Surgical Access to Lower 3rd of Face 20.12.11

SURGICAL ACCESS TO RD OF FACE LOWER 1/3

Presented by M.Zavir khan JR1

Despite the importance of

understanding technical detailes of specific facial surgical procedure,little can be accomplished without proper access through the skin/mucosa. Such access provides critical exposure to the defect site

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With this exposure,the

contemporary technique of rigid fixation.placement of bone graft or biomaterial or alteration of regional bony or soft tissue anatomy can be done. For the ease of T/t facial skeleton can be devide in 3 halves. Upper,mid & lower 3rd of face.12/20/2011

Introduction Adequate access & exposure. Importance of incision in H & N region. Avoidance of damage. Proper planing & technique.

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Factors determining access Facial aesthetics presence of the muscles and nerve (cranial nerve VII) of facial expression. presence of many important sensory nerves exiting the skull at multiple locations. Age of the patient Existing unique anatomy Patient expectations.12/20/2011

Principles of incision placement Avoid Important Neurovascular Structures Use as Long an Incision as Necessary Place Incision Perpendicular to the Surface of Nonhair-bearing Skin Place Incisions in the Line of Minimal Tension Seek for Other Favorable Sites for Incision Placement Cold Vs Hot cutting12/20/2011

Intraoral approaches

mandibular vestibular incision mandibular marginal rim incision BSSO incision

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MANDIBULAR VESTIBULAR APPROACH

useful for a wide variety of procedures. Allows relatively safe access to the entire facial surface of the mandibular skeleton, from the condyle to the symphysis. Constant assesment of occlusion during surgery. Hidden intraoral scar Very few complications,rapid & simple.12/20/2011

used to expose the entire surface of the

mandible. The length of the incision and the extent of subperiosteal dissection,however depend on the area of interest and the extent of surgical intervention.

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Significant structures

Mental nerve Facial vessels Mentalis muscle Buccal fat pad

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TechniqueCurvilinear Incision through the oral mucosa in the anterior region is out in the lip, exposing the underlying mentalis muscle fibers.

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In the body and posterior portion of the

mandible, the incision is placed 3 to 5 mm inferior to the mucogingival junction. The posterior extent of the incision is made over the external oblique ridge, traversing mucosa, submucosa, buccinator muscle, buccopharyngeal fascia, and periosteum

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Dissection of the mental nerves. The periosteum is incised and stripped laterally to expose nerve branches.12/20/2011

Subperiosteal dissection of the ramus.12/20/2011

Closure of the posterior incision is performed in one layer.12/20/2011

MANDIBULAR INTRAORAL MARGINAL RIM INCISION For exposure of alveolar crest or T/t of

traumatised teeth,then protection of lacerated mucosa is preferred Allows direct elevation of underlying periosteum without involving incisions into the overlying mucosa,submucosa,muscle & periosteal layers Excellent wound healing without visible scarring12/20/2011

BSSO INCISION A vertical incision on the buccal alveolus

extending into the sulcus at the ant region of the 1st molar & a Hz incision 2 mm below the cervical region of tooth is made. Another incision in the retromolar region extending upward through the ant border of ramus upto the level of its deepest concavity. Subperiosteal dissection & flap elevation.12/20/2011

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Extraoral Approaches in lower 1/3rd of faceSubmandibular approach Retromandibular approach Submental approach Lip split approach Modified Blair approach Face lift/Rhytidectomy approach12/20/2011

SUB MANDIBULAR APPROACH AKA Risdon incision To expose mandibular ramus and posterior body region

indications access to a myriad of mandibular osteotomies Angle/body fractures, condylar fractures TMJ ankylosis.

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Significant structures Marginal mandibular nerve Facial artery Facial vein

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Anato mic dissec tion of the lateral face

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technique Prep and Drap Marking the Incision and

Vasoconstriction-The incision is 1.5 to 2 cm inferior to the mandible. Skin incision

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Two locations of submandibular incisions. Incision A parallels the inferior border of the mandible. Incision B parallels or is 12/20/2011 within the resulting skin tension lines.

4.Incising the Platysma Muscle

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Sharp dissection through the platysma muscle that has been undermined with a hemostat.

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5.Dissection to the Pterygomasseteric Muscular SlingRelationship of the facial artery and vein, the marginal mandibular branch of the facial nerve, and the submandibular (premasseteric) lymph node to the inferior border of the mandible and masseter muscle.12/20/2011

Coronal illustration of the path of dissection. The initial dissection is through the platysma to the superficial layer of deep cervical fascia then through it in the area of the submandibular gland to the periosteum (P) of the mandible which is incised at the inferior border.12/20/2011

6. Division of the Pterygomasseteric Sling and Submasseteric Dissection

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Amount of exposure obtained with the submandibular approach. The channel retractor is placed into the sigmoid notch, elevating the masseter, parotid, and superficial tissues.12/20/2011

ECKELT (1991) technique for lag screw

osteosynthesis of condylar fracture. A skin incision is made 1 cm superior to the inferior border of the mandible & extended to the level of platysma Facial nerve is identified Masseter is incised superior to the inferior border of the mandible & reflected inferiorly12/20/2011

RETROMANDIBULAR APPROACH Hinds approach. Exposes the entire ramus from behind the

posterior border. Useful for procedures involving the area on or near the condylar neck/head,or ramus itself. Significant structures-Facial nerve Retromandibular vein12/20/2011

Anatomic dissection showing the relationship of the retromandibular vein (RV) , and inferior (+) and superior divisions (*) of the VII to the mandible.12/20/2011

Technique Varies with surgeon in position of skin incision

1. approximately 2 cm posterior to the ramus. advantage-it avoids the branching facial nerve. Disad-the direct proximity of the skin incision to the mandible, is then lost. 2. The incision is placed at the posterior ramus, just below the earlobe.12/20/2011

Vertical incision just posterior to the mandible through skin and subcutaneous tissue to the depth of the platysma muscle.12/20/2011

Sharp dissection through the thin platysma muscle, SMAS, and parotid capsule after undermining with a hemostat12/20/2011

Blunt hemostat dissection through the parotid gland, spreading in the direction of the fibers of VII.12/20/2011

Incision through the pterygomasseteric sling along the posterior border of the mandible. The inferior division of VII is being 12/20/2011 retracted superiorly.

Subperiostea l dissection of the masseter muscle. The periosteal elevator is used to strip the muscle fibers from the top to the bottom of the ramus.12/20/2011

Anatomic dissection showing exposure of the post ramus with retraction of the superior division of VII by the channel retractor12/20/2011

SUB MENTAL APPROACH Most anterior inferior approach Provide access to anterior mandible

for symphysial manipulation No significant anatomic structures between skin & bone

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Dissection may be sharp with impunity Incision should give in Submental skin crease I cm below the lower border of mandible and parallel to it Access is direct to the bone where good expo is achived for fracture repair or implant placement.12/20/2011

Variations in incision: A) Following curvature of anterior mandible B) Hidden in submental skin crease

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LIP SPLIT APPROACHIndications This approach allows access to the oral cavity and pharynx for excision of mucosal and submucosal tumors. In conjunction with a transcervical extension, this approach may also be used to gain access to the parapharyngeal space for excision of tumors in this area.12/20/2011

contraindications Patients who strongly object to a lip-split incision should be considered for a lingual releasing approach A small atrophic mandible Poor dental hygiene adjacent to the mandibulotomy may predispose to osteotomy sepsis.12/20/2011

If there is a question of tumor

invasion of the more distal mandible, an anterior mandibulotomy should not be created until after the extent of mandibular resection required to remove the tumor is determined12/20/2011

Anatomy The depressor labii inferioris, depressor anguli oris, and mentalis muscles are to some degree disrupted if a circummental lip-split incision is made. For this reason, the midline Z-type incision is preferred. The mental foramen The canine is an excellent tooth for use as a dental abutment for tissue-borne dental prostheses. The mandibulotomy should not compromise this tooth or its root.12/20/2011

With care, there is sufficient space between the incisor s roots to perform a mandibulotomy without the need to extract a healthy tooth. The digastric and genioglossus muscles attach in the midline. The mandibulotomy (if performed in a paramedian position) may be placed lateral to these muscles and medial to the mental foramen.12/20/2011

(A) Roux-Trotter incision. (B) McGregor incision. (C) Hayter et al modification of the McGregor incision. (D) Robson incision.12/20/2011

Bhatt et al. Modified Lip Split Incision.

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Lip-split access to the anterior mandible The mucosal incision in the floor of mouth and through the gingiva should not be directly over the mandibulotomy. A lip-split with a midline-Z incorporating the mental crease is used. The skin incision descends vertically from the vermilion to a point about 0.8 to 1 cm above the mental crease. At this point, it is angled to join the mental crease about 0.8 to 1 cm off the midline. The incision then travels horizontally within the crease to a symmetric point on the contralateral side12/20/2011

From this point, it is angled back to the midline, opposite but symmetric with the angled incision above the mental crease. A step at the vermilion border allows the incision through the red lip, gingivolabial sulcus, and floor of mouth to be in a paramedian position on the side opposite the paramedian mandibulotomy. This is preferred to a circummental incision and places the incision through the mucosa away from the intended mandibulotomy site.12/20/2011

One technique of splitting the lower lip in the midline. This incision can be connected to submandibul ar incisions on either side.12/20/2011

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A technique of splitting the lip following the mentolabial crease. This technique is used in conjunction with a contralateral submandibular incision to increase exposure of that side of the mandible.

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Alternative approach to the mandibular Ramus Added exposure of the mandibular

ramus is frequently required. Combinations of approaches such as the preauricular and the retromandibular offer increased exposure for some procedures, such as those for temporomandibular ankylosis..12/20/2011

If even greater exposure is required,

one can connect these two approaches using a MODIFIED BLAIR

INCISION

This incision is used frequently for

operations involving the parotid, but it can be useful for those involving the mandibular ramus12/20/2011

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RHYTIDECTOMY APPROACH The rhitidectomy or facelift approach to

the mandibular ramus is a variant of the retromandibular approach. The only difference is that cutaneous incision is placed in a more hidden location. Advantage-less conspicuos facial scar. Disad-added time required for closure.12/20/2011

Significant structures Greater auricular nerve. Retromandibular vein. Facial nerve.

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conclusion Many areas of facial skeleton can be

assesed by an intraoral approach and this should be the first choice. Those areas not assesed via the mouth can usually be reached by extraoral approach.

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in general, the surgical incisions are

always based upon anatomical landmarks and facts, to protect certain important structures, keeping in mind the cosmetic effects. This is even more important in facial region for obvious reasons. So a thorough knowledge of anatomy of the region is a must, before surgery is attempted.12/20/2011

References Surgical approaches of facial skeleton-Ellis

& Zide Maxillofacial trauma & esthetic facial reconstruction-Peterward Booth Trauma VOL 3-Fonseca Fracture of the facial skeleton-Banks & Brown. Surgical approaches-Franz Harle.12/20/2011

Surgical Incisions -Their Anatomical Basis: Part 1 -

Head And Neck.Patnaik V.V.G.*, Singla R.K. and Bala SanjusVol. 49, No. 1 (2000-01 - 2000-06)

Lip split wth mandibulotomy approachChristanson & Hoffman. Submental approach-Cornellius , Ellis & Kushner Miscellaneous.

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