Orthognathic surgery for children

Int. J. Oral Surg, 1985: 14: 466--471 (Key words: surgery, ortnognathic; osteotomy; slIrgery, ural and maxillofacial)

Orthognathic surgery for children Analysis of 88 consecutive cases D. S. PRECIOUS, L. R. McFADDEN AND S. J. FITCH Graduate Oral Surgery Training Programme, Dalhousie University, Halifax, Canada

ABSTRACT - A retrospective analysis of 88 consecutive pediatric patients who underwent surgical correction of their dentofacial deformities is presented. There were twice as many female as male patients and the most common deformities were of the skeletal Class II type. The LeFort I osteotomy was the most frequently performed operation. The effect of controlled hypotensive anesthesia on the duration of both anesthesia and surgery, estimated blood loss and incidence of transfusion is discussed. Surgery for the correction of dentofacial deformities can be performed on children and adolescent patients with little morbidity and few complications.

( Received for publication 24 January, accepted 10 September 1984)

Orthognathic surgery in conjunction with orthodontic treatment has become the method of choice in management of adult patients with dentofacial deformities. The experience which has been gained with these patients is being used to advantage with increasing frequency in the treatment of children and adolescent patients. Although existing data are both conflicting and somewhat confusing, fear that surgical correction of dentofacial deformities during growth would "freeze" subsequent remaining growth of the jaws has been largely unsubstantiated when careful attention has been paid to diagnosis, patient selection, timing of surgery, choice of operation and technical surgical precision.'·4,5.9,13.14

The reasons for which early orthognathic surgery is included in the treatment plan for children with dentofacial deformities are listed below.2 •s, lo 1. Surgery is indicated when there exists a skeletal disproportion of the jaws, the correction of which exceeds the limits of orthodontic and/or orthopaedic treatment. 2. Orthognathic surgery can reduce the duration of orthodontic treatment. 3. Children do not "grow out of' some specific dentofacial deformities. 4. It is possible that early surgery can beneficially alter remaining growth by changing the functional milieu of both the jaws and associated soft tissue elements.

ORTHOGNATHIC SURGERY IN CHILDREN 5. Recovery from surgery is rapid and uneventful in most children. 6. Timely psychological benefits can accrue to the young patient, thus avoiding lasting deleterious effects on his/her selfimage. The purpose of this study was to review the records of eighty-eight consecutive pediatric patients who underwent orthognathic surgery for the correction of dentofacial deformities. The results of this retrospective study reveal that on otherwise healthy pediatric patients, orthognathic surgery can be performed with predictability and safety.

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mated to the nearest 5 min. Blood loss during surgery was estimated, to the nearest 5 ml by substracting the measured amount of irrigation from the total volume of blood and irrigation in the suction bottle. Whcn deliberate controlled hypotensive anesthesia was used, its elfect on duration of the surgical procedure and estimated blood loss was recorded. To achieve deliberate hypotension several techniques, according to the preference of the anesthesiologist, were employed including those using halothane and a narcotic analgesic and those using ganglionic blocking agents. Regardless of the anesthetic technique which was used to produce hypotension, one goal of the anesthesiologist was to reduce the patient's systolic blood pressure during surgery to about 80 torr.

Material and methods The records of 88 consecutive patients who un'd erwent surgical correction of their dentofacial deformities during the period January I, 1980 to December 31, 1982, at the Izaak Walton Killam Hospital for Children, Halifax, Canada, were evaluated. The parameters recorded were age and sex of the patient, diagnosis, surgical procedure, duration of anesthesia, duration of surgery, estimated blood loss, incidence of blood transfusion, duration of hospital stay and complications which resulted from surgery. Duration of anesthesia and surgery were esti-

Table I. Classification of 88 children and adolescent patients by diagnosis Diagnosis Number Percent of of patients total 1. Vertical maxillary excess with relative or absolute mandibular deficiency 37 42 .1 2. Mandibular deficiency syndrome 22 25.0 3. Mandibular excess 14 15.8 4 . Posteroanterior maxillary excess 5 5.7 5. Maxillary excess with mandibular excess 4 4.5 6. Maxillary deficiency 2 2.3 7. Maxillary deficiency with mandibular excess 2 2.3 2 2.3 8. Asymmetry

Results 1. General The mean age of the patient population which we examined was 13.9 years (range 6-15 years) . There were 29 (33 % ) males and 59 (67%) females. These patients represented 14% of the total number of patients, both adult and children, who were treated during the 1980-82 period for the correction of dentofacial deformities in the graduate training programme in oral and maxillofacial surgery at Dalhousie University.

2. Diagnosis The incidences of the vanous deformities are listed in Table I.

3. Surgical procedures The frequencies with which specific surgical procedures were performed are listed in Table 2. Simultaneous maxillary and mandibular surgery was performed for 28 .2% of the patients.

4. Duration of anesthesia Mean values of duration of anesthesia, for one and two jaw surgery, with and without controlled hypotensive anesthesia are given in Table 3.

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Table 2. Frequency of surgical procedures in 88 children and adolescent patients with dentofacial deformities Surgical procedures Number Maxillary surgical procedures LeFort I Osteotomy One segment 17 Two segments 14 Three segments 4 Four segments 5 Anterior maxillary osteotomy 4 Posterior maxillary osteotomy 2 Mandibular surgical procedures Modified sagittal ramus osteotomy 34 Vertical ramus osteotomy 5 Body ostectomy 1 Subapical osteotomy 4 Anterior horizontal osteotomy 6 Coronoidectomy I TMJ reconstruction with costochondral graft Other surgical procedures Alloplasts 4 Bone graft 8

5. Duration of surgery Mean values of duration of surgery, for one and two jaws procedures, with and without

controlled hypotensive anesthesia are given in Table 3.

6. Estimated blood loss Mean values of estimated blood loss (E.B.L.) for one and two jaw procedures, with and without controlled hypotensive anesthesia are given in Table 3. The effect of controlled hypotension on estimated blood loss can be more fully appreciated by comparing E.B.L. for specific surgical procedures when performed with and without this anesthetic technique. Such comparisons are given in Table 4 for isolated sagittal osteotomy of mandible and isolated LeFort I osteotomy of the maxilla. Segmentalization of the maxilla did not appreciably alter the amount of blood loss at surgery. 7. Incidence of blood transfusion Four patients, 3 of whom were females, received whole blood or packed red cells. None of these patients was given a controlled hypotensive anesthetic. Three of these 4 patients underwent isolated LeFort

Table 3. Mean duration of anesthesia and surgery, and mean estimated blood loss for one and two jaw surgical procedures with and without controlled hypotensive anesthesia Estimated Duration of Duration of blood loss anesthesia surgery (min) (min) (ml) One jaw surgery Controlled 72 patients hypotensive anesthesia 155±25 S.D. 115±30 S.D. 140±55 S.D. 13 patients range 100-195 range 50-160 range 100-250 No controlled hypotensive anesthesia 150±30 S.D. 120±40 S.D. 260 ± 200 S.D. 59 patients range 100--225 range 100-745 range 65-230 Two jaw surgery Controlled 16 patients hypotensive anesthesia 240 ± 130 S.D. 225±50 S.D. 160±35 S.D. 6 patients range 160-310 range 105-200 range 110-450 No controlled hypotensive anesthesia 21O±40 S.D. 190±35 S.D. 355±210 S.D. 10 patients range 150-310 range 140-260 range 120-800

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Table 4. Mean estimated blood loss for modified sagittal osteotomy and LeFort I osteotomy, with and without controlJed hypotensive anesthesia Estimated blood loss (m!)

Modified sagittal osteotomy of the mandible

LeFort I osteotomy of the maxilla

Controlled hypotensive anesthesia 4 patients No controlJed hypotensive anesthesia 24 patients Controlled hypotensive anesthesia 9 patients No controlled hypotensive anesthesia 18 patients

I osteotomies while the fourth patient had simultaneous maxillary and mandibular surgery.

8. Duration of hospital stay Mean duration of hospital stay was 4 days (range 3-6 days).

Discussion That the mean age was 13.9 years and because most of the patients in our study either were in the very late mixed dentition, or had no remaining deciduous teeth, perhaps it would be more accurate to consider this group of patients, rather than children, early adolescents. It has been our experience that at this age they are co-operative, intelligent and remarkably tolerant of their surgical experience. The fact that there were more than twice as many females as male patients suggests that similar factors as those which influence adults to seek and accept elective surgical treatment of this kind, are already in place at a relatively young age.

105± IS S.D.

range 105-125 220± 125 S.D.

range 10Q-{)00

170±50 S.D.

range 100-250 385 ± 185 S.D.

range 150-745

Our largest patient sub-group consisted of those who had vertical maxillary excess with either relative or absolute mandibular deficiency. Skeletal Class II type deformities (Sub-groups land 2, Table 1), totalled slightly more than 69% of the entire patient population. Although this figure is comparatively high it can be explained, at least in part, by the fact that young males with skeletal Class III deformities are much less frequently operated upon in this age group and, therefore, are excluded from our study. Of the patients who had simultaneous maxillary and mandibular osteotomies, nearly 60% had skeletal Class II deformities. This figure is not dissimilar with that reported by LABANC et a/.6 in their analysis of 100 adult patients who had simultaneous maxillary and mandibular surgery. Slightly more than 18% of our patients had simultaneous maxillary and mandibular surgery. We are unaware of other studies with which we can compare the incidence of bimaxillary surgery in adolescents. Germane to this point, however, is our preference, rather than to perform simultaneous

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mandibular advancement surgery in vertically excessive skeletal Class II female patients, to accept a slightly reduced facial angle when isolated LeFort I osteotomy can establish correct vertical dimension and a Class I dental occlusion. The indication for genioplasty is frequently centred about this decision which is ultimately made on the basis of clinical judgment and cephalometric analysis. Controlled hypotensive anesthesia not only appears to reduce the duration of surgery, particularly in the case of bimaxillary procedures, but also it is effective in limiting blood loss at surgery. These findings are in concert with those of both SCHABERG e t al.", and WASHBURN & HYER 12, of whom the latter reviewed the use of controlled hypotensive anesthesia for major maxillofacial surgery in 58 patients. Our findings suggest that controlled hypotension should be considered at least for maxillary surgery, on the basis of the observed, reduced incidence of blood transfusion associated with this anesthetic technique. Further, it is particularly important to avoid, if possible, unwanted antibody formation in a patient group which is made up predominantly of future child-bearing females. No patient required emergency release of maxillomandibular fixation due to post-operative airway embarassment. No patient experienced acute infection of the wound sites, although one patient who had undergone surgery 14 months earlier, had an intraosseous wire removed from the sagittal osteotomy site. No loss of teeth or alveolar bone occurred. One patient required re-admission to hospital for management of epistaxis 8 days following LeFort I osteotomy. This problem, which has recently been reviewed by LANNIGAN et all, apparently occurs very rarely but when it does present, it is both trying for the patient to endure and challenging for the clinician to manage. Neither infraorbital nor mental nerve

function was subjectively altered in any patient at last recall. The incidence of sensory dysfunction, even immediately post-surgery, seems to be lower in children than in adults. With specific regard to the modified sagittal ramus osteotomy,' although the procedure can be more demanding in children due to the presence of unerupted permanent teeth and the physical properties of young bone, if carried out carefully, it is not at all uncommon for the patient to have subjectively normal sensation on the day following surgery. Impacted third permanent molar teeth are routinely removed through the sagittal osteotomy sites. In our opinion, both patient and parent acceptance of treatment is highest when the surgeon who actually performs the surgery, takes as his responsibility, the pre-operative explanation of the expected course of events as regards hospitalization, surgery and postsurgical care. We believe that surgical correction of dentofacial deformities can be carried out for children and adolescent patients with little morbidity and few complications, however, the clinician must ever by wary of and prepared for unwanted sequelae when they do occur.

References I. BJORK, A. & SKLELLER, Y.: Facial development

and tooth eruption; an implant study at the age of puberty. Am. J. Orthodont. 1972: 62: 339-383. 2. DELAIRE, J. & TuLASNE, J. F.: Les desequililres

labiomentonniers par execs vertical anterieur de la face. Apport de la geniectomie segmentaire horizontal. r.:Orthodontie Francaise. Extraits due Vol. 50. Tixier et Fils. Lyon. 1979, pp. 353-375. 3. EpKER. B. N.: Modifications in the sagittal osteotomy of the mandible. J. Oral Surg, 1977: 34: 157-159. 4. LABANC, J. P. & EPKER, B. N.: Mandibular

advancement and mandibular growth. (Letter to ed). Ann. J. Orthodont . 1983: 84: 80-81.

ORTHOGNATHIC SURGERY IN CHILDREN 5. HUANG, C. S. & Ross, R . S. : Surgical advancement of the rctrognathic mandible in growing children. Am. J. Orthodont . 1983:82: 89-103 . 6. LAlIANC, J. P., 1'uRVERY, T. & EPKER, B. N .: Results following simultaneous mobilization of the maxilla and mandible for the correction of dcntofacial deformities: Analysis of 100 consecutive patients. Oral Surg: 1982: 54: 607-612. 7 . LANNIGAN, D. T. & WEST, R. E.: The management of post operative hemorrage following LeFort I osteotomies. J . Oral Maxlllofuc. Surg: 1984: 42: 367-375. 8. NANDA, R., SUGAWARA, J. & TOPAZIAN, R. G.: Effect of maxillary osteotomy on subsequent craniofacial growth in adolescent monkeys. 1983: 83: 391-407. 9. O'RYAN, F. & EPKER, B. N .: Dcliberate surgical control of mandibular growth . Oral Surg,

1982: 53: 2-17. l O, PLENI£R, Y. & DELAIRE, J.: La genioplasty «fonctionclle». Rev. Siomatol. 1983: 84: 54-61. II. SCHABERG, J. S., KELLY, J. F., TERRY, B. C., POSNER, M. A . & ANDERSON, E. F.: Blood

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loss and hypotensive anesthesia in oralfacia1 corrective surgery. J. Oral Surg. 1976: 34: 147-156. 12. WASHBURN, M. C. & HYEll, R. L.: Deliberate hypotension for elective major maxillofacial surgery: a balanced halothane and morphine techn ique. J. Maxillofac. Surg , \982: 10: 50--55. 13. WASHBURN, M. C., SCHENDEL, S. A. & EPKER, B. N. : Superior repositioning of the maxilla during growth. J. Oral Maxillofac. Surg, 1982: 40: 142-149. 14. WOLFORD, L. M., SCHENDEL, S. A. & EpKER., B. N.: Surgical orthodontic correction of mandibular deficiency in growing children. J. Maxlllofac. Surg. 1979: 7: 61-72. Address: D. S. Precious

Graduate Oral and Maxillofacial Surgery Programme Dalhousie University Halifax N.S. B3H 2375 Nova Scotia Canada