|Correction of dentofacial deformities with orthognathic surgery: Outcome of treatment with special reference to costs, benefits and risks|
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The historical development of orthognathic surgery has not been uniform and continuous but has rather followed a stepwise, intermittent course. The early-phase surgery was mainly limited to the mandible, while maxillary procedures were to come later. Orthognathic surgery was originally developed in the United States of America (Steinhäuser 1996). The first mandibular osteotomy is considered to be Hullihen´s procedure in 1849 to correct a protrusive malposition of a mandibular alveolar segment caused by a burn (Hullihen 1849). Osteotomy of the mandibular body for the correction of prognathism was first carried out in 1897 as so called ´St Louis operation´. The osteotomy was performed by Vilray Blair, who later described several methods to correct maxillofacial deformities and was the first to present a classification of jaw deformities: mandibular prognathism, mandibular retrognathism, alveolar mandibular and maxillary protrusion and open bite. He was also the first to underline the importance of orthodontics in treatment. (Steinhäuser 1996). The first phase of development in the USA came to an end at World War I (WW I), when surgeons had to concentrate on trauma surgery.
Not much progress was made in Europe during the first phase of orthognathic history. Berger (1897) described a condylar osteotomy for the correction of prognathism. This technique was elaborated by others, but the results were not satisfactory due to problems of relapse and open bite. Only slight development took place between the two World Wars (second phase), and during WW II, surgeons were again committed to the treatment of facial injuries. The concentration on trauma surgery was not, however, only a disadvantage to the development of orthognathic surgery, but also helped in many ways to apply these experiences to the principles of orthognathic surgery.
The third phase, which began in the early 1950´s, was a period of rapid development in the whole field of orthognathic surgery. In 1954, Caldwell and Letterman developed a vertical ramus osteotomy technique, which had the advantage of minimizing trauma to the inferior alveolar neurovascular bundle. This method could be used instead of body ostectomy to correct mandibular excess.
Europe now became the center of progress. Pupils of the ´Vienna School´of maxillofacial surgery, Trauner and Obwegeser (1957), introduced intraoral bilateral sagittal split ramus osteotomy (BSSO), although the first description was published as early as 1942 (Schuchardt). The technique was further modified by Dal Pont (1961), Hunsuck (1968) and Epker (1977) among others. It was a versatile procedure that allowed corrections in all three planes of space without a need for a bone graft. There were, however, still many problems and much hesitation before this procedure made a breakthrough in the late 1970´s and now sagittal split osteotomy has become the most commonly performed mandibular procedure (Wyatt 1997). The risk of damage to the inferior alveolar nerve still remains. The introduction of an internal rigid fixation method — bone screws and plates — instead of 5- to 6- week intermaxillary fixation radically improved patient convenience (Steinhäuser 1996). This new method was motivated by innovations within trauma surgery, from where it was gradually applied to orthognathic surgery. Biodegradable osteosynthesis material (Suuronen R et al. 1999) and application of the principles of distraction osteogenesis represent the latest innovations in orthognathic surgery.
There seems to exist only one report on early Finnish orthognathic surgery, closed condylotomy for the correction of prognathism in 31 patients (Tasanen et al. 1981), although osteotomies for correction of dentofacial deformities have been performed ever from the 1960’s.
Although Cheever was the first to do downfracture of the maxilla as early as 1864 to resect a nasopharyngeal mass in two patients, it took decades until further maxillary procedures were attempted (Moloney & Worthington 1981). Between the World Wars in 1921, 72 years after Hullihen´s first mandibular osteotomy, Wassmund reported his initial attempt to perform maxillary osteotomy. Wassmund did not mobilize the maxilla, but employed orthopedic traction postoperatively to position the maxilla. (Turvey & White 1991). Again, it was not until the third phase of the development of orthognathic surgery in 1960 that Obwegeser started to perform maxillary surgery and described a large series of LeFort I osteotomies in 1969. That marked the beginning of a new era in the correction of maxillofacial deformities: before the mid-1960´s, dentofacial deformities were treated by performing mandibular surgery, although the patient would also have benefited from complementary or exclusive maxillary surgery. This technique was just as revolutionary in the maxilla as sagittal split osteotomy had been in the mandible: the maxilla could now be moved in all three planes of space. The major concerns had been intraoperative bleeding, revascularization and healing of the maxilla. After studies of vascular perfusion and the anatomy and relevance of the maxillary artery, it was found that the most important thing would be to preserve a wide, intact palatal and maxillary soft tissue pedicle attached to the ostetomized segments. This allows good healing and minimizes the risk of tissue necrosis. (Bell et al. 1975, Turvey & Fonseca 1980).
The improvement of surgical techniques, and the progress in anesthesia, enabled surgery on two jaws, called bimaxillary surgery, and the introduction of rigid internal fixation made it more predictable and decreased morbidity. Köle had, as early as 1959, performed simultaneous segmental osteotomies on both jaws (Köle 1959), but the first total two-jaw operation was done by Obwegeser in 1970. This technique facilitates the correction of extensive dentofacial deformities in a single operation.
Orthodontics is an essential part of modern orthognathic surgery. This was stressed by the surgeon Converse and the orthodontist Horowitz in 1969. It is important that the dental arches are properly aligned before the operation. This makes accurate correction of the skeletal discrepancy possible, not only in the antero-posterior and transverse direction, but also vertically.
Before 1960"s the surgical correction of dentofacial deformities was done either without patient ever having orthodontic treatment, after orthodontic appliances had been removed, or, occasionally before any orthodontics was begun. Coordinating the two types of treatment more carefully was not highly appreciated.
At that time, rigid arch bar constructions, familiar from trauma surgery, were used perioperatively when needed. Technical development of orthodontic brackets and steel rectangular wires, edgewise technique, could give excellent and sufficiently rigid control of occlusion to be utilized also in surgery. The more precise tooth movements allowed finishing of the occlusion postoperatively.
The introduction of occlusal wafer splint was an important step in allowing surgery to occur before orthodontic detailing of the occlusion was completed. Consequently, the total treatment time reduced significantly, when some type of tooth movements could be more efficiently accomplished postoperatively. (Proffit & White 1991).