Initiatief: NVPC Aantal modules: 51

Hypernasaliteit bij patiënten met een schisis

Deze module is onderverdeeld in de volgende submodules:

  • Diagnostiek van hypernasaliteit bij schisis
  • Behandeling van hypernasaliteit bij schisis

Autorisatiedatum en geldigheid

Laatst beoordeeld  : 01-09-2018

Laatst geautoriseerd  : 01-09-2018

Geplande herbeoordeling  : 01-01-2027

The Board of the Dutch Society for Plastic and Reconstructive Surgery (NVPC) will assess whether this guideline module is still up-to-date in 2026 at the latest. If necessary, a new working groupwill be appointed to revise the guideline module. The validity of the guideline or modules of the guideline may lapse earlier when new developments arise. As the holder of this guideline, the NVPC is chiefly responsible for keeping the guideline up to date.


Responsible party1

Year of autorisation

Next assessment of actuality guideline2

Frequency of assessement of actuality3

Supervising party of actuality4

Relevant factors for changes in recommendations5




every 5 years



[1] Responsible party for the module

2 maximum of 5 years

3 half a year, every (other,..) year

4 supervising party or parties

5 Current reseach, changes in organizations/restrictions, new available resourses


Other scientific organizations participating in the guideline or users of the guideline share the responsibility to inform the chiefly responsible party (NVPC) about relevant developments within their fields.

Initiatief en autorisatie

  • Nederlandse Vereniging voor Plastische Chirurgie
Geautoriseerd door:
  • Nederlandse Vereniging voor Keel-Neus-Oorheelkunde en Heelkunde van het Hoofd-Halsgebied
  • Nederlandse Vereniging voor Kindergeneeskunde
  • Nederlandse Vereniging voor Obstetrie en Gynaecologie
  • Nederlandse Vereniging voor Plastische Chirurgie
  • Vereniging Klinische Genetica Nederland
  • Nederlandse Verenging voor Schisis en Cranio Faciale Afwijkingen
  • Nederlandse Vereniging van Orthodontisten

Algemene gegevens

The revision of this guideline module was supported by Knowledge Institute Federation of Medical Specialists ( and was financed by the Quality Foundation of the Dutch Medical Specialists (SKMS). The funding organization did not have any influence on the content of the guideline in any way.

Doel en doelgroep

Objectives of the guideline

The aim of this guideline is to improve the care of children/patients with CLA/Ps in The Netherlands ranging from prenatal detection to young adulthood, substantiated by scientific knowledge from research where possible. ‘Improving’ also means providing insight in the differences in practices between cleft teams and discriminating between wanted and unwanted (i.e. scientifically based or non-scientifically based) practice variation. This resulted in recommentations for a more uniform treatment. However, the lack of high-quality studies and evidence remains a serious limiting factor and forced the working group to define some conclusions in a more generalized way than was wished for at the start.


Specific attention will be given to the following aspects:

  1. reducing undesirable/unfounded practice variation in the working method and treatment protocols of the Dutch cleft teams, without hampering custom work, innovation or research;
  2. making objective / evidence-based information about the treatment of CLA/Ps available and accessible to healthcare providers, patients, parents and other parties;
  3. determine to what extent the existing organisation of care needs to be changed in order to meet the requirements regarding “state of the art” treatment of a child or adult with CLA/Psand the follow-up to this treatment.


In this manner, the guideline offers a tool to create more uniform care in the field of the prenatal and postnatal treatment of a child with CLA/Ps and the implementation of this care in the Netherlands.


Intended users of the guideline

The guideline is primarily intended for all healthcare professionals who are involved in caring for a child with CLA/Ps: general practitioners, midwives, gynaecologists, paediatricians, ENT physicians, plastic surgeons, maxillofacial surgeons, orthodontists, clinical geneticists, specialised nurses, speech therapists, (paediatric) dentists, medical psychologists, remedial educationalists and social workers. The secondary target group involves patients, parents and their surroundings.

Samenstelling werkgroep

A multidisciplinary working group was appointed by the Dutch Society for Plastic and Reconstructive Surgery in October 2019 to update the existing guidelines for clefts of the lip and palate. The original guidelines were initiated by the Dutch Society for Plastic and Reconstructive Surgery and this Society remains responsible for the revisions. The working group subsequently updated both the guideline for prenatal counsellling for clefts of the lip, alveolus, and/or palate (Counseling na prenataal vastgestelde schisis, 2011) and postnatal treatment (Behandeling van patiënten met een schisis, 2018). The working group consisted of representatives from all relevant specialties involved in the care for patients with cleft lip, alveolus and/or palate. Members were mandated by their professional organizations. The working group consisted of a mix of new members and members, who worked on previous editions as well. The group worked on the update of the guideline for two years. The working group is responsible for the full text of this guideline.


Working group

  • Dr. A.B. Mink van der Molen, MD, plastic surgeon, Universitair Medisch Centrum Utrecht, (chairman), NVPC
  • Dr. M.F. van Dooren, clinical geneticist, Erasmus MC Rotterdam, VKGN
  • Dr. M.J.H. van den Boogaard, clinical geneticist, Universitair Medisch Centrum Utrecht, VKGN
  • Dr. L.N.A. van Adrichem, MD, plastic surgeon, Universitair Medisch Centrum Utrecht, NVPC
  • Dr. H.F.N. Swanenburg de Veye, psychologist, Universitair Medisch Centrum Utrecht/Wilhelmina Kinderziekenhuis, Utrecht, NIP
  • Dr. C.J. Bax, MD, gynaecologist, Amsterdam UMC, NVOG
  • Prof. dr. C.C. Breugem, MD, plastic surgeon, Amsterdam Medical Center and Meander Medical Center, NVSCA
  • Drs. F. Bierenbroodspot, MD, Oral and maxillofacial surgeon, Isala, Zwolle, NVMKA
  • Drs. M. Haasnoot, MD, paediatrician, Wilhelmina Kinderziekenhuis, Utrecht, NVK
  • Drs. H.H.W. de Gier, MD, otolaryngologist, Erasmus MC Rotterdam, NVKNO
  • Dr. M.A.R Kuijpers, orthodontist, Radboud University Medical Center, NVvO
  • Dr. M.E.L. Nienhuijs, MD, Oral and maxillofacial surgeon, Radboud University Medical Center, NVSCA
  • Dr. D. de Haan, patient representative, Schisis Nederland


Advisory board

  • Drs. B. Spaan, dentist, CBT Vogellanden Zwolle, NVvK
  • I. Noureldin - Hop, orthopedagogue, NSDSK, NVO
  • M. J. Coerts, speech therapist, Amsterdam UMC, NVLF


With methodological support of

  • Drs. A.A. Lamberts, senior advisor, Knowledge Institute Federation of Medical Specialists
  • Dr. M. Vierwind - den Ouden, advisor, Knowledge Institute Federation of Medical Specialists


According to the KNMG-code, all members of the working group have declared in writing if, in the last five years, they have held a financially supported position with commercial businesses, organisations or institutions that may have a connection with the subject of the guidelines. Enquiries have also been made into personal financial interests, interests pertaining to personal relationships, interests pertaining to reputation management, interests pertaining to externally financed research, and interests pertaining to valorisation of knowledge. These Declarations of Interest can be requested from the secretariat of the Knowledge Institute of Medical Specialists. See below for an overview.




Side jobs

Declared conflicting interests


Dr. A.B. Mink van der Molen

plastic surgeon,



No actions

Dr. M.F. van Dooren

clinical geneticist

Co-chair VKGN


No actions

Dr. M.J.H. van den Boogaard

clinical geneticist



No actions

Dr. L.N.A. van Adrichem

plastic surgeon

DGA van Adrichem Medical B.V.

Chairman Concilium plastico chirurgicum

Member Raad Opleiding


Advisor Hoofdmaatje

Chairman Medical Council Equipe Zorgbedrijven

Member Medicatie Commissie Equipe Zorgbedrijven

Member stuurgroep STW project TU-Twente


No actions

Dr. H.F.N. Swanenburg de Veye




No actions

Dr. C.J. Bax


Volunteer hospice

Member NIPT consortium

Member committee quality documents NVOG

Secretary committee Otterlo NVOG

Treasurer working group infectious diseases NVOG


No actions

Dr. C.C. Breugem

plastic surgeon



No actions

Drs. F. Bierenbroodspot

Oral and maxillofacial surgeon

Working Group Esthetische Aangezichtschirurgie


No actions

Drs. M. Haasnoot




No actions

Dr. J. de Gier


Board member NVSCA


No actions

Dr. M. Kuijpers


Guideline committee Mondzorg voor jeugdigen preventie diagnostiek behandeling


No actions

Dr. M. Nienhuijs

Oral and maxillofacial surgeon

Boardmember NVSCA


No actions

Dr. D. de Haan

patient representative,

Teacher/ education advisor HU-PABO, Hogeschool Utrecht


No actions

Inbreng patiëntenperspectief

Patients were represented by Schisis Nederland. Schisis Nederland is an independent organization representing patients with CLA/Psand their parents in the Netherlands. Representatives from Schisis Nederland participated in the working group. The concept guideline module was presented to Schisis Nederland for their comments.

Methode ontwikkeling

Evidence based


Guideline implementation and practical applicability of the recommendations was taken into consideration during various stages of guideline development. Factors that may promote or hinder implementation of the guideline in daily practice were given specific attention. The guideline is distributed digitally among all relevant professional groups. The guideline can also be downloaded from the Dutch Society for Plastic and Reconstructive Surgery website:, and the guideline website: The implementation table can be found in the related products.



The guideline has been drafted in accordance with the requirements outlined in the ‘Guidelines 2.0’ report of the Guideline Advisory Committee of the Council on Science, Education and Quality (WOK). This report is based on the AGREE II instrument (Appraisal of Guidelines for Research & Evaluation II) (Brouwers, 2010), an instrument designed to assess the quality of guidelines with broad international support (Brouwers, 2010). The development of a evidence-based guideline module is described step-by-step in “Ontwikkeling van Medisch Specialistische Richtlijnen” of Knowledge Institute for Medical Specialists.


Inventory of the problem areas

During the preparation phase the working group used an inventory to find the problem areas. A report of this inventory can be found in the related products.


Primary questions and outcome measures

Based on the outcomes of the bottleneck analysis, the president and advisor formulated draft primary questions. These were discussed and defined together with the working group. Subsequently, the working groupdetermined which outcome measures were relevant for the patient for each primary question, examining both desired and undesirable effects. The working groupvaluated these outcomes based on their relative importance as crucial, important and unimportant.


Literature search and selection strategy

Specific search terms were used to identify published scientific studies related to each individual primary question in electronic databases like Medline, Cochrane, and Embase. Additionally, the references of the selected articles were screened for additional relevant studies. Studies offering the highest level of evidence were sought out first. Members of the working group selected articles identified by the search based on predetermined criteria. Theselected articles were used to answer the primary question. The searched databases, the search string or terms used during the search and selection criteria applied are listed in the module for each individual primary question.


Quality assessment of individual studies

Individual studies were assessed systematically based on predefined methodological quality criteria in order to assess the risk of biased study results. These assessments may be found in the column ‘Study quality assessment’ in an evidence table.

  • AMSTAR - for systematic reviews.
  • Cochrane - for randomized controlled trials.
  • ACROBAT-NRS - for observational studies.
  • QUADAS II - for diagnostic studies.


Summary of the literature

The relevant study results from all selected articles were presented clearly in evidence tables. The key findings from the literature are described in the literature summary. If studies were sufficiently similar in design, data were also summarized quantitatively (meta-analysis) using Review Manager 5.


Assessment of the level of scientific evidence

With regard to intervention questions, the level of scientific evidence was determined using the GRADE method. GRADE is short for ‘Grading Recommendations Assessment, Development and Evaluation’ (see


GRADE distinguishes four grades of quality of evidence, i.e. high, moderate, low and very low. These grades indicate the degree of confidence in the conclusions in the literature ((Schünemann, 2013; Hultcrantz, 2017).





  • There is a high degree of confidence that the true effect of treatment is very close to the estimated effect of treatment as reported in the conclusion in the literature.
  • It is very unlikely that the conclusion drawn in the literature will change if further research is done.


  • There is a moderate degree of confidence that the true effect of treatment is very close to the estimated effect of treatment as reported in the conclusion in the literature.
  • It is possible that the conclusion drawn in the literature will change if further research is done.


  • There is a limited degree of confidence that the true effect of treatment is very close to the estimated effect of treatment as reported in the conclusion in the literature.
  • It is probable that the conclusion drawn in the literature will change if further research is done.

Very low

  • There is little confidence that the true effect of treatment is very close to the estimated effect of treatment as reported in the conclusion in the literature.
  • The conclusion is very uncertain


According to the GRADE methodology the clinical decision threshold should play an important role in assessing the level of evidence (grading) in guidelines (Hultcrantz, 2017). To set the threshold all critical outcomes, and the considerations should be determined. The clinical decision threshold is not exactly the same as the Minimal Clinically Important Difference (MCID). In situations in which an intervention has no important disadvantages and low costs, the clinical decision threshold with regard to the efficiency of an intervention can be lower (closer to zero/ no effect) than MCID (Hultcrantz, 2017).


Formulation of conclusions

For interventions, the conclusion does not refer to one or more articles, but is drawn based on the body of evidence. The working group looked at the net benefits of each intervention. This was done by determining the balance between favourable and unfavourable effects for the patient.


With regard to questions about the value of diagnostic tests, harm or adverse effects, aetiology and prognosis, the scientific evidence is summarized in one or more conclusions, listing the level of evidence for the most relevant data.



When making recommendations, scientific evidence was considered together with other key aspects, such as expertise of the group members, patient preferences, costs, availability of facilities and/or organizational aspects. Insofar as they are not part of the systematic literature review, these aspects are listed under ‘Considerations’. The considerations are written using a structured format based on the evidence-to-decision framework of the international GRADE Working Group, and part of the GRADE methodology (Alonso-Coello, 2016a; Alonso-Coello 2016b).


Formulation of recommendations

Recommendations provide an answer to the primary question and are based on the best scientific evidence available and the most important considerations. The level of scientific evidence and the importance given to considerations by the working group jointly determine the strength of the recommendation. In accordance with the GRADE method, a low level of evidence for conclusions in the systematic literature review does not rule out a strong recommendation, while a high level of evidence may be accompanied by weak recommendations (Agoritsas, 2017; Neumann, 2016). The strength of the recommendation is always determined by weighing all relevant arguments.


Preconditions (Organisation of care)

In the analysis of problem areas, the organisation of care (all those aspects that are preconditions for the provision of care) were explicitly taken into account. These aspects include coordination, communication, materials, financial means, work force and infrastructure. Preconditions that are relevant to the answering of a specific clinical question are part of the considerations related to that specific question.


Knowledge gaps

During the development of this guideline, systematic searches were conducted for research contributing to answering the primary questions. For each primary question, the working group determined whether (additional) scientific research is desirable.


Commentary and authorization phase

The draft guideline was submitted to the (scientific) organizations involved for comment. The guideline was also submitted to the following organizations for comment: Dutch College of General Practitioners (NHG), Healthcare Insurers Netherlands (ZN), The Dutch Healthcare Authority (NZA), the National Health Care Institute (ZINL), the Health Care Inspectorate (IGJ), Dutch Organisation of Hospitals (NVZ), Dutch Federation of Academic Hospitals (NFU), Dutch Organisation of Independent Clinics (ZKN), the Netherlands Patients Federation, Dutch Organisation of nurses and caregivers (V&VN), Dutch Association of Physician Assistants, and Collaborating Top Clinical Training Hospitals (STZ). Comments were collected and discussed with the working group. The draft guideline was updated and finalized by the working group based on the comments. The final guideline was submitted for authorization to the (scientific) organizations involved and authorized or approved by them.



Agoritsas T, Merglen A, Heen AF, Kristiansen A, Neumann I, Brito JP, Brignardello-Petersen R, Alexander PE, Rind DM, Vandvik PO, Guyatt GH. UpToDate adherence to GRADE criteria for strong recommendations: an analytical survey. BMJ Open. 2017 Nov 16;7(11):e018593. doi: 10.1136/bmjopen-2017-018593. PubMed PMID: 29150475; PubMed Central PMCID: PMC5701989.

Alonso-Coello P, Schünemann HJ, Moberg J, Brignardello-Petersen R, Akl EA, Davoli M, Treweek S, Mustafa RA, Rada G, Rosenbaum S, Morelli A, Guyatt GH, Oxman AD; GRADE Working Group. GRADE Evidence to Decision (EtD) frameworks: a systematic and transparent approach to making well informed healthcare choices. 1: Introduction. BMJ. 2016 Jun 28;353:i2016. doi: 10.1136/bmj.i2016. PubMed PMID: 27353417.

Alonso-Coello P, Oxman AD, Moberg J, Brignardello-Petersen R, Akl EA, Davoli M, Treweek S, Mustafa RA, Vandvik PO, Meerpohl J, Guyatt GH, Schünemann HJ; GRADE Working Group. GRADE Evidence to Decision (EtD) frameworks: a systematic and transparent approach to making well informed healthcare choices. 2: Clinical practice guidelines. BMJ. 2016 Jun 30;353:i2089. doi: 10.1136/bmj.i2089. PubMed PMID: 27365494.

Brouwers MC, Kho ME, Browman GP, et al. AGREE Next Steps Consortium. AGREE II: advancing guideline development, reporting and evaluation in health care. CMAJ. 2010;182(18):E839-42. doi: 10.1503/cmaj.090449. Epub 2010 Jul 5. Review. PubMed PMID: 20603348.

Hultcrantz M, Rind D, Akl EA, et al. The GRADE Working Group clarifies the construct of certainty of evidence. J Clin Epidemiol. 2017 Jul;87:4-13. doi: 10.1016/j.jclinepi.2017.05.006. Epub 2017 May 18. PubMed PMID: 28529184.

Medisch Specialistische Richtlijnen 2.0 (2012). Adviescommissie Richtlijnen van de Raad Kwalitieit.

Schünemann H, Brożek J, Guyatt G, et al. GRADE handbook for grading quality of evidence and strength of recommendations. Updated October 2013. The GRADE Working Group, 2013. Available from

Schünemann HJ, Oxman AD, Brozek J, et al. Grading quality of evidence and strength of recommendations for diagnostic tests and strategies. BMJ. 2008;336(7653):1106-10. doi: 10.1136/bmj.39500.677199.AE. Erratum in: BMJ. 2008;336(7654). doi: 10.1136/bmj.a139. PubMed PMID: 18483053.

Wessels M, Hielkema L, van der Weijden T. How to identify existing literature on patients' knowledge, views, and values: the development of a validated search filter. J Med Libr Assoc. 2016 Oct;104(4):320-324. PubMed PMID: 27822157; PubMed Central PMCID: PMC5079497.

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