERATIVE CARE
Use of Elastic Bands
Temporary elastics used to secure desired occlusion during
fixation
Often removed prior to extubation
May be left in place as “guiding elastics”
Class II elastics
Used to “correct” a class II malocclusion
Vector from anterior maxilla to posterior mandible
Class III elastics
Used to “correct” a class III malocclusion
Vector from anterior mandible to posterior maxilla
MMF
Used in cases of suboptimal fixation or in large/unstable
skeletal movements
May be kept in place for several months
Wire cutters required at bedside in cases of airway
compromise and/or emesis
Steroid (fluocinolone) cream used for labial swelling
Peridex mouth rinses
Soft diet
Elevate head of bed and employ cool compresses
https://t.me/medicina_free
COMPLICATIONS
Relapse
Surgical: loss of plate fixation (malunion).
Dental: persistent malocclusion; requires appropriate
decompensation—MMF not performed appropriately with
bimaxillary surgery or elastics not used postoperatively for
maintenance of occlusion may lead to relapse and need for
reoperation.
Condylar
Resorption of bone at condyle (progressive condylar
resorption)
Related to residual apertognathia and unfavorable TMJ
dynamics
TMJ displacement may require reduction
Soft tissue: recoil forces from “Moss functional matrix”
*Paresthesia
Risk of inferior alveolar nerve injury in BSSO is 10%.
About 90% of patients have temporary postoperative
symptoms.
Temporary paresthesia may last anywhere from 2 to 12
months postoperatively.
Infection: may require abscess drainage but not removal of
hardware in most cases
Acute versus chronic: <6 weeks or >6 weeks
Penicillin prophylaxis commonly used but postoperative
infection still possible
Hemorrhage
Le Fort osteotomy may damage internal maxillary
artery branches and pterygoid venous plexus during
pterygomaxillary disjunction
Maintain subperiosteal dissection.
Ensure osteotome placement in pterygopalatine fossa.
Use hypotensive anesthesia (SBP ~ 80 mm Hg) and
reverse Trendelenburg position
Ischemia
https://t.me/medicina_free
Соседние файлы в папке @xirurgi_2025