THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOPtEDICS

Transcription

1 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOPtEDICS By N. R. E. ROBERTSON, D.D.S., F.D.S., D.D.O. Professor of Orthodontics, Dental School, Welsh National School of Medicine, Cardiff (formerly Senior Lecturer, Turner Dental School, University of Manchester) and R. HILTON, L.D.S., D.D.O. Lecturer in Orthodontics, Turner Dental School, University of Manchester PRE-SURGICAL oral orthopaedic preparation of the mouth of newborn infants with orofacial clefts is now practised in many cleft palate treatment centres, although comparatively little work has been done to date to establish the precise nature of the changes it produces (Huddart et al., 1965). McNeil (195o) introduced pre-surgical oral orthopaedics. Latham and Burston (1964) have shown that tissues from the sutures posterior to the maxilla on the cleft side differ from tissues from similar areas on the non-cieft side and Burston associates this with the disconnection of the minor segment from the nasal septum. Scott (1953) and Burston (1958) both emphasise the part played in maxillary growth by the rapidly growing septal cartilage during the period immediately prior to and after birth. Gross changes in position of the segments of the upper jaw are demonstrable on serial study models of the patient, but such models do not indicate which segments move, or the direction and extent of the movement. If pre-surgical oral orthopaedic treatment merely produces a collapse mesially of the entire jaw segments in patients with complete clefts of lip, palate and alveolus, then it is likely that the long-term results of patients treated in this way will not differ greatly from those achieved by Brophy (1927) using another and now discarded technique. Alternatively it may be postulated, for example, that the minor segment is moved forwards ; that the premaxillary segment is moved back or restrained ; that there is collapse of the segments towards the mid line, and the like, but no evidence has been produced to support any of these theories. To this end, and also in order that more precise and rationalised movements of the jaw segments may be attempted, a method of demonstrating the changes produced by pre-surgical oral orthopmdics was sought. Broadbent (1937), Brodie (1941) and Ortiz and Brodie (1949) have used cephalometric radiography to study the growing head in infants and children and also the changes produced by means of orthodontic treatment. The method is well known and fully described in the papers mentioned ; in essence the technique is the production of standardised, reproducible radiographs of patients, using a cephalometer. BjiSrk (1955, 1963) has described a method of inserting small tantalum pins into the maxilla and mandible to serve as radiopaque markers which may be used as registration points. He has shown that tantalum markers are inert and remain in situ, and provided the pins are not placed in the path of erupting teeth their position is stable. A method of showing the movement of jaw segments using tantalum implants and cephalometric radiography has been devised (Robertson and Hilton, 1968). Possible Changes.--The changes found might come about: (a) as a result of growth--the overall pattern of head and face growth is predictable from previous cephalometric and other growth studies ; (b) as a result of treatment--e.g, mechanical rotational swing of the major and minor segments around axes, possibly situated in the retromaxillary sutures ; (c) as a result of treatment plus growth--e.g, reharnessing of the minor segment to the nasal septum, or stimulation of the palatal folds. The rapid growth changes normally occurring during the first few weeks of postnatal life will coincide with any changes produced by means of pre-surgical oral orthopaedic treatment, because such treatment is usually carried out at this same time.!t is 57

2 58 BRITISH JOURNAL OF PLASTIC SURGERY clear that the tbrmer growth changes will tend to mask, and render the latter treatment changes more difficult to assess and it is therefore highly desirable to develop a technique which will, if possible, permit differentiation between the two simultaneously occurring changes. Bj6rk (1955) has shown that tantaium implants, inserted as described below, retain constant relative positions to one another throughout growth, and it may therefore be postulated that changes in the relative positions of implants following pre-surgical orthopaedic treatment will give a direct indication of changes resulting from such treatment, rather than changes due to growth. Terminology.--Two terms, orthodontics and oral orthopaedics, are used in the literature rather loosely. It would seem desirable to give a more precise meaning to each and apply the terms in appropriate circumstances. ~Io.~,~tL~,~, ~.~.T ~.j LOWE~RC. ErT M*XtLLARY S~GI~N'r ~ ~ ~ ~RE M~tLL~ S~E~T A FIG. I B Diagrammatic representation of occlusal views of complete unilateral (A) and bilateral (B) clefts of the lip and palate. Orthodontic treatment is a term used to describe the changes produced by conventional orthodontic appliances ; these changes are limited to movement of teeth and adaptation of the supporting alveolar bone (Brodie et al., I938 ; Bj6rk, 1951). Oral orthopaedics is a term used by a number of workers including McNeil, the intention being to convey that a different type of movement is achieved by certain appliances, i.e. a movement of the entire jaw segment, tooth, bone and soft tissues, as one unit. A further term, stimulation, is used by McNeil by which he means the application of gentle pressure near but not at the edges of the palatal cleft. Such stimulation, it is claimed, will produce continued or increased growth of, for example, the bony palatal shelves. The effects of stimulation have not been considered in this paper. Figure I shows the meaning of the terms major and minor segments in cases of unilateral complete clefts of the lip, palate and alveolus and also maxillary and premaxillary segments in cases of complete bilateral clefts. Instrumentation.--I. Cephalometer.--Brodie (1941) adapted cephalometry for use in the study of the growing infant head. The principal changes from Broadbent's original cephalometer involved designing the head holder around a smaller head and the use of a horizontal couch instead of a dental chair. Pruzansky and Lis (1958) described an improved cephalometer which they had designed for use in the study of infants with major facial deformities. Their paper describes the cephalometer fully and it is based on the principles evolved by Brodie. The cephalometer used in this study was designed by Pruzansky and Lis with minor modifications. It operates on a 5 ft. anode to midsagittal plane distance for lateral headplates and a 3 ft. anode to transmeatal axis distance for frontal films. Figure 2 shows the apparatus. The platform on which the infant lies

3 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOP/~DICS 59 is adjustable for height and may also be moved longitudinally. Graduated mill/metric scales cart be mounted in the mid-sagittal and transmeatal coronal planes to permit the measurement of the precise amount of enlargement in both antero-posterior and lateral head plates. 2.. Tantalum implants.--in his publications BjSrk described a method of inserting tantalum pins into the jaw bones to act as markers on lateral and frontal headplates of FIG. 2 Wehmer infant cephalometer. children aged from 9 to I4 years attending his department for orthodontic treatment. It seemed possible that this method could be adapted for use in an infant growth study. Pins cut from hardened tantalum wire, together with an instrument for inserting the ---"x BIGHT MAXILLARY SEGMENT~ /~ 'L0ffER ARCH %k~lgft (Minor MAXILLAflY ae~ment) SEGMENT RO MID -LINE 0 T FIG. 3 Diagrammatic representation of an occlusal view of complete unilateral cleft of lip and palate showing sites used for insertion of tantalum implants. implants into bone, were obtained from Denmark and after experimentation had shown that the method could be used in this investigation, a supply of implants, together with instruments for inserting them, were made by a local instrument maker. Tantalum implant markers of 0"5 I "5 ram. dimension pointed at one end to faciliate insertion into the bone were used. The implants were inserted into the bone of the maxilla and mandible at sites remote from the developing teeth as Bj6rk has shown the implants may be displaced if placed in the path of erupting teeth. An intra-oral approach was used and the implants were placed, as shown in Figure 3 :--(a) at the

4 6O BRITISH JOURNAL OF PLASTIC SURGERY A Fig. 4.--Insertion of implants. A shows implant pushed through muco-periosteum by manual pressure. B shows implant driven a fixed distance into the bone by sharp tap of mallet on head of instrument. Fig. 5.--Insertion of implants. Instrumentation. Fig. 6.--Infant in cephalometer prepared for lateral headplate.,:t B FIG. 4 FIG. 5 FIG. 6

5 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOP.t~LDICS 61 posterior end of each maxillary segment (point G in major segment, point H in minor segment) ; (b) beneath the anterior nasal spine (Point F) ; (c) immediately above the chin point (point E). 3. Instruments for inserting implants.--the instruments used for inserting the tantalum implants were made locally to a design similar to that described by Bj6rk (1955). Figure 4 shows how the instrument operates. The tip of the instrument is pushed through the mucoperiosteum by manual pressure (Fig. 4, A) and then a sharp tap from a mallet, on the head of the instrument, drives the implant a fixed distance into the bone (Fig. 4, B). Teehnique.--The infant is sedated using Vallergan given orally two hours prior to the procedure--up to 4 mg. per kilogram body weight is given. After sedation the child is left in a quiet cubicle until operative procedures are begun. The surface of the gums is wiped over with gauze swabs and surface a~na~sthetic is applied. The implants are then inserted in the sites as described above. To ensure sterility a separate instrument is used for each implant. The tray containing the instruments required for the insertion of each implant is shown in Figure 5. After the implants have been placed, lateral and frontal cephalograms are obtained while the infant is still sedated. Figure 6 shows an infant in the cephalometer ready for a lateral headplate. Reduction of Errors.--So that errors may be kept to a minimum, as short an exposure time as possible is used. The infants are sedated for all cephalograms and consequently the likelihood of blurring due to movement is reduced. The cephalometer has a large anode to subject distance which also helps to cut down blurring and enlargement. The use of a Schonander screen reduces the amount of secondary radiation. All tracings have been done by the same experienced tracer. Method.--A group of 22 consecutive new-born infants with complete unilateral clefts of the lip, palate and alveolus, referred to the Royal Manchester Children's Hospital for treatment, were used as the basis for this particular study. On admission full records were obtained--written, photographic and radiographic records and study models (Robertson, 1969). Lateral and frontal headplates were made on the sedated infant after the insertion of the tantalum marker implants. This was done immediately after admission and the films were repeated I2 weeks later just before lip surgery. In addition to the above mentioned films occlusal radiographs were taken using the technique described by Robertson (I965). Gephalometric Analysis.--Frontal Headplates.--Harvold's method (1954) was used. The most laterally situated points in the zygomatico-frontal sutures (FMT points) are joined and a perpendicular to this line is drawn in at point X (the centre of the base of crista galli). This perpendicular is referred to as the X line which is taken as representing the mid-sagittal plane of the head. Tracings were made from the headplates of the outline of cranium, mandible, orbits and the positions of each tantalum marker. The tracings were superimposed on the line FMT-FMT with X points coincident. Measurements were made of the position of each implant in relation to the X line. This was done by measuring from the X line along a line at right angles to the nearest point on each implant. The movement of each implant, relative to the mid-sagittal plane for each case in the series, is shown on Table I.

6 62 BRITISH JOURNAL OF PLASTIC SURGERY TABLE I Movement in mm., of implants, relative to mid-sagittal plane +, away from mid-sagittal plane ; --, towards mid-sagittal plane Case No. Implant G Implant F Implant H I IO II I2 I3 I4 15 i6 r7 I I'5 O'O i. 5 O'O -~ I "o O'O - - 3"0 +z.o -- 2"0 --3"0 --0" 5 --0" 5 -- I'5 -- I ' O -- i "5 -- 2"0 -- I ' O -- 2"0 +I" I'5 - - I ' O " " "0 +3"0 -- I ' o -- I'O o'0 +i.o +2"0 -- 2"0 -- 2"0 --2"5 +3"5 -+-2"5 -c I'O -- I ' O -- I ' O Present Recording and Treatment methods.--thc child is seen as soon as possible after birth, preferably within 24 hours, and following clinical examination, and written records, initial upper and lower impressions are taken using Kerr's white impression compound. This material softens at a temperature of I3z-I35 F. and although a number of other impression compounds have been tried, this has been found to be far the most satisfactory. From these impressions, models are prepared upon which are made special trays for rubber base impressions, and an instant feed plate. After a few days when the child has settled to the use of the feed plate, implants are inserted and cephalograms, occlusal X-rays and standard photographs are taken as described above. Upper and lower impressions are taken in the" special "trays using Kerr's heavy-bodied permalastic rubber impression material. This has been found to give an accurate impression and to have sufficient body and viscosity to avoid undue spread of the material into the oroand naso-pharyngeal areas. Study models are prepared from these impressions and accurately orientated in centric occlusion, using a specially prepared wax squash bite. Measurements are made on the upper study model as follows :- Anterior cleft width.--the shortest distance between the anterior ends of the alveolar segments. Posterior arch width.--the distance between the most distal points of the gingival groove. Posterior cleft width.--the shortest distance between the palatal shelves at the level of a line joining the most distal points of the gingival groove. A further upper model is also made which is used to construct the first correction appliance. Using the study models, radiographs and further clinical examination, a final assessment of the nature and degree of the defect in terms of the alveolar segmental displacement and/or tissue deficiency is now made. The segmental movements necessary to correct this, as far as is considered possible and practical, are determined, and a preliminary treatment plan is thus prepared.

7 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOP2~DICS ~3 Two basic methods of pre-surgical alignment are used :--(I) extra-oral strapping ; (2) correction appliances. The former applies pressure in a pre-determined direction as considered necessary in any specific case and also reinforces the anchorage of the correction plate by allowing it to move within the mouth, only in a pre-determined direction. The appliances are constructed to precise prescription by indicating in diagrammatic form on a specially designed laboratory instruction sheet, the degree and direction of corrections to be effected and the type of plate to be used. (The technical details of appliance construction have been well described by Volp, r97o. ) The number of appliances required and the type of extra-oral strapping necessary will vary with each particular case and treatment plans may be modified as treatment progresses satisfactorily or otherwise. The aim is to achieve the desired alignment within about three months, when lip and soft palate closure is normally performed, immediately prior to which, further standard records are taken ag already described. The following summaries of five case reports of typical varieties of unilateral clefts give the results obtained using the methods developed to date. Case I.--G. C. Male. Born I Left complete unilateral cleft of lip and palate with moderate tissue deficiency and mild buccal displacement of anterior end of both major and minor segments. Class Uz (Robertson and Jolleys, I968). The width of the cleft anteriorly = i 1.5 nun. The width of the cleft posteriorly = I6"5 ram. The posterior arch width = 33"o ram. Treatment Plan.--Move the anterior end of the major segment mesially retaining the position of the minor segment. Results.--AP Cephalograms. Active treatment begun Active treatment completed 4.II.69. Distance between anterior implants reduced from 28.o to 23.5 ram. = 4"5 reduction. Distance between posterior implants increased from 33"5 to 34"5 mm. = r-o increase. Models.--The major segment has moved mesially with improvement in the anteroposterior and lateral relation to the lower gum pad. The minor segment has moved slightly lingually and also vertically downwards to a slight degree, at its anterior end. Anterior cleft width 5"o nun. a reduction of 6"5 mm. Posterior cleft width I4.O ram. a reduction of 2"5 mm. Posterior arch width 3 r.o ram. a reduction of2.o rnm. Photographs.--Improvement in L and R profiles. Both lip and alveolar clefts have been much reduced. ColumeUa has been moved towards the facial mid line with reduction in the size of the left nostril and improvement of the left alar cartilage. Conclusions.--Considerable improvement has b.een achieved and aims have been satisfactorily achieved with the exception of a mild degree of unrequired movement of the minor segment. Case z.--p. B. Male. Born Left complete unilateral cleft of lip and palate with considerable tissue deficiency and displacement of major segment both buccally and anteriorly; the minor segment is displaced somewhat posteriorly. Class U4. The width of the cleft anteriorly = r6.o ram. The width of the cleft posteriorly = r7. 5 mm. The width of the arch posteriorly = 33"5 mm.

8 64 BRITISH JOURNAL OF PLASTIC SURGERY Treatment Plan.--Move the major segment mesiatly and distally and the minor segment anterio:"~y and buccally. Active treatment begun Active treatment completed 5.I2.68. Results.--AP Cephalograms. Distance between anterior implants reduced from 27"0 to 25"o ram. = 2.0 ram. reduction. Distance between posterior implants reduced from 43 "o to 40"5 ram. = 2.5 ram. reduction. Models.--The major segment has moved mesially and distally and the fr~enum moved over towards the centre line. The minor segment has moved slightly palatally and its anterior end is now in lingual relation to the lower gum pad. Anterior cleft width Posterior cleft width Posterior arch width 7"5 mm. a reduction of 8"5 mm. 7"5 ram. a reduction of Io'o mm. 29"5 mm. a reduction of 4'0 ram. Photographs.--Show considerable improvement in both L and R profiles. Midline of nose has moved towards the facial centre line. Left nostril considerably reduced and left depressed alar cartilage has now much improved contour. Conclusions.--Aims of treatment plan have not been completely achieved--minor segment now in lingual occlusion but considerable improvement in alignment has been achieved and also in reduction of cleft width anteriorly and posteriorly. General appearance considerably improved. Case 3.--A. R. Male. Born Left unilateral incomplete cleft of lip and complete cleft of palate. Mild displacement of major segment buccally at the anterior end, and very little alveolar tissue deficiency. Wide palatal cleft with moderate tissue deficiency. Class UI. The width of the cleft anteriorly -- 7"5 mm. The width of the cleft posteriorly = I2.o mm. The posterior arch width = 27-5 mm. Treatment Plan.--Move the major segment mesially while retaining the minor segment. Palatal stimulation in attempt to promote growth of palatal tissue. Active treatment begun Active treatment completed 8.IO I.69. Results.--AP Cephalograms. Distance between anterior implants remained constant at I9"5 ram. Distance between posterior implants remained constant at 39"o mm. Models.--The framum has moved round towards the centre line of the face and there is now a normal relationship between the upper and lower gum pads in both the antero-posterior and lateral dimensions. Width of cleft anteriorly Width of cleft posteriorly Posterior arch width I "5 mm. a reduction of 6.0 ram. 8.o ram. a reduction of 4.0 mm. 27" 5 mm. is unchanged. Photographs.--Little change in profiles. Lip and alveolar cleft reduced. Limited improvement in left nostril and alar cartilage. Conclusions.--The aims of the treatment plan have been satisfactorily achieved in relation both to alignment and growth of the palatal shelves. Case 4.--N. S. Female. Born Left complete unilateral cleft of lip and palate with mild buccal and anterior displacement of major segment and moderate tissue deficiency at alveolus and wide palatal cleft. Class U 4.

9 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOPAEDICS 6 5 The width of the cleft anteriorly = 15.o ram. The width of the cleft posteriorly = 15"5 mm. The posterior arch width -- 3o.o ram. Treatment Plan.--Move the major segment round towards the mid line and back a little, retaining minor segment. Some residual space between alveolar ends will probably be necessary due to tissue deficiency. Results.--AP Cephalograms Active treatment begun 8.1o.68. Active treatment completed Distance between anterior implants reduced from 27"5 to 23-5 ram. = 4.o ram. reduction. Distance between posterior implants reduced from 35"5 to 33"5 ram. = 2.o ram. reduction. Models.--The major segment has been moved round towards the mid line. The anterior end is now a little too far palatal in its relation to the lower arch. The minor segment has moved slightly lingually also. Anterior cleft width 4"5 mm. a reduction of Io- 5 ram. Posterior cleft width 7"5 ram. a reduction of 8-o mm. Posterior arch width has remained constant at 3o.o mm. Photographs.mLittle apparent change in profiles but considerable reduction in the size of the left nostril. Nasal mid line and columella moved towards facial centre line. Improvement of left Mar cartilage. Moderate reduction in width of lip cleft. Conclusions.--The minor segment has been moved too far lingually and the major segment too far mesially and backwards, probably in an attempt to reduce cleft width beyond a desirable limit. Nevertheless lip surgery has probably been facilitated and a pleasing facial result obtained although the occlusion seems unlikely to be good. N.B.--Subsequent growth and development to October, 1969 has further improved the facial appearance and the deciduous anteriors have erupted into a good occlusion without crossbite, despite original expectations as above. Case 5.--D. H. Male. Born 7.1o.68. Right incomplete cleft of lip with Simonart bar, complete cleft of alveolus and palate. Very little displacement or tissue deficiency. Some vertical displacement of minor segment. Wide palatal cleft. The width of the cleft anteriorly = 2. 5 mm. The width of the cleft posteriorly ram. The posterior arch width = 41"5 ram. Treatment Plan.--Retain segmental positions and attempt to promote palatal growth by stimulation. Active treatment begun 29.1o.68. Active treatment completed Results.--AP Cephalograms. Distance between anterior implants has increased from to 17-5 ram. = I-O ram. increase. Distance between posterior implants increased from 44"o to 47"o mm. = 3"o ram. increase. Models.--The relationship of upper and lower arches has been maintained. There has been some closure of cleft at arch end and a little change in the vertical relationship of both major and minor segments to lower. The anterior end of the cleft is almost completely closed. IE Anterior cleft width o,o ram. a reduction of 2.5 ram. Posterior cleft width 13.o mm. a reduction of 2. 5 mm. Posterior arch width 42"o mm. an increase of o. 5 mm.

10 66 BRITISH JOURNAL OF PLASTIC SURGERY Photogr~phs.--There has been little change in profiles, nose or Mar cartilages. Conclusions.--This case is in many respects a form of control. No segmental movements have been attempted and the changes seem to underrate the naturally occurring changes due to growth. DISCUSSION A method of demonstrating changes occurring in infants having had a course of pre-surgical oral orthopmdic treatment has been described. As mentioned, very few studies have been carried out to determine the precise nature of the changes produced by such treatment. A computer search of the literature also failed to disclose any papers on this subject. As this type of treatment is carried out in many centres it has been considered desirable to determine more precisely the types of changes occurring. By means of tantalum markers in the jaw segments, cephalometric films taken on admission and again just prior to the first surgical repair, changes due to treatment and growth may be seen. Study of the results given in Table I will show that considerable variation in the nature of changes produced by pre-surgical oral orthopaedic treatment may be effected. This variation will depend to a large extent on the design and construction of the appliances used in any given case, and it would appear that many desired changes in segmental alignment and/or relations can be produced with appropriate appliance design. This present work has been confined to the early development of the implant technique and an analysis of the antero-posterior cephalograms of some 22 unilateral cases. Although ideally, controls of untreated cases are required, it is possible to draw certain conclusions from this study bearing in mind the work of Orfiz and Brodie (1949) on the growing infant. It should also be recalled that Subtelny (1955) found that the arch width in unoperated infants with cleft lip and palate is wider than in normal infants, and some mild degree of collapse is possibly desirable. Results in Table I indicate that it is possible to maintain the posterior arch width, or if necessary, increase or alternatively reduce it. Rotation of the segments about axes situated in the retro-maxillary areas (points R and T on Fig. 3) can be achieved. Further work is in progress and the study is also being extended to include the changes following lip repair. It is hoped to obtain the collaboration of other cleft palate centres where pre-surgical orthopmdic treatment is not practised, to provide controls. Certain conclusions may however be drawn from the work done to date and in the light of these, both recording and treatment methods are improved as the work proceeds. The more significant of these conclusions to date may be summarised as follows :-- I. Variation in the distance of point E from the X line in any given case indicates a rotation of the head about the mid-sagittal plane. Extreme care is necessary to obtain accurate cephalograms, and although some workers have maintained that sedation of infants for cephalometric radiography is unnecessary, our experience would indicate that consistently accurate results could not be obtained without adequate sedation, and indeed, improved methods of sedation are being sought. It is felt that a well designed unit with "sedation room" and closely adjacent cephalometer would provide best results. In this present series four cases tlave been deleted, as the headplates were not considered to be of adequate quality for the reasons stated above. 2. In the earlier cases, four implants were inserted, but it soon became apparent that an additional implant at point K (see Fig. 3) would improve the technique, and this is now being done.

11 THE CHANGES PRODUCED BY PRE-SURGICAL ORAL ORTHOPEDICS Careful clinical examination of each case, together with accurate upper and lower study models orientated in true centric occlusion, are necessary to determine the nature of the movements (if any) that it is desired to produce by the pre-surgical treatment. 4. Further development and evaluation of more precise methods of appliance design for the production of more rationalised predictable movements is necessary. TABLE II Changes in the distance between implants in mm. before and after treatment compared with measurements made on study models Case x Case 2 I Case 3 Case 4 Case 5 Distance between anterior Reduced Reduced I t Unchanged Reduced Increased implants 4"5 2"o 4"o z-o Anterior cleft width on model Reduced Reduced Reduced Reduced 6"5 8"5 6"0 Io'5 Distance between posterior implants Increased I'O Reduced 7.'5 t Unchanged Reduced 2"0 Reduced Increased 3"0 Posteriorcleffwidthonmodel Reduced Reduced Reduced Reduced Reduced 2. 5 Io'9 4"0 Io'5._ 2"5!Posteriorarchwidthonmodel Reduced Reduced Unchanged Unchanged Increased 2-0 4"0 0"5 N.B.--In Case 5 no segmental movements were attempted, although stimulation of the palatal shelves was applied. The changes arising here may therefore be regarded as primarily those which would naturally occur as a result of growth and to this extent this case may be regarded as a control or base line with which to compare changes in the other cases. 5. Table II shows a comparison of changes in the distances between the implants as seen in the five cases described above and the measurements made on the study models as described. It can be seen that in each case changes at the level of the alveolar segments and palatal shelves are greater than those at the level of the implants, i.e. basal bone. It may therefore be concluded that in these cases at least, arch alignment effected by the orthopaedic treatment occurs primarily as a result of movement of the alveolar portion of the maxilla and movement of the basal bone is minimal. Further, it has been suggested (Huddart, 1968) that any reduction in the width of the palatal cleft is achieved at the expense of increase in the overall width of the arch. These present figures refute this and indicate that a real reduction in the width of the palatal cleft can be achieved. We wish to acknowledge the assistance of the Department of Medical Illustration, Manchester Royal Infirmary in the preparation of the illustrations, and of Mr C. R. Volp, Research Technician, in carrying out the tracings.. The Medical Research Council provided the infant cephalometer and financial assistance. REFERENCES BJ6RK, A. (I947). " The Face in Profile." Lund : Berlingska Boktryckeriet. BjORK, A.(x95I ). Nature of facial prognathism and its relation to normal occlusion of teeth. American ffournal of Orthodontics, 37, ro6-i24. BJ6RK, A. (I955). Facial growth in man, studied with aid of metallic implants. Acta odontologica scandinavfca, I3, Bj6RK, A. (I963). Variations in the growth pattern of the human mandible : longitudinal radiographic study by the implant method, ffournal of Dental Research, 42, 4oo-4II.

12 68 BRITISH JOURNAL OF PLASTIC SURGERY BROA~BENT, B. H. (1937). Bolton standards and technique in orthodontic practice. Angle O-thodontist, 7, BRODIE, A. G. (1941). On growth pattern of human head from third month to eighth year of life. American Journal of Anatomy, 68, 2o BRODIE, A, G., DOWNS, W. B., GOLDSTEIN, A. and MYER, E. (1938). Cephalometric appraisal of orthodontic results. Angle Orthodontist, 8, BROPHY, T. W. (1927). Cleft lip and cleft palate. Journal of American. Dental Association, 14, 11o BURSTON, W.R.(I958). The early orthodontic treatment of cleft palate conditions. Dental Practitioner, 9, HARVOLD, E. (1954). " The Post-natal Morphogenesis of the Facial Skeleton in Cleft Palate." Oslo : Boktrykkeri A/S. HUDDART, A. G. (1968). Studies in the form and dimensions of the prediciduous maxillary arch in unilateral cleft lip and palate cases. Dental Practitioner, 18, 449- HUDDART, A. G., NORTH, J. F. and DAVIS, M. E. H. (1965). Transactions of the British Society for the Study of Orthodontics, p. lo7. LATHAM, R. A. and BURSTON, W. R. (1964). The effect of unilateral cleft of the lip and palate on maxillary growth pattern. British Journal of Plastic Surgery, 17, lo-17. MCNEIL, C. K. (195o). Ph.D. Thesis, University of Glasgow. ORTIZ, M. H. and BRODIE, A. G. (1949). Growth of human head from birth to third month of life. Anatomical Record, IO3, PRUZANSKY, S. and LIS, E. F. (1958). Cephalometric roentgenography of infants: sedation, instrumentation and research. American Journal of Orthodontics, 44, ROBERTSON, N. R. (1965). An occlusal X-ray film holder for infants with cleft lip and palate. British Journal of Radiology, 39, 152- ROBERTSON, N. R. (1969). D.D.S. Thesis, University of Manchester. ROBERTSON, N. R. and HILTON, R. (1968). A method of demonstrating changes produced by pre-surgical oral orthopaedics. Dental Practitioner, 18, o- ROBERTSON, N. R. and JOLLEYS, A. (1968). Effects of early bone grafting in complete clefts of lip and palate. Journal of Plastic and Reconstructive Surgery, 42, SCOTT, J. H. (1953). The cartilage of the nasal septum (a contribution to the study offacial growth). British Dental Journal, 9"5, SUBTELNY, 7- D. (1955). Width of nasopharynx and related anatomic structures in normal and unoperated cleft palate children. American Journal of Orthodontics, 41, 889-9o 9. MOLP, C. R. (197o). Oral orthopaedic appliance construction. Dental Technician, 23, 96.