Mid-facial growth following functional cleft surgery

‘0 1997 The British Association of Oral and Maxdlofacml Surgeons

Mid-facial growth following functional cleft surgery S. Adcock, A. F. Markus Oral and Maxillqfacial

Surgery, Poole Hospital NHS Trust, Poole, Dorset, UK

SUMMARY. The stigmata of lip and palate clefting are well recognized, but recently it has been thought that these may be exacerbated by the surgical repair. Functional repair, however, with re-establishment of muscle continuity may result in less disruption to normal facial growth. This study examines mid-facial growth in 10 consecutive children aged 6.5 years with complete unilateral cleft lip and palate who had undergone functional repair. Outcomes were compared with non-cleft children and children who had undergone non-functional surgery.

INTRODUCTlON

Poor mid-facial growth with aesthetic and functional implications including compromised speech and hearing are not uncommon sequelae of surgery for cleft lip and palate. Delairel suggested that normal midfacial growth is only possible if there is formal restoration of the disrupted anatomy and, in particular, re-establishment of the continuity of all the muscles involved in the deformity. Clefting of the lip and palate is a pan-facial problem with disruption of all the interrelated muscle groups. The naso-labial and bi-labial muscle groups are involved directly and the labio-mental muscles indirectly, in that they are also displaced inferiorly.2 In the unilateral cleft lip, not only is there significant deviation of structures either side of the cleft, but also an adverse effect on the growth of the underlying premaxilla.3 In the bilateral cleft, the disruption is symmetrical, though the effect on the premaxilla is magnified. There are equally important considerations present in surgery of the hard and soft palate where careful restoration of the velar sphincter and avoidance of the use of vomerine mucosa in hard palate repair are amongst some of the factors thought to be important if surgery is not to have an adverse effect on speech and facial growth respectively.4m6 Being a complex deformity affecting the entire face, the outcome of cleft surgery may be assessed from many viewpoints and can be difficult. Whatever parameters are used should be simple and easy to measure accurately. Joos’ stressed the importance of relating assessment of maxillary growth to the inherent skeletal potential of the child by assessing the cranial base predisposition to a particular skeletal form. Ross’ also emphasizes the importance of the cranial base and its influence on maxillary growth. MATERIALS

AND METHODS

The aim of this study was to assessmaxillary growth in children having undergone functional primary cleft

surgery, as described by Delaire.3.5 Ten consecutive cases of complete unilateral cleft lip and palate with a mean age of 6.5 years were identified (range 5.9-7.2 years). These patients were compared with two other groups, first with non-cleft children matched by age and sex with data from Leighton and Bhatia,’ and second. with data published by Joos7,io regarding outcome following non-functional cleft surgery, in particular, the study of unilateral cleft lip and palate patients with a mean age of 6.5 years.” The group was assessed by cephalometric analysis and study model measurements. All radiographs were taken using the same equipment to minimize radiographic error. All tracing and model measurements were performed independently by two assessors on two separate occasions. The method error, which is the standard deviation of errors in individual measurements, was tested using Dahlberg’s formula. The maximum error in this study was 1 mm and 2 to maintain confidence at the 5% level.

Radiographic examination

From the cephalometric analysis of Delaire” an assessment was made of the cranial base and maxillary development, both vertically and anteroThe Architectural and Structural posteriorly. Craniofacial Analysis of Delaire (Fig. 1 ), enables not only the assessment of the cranial base, but also the facial type that would normally be associated with that cranial base. Therefore, any effects of cleft lip and palate surgery may be assessed against that child’s inherent skeletal predisposition. From the lines of skeletal balance and angles measured, the cranial base may be assessed. Line Cl (M-Oi) is divided by point Cp (posterior border of mandibular condyle on line Cl) into craniospinal and craniofacial areas (Fig. 2). A reduction in the craniofacial area implies a tendency to a Class III skeletal relationship. Lengthening of M-Cp is associated with a Class II relationship. An increase in the

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facial balance in the Delaire analysis (Fig. 3). CFl is traced through point FM (Frontomaxillary pointmidpoint of upper border of ascending nasal process of maxilla) with angle C3/CFl being 85” in children and adult females and 90” in adult males. The relationship of CFl to various points allows assessment of the antero-posterior position of the maxilla. In the normally positioned maxilla CFl passes through the frontal sinus, FM, the anterior border of the nasopalatine canal (in children the forming tip of the permanent canine may superimpose on this point), the point of union of the apical one third and coronal two thirds of the root of the non-resorbed deciduous canine, or permanent canine after eruption and the distal slope of the occlusal edge of the crown of the upper canine (deciduous or permanent). The relation of the maxilla to this line allows assessment of its antero-posterior position. Line CFl continues on to pass through the apex of the lower central incisor and menton. In this sample the distance of the nasopalatine canal to CFl was measured. This gave an objective measure of the position of the maxilla compared to its ideal. Fig. 1 - The Delaire

craniofacial

analysis.

Study models

2=(80%(+5%)

Fig. 2 -The

cranial

of Cl)

The widths between the maxillary deciduous canines and between the maxillary tuberosities, being an indicator of transverse maxillary growth, were measured. Angles classification of upper and lower incisors, a linear indicator of anterior maxillary growth, was assessed. The study group was compared to data from the non-functional surgery group studied by Joos.‘~

lines.

anterior cranial base angle (Cl/C3-normal range 20-22”) is associated with a Class III skeletal relation and a reduction with Class II. Increase in the sphenoidal angle, (C3/C4-normal range 115-120”) is associated with a Class II skeletal relation and a decrease with Class III. Vertical maxillary growth is assessed by measuring anterior and posterior upper and lower facial heights. These measurements were compared to age and sex matched non-cleft children by reference to data by Leighton and Bhatia.’ Anterior maxillary growth is assessed by comparing the relation of the maxilla to CFl, the line of anterior

Me Female Adult Fig. 3 - Relation

of the naso-palatine

Me Male Adult foramen

to CFl.

Coincidence of the maxillary and mandibular incisor centre lines was assessed as an indicator of symmetrical facial development.

cleft population and matched patients who had undergone functional surgery (Two-tailed Student’s t-test, 5”/u confidence level). Facial symmetry was measured as coincidence of upper and lower dentoalveolar mid-lines, noting deviation to cleft or non-cleft side (Table 4).

RESULTS

Using the above parameters, an assessment of midfacial development was made. This was compared with the outcome of non-functional surgery and with non-cleft children of age 6.5 years.

Antero-posterior

This was assessed by noting the position of the nasopalatine canal to the line CF 1 as described above. The mean distance of the naso-palatine canal was 0.9 mm (k2.5 mm) posterior to its ideal on line CFI.

Cranial base predisposition: dento-alveolar relationship

The cranial base predisposition and dento-alveolar relationship (Angles classification of incisor relationship) of the study group are shown in Table IA, after Delaire lip closure and palatoplasty. The figures denoting cranial base predisposition in the cleft population to a particular skeletal relationship, contrast with the non-cleft population (Table 1B), as noted by Foster and Walpole DayI in their study of Shropshire school children. Also in contrast to the figures in Table 1, Jooslo in his study of 60 cases of unilateral cleft lip and palate (mean age 6.5 years), reported Angles Class III in 48 cases (80%) after Millard lip and modified von Langenbeck palate repair. Transverse maxillary arch widths in this study are compared with those after non-functional surgery as reported by Joos” in Table 2. The differences in maxillary arch widths are not significant (5% confidence level ) using a two-tailed Student’s f-test. Upper anterior and posterior facial heights as an indicator of vertical maxillary growth, compared to matched non-cleft children are shown in Tables 3A and B. There was no statistical difference between vertical maxillary heights (in mm) when comparing the non-

Table

Dento-alveolar

base predisposition 40% 4O’i/ 0 20%

I II 111 Table

DISCUSSION

Although this is a relatively small group of patients, it indicates that some of the stigmata of cleft surgery may be avoided or greatly reduced. Maxillary growth is shown to be improved when compared to a group of children of the same mean age, who underwent non-functional surgery. It is important to note that the facial type associated with a given cranial base is different in the cleft and non-cleft population and must be acknowledged, as was stressed by Ross.* Foster and Walpole Day” reported that skeletal relationship in school children was Class III in 5.3%. The cranial base predisposition to Class III in this study was 20% with Joos’ also noting a 20% cranial base predisposition in his study of 60 adult unilateral cleft lip and palate patients. It may therefore be that there are differences in cranial base conformation between cleft and non-cleft groups and this is the subject of a further study. The results of this study compare well with the different outcomes presented by Joosi” in his comparison of functional and non-functional repair in children of the same age. In the non-functional group a Class III tendency was noted in 80% of 6.5 year olds compared with 10% in this study. It is also of interest to note that an earlier study by Joos7 in which 60 adult unilateral cleft lip and palate patients, who had undergone Millard lip and modified von Langenbeck repairs, showed that 80% developed a Class III incisor relationship despite only 20’%) having a cranial base predisposition to Class III. The patients in the current study had a similar cranial base predisposition to Class III (20%1), but as above this was reflected in incisor relationship in just 10% at age 6.5 years. There was no statistical difference in transverse palatal dimensions at age 6.5 years, when comparing outcome of functional and non-functional groups. There is close correlation between the vertical maxillary heights of children in this study and non-

1A

Cranial

relationship

70’%> 20% 10%

1B

Skeletal

relationship

Class Class Class

1 II III

Table

2 - Maxillary

(Foster

& Walpole

Day”) 40.8% 53.8% 5.31%)

arch width

(mean

values) Functional

Inter-canine Inter-tuberosity

width

(anterior) width (posterior)

position of maxilla

surgery

28.6 mm (range 38.6 mm (range

X.5- 31.7 mm) 35.9.-41.3 mm)

Non-functional

surgery

26.8 mm (range 38.7 mm (range

24.3-29.3 36.1-41.3

mm) mm)

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Table 3 -Vertical

of Oral

and Maxillofacial

Surgery

height of maxilla (mean values)

This study

Non-cleft9 A Upper anterior facial height.

42.2 mm Range 40.8-44.0 mm % of total facial height 44.6

42.5 mm 44.1

B Upper posterior facial height. 35.0 mm Range 33.4-36.6 mm % of total facial height 55.2

34.7 mm 59

Table 4 - Facial symmetry Coincidental mid-line Deviation to non-cleft side Deviation to cleft side

90% 10% 0%

anatomy and physiology is restored. The importance of functional surgery of the lip has been stressed by Delaire’ and Nicolau.r4 Non-violation of important areas of the maxilla in hard palate repair, such as the avoidance of vomerine mucosal flaps6 and the medial mobilization of maxillary fibromucosa4 is also considered critical. With respect to the cleft palate, in which area surgery can have adverse effects on midfacial growth, this has been further confirmed by Rossi in his study of facial growth following Malek repair (a method not dissimilar to Delaire’s) of the palate. Functional surgery should enable the cleft child to develop in such a way that maxillary growth may approach that of the non-cleft child. This group of children will continue to be monitored as they grow to ensure that these results are maintained into adult life. Acknowledgements

cleft children aged 6.5 years from the data by Leighton and Bhatia (no SD at a 5% confidence level). Upper anterior facial height compared well with the non-cleft population of the same age, particularly when expressed as a percentage of total anterior facial height. Mean upper posterior facial height also compared favourably (35 mm in this study and 34.7 mm in the non-cleft population). Expressed as a percentage of the total posterior facial height, the study group mean was 55.2% but in the non-cleft population at age 6.5 years this is 59%. This may imply a lengthening of the mandibular ramus in our patients and will be monitored as the population group ages and increases in number. Assessment of the co-incidence of dentoalveolar mid-lines as a measure of facial symmetry may, in isolation, be of limited value. Nevertheless, it is one indicator that should not be ignored. Dento-alveolar mid-lines were coincident in 90% of this study group, In previous studies,13 nasal symmetry following primary cleft repair using Delaire techniques showed significant improvement, when compared with modified rotation and advancement techniques. Antero-posterior positioning of the maxilla, as a further indicator of maxillary growth, was assessed by noting the position of the nasopalatine canal (NP) relative to the line CFl on the Delaire analysis. Good radiographic technique is important to allow easy visualization of NP which otherwise may be difficult to identify. NP, which ideally should lie on line CFl, was 0.9 mm posterior to CFl. (NP-CFl: mean distance = 0.9 mm_+ 2.8 mm.) Overall, these results suggest that at age 6.5 years, functional surgery may enable better anterior maxillary growth than nonfunctional surgery, with anterior vertical growth similar to the non-cleft population. Difference in outcome between the functional and non-functional groups may be due to differing surgical techniques, in particular those in which muscular

The authors would like to express their thanks to Mrs Maureen Peters for preparing the manuscript, to the Department of Oral and Maxillofacial Sciences at Dalhousie University and to Mr Simon Rutherford of the Department of Medical Illustration at Poole Hospital.

References 1. Delaire J. La cheilo-rhinoplastie primaire pour fente labiomaxillaire unilaterale. Rev Stomatol et Chir Maxillofac 1975; 76: 193. 2. Delaire J, McNamara J (eds). Craniofacial Growth Series No. 18. Ann Arbor, Michigan: Center for Human Growth and Development, University of Michigan. 1978; The potential role of facial muscles in monitoring maxillary growth and morphogenesis. pp. 157-180. 3. Markus AF, Delaire J. Functional primary closure of cleft lip. Br J Oral Maxillofac Surg 1993; 31: 281-291. 4. Markus AF, Delaire J, Smith WP. Facial balance in cleft lip and palate. I. Normal development and cleft palate. Br J Oral Maxillofac Surg 1992; 30: 287-295. 5. Markus AF, Smith WP, Delaire J. Primary closure of cleft palate: a functional approach. Br J Oral Maxillofac Surg 1993; 31: 71-77. 6. Delaire J, Precious DS. Avoidance of the use of vomerine mucosa in primary surgical management of velopalatine cleft. Oral Surg 1985; 60: 589-597. I. Joos U. Evaluation of the Result of Surgery on Cleft Lip and Palate and Skeletal Growth Determinants of the Cranial Base. J Cranio-maxillofac Surg 1989; 17: 23-25. 8. Ross RB. My Friend the Cranial Base: Why Is it So Normal? Cleft Palate-Craniofac J 1993; 30: 51 l-512. 9. Bhatia SN, Leighton BC. A Manual of Facial Growth, Oxford University Press 1993. 10. Joos U. Skeletal growth after muscular reconstruction for cleft lip, alveolus and palate. Br J Oral Maxillofac Surg 1995; 33: 139-144. 11. Delaire J. L’analyse architecturale et structurale crania-faciale (de profil). Principles theoretiques. Quelques exemples d’emploi en chirurgie maxillo-faciale. Rev Stomatol Chir Maxillofac 1978; 79: l-33. 12. Foster TD, Day AJW. A survey of malocclusion and the need for orthodontic treatment in a Shropshire school population. Br J Orthod 1974; 1: 73-78. 13. Horswill BB, Pospisil OA. Nasal symmetry after primary cleft repair; comparison between Delaire cheilo-rhinoplasty and modified rotation and advancement. J Oral Maxillofac Surg 1995; 53: 102551030. 14. Nicolau PJ. The orbicularis muscle; a functional approach to its repair in the cleft lip. Br J Plast Surg 1983; 36: 141-153.

Mid-facial growth following functional cleft surgery 15. Ross RB. Growth of facial skeleton following Maiek repair for unilateral cleft lip and palate. Cleft Palate-Craniofac J 1995: 32: 1944198.

The Authors S. Adcock

FRCS,

FDSRCS

Oral and Maxillofacial Surgery Poole Hospital NHS Trust Longfleet Road Poole Dot-set BHI 5 2JB UK Correspondence and requests for offprints to A.F. Markus

Senior Registrar A.F.

Markus

Consultant

FDSRCS

Paper received 26 January 1996 Accepted 2 October 1996

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