A comparison of results using nasoalveolar moulding in cleft infants treated within 1 month of life versus those treated after this period: development of a new protocol

Abstract

The objectives of this study were to: evaluate the effects of nasoalveolar moulding (NAM) in complete unilateral cleft lip and palate infants presenting for treatment at different ages; propose a new NAM protocol in these patients; improve the predictability of NAM. Study groups comprised: group I ( n = 15) treated with NAM within 1 month of age; group II ( n = 15) treated with NAM between 1 and 5 months of age. Control: group III ( n = 15) comprised of non-cleft 18-month old children. A standard protocol was followed. Patients were evaluated before initiation of NAM, before cheiloplasty and at 18 months. 7 linear anthropometric measurements were compared using dento-facial models. Statistical analysis before and after NAM revealed that group I patients demonstrated 81%, 198%, 69% and 145% improvement in intersegment distance, nasal height, nasal dome height and columella height respectively; whilst group II patients demonstrated 51%, 33%, 21% and 38% improvement for the same. At 18 months, group I patients closely resembled group III patients. This study concluded that the effects of NAM were most significant in group I. Group II patients also benefited from NAM, although to a lesser extent. This study validates the use of NAM in infants presenting late for treatment.

The inclusion of neonatal maxillary orthopaedics in the comprehensive management of cleft lip and palate patients remains controversial even though it was first considered by M c N eil in 1950. This can largely be attributed to the inadequately substantiated and often implausible claims of its early proponents and the use of active appliances that have been shown to impede maxillary growth . According to H otz & G noinski the primary objective of early orthopaedics is not to facilitate surgery, as postulated by McNeil, but to take advantage of intrinsic developmental potentialities.

Use of nasoalveolar moulding (NAM) as a medium for pre-surgical infant maxillary orthopaedics was propagated by G rayson et al. The optimal time for the start and end-point of nasoalveolar moulding has been much discussed and currently lacks a consensus. Comparative longitudinal evaluation of NAM related changes in the nasoalveolar morphology in complete unilateral cleft lip and palate (UCLP) infants presenting for treatment at different ages, has not been well documented. A study comparing the results with a control group consisting of healthy, non-cleft children has not been previously reported in the English literature.

The purpose of this prospective, controlled clinical trial was to compare the morphological changes in the nasoalveolar complex in 2 groups of complete UCLP infants; one in which NAM was started before 1 month of age and the other in which NAM was started between 1 and 5 months of age, by means of linear anthropometric measurements. Results from this study should help improve the predictability of NAM in complete UCLP infants presenting for treatment at different ages.

Materials and Methods

Only non-syndromic complete UCLP infants less than 5 months of age whose parents provided written consent for the study were included in the study population. Only healthy, non-cleft 18-month old children whose parents provided written consent for obtaining alveolar and nasal impressions were included in the control group.

The study population ( n = 30, statistical power = 80%, confidence level = 95%) consisted of two separate groups of complete UCLP infants. Group I consisted of 15 infants (7 girls and 8 boys) who presented for treatment before 1 month of age. Group II consisted of 15 infants (6 girls and 9 boys) who presented for treatment between 1 and 5 months of age. The control group (group III) consisted of 15 healthy, non-cleft 18-month old children (7 girls and 8 boys). Average age at initiation of NAM in group I was 15 days (range 1–29 days) and 116 days (range 48–144 days) in group II.

Nasoalveolar Moulding

The authors’ unit, which pioneered NAM in India in 2005, formulated a new NAM protocol in May 2008 ( Table 1 and Fig. 1 ). In group I NAM was continued until 6 months of age. In group II NAM was carried out for a minimum period of 3 months thereby delaying surgery up to the 8 months of age in some cases, depending on the age at presentation.

Table 1
NAM protocol for unilateral cleft lip and palate patients.
Presurgical nasoalveolar moulding
Patients inducted into the NAM protocol as below:
Group I: Infants less than 1 month of age – NAM till 6 months of age
Group II:
A. Infants between 1 and 3 months of age – NAM till 6 months of age
B. Infants between 3 and 5 months of age – NAM for a period of 3 months
1st visit:
Parent education and counselling
Use of audio-visual aids and live demonstrations
Interaction with parents of older NAM patients
Diet counselling
Detailed documentation
Photographs – standard 1:1 ratio frontal and basilar view
Dento-facial impressions
Medical evaluation of patients
Fabrication of NAM appliance
>8–10 mm intersegment distance – alveolar moulding
<8–10 mm intersegment distance – nasoalveolar moulding
Demonstration of home care instructions
Daily appliance care
Awareness about possible complications and their management
Telephonic correspondence after 2 days to ascertain parent and patient compliance
2nd visit (1 week subsequent to 1st visit):
Evaluation of parent – patient compliance
Detailed documentation
Photographs – Standard 1:1 ratio frontal and basilar view
Alveolar surface impressions
Treatment outcome assessment
Compatibility of appliance and required modifications
<8–10 mm intersegment distance – initiate nasoalveolar moulding
>8–10 mm intersegment distance – aggressive alveolar moulding
Recall visits every 3 weeks:
Evaluation of parent – patient compliance
Detailed documentation
Photographs – Standard 1:1 ratio frontal and basilar view
Alveolar surface impressions
Dento-facial impressions recorded prior to primary lip repair
Treatment outcome assessment
Compatibility of appliance and required modifications
Nasal moulding started at the earliest and continued till completion
Active alveolar moulding continued till completion
Passive alveolar moulding started once complete approximation of alveolar segments is achieved
Fabrication of new appliance every 2 months
Parents participation in periodic NAM workshops
Post surgery nasal moulding
Use of customised silicone nasal conformer for 6 months after primary lip repair

Fig. 1
Nasoalveolar moulding appliance.

In the study group, dento-facial impressions (nasal and alveolar surface impressions) were recorded at the time of initiation of NAM (T1), on completion of NAM (T2) and at 18 months of age (T3). All impressions were recorded in the outpatient department with the patient awake and lying supine. Nasal impressions extending from the upper lip to the forehead were recorded at T1, T2 and T3 using fast setting alginate. Alveolar surface impressions were recorded at each recall visit using heavy bodied condensation silicone impression material. In the control group, nasal and alveolar surface impressions were recorded for all patients at T3. Type III dental stone was used to pour the impressions. A base was prepared for the nasal casts such that the nasal tip was at the level of the eyebrows when viewed from the basilar aspect. All nasal measurements were recorded from this position. Appliances were fabricated using autopolymerising acrylic resin. Nasal stents were made using 0.032 gauge round stainless steel wire. Soft denture liner was used to cushion the nasal stent. Heavy orthodontic elastics (red) and half inch hypoallergic surgical tapes were used to retain the plate in the infant’s mouth. Parents were advised to make the child wear the plate for 24 h a day, 7 days a week, apart from a brief period for cleaning the plate twice daily.

During each recall visit, the active participation of the parents and their ability to follow the home care instructions was assessed. The alveolus was actively moulded by selective trimming of the appliance and addition of a layer of soft liner as needed. Nasal moulding was initiated at the earliest once cleft width was <8–10 mm. Aggressive alveolar moulding was undertaken if the cleft alveolar width was >8–10 mm. Upon complete approximation of the alveolar segments, passive moulding was undertaken to retain the alveolar segments in the new improved position whilst active nasal moulding continued. All impressions, casts and NAM appliances were made by the same author (H.J.V.).

In order to blind the examiner to the group status (group I, group II or group III) and treatment stage (T1, T2 or T3) of the dental stone models, each one was assigned a randomized number. All measurements were obtained twice following a period of 1 month by the same investigator (S.M.S.). The examiner was blinded to the previously completed measurements. As some of the photographs, early on in the course of this study were found not to be standardized, dental stone models of the dento-facial impressions were used for the purpose of evaluation.

Linear anthropometric measurements as indicated by E zzat et al. for maxillary arch measurements and L iou et al. for nasal measurements were used for this study ( Table 2 and Fig. 2 ). Nasal measurements were referenced to a horizontal line which connected the most inward points at the outer lateral border of the cleft and non-cleft nostrils and were recorded for the cleft and non-cleft side. All measurements were recorded using a sliding calliper with 0.01 mm precision at T1, T2 and T3. Measurements in group III were recorded at T3.

Table 2
Maxillary arch and nasal measurements.
Maxillary arch measurements (adapted from E zzat et al. ) :
Intersegment distance : Measurements between the tangents to the most medial curvature at the centre of the ridges
Arch width : Measurements between the tangents to the widest curvature of the maxillary arches
Nasal measurements (adapted from L iou et al. ) :
Nostril height : vertical distance between the horizontal reference line and the intersection point of the inner upper border of nostril and the perpendicular bisecting line of the nostril width.
Nasal dome height : vertical distance between the horizontal reference line and the intersection point of the outer upper border of nostril and the perpendicular bisecting line of the nostril width.
Columella length : vertical distance between the most inferior-medial and superior-medial points along the inner medial surface of the nostril apertures.
Nostril basal width : horizontal distance between the outer lateral border and the inner medial border of the nostril.
Nostril width : horizontal widest distance between the inner lateral and medial borders of the nostril aperture.

Fig. 2
(a) Maxillary arch and (b and c) nasal linear anthropometric measurements. ISD, intersegment distance; AW, alveolar width; NDH, nasal dome height; CH, columella height; NH, nostril height; NBW, nasal basal width; NW, nostril width.

Primary cheiloplasty was carried out for all patients on completion of presurgical nasoalveolar moulding as per the authors’ NAM protocol ( Table 1 ). All surgery was carried out by the same author (V.S.). The surgical procedure was a modified rotation–advancement cheiloplasty. The incision of the cleft margin was extended superiorly to the junction of the nasal mucosa and skin, where a release incision was given to mobilize the alar base. This was used to reconstruct the nasal floor. The orbicularis oris muscle on the cleft segment was mobilized adequately whilst that on the non-cleft segment was mobilized in all areas except underlying the philtral dimple. The lower lateral nasal cartilage on the cleft side and the columella were dissected up to the lower border of the upper lateral cartilage. Nasal septal mucosa was conservatively elevated to recreate the floor of the nose. Following muscle approximation, the alar base on the cleft side was advanced medially and superiorly. The non-cleft segment was elongated using a back-cut whilst the cleft segment was elongated using an oblique release incision. Supra white roll Z-plasty was carried out. Gingivoperiosteoplasty was not carried out for any patient. Following surgery, patients were continued with post surgical nasoalveolar moulding as per the authors’ NAM protocol ( Table 1 ).

Statistical Analysis

All data were analysed by statistical analysis package SPSS vers. 17.0 (SPSS Inc., Chicago, IL, USA). Data were analysed for intra-observer correlation using the Mann–Whitney U -test. Mean and standard deviation values were calculated for the evaluation parameters for groups I and II at T1, T2 and T3 ( Tables 3 and 4 ) and at T3 for group III ( Table 5 ). The effect of NAM on the study groups was established by determining the changes in the nasoalveolar morphology before and after completion of NAM (T1–T2). The percentage change in each group was noted. A 2 tailed unpaired t -test was used to determine the equality of mean ( Table 6 ). P < 0.05 was employed as the level of significance. Fisher’s test was used for variance analysis and Tukey’s test was used for pair wise comparison between the two cleft groups and the control group at T3 ( Table 7 ).

Table 3
Group I maxillary arch and nasal linear measurements at T1, T2 and T3.
T1 T2 T3
Measurements Side Mean SD Mean SD Mean SD
Intersegment distance 12.4 3.9835 2.3 1.9552 2.207 2.8776
Alveolar width 42.027 10.769 43.0 10.2688 44.007 10.0827
Nasal basal width C 17.507 1.8219 14.273 1.9159 12.979 2.3606
NC 7.24 1.4312 10.087 1.6907 13.127 2.1137
Nostril width C 14.9 2.5612 11.95 2.94 8.69 2.72
NC 4.5 1.6427 6.04 1.86 9.28 4.68
Nostril height C 2.513 0.8236 6.42 1.2835 7.687 2.4643
NC 6.027 1.4185 8.36 1.4441 8.807 2.2626
Nasal dome height C 7.48 1.6297 12.187 1.7699 14.747 3.4523
NC 10.727 1.4089 13.28 1.6196 15.773 2.5839
Columella height C 0.927 0.6573 2.633 0.5888 2.46 0.6231
NC 3.093 0.5444 3.593 0.3654 3.087 0.6424
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Jan 26, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on A comparison of results using nasoalveolar moulding in cleft infants treated within 1 month of life versus those treated after this period: development of a new protocol
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