Pre‐surgical orthopaedics (PSO) for infants with complete cleft lip and palate
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To evaluate the effectiveness and long‐term results of pre‐surgical orthopaedics (PSO) for infants with complete cleft lip and palate in maxillary growth, dental occlusion, feeding, speech and language development and facial appearance.
Background
Description of the condition
One in every 600 newborn babies worldwide is born with a cleft lip or palate or both according to the World Health Organization (WHO 2005). The incidence of non‐syndromic cleft lip and/or palate ranges from 70% to 80% of the total cleft population (Saal 2002).The non‐syndromic cleft lip with or without palate is a complex, multifactorial disorder with several anatomical defects and functional problems. Cleft defects can occur unilaterally or bilaterally and can be submucosal, partial or complete. The cleft defect can result in dentomaxillofacial deformities characterized by maxillary growth inhibition, arch collapse, and severe malocclusion, but can also lead to facial asymmetry, affect psychosocial well‐being and functional problems (such as feeding, speech development and hearing) (Choi 1991; Molsted 2005).
Description of the intervention
Infants born with cleft lip and palate are ideally treated with a team approach in order to repair the defect(s) and treat the functional problems.The team approach can include pre‐surgical orthopaedics, reconstructive surgery, speech therapy, paediatric guidance, psychological support, ear, nose and throat (ENT)/hearing support, orthodontics and dental reconstruction.
In the early 1950s, pre‐surgical orthopaedics (PSO) was introduced by McNeil. It was claimed to produce favourable maxillary, nasal and lip growth, and also position the palatal shelves more appropriately, prevent maxillary retrusion and allow for a more stable correction of the dental occlusion (McNeil 1950; McNeil 1956). The concept of PSO was quickly adopted. There are many other names for PSO and its variations including neonatal maxillary orthopaedics, pre‐surgical infant orthopaedics and most recently nasoalveolar molding (NAM). Appliances used in PSO can be divided into two main categories: active and passive appliances.
The first category of appliances to be introduced were semi‐active or active appliances. Semi‐active appliances are constructed on plaster models after alignment of the alveolar segments by sectioning the plaster models. Active appliances are constructed with palatal screws or springs and sometimes pinned to the underlying bone. Both are often used in combination with extraoral strapping in order to push and rotate the alveolar segments together. The effects of this new treatment modality, which was at the time used in combination with early bone grafting, resulted in severely impaired forward growth of the maxilla. The use of PSO has divided opinion between cleft clinicians from its introduction (Pruzansky 1964).
The second category of appliances used in PSO, passive appliances, was introduced some years later (Hotz 1976). Its objectives are the same with the difference that users of the passive appliances claim that the intrinsic growth becomes manifest without manipulating the maxillary segments.
In 1993, the latest form of PSO, nasoalveolar molding (NAM), was introduced by Grayson and Cutting. Its objective was to precisely shape the nasal cartilages in addition to molding the alveolar segments by using a molding plate with nasal stents and extraoral taping (Grayson 1993).
Why is it important to do this review?
The use of PSO has been controversial since McNeil first introduced it and continues to the current day. Advocates of PSO claim that the PSO molds the alveolar segments into a better arch form and prevents the tongue from positioning itself in the cleft gap prior to surgery. Therefore, the dentomaxillary development, occlusion, feeding and speech could be improved with PSO (Burston 1959; Huddart 1987; Mishima 1996). Opponents criticized PSO based on their own opinions and that the claimed benefits of PSO were not supported by reliable evidence in the literature (Pruzansky 1964). PSO has been claimed to inhibit maxillary growth (Pruzansky 1964), have no influence on the maxillary arch dimensions (Bongaarts 2006; Kujipers‐Jagtman 2000; Prahl 2003), but have a positive impact on speech and language development (Konst 2003; Stuffins 1981). Although this review will look at the impact of PSO on feeding of children born with cleft lip or palate or both, another Cochrane review aims to assess the effects of a variety of advice and devices recommended to aid feeding of children with clefts (Glenny 2004).
Most reports of PSO are largely anecdotal or observational in nature; therefore, these studies do not provide a high level of scientific basis for arguments regarding the relative value of PSO. From this, it is difficult to conclude whether or not PSO is an effective treatment for patients with cleft defect at birth. Therefore, this review attempts to identify the best available evidence and objectively assess this to ascertain if there is any support for this modality of treatment in children born with cleft lip or palate or both.
Objectives
To evaluate the effectiveness and long‐term results of pre‐surgical orthopaedics (PSO) for infants with complete cleft lip and palate in maxillary growth, dental occlusion, feeding, speech and language development and facial appearance.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials (RCTs) comparing patients treated with PSO (PSO+) with no treatment (PSO‐).
Types of participants
Children born with complete cleft lip and palate including unilateral cleft lip and palate (UCLP) and bilateral cleft lip and palate (BCLP). No other malformations recorded. No restrictions for gender or race.
Types of interventions
Interventions: pre‐surgical orthopaedics (active or passive).
Control: without pre‐surgical orthopaedics.
Types of outcome measures
Primary outcomes
Maxillofacial growth, dental occlusion, feeding.
Secondary outcomes
Facial appearance, speech quality, parent satisfaction, psychological support, surgical closure of the cleft, cost‐effectiveness.
The primary and secondary outcomes will be reported according to the most common endpoints identified in the included trials.
Search methods for identification of studies
For the identification of studies to be considered or included for this review detailed search strategies will be developed for each database searched. These will be based on the search strategy developed for MEDLINE but revised appropriately for each database.
For the MEDLINE search, the subject search (Appendix 1), will be run with the Cochrane Highly Sensitive Search Strategy (CHSSS) for identifying randomised trials in MEDLINE: sensitivity maximising version (2009 revision) as referenced in Chapter 6.4.11.1 and detailed in box 6.4.c of the Cochrane Handbook for Systematic Reviews of Interventions version 5.0.2 (updated September 2009) (Higgins 2009).
Databases to be searched
The following electronic databases will be searched:
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Cochrane Oral Health Group Trials Register (to present)
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Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, current issue)
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MEDLINE via OVID (1950 to present)
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EMBASE via OVID (1980 to present)
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Chinese BioMedical Literature Database (CBM) in Chinese (1978 to present)
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China National Knowledge Infrastructure (CNKI) in Chinese (1994 to present).
Handsearching
Handsearching of the following journals, which has been carried out as part of the Cochrane Oral Health Group's handsearching programme, will be updated to the most current issue:
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Cleft Palate‐Craniofacial Journal (1991 to present)
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Cleft Palate Journal (1966 to 1990).
In addition, the following Chinese journals will be handsearched by two of the review authors:
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Chinese Journal of Stomatology (1953 to present)
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West China Journal of Stomatology (1983 to present)
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Chinese Journal of Orthodontics (1994 to present).
The bibliographies of the clinical trials identified will be checked for references to trials published outside the handsearched journals. Personal references will be checked.
Language
Databases will be searched to include all languages and attempts will be made to translate non‐English language papers. We will contact all first authors of trials, whose articles are in other languages, by mail or email, to have the articles translated, or ask the Cochrane Oral Health Group for help with the translations. The review authors will translate the Chinese articles.
Searching other resources
To identify ongoing studies and unpublished trials the WHO International Clinical Trials Registry Platform (WHO ICTRP), Science Paper Online and System for Information on Grey Literature in Europe (OpenSIGLE) (1990 to present) will also be searched. The first named authors of all trial reports will be contacted in an attempt to identify unpublished studies and to obtain any further or missing information about the trials. Reference lists of included studies will be screened for further trials.
Data collection and analysis
Selection of studies
The titles and abstracts (when available) of all reports identified through the searches will be examined independently by two review authors. Obviously irrelevant reports will be excluded. For studies appearing to meet the inclusion criteria, or for which there are insufficient data in the title and abstract to make a clear decision, the full report will be obtained. The full reports obtained from all the electronic and other methods of searching will be assessed independently by two review authors to establish whether the studies meet the inclusion criteria or not. The review authors will not be blinded to author(s), institution or site of publication. Where necessary authors will be contacted for clarification. Any disagreement or doubt will be discussed with the involvement of a third review author to achieve consensus. Studies rejected at this or subsequent stages will be recorded in the 'Characteristics of excluded studies' table, and the reasons for exclusion recorded.
Data extraction and management
Data will be extracted independently and in duplicate by two review authors using specially designed data collection forms. The review authors will only include data if there is an independently reached consensus; any disagreements will be resolved by discussion with the help of a third review author. The following data will be extracted for each trial.
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Date of the study, year of publication, country of origin and source of study funding.
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Details of the participants including age, demographic characteristics and criteria for inclusion.
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Details on the type of intervention.
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Details of the outcomes reported, including method of assessment.
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Duration of follow‐up.
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Sample size and the number of male subjects and female subjects per study group.
Where necessary authors will be contacted for clarification or missing information. Study details will be entered into the 'Characteristics of included studies' table.
Assessment of risk of bias in included studies
We will assess and report on the risk of bias in included studies using the Cochrane Collaboration's tool for assessing risk of bias and a 'Risk of bias' table will be completed for each study as outlined in the Cochrane Handbook for Systematic Reviews of Interventions version 5.0.2 (Higgins 2009).
Six domains, namely sequence generation, allocation concealment, blinding, incomplete outcome data, selective outcome reporting and other sources of bias will be assessed according to the tool. Each domain will include one or more specific entries in a 'Risk of bias' table. Within each entry, what was reported to have happened in the study will be described and a judgement relating to the risk of bias for that entry will be assigned. This will be achieved by answering a pre‐specified question about the adequacy of the study in relation to the entry. A judgement of 'Yes' indicates low risk of bias; 'No' indicates high risk of bias; and 'Unclear' indicates unclear risk of bias. An overall risk of bias assessment will also be made.
Measures of treatment effect
The statistical procedures outlined in the Cochrane Handbook for Systematic Reviews of Interventions 5.0.2 (Higgins 2009) will be followed and the data will be analysed using Review Manager (RevMan) software and reported according to Cochrane Collaboration criteria. Risk ratios (RR) and corresponding 95% confidence intervals (CI) will be calculated for dichotomous data; difference in means (MD) or standardized mean difference (SMD) and 95% CI for continuous data. Standardized mean differences (SMD) will be used to report the same outcomes when different scales are used.
Dealing with missing data
In case of missing data in the included studies, we will attempt to contact the authors to obtain the data and clarify any uncertainty. The potential impact of missing data will be discussed in the discussion section of the review.
Assessment of heterogeneity
Statistical heterogeneity will be assessed using a Chi2 test (we will consider heterogeneity to be significant when the P value is less than 0.10) and the I2 statistic (where I2 values over 50% indicate substantial to considerable heterogeneity). When significant heterogeneity is present, further reasons for this heterogeneity will be explored by using a sensitivity analysis.
Assessment of reporting biases
A test for funnel plot asymmetry to assess publication bias will be performed only if at least 10 studies suitable for inclusion in a meta‐analysis are identified.
Data synthesis
Meta‐analyses will be done only with studies of similar comparisons reporting the same outcome measures. Risk ratios will be combined for dichotomous data, and mean differences for continuous data, using the random‐effects model if there are more than three trials, otherwise the fixed‐effect model will be used.
Available results for the outcomes of interest of the systematic review of all studies included will be tabulated if they cannot be included in a formal meta‐analysis.
Subgroup analysis
If sufficient data are available, subgroup analyses will be conducted to explore the influence of study characteristics such as the types of cleft, the types of intervention, and different observation time on the meta‐analysis outcome.
Sensitivity analysis
If there are sufficient included studies, a sensitivity analysis will be undertaken to examine the effect of random sequence generation, allocation concealment, blinding and loss to follow‐up on the overall estimates of effect. We plan to perform a sensitivity analysis where appropriate to explore the influence of the following factors on effect size:
‐ Random sequence generation: if this domain is assessed as 'Unclear' in a study, we will perform a sensitivity analysis without these studies.
‐ Allocation concealment: if this domain is assessed as 'Unclear' or 'No' in a study, we will perform a sensitivity analysis without these studies.
‐ Overall assessment of risk of bias: we will perform a sensitivity analysis excluding studies at high risk of bias (defined as two or less domains assessed as 'Yes').
