ORTHOGNATHIC SURGERY: TECHNIQUES OF MAXILLA AND MANDIBLE: LITERATURE REVISÃO
ANA CLARA LEAL ROSA,MARIA CLARA BARRETO DE ALMEIDA,FELIPE CITRINITI STUCK PINHEIRO,
UNIGRANRIO - Campus Barra
The restoration of dental occlusion, mastication, phonetic functions and facial aesthetics, respiratory, with decisive contribution to the emotional state of the patient, made of orthognathic surgery an option increasingly popular in the treatment of facial deformities. In addition to the congenital anomalies or development, are restored by orthognathic surgery, those acquired during growth, trauma, tumors or infections. (MANN, 1987).
The technique of sagittal osteotomy of the mandibular branches is the most used for correction of facial deformities within (VAN SICHELS; HATCH; DOLCE et al., 2002). This is because the same present numerous advantages, such as: large contact area between the bone fragments, eliminating the need for the filing of grafts, bone repair, improves performance of intraoral access by reducing the risk of injury of facial nerve and eliminating external scarring, and stability in most movements (RAJCHEL; ELLIS III; FONSECA, 1986).
With technical advances for the improvement of fastening materials, associated with a new surgical perspective correction of deformities within. The combination of the maxilla osteotomies (type osteotomy Le Fort 1) with sagittal mandibular branch osteomia, optimized aesthetic and functional results and improvements in the quality of life of patients. Some complications are related to this type of osteotomy, as undesirable fracture, vascular or beam-snowy injury, hemorrhage, and necrosis and relapse (AHMAD, 1999). But these complications have become less common, due to modifications of the technique and greater experience of the surgeons. However, few studies in the literature to evaluate the anatomy of the sagittal osteotomy of the mandibular branch and total maxilla osteotomy Le Fort – type 1 (FERNANDES, FRAGA, TRINITY GRANDSON et. al., 2009).
The Facial Deformities Within (DDFs), are understood as changes in the relationship of the maxilla and mandible, and may relate only to changes in alveolar level (dental, dental crowding, inclinations, giroversões, diastema) or compromise the mandibular maxillary bone growth three-dimensionally (anterior posterior, superior or inferiorly, or transverse).
The Facial Deformities Within (DDFs), often provide functional and aesthetic changes, and may bring major psychological implications to the patient. At present, treatment is multidisciplinary. Psychologists are enabled to evaluate these patient and identify if they understood the proposal of surgical treatment, as well as the biopsychosocial factors: their beliefs, motives and related perspectives on changes in your image including issues related to the patient's personality (CUNNINGHAM ; et al., 1995).
The scientific literature is unanimous in saying that the orthognathic surgery provides the patient with facial harmony, in addition to restore function, bringing a psychosocial improvement, and provide a better quality of life (CUNNINGHAM ; et al., 1995).
Orthodontic treatment can resolve some discrepancies related to improper positioning of the dental elements regarding their respective bases, both in the jaw bone and the jaw. The literature reports that the term "camouflage", applies when it aims through orthodontic movement provide compensations and consequently the repercussions of these dental movements in the soft tissue of the face. However when the discrepancies are related to changes in growth of skeletal structures (excess or lack of growth) dental movements are indicated by the magnitude against compensatory movement required (TOLEDO-SON, MARZOLA, TOLEDO-NETO, 1998).
The literature emphasizes that the main complications related to "camouflage" orthodontics in these patients are related to the impairment of tooth support structure (periodontal health, bone loss, root resorption and bone fenestrations) and instability in the result required and recurrence of deformity (PROFFIT; et al., 2003).
Some facial deformities within, because changes in relative mandibular maxillary, can affect the temporomandibular joints providing tables of: arthralgia, clicks, crackles, changes in the positioning of the articular disc, condylar resorption and degenerative processes in the joint structures (CORTEZZI, 1996). So in the initial assessment, both the orthodontist and maxillofacial surgeon, as should consider the presence of signs and symptoms of temporomandibular disorders of joint origin according to the severity of the clinical picture and decide the hierarchy of surgical procedures that are performed in the orthodontic-surgical treatment plan (WOLFORD, 2007).
TECHNIQUES OF MANDIBLE
The anatomical and surgical study of maxilla and mandible is of extreme importance, regardless of the experience of the surgeon, the deformities may change the local Anatomy (EL DUBRUL, 1991). In sagittal osteotomy of the mandibular branch, the lingula is a bony process with size and variables being forms a reference point for the horizontal medial osteotomy, performed on the inner surface of the mandibular branch above this structure (fig. 1) (wood, 1998 and JANSISYANONT, APINHASMIT, CHOMPOOPONG, 2009).
Fig. 1- location of the lingula on the medial aspect of the jaw. Reference point for horizontal osteotomy
The surgical technique used in the mandibular advancement procedures is the sagittal osteotomy of the mandibular branches (VAN SICKELS; JETER; ARAGON, 1992). Among its advantages are: the possibility of advances or setbacks, asymmetric movements, intraoral access with little or no external SCAR and allowing rotations in vertical direction (WYATT, 1997 and BLAKEY; WHITE., in PROFFIT; WHITE; SARVER, 2005).
Fig. 2-illustration of the variations of the sagittal osteotomy technique in the business by Del Pont.
Fig. 3- illustration of the sagittal osteotomy techniques variations of the mandibular branch.
One of the complications of surgical technique: edema, excessive bleeding, fractures neurological deficit of inadequate, inferior alveolar nerve, infection, kidnapping of fragments, delayed Union, bad or fibrous Union Union of osteotomizadas areas, causing malfunctions in temporomandibular joint (fig. 4) (SMITH, 1991). There is possibility of undue displacement in mandibular condyles (fig. 5) (fig. 6), causing malfunctions in temporomandibular joint (fig. 4) (WHITE; DOLWICK, 1969; VAN SICKELS; JETER; THERIOT, 1985 and the ' RYAN 1999). The literature classifies the inferior alveolar nerve damage such as: direct or indirect. The direct damage can be caused by retraction during surgery, the nerve section, when supplemented cortical osteotomies or separate from the jaw or by compression of the segments in the fixation with wires or screws. The indirect damage can be due to vascular changes with subsequent nerve degeneration (TEERJOKI-GMINA OKSA, 2002).
Fig. 4-(1) Articular Disk; (2) Articular Eminence; (3) Supradiscal Compartment; (4) head daMandíbula; (5) Articular cartilage; (6) Infradiscal Compartment; (7) joint capsule; (8) disc Retro Cushion; (9) External Acoustic Meatus; (10) Lateral Pterigoideo muscle internal beam; (11) tendon of the Temporalis.
Figura 5– Método de mobilização e separação do segmento proximal.
NOTE: During this procedure increases the risk of fracture, bleeding, trauma in ATM, injury to the inferior alveolar nerve.
The proximal portion must be repositioned in your ideal position and the individual technique used by each surgeon in condylar segment fixation, possessing great importance on the outcome of treatment. (INGERVALL; THÜER; VUILLEMIN T, 1995 and CHUNG; YOO; LEE et al., 2008).
With respect to surgical technique, especially in advances, skeletal recurrence can be found in only two locations, at the site of the osteotomy, a slide between the segments and, in temporomandibular joint with an inclination or condylar compression with morphological changes (ARNETT; TAMBORELLO; RATHBONE, 1992; ELLIS; CARLSON; BILLUPS, 1992; PROFFIT; TURVEY; PHILLIPS, 1996 and NEMETH; RAO-GARCIA; SAKAI et al., 2000). In response to the slide of the osteotomy and subsequent further movement from the front of the jaw, when the use of elastic intermaxilares, dental compensation can be observed in the upper and lower incisors, skeletal recurrences soft masking. These dental changes tend to return to its original position in the long term, after the removal of the rubber bands and the retainer, period in which the final positioning is evidenced (ARNET, 1993; ARNET; MILAM; GOTTESMAN, 1996 and ARNET; MILAM; GOTTESMAN, 1996 b). Were submitted to orthodontic-surgical treatment, 241 patients with skeletal malocclusion type Class III, with the purpose to meet the possible complications arising from bilateral sagittal osteotomy of the mandible using stable internal fixation. In the immediate postoperative period, three osteotomies showed little stability due to the loss of fixing screws and, in the first month after surgery infection occurred in 12 osteotomies. Were recorded on stability after a year in all osteotomies evaluated, being recommended constant assessments during the first two months after surgery to check the oral hygiene, presence of infection, skeletal, or instabilities recurrences (BECELLI; FINI; RENZI et al., 2004).
During the execution of the technique must pay attention about the lack of control of the correct positioning of the mandibular condyle in their most varied possibilities as lateral and medial torques without contact with the glenoid cavity and anteroposterior position (ARNETT, 1993). The use of surgical techniques that do not permit an assessment during the surgery, the obtaining of the centric relation and its relation to the centric occlusion or maximum intercuspation, can lead to failure of the technique (WOLFORD, 2000).
Figure 6 – method of determination of bone segments with steel wire. Less instability.
Figure 7 – method of determination of bone segments with screws-cortical
Figure 8 – method of determination of bone segments with a single plate
The jaw is responsible for a series of bad accented, varied etiologies occlusions and, when the orthodontic treatment can not solve, surgery is the fastest and secure professionals meet to correct such deformities (MENUCI-GRANDSON; POLISHED; MAZZOLENI et al., 2004).
In the absence of severe intermaxilares disproportions, one can make use of several techniques allowing the surgical repositioning of dental groups or full jaw replacement. These techniques range from single and serial cortectomies, earlier, later or even the jaw totals for correction of malocclusion and dent facial deformities (KOLE, 1959 and MOHNAC, 1966).
The Le Fort I osteotomy is frequently used for correction and treatment of dent facial deformities, especially those related to the middle third of the face (UEKI; HASHIBA; MARUKAWA et al., 2007).
One of the first interventions Le Fort I (WASSMUND, 1939), describing the osteotomy performed in 1927 and effected by means of the canine and cheek pillars, in addition to the partial section of the side wall of the cavity and the nasal septum (ARAÚJO, 1999). Authors demonstrated that could be performed in total maxillary osteotomy, without major damage to the blood supply in the region, only preserving a "pedicle" of soft tissue in the palate and jaw regions (BELL; FONSECA; KENNEDY et al., 1975).
From the years 70 there was a big evolution in the treatment of dent facial deformities once facial osteotomy Le Fort I allowed almost all the movements, respecting the limitations of each case. Transverse, anteroposterior and vertical changes of the jaw can be resolved using this procedure.
This technique is performed working the jaw in a single block, after the separation of the nasal septum, medial and lateral wall of the maxillary sinus, in addition to the pterygoid process. There are some specific cases that the maxilla can be split into smaller segments allowing larger drives (fig. 9) (BELL; PROFFIT; WHITE, 1980; GRAZIANI, 1986 and SAMUEL Jr., 2001).
The specific factors that appear to have greater contribution to recurrences of type Le Fort I osteotomies include orthodontic pre-and postoperative stability, the scar retraction, presence of cracks, previous surgeries and interference with the nasal septum altering respiratory function. In addition, the type of fixation used quality of the final occlusion and passive repositioning of the maxilla, no approximation of the osteotomizadas bone walls. The surgical technique employed and the type of movement carried out were also cited as factors that may influence the stability of osteotomies. (PROFFIT; TURVEY; PHILLIPS, 1996 and YOON; REBELLATO; KELLER, 2005). In previous studies, the upper jaw surgical repositioning proved to be a stable procedure when assessed by radiographs (BELL, 1975 and EPKER, 1981). The impaction is the jaw movement more stable as long as there is adequate fixation and bone contact. When occurs a change of movement in this type of surgery, its direction is towards higher, by bone resorption in the osteotomy. This stability is greater when soft tissues are relaxed and less when they are lengthened (ROTTER, 1999).
An additional factor that affects the stability of the upper jaw repositioning and mandibular advancement is simultaneously the quantity and quality of bone in the posterior maxilla interface. Two consequences may occur in this case, the first, the jaw is expanded, with poor contact of bone subsequently and, second, the posterior bone is thin and structurally does not produce a stable interface. When any one of the factors is present, there is a chance the jaw potential tilt-up in the posterior region and down the previous region, resulting in the rotation time of the Chin, rotation of the proximal segment eon recurrence eon excessive condylar (EPKER overload; STELLA; FISH, 1996). The surgical technique employed and the type of movement carried out were also cited as factors that may influence the stability of osteotomies (PROFFIT; TURVEY; PHILLIPS, 1996 and YOON; REBELLATO; KELLER, 2005).
Fig. 7 – the hierarchy of stability of orthodontic-surgical treatment.
Source: PROFFIT, W. R.; TURVEY, T. A; PHILLIPS, c. Orthognathic surgery: the hierarchy of stability. Int. J. Adult. Orthod. Orthognath. Surg, Chicago.2000,11(3):191-204
Fig. 9-frontal Aspect, after completion of the osteotomy in the side wall and jaw medialda.
Source: BELL, W. H.; PROFFIT, W. R.; WHITE, r. p. Surgical correction of dentofacial deformities. Philadelphia: w. b. Saunders, 1980.
Skeletal stability after Le Fort I surgery for jaw advancement in 30 patients was studied in x-rays side, in the pre-and immediate postoperative period and late. The stability seen in the isolated jaw advancement was equal when held concurrently with mandibular surgery. All the skeletal changes occurred within the first five months after surgery. Eight cases individually examined showed movements greater than desired. In six (6) cases, undesirable postoperative changes occurred due to errors in preoperative orthodontics. This study confirmed that the position of the upper incisors preoperative must be evaluated and should have adequate slopes, in addition to being inside their bases. Wired fixation and bone graft are sufficient to obtain stability in case of maxillary advancement up to 11 mm and, in more complex cases we recommend the stable internal fixation (CARLOTTI; SCHENDEL, 1987). In most cases, where one uses non-stable as means of fixation, relapse is almost complete. Interposition with bone grafts between the caliper and the osteotomized portion and stable internal fixation are ways to minimize this unpleasant problem of relapse (PROFFIT; TURVEY; PHILLIPS, 1996).
There are several ways to avoid problems with relapse after the advance of the maxilla, and the modification of the technique of osteotomy Le Fort I, the fixing method used, the use of grafts or bone substitutes and the association with bilateral sagittal osteotomy of the mandibular branches, those more reported and studied. It is considered as less stable lowering movements of the jaws, the force that the masticatory musculature has maxillary expansion by force and that the fibro mucosa palatine makes to reconnect the bone segments with recurrence of about 50 of the movement.
The Facial Deformities Within (DDFs), often provide functional and aesthetic changes, and may bring major psychological implications to the patient, being important multidisciplinary evaluation (CUNNINGHAM ; et al., 1995).
Psychologists are enabled to evaluate these patient and identify if they understood the proposal of surgical treatment, as well as the biopsychosocial factors: their beliefs, motives and related perspectives on changes in your image including issues related to the patient's personality.
The scientific literature is unanimous in saying that the orthognathic surgery provides the patient with facial harmony, in addition to restore function, bringing a psychosocial improvement, and provide a better quality of life (CUNNINGHAM; et al., 1995).
Some facial deformities within, because changes in relative mandibular maxillary, can affect the temporomandibular joints providing tables of: arthralgia, clicks, crackles, changes in the positioning of the articular disc, condylar resorption and degenerative processes in the articular structures, being vital pre-operative assessment. (CORTEZZI, 1996).
One of the complications of surgical technique: edema, excessive bleeding, fractures neurological deficit of inadequate, inferior alveolar nerve, infection, kidnapping of fragments, delayed Union, bad or fibrous Union Union of osteotomizadas areas, causing malfunctions in temporomandibular joint (SMITH, 1991).
Both osteotomy techniques (sagittal mandibular branch and Le Fort 1) require predictability being important the pre-operative planning and in conjunction with the orthodontist and the surgeon. Rigid anchorages by means of mini plates and screws for fixation and immobility of the segments osteotomizados, showed better results when compared to other methods (WOLFORD, 2000).
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