CORRECTION OF DEFORMITIES OF THE JAW by Patrick Clarkson M.B.E., M.B., B.S., F.R.C.S. Casualty Surgeon, Guy's Hospital and Plastic Surgeon, Basingstoke Plastic;Ccntre. I. INTRODUCTION Degrees of Deformity and Pathology. Cooperation between Surgeon and Orthodontist. Surgical Treatment: Indication and Scope. Choice between radical surgery and " masking" operations. II. SURGICAL METHODS OF CORRECTION 1. Symmetrical Prognathism of the Mandible. 2. Asymmetrical Prognathism of the Mandible. 3. Symmetrical Recession of the Mandible. 4. Asymmetrical Recession of the Mandible. 5. The Jaw Deformities in Cleft Palate: Mandible and Maxilla. 6. Combined Jaw and Nasal Reductions. III. SUMMARY AND CONCLUSION I. INTRODUCTION A deformity of the jaw can be defined as any variation in these bones from the normal for the sex, age, and race of the patient; but only rela- tively gross variations come within the field of surgical repair. It is always possible by close examination to discover some degree of asymmetry in soft and bony tissues of the face, but the great majority of variations in facial skeleton, both symmetrical and unilateral, are scarcely noticeable to ordinary examination and require no treatment. Next in order of severity are a group of congenital origin which, given early and full ortho- dontic treatment, respond well without the need of surgery. This group includes a few of the early-cases of prognathism, of congenital open bite, and of recession of the jaw. Almost every case with these deformities can be improved by early orthodontic treatment. But all the more severe cases of prognathism, of recession, and the jaw deformities seen in patients with cleft palate, need surgical intervention if the correction is to be a complete one. When surgery is undertaken the operation is merely one stage in the total treatment, the major part of which remains the care of the orthodontic specialist, whose splints and appliances maintain the position obtained by surgery. Continued orthodontic treatment may improve the surgical result, especially in those cases where the operation has been undertaken before growth of the jaw ceases. Trauma, infection and neoplasm account for many of the deformities needing treatment. I shall not separately consider here the correction of deformities in diseased bone or those deformities produced by bone 23 P. CLARKSON removals, but will confine myself chiefly to a consideration of certain common congenital malformations. The proportion of asymmetrical deformities is higher in the acquired group, but the same surgical measures are used in respect of deformity due to accident or past disease as in that of congenital origin. There are certain disease states such as Paget's disease, acromegaly and scleroderma, in which the jaw deformity may need correction for functional reasons wbile the disease is active elsewhere; the method of treatment is then that described for the same deformity when it is seen in a congenital case. Another group of deformities due to neoplasm is that seen in patients with massiN e hemangiomata and neuro- fibromata affecting the jaw either primarily, or by pressure effect, or as a result of treatment of the growth by ionising radiations. Each one of these serious cases is an individual surgical problem necessitating treat- ment in more than one stage. Correction of the disfigurement is secondary to care of the primary disease. For some of these patients a normal appearance is still unobtainable. Operations for deformities of the jaw are sometimes undertaken solely for improvement of function. This minority group includes those in whom the articulation of the teeth is so disordered or, indeed, so lacking, that without surgical reduction of the deformity, upper and lower teeth cannot be brought into occlusion and a normal diet taken. Patients with very severe prognathism belong to this group, and so too do some of the bad cleft palate cases. Others for whom operation is undertaken for functional reasons are those with hypoplasia of the mandible, asym- metrical or symmetrical, who often have severe restriction in range of temporomandibular movement, gravely impaired power of mastication, and a marked liability to gum infection and caries. When the condyle is affected in the deformity (as in asymmetrical prognathism) it may be the arthritic symptoms in the temporomandibular joint which cause the patient to seek treatment. It is however most commonly for reasons of appearance that operations for jaw deformities are undertaken, and relief of ugliness is often an addi- tional indication for those patients who need an operation for treatment of symptoms. For a given size of distortion from normal, asymmetrical deformities are more noticeable than symmetrical ones ; but no two patients react similarly to a given facial deformity. Nor, with existing differences in temperament, race, class, creed, in addition to age and sex, could this be expected. What may be an intolerable affliction, causing virtual with- drawal or exclusion from normal social life and a severe economic handicap to one patient, is often a matter of slight concern to another. In this respect it is obvious that women are more handicapped than men. Occupa- tion is also of importance in determining whether a protracted course of treatment, needing a considerable degree of cooperation from the patient, will be worthwhile. It is not only on the stage that facial disfigurement is a special handicap. Those concerned with the sale and distribution ofgoods may well find that a relatively minor facial asymmetry 24 CORRECTION OF DEFORMITIES OF THE JAW is a bar to entry or promotion in their occupation ; whereas those engaged in manual labour and the learned professions may suffer no comparable handicap in their work from the same order ofdisfigurement. For them, as for most people, it is the individual reaction to their appearance which brings them to the surgeon, and which in cases of moderate deformity determines his decision. It is always reasonable to advise treatment for any child, when such can be expected to relieve a disfigurement or to improve it. With increasing age most patients accommodate themselves to small or moderate degrees of facial deformity. But few patients with a well developed prognathism or a bad cleft palate type of facial deformity ever make this accommodation completely or cease to have a tremedous sense of handicap, and of exclusion from the pursuits and enjoyments of their normal friends. The psychological picture when one of these severe cases is corrected in late youth or middle life is almost uniform. A virtual " release " phenomenon is seen in the first few weeks after operation, with attempts, which are often excessive and too optimistic, to recapture the opportunities from which they feel they have in the past been almost totally excluded. The end-psychological result is often the appearance of a more friendly, confident, and self-reliant character in the patient. Psychological indications for operation are a matter for careful individual assessment in moderate jav deformities. But I would always accept any appearance which can fairly be called grotesque or very ugly in a patient of normal intelligence as an adequate reason by itself for a course of treatment which may take several months and a number of operations to complete. My purpose here is to discuss current methods in treatment of certain common congenital jaw deformities. For most of these conditions choice of treatment is still a very open one; once the decision has been made to intervene surgically it will often rest between radical correction of the bony deformities (by osteotomy with mobilisation and bone graft, and fixation in cast metal cap splints for some months) and a single " masking " operation, such as an epithelial inlay, or an onlay graft. In some patients only a combination of skeletal resections and " masking " procedures offers the best results. Treatment in every case is in close asso- ciation with an orthodontist. It includes repeated pre-operative consulta- tions with the dental models, photographs, and X-rays which can include cephalometric studies with advantage. II. SURGICAL METHODS OF CORRECTION (1) Symmetrical Prognathism of the Mandible The onset of this condition is commonly in childhood. When the lower incisors are as much as 1 cm. in front of the upper there is no prospect of orthodontic methods alone reducing the deformity. This degree of protrusion may be apparent by the age of 10 or shortly after; but some of these prognathic jaws continue to grow after normal jaw growth ceases (at 18 to 20); the deformity not uncommonly piogresses up to the age of 30 or more. By this time there may not be a single occluding tooth 25 P. CLARKSON (~~~~~ 1. Ascending ramus 2. Horizontal ramus section and "push back" resection and "push back" Correction of Deformities of the Mandible. Diagram I. Symmetrical Prognathism. between the two jaws and the patient may be confined to a soft diet. -Operation for these cases is necessary on the grounds of function alone. Patients with lesser degrees of prognathism often provide strong grounds for psychological relief, especially women, whose appearance, if it is not ludicrous, tends to be forbidding and distinctly masculine. The backward displacement of the chin to a plane behind the upper lip has a remarkably feminizing effect on appearance, and it may lead to a great modification in the role and status of the patient in domestic and social life. It is common practice to delay the operative correction of prognathic jaws until about the age of 20 because continued growth of the mandible, by subcondylar deposit, will cause not only some recurrence of the deformity but severe gagging and open bite. I myself do not believe that treatment should always be delayed in young girls for this reason. A disfigurement is probably more important to a girl between 14 and 20 than at any other age.