access osteotomies in oral and maxillofacial surgery

PRESENTERDR.REHANA SULTANA

POST GRADUATE STUDENT

Access osteotomies in oral and maxillofacial surgery

CONTENTS

INTRODUCTIONHISTORYCONCEPT OF MODULAR OSTEOTOMIESVARIOUS OSTEOTOMIES MAXILLARY OSTEOTOMIESMANDIBULAR OSTEOTOMIESMODIFICATIONSCONCLUSIONREFERENCES

Introduction

The craniofacial skeleton can be regarded as an osteoplastic structure as its excellent blood supply allows the mobilisation and replacement of bone fragments,either pedicled on their soft tissues or as free bone segments

History

Von langenbeck in 1859 performed a horizontal osteotomy at the level of fracture line

Later in 1901, it was described as the lefort 1 position to access the pathology in the nasopharynx

Kocher modified vonlangenbeck’s technique by dividing the maxilla in the midline to approach the pituitary fossa

Concept of modular osteotomies

Various osteotomies to access various areas

Infratemporal fossa :zygomatic arch osteotomy with or without lateral orbital rim or

Inverted L zygomatic bone osteotomy with or without involvement of lateral orbital rim

Lesions involving parapharyngeal, lateral pharyngeal and deep spaces of neck, posterior oral floor, retromaxillary and tonsillar fossa can be accessed by mandibular osteotomies

For increased exposure of the parapharyngeal space, infratemporal fossa and pterygomaxillary region upto the skull base --- a second horizontal osteotomy of the mandibular ramus above the lingula.

Skull base can be approached anteriorly and laterally---bitemporal craniotomy with frontonasalorbital osteotomy

Middle cranial base approaches include Le Fort I maxillary osteotomy, sometimes combined with mandibulotomy and frontonasoorbital osteotomy

Pedicled osteotomy of maxilla/hard palate & zygoma

Maxillary osteotomy

Provides wide exposure of soft palate and nasopharynx

IF INFRAORBITAL NERVE HAS TO BE LIGATED

IF INFRAORBITAL NERVE HAS TO BE SACRIFICED

Nasal osteotomy

Primarily for the resection of any pathology within nasal cavity,ethmoid and sphenoid sinuses

Modification -- maxillary nasal osteotomy

Lefort 1 osteotomy

In 1986, Sailer described the use of the Le Fort I osteotomy as a surgical approach for the removal of pathological conditions within the maxilla.(Sailer and Makek, 1986)

Different approaches for removal of tumours in the midface, pterygomaxillary region, skull base and nasopharynx have been described. Most of these use the Ferguson Weber incision or modifications thereof, giving access to the facial skeleton in order to perform osteotomies or en bloc resections (Shah and Galicich, 1977; Altemir, 1986a; Brusati, 1991; Salins, 1997).

Anatomic boundaries/surgical exposure The LeFort I downfracture creates a funnel-like opening with

a 3:1 ratio of anterior to posterior displacement of the inferior maxilla. The anterior nasal spine travels 3.5-4.5 cm inferiorly compared with the 1-1.5 cm for the posterior nasal spine.

Superior extent: sella turcica, cribiform plate. Inferior extent: C1 (possibly C2) Lateral extent: pterygoid and temporalis muscle Posterior extent: Clivus, posterior wall of sphenoid

sinus, greater wing of sphenoid bone

Accessible areas

View after lefort 1 down fracture

Exposure from posterior ethmoidal cells to craniocervical junction

Advantages

No visible scar

The aesthetic aspect of this approach is not only relevant in younger patients, but is even more important in patients undergoing radiotherapy

Facilitation of the ensuing reconstructive procedures. It allows excellent access to mobilize and fix the buccal fat pad to the medial aspect of the defect following partial maxillary resection in order to cover the nasal aspect of bone grafts in resections involving the whole maxillary sinus floor(Egyedi, 1977; Sailer and Makek, 1986).

Indications : for the tumours situated in or extending into the maxillary sinus, the sphenoid sinus or the nasopharynx

Accessible areas: nasal cavity, maxillary sinuses & nasopharynx

The Le Fort I osteotomy was even described as a single access for exposing the medial compartment of the inferior skull base from the tuberculum sellae to the foramen magnum,in order to perform neurosurgical procedures following pharyngotomy, clivectomy and dural opening (van Loveren et al., 1994).

The LeFort I osteotomy for approaching diseases in the cranial base was first described by Cheever (Moloney and Worthington, 1981) in which a maxillary osteotomy was used for removing a tumour from the nasopharyngeal area.

Limitations: vascular supply to mobilised maxillaRestriction of lateral access due to pterygoid platesThe incidence of other minor intra-operative and

peri-operative complications are considered low (Kramer et al., 2004).

Avascular necrosis of maxilla in 1% of cases (Lanigan, 1997). The possible factors could be rupture of the descending palatine artery (DPA) during surgery (Sasaki et al., 1990), post-operative vascular thrombosis, perforation of the palatal mucosa that impairs blood supply to the maxillary segment (Pereira et al., 2010).

Complications

Rare complications with this procedure includes subcutaneous emphysema (Stringer et al., 1979)

Unilateral abducens nerve palsy (Watts, 1984),

Upper lip hypoesthesia (Ueki et al.,2008) Aseptic necrosis of the maxilla (Lanigan et

al.,1990),Fatal arteriovenous fistula (Laetitia Goffinet

et al.,2010) and Blindness(Cruz and dos Santos, 2006).

Lip split /mandibular split – mandibular swing approach

An incision to divide the lower lip and chin

Division of the mandible anterior to mental foramen

Dissection of tissues in the floor of mouth, submandibular region and neck

Access areas : floor of mouth

Tongue, tonsillar fossa, soft palate, oropharynx including the posterior pharyngeal wall,supraglottic larynx and the pterygomandibular region

MANDIBULAR SWING OSTEOTOMY

Various osteotomies for tumors of parapharyngeal space

The rigid bony walls of the mandible direct tumour growth medially to the parapharyngeal space

Bulge of soft palate is the diagnostic sign

Double mandibular osteotomy with coronoidectomy for tumours in the

parapharyngeal spaceBritish Journal of Oral and Maxillofacial Surgery (2003) 41, 142–146

Vertical ramus osteotomy

Osteotomy in the vertical ramus outside the mandibular foramen for tumours in the

parapharyngeal spaceJournal of Cranio-Maxillo-Facial Surgery 42 (2014) e29- e32

Mandible osteotomies

Inverted L or C osteotomy

Inverted L or C osteotomy

Lateral zygomatic osteotomy

Conclusion

Tumors occurring in the inaccessible regions present a surgical challenge and access osteotomies of the facial skeleton is the answer to access these deeply situated, inaccessible tumors of the head and neck.

Various approaches have been devised for their better exposure and it is our expertise as maxillofacial surgeons to provide surgical access by various approaches.