Presurgical orthopedics by drink plates does not significantly normalize deglutition in infants with cleft lip and palate

Transcription

1 Originl Article Presurgicl orthopedics by drink pltes does not significntly normlize deglutition in infnts with cleft lip nd plte Michel Knösel ; Christine Fendel b ; Klus Jung c ; Pulo Sndovl d ; Wilfried G. Engelke e ABSTRACT Objective: To test the null hypothesis of no significnt difference between introrl pressure chrcteristics in infnts with cleft lip nd plte (CLP) with or without presurgicl orthopedic (PSO) pltes (groups CLP nd CLP-PSO), compred with noncleft infnts. Mterils nd Methods: Introrl tmospheric pressure ssessments were performed on 17 subjects with preopertive CLP (m/f, 11/6; men/sd, 4.76/0.92 months) nd mtched control group (n 5 24; m/f, 15/9; men/sd, 4.88/0.9 months), for 200 seconds, simultneously t the vestibulum (vestibulr spce [VS]) nd t the plte (subpltl spce [SPS]), using prepred pcifier connected to digitl mnometer. Ares under the pressure curves (AUC), frequencies, durtions, nd mgnitudes of swllowing peks nd pressure resting plteus were compred between tril groups nd loctions (VS, SPS) using two-fctor nlysis of vrince for repeted mesures, Kruskl-Wllis test, nd Mnn-Whitney U-test ( 5.05). Results: The null hypothesis ws rejected: Globlly, there were sttisticlly significnt differences in introrl pressure chrcteristics between groups CLP, CLP-PSO, nd control (ll P,.01), with significntly higher negtive pressures (AUC) in the control subjects compred with those of CLP or CLP-PSO. There were significnt effects by the loction of pressure recordings (VS, SPS) nd their interction with ll tretment groups. Differences between noncleft nd CLP subjects were more pronounced in the VS thn in the SPS. There ws no significnt effect by PSO. Conclusion: PSO does not improve devited swllowing chrcteristics during suction in CLP infnts. (Angle Orthod. 2016;86: ) KEY WORDS: Cleft lip nd plte; Drink plte; Introrl pressure monitoring; Pthophysiology of deglutition; Swllowing; Infnts INTRODUCTION Introrl soft tissue fctors such s tongue dynmics, swllowing chrcteristics, nd hbitul orl posture re known to hve n impct on the Professor, Deprtment of Orthodontics, University Medicl Center Göttingen, Göttingen, Germny. b Reserch Fellow nd Medicl Student, University Medicl Center Giessen & Mrburg, Giessen, Germny. c Senior Lecturer nd Biosttisticin, Deprtment of Medicl Sttistics, University Medicl Center Göttingen, Göttingen, Germny. d Professor nd Deprtment Chir, Deprtment of Orthodontics, Universidd de l Fronter, Temuco, Chile. e Professor, Deprtment of Orthodontics, Universidd de l Fronter, Temuco, Chile. Corresponding uthor: Prof Dr med. dent. Michel Knösel, University Medicl Center Göttingen, Germny (e-mil: mknoesel@yhoo.de) Accepted: April Submitted: Februry Published Online: My 20, 2015 G 2016 by The EH Angle Eduction nd Reserch Foundtion, Inc. development of norml occlusion. 1,2 They my mnifest s vrious mlocclusions such s open bites, crossbites, nd nrrow mxille tht re known to be triggered or ggrvted by devitions from norml nose-brething ptterns, tongue-thrust swllowing, or sucking hbits in infnts. 3,4 Cleft lip nd plte (CLP) is one of the most frequent combintions of embryonic developmentl disorders with crniofcil expression, 5 nd its prevlence vries between different popultions. 6 CLP etiology is multifctoril nd is bsed on both exogenous nd endogenous fctors. 7 Tretment of CLP usully strts t birth with presurgicl orthopedics (PSO) such s the use of drink pltes or feeding pltes. The purpose of PSO is to seprte the orl from the nsl cvity, thereby fcilitting nose brething nd preventing bnorml tongue positions, such s plcing the tongue between the seprted pltl segments. Thus, PSO hs been indicted s being helpful in controlling the growth direction of the seprted mxillry segments, lso in nrrowing the cleft region presurgery. 8 DOI: /

2 316 KNÖSEL, FENDEL, JUNG, SANDOVAL, ENGELKE But, while the effect of PSO on lnguge development, nutrition, growth increments, nd improving the shpe of the nose hve been investigted frequently, longterm benefits of PSO therpy re still subject of controversy Thus, preferences for PSO therpy seem to be bsed on clinicl experience rther thn being supported by hrd evidence. Genertion of negtive introrl pressures t rest nd during suction is considered to be norml feture in helthy, noncleft newborns, with men vlues between 8.4 mbr (SD, 5.8) during interburst periods nd 58 mbr (SD, 14.6) during sucking. 13 In contrst, CLP children mostly fil to generte comprble vcuum in the orl cvity, due to lck of seprtion of the orl nd nsl cvities. 14 As consequence of insufficient suction, CLP bbies re often underweight compred with noncleft newborns. 15 Furthermore, the genertion of negtive introrl pressure during swllowing nd t rest hs been estblished s prerequisite for inititing deglutition, nd is lso seen s the bsis of norml dentofcil development with neutrl occlusion. 1,2,14,16,17 As norml feture in subjects with neutrl permnent dentition, swllowing dynmics include the formtion of two seprte introrl spces, or comprtments: The subpltl spce (SPS), the functionl spce tht forms between the bck of the tongue nd the pltl vult during deglutition nd the vestibulr spce (VS), the functionl comprtment bordered on the lingul side by the tongue nd by the lips nd cheeks s the outer limit). 17,18 This biofunctionl model of the ct of physiologicl deglutition my serve s bsis for screening nd nlysis of introrl comprtment formtion by mnometry. 17 It my lso be helpful in shedding light on whether PSO bsiclly contributes to n improvement in deglutition nd normliztion of tongue position in CLP newborns, thereby providing for deeper understnding of the function nd benefit of PSO in dentofcil development. Study Objective The im of this study ws to clrify the effect of PSO (represented by drink plte tht ws djusted on regulr bsis) on the normliztion of deglutition in CLP newborns, s prmeterized by the formtion of introrl comprtments (VS nd SPS), compred with noncleft control infnts. We tested the null hypothesis of no significnt differences between introrl pressure chrcteristics ssessed in CLP infnts, with nd without PSO pltes (groups CLP nd CLP-PSO), nd mtched sound, non-clp control group. MATERIALS AND METHODS Subjects After obtining permission from the ethics committee of the University of Göttingen, Germny (3/8/09), nd informed consent from the study children s prents nd gurdins, we recruited 17 subjects with preopertive CLP (m/f, 11/6; men ge/sd, 4.76/0.92 months; min, 4 months; mx, 6 months; bilterl CLP, n 5 6; left-/ right-sided CLP, n 5 10/1) nd mtched control group (n 5 24; m/f, 15/9; men ge/sd, 4.88/0.9 months; min, 4 months; mx, 6 months) between September 1, 2009, nd July 31, 2014, from the three CLP centers of the universities of Göttingen, Bonn, nd Giessen, Germny. The control subjects were recruited from the Children s Hospitl of Göttingen University. The CLP subjects hd been ccustomed to PSO therpy by drink pltes for t lest 3 months. The PSO pplinces used here hve double function: Primrily, they serve s drink pltes; second, these crylic pltes re either dpted to growth increments on regulr bsis by molding or re replced by new drink pltes in n ttempt to improve the rch form. The pplinces cover the plte nd cleft re s widely s possible. The posterior mrgins re trimmed s much s needed to void phryngel reflex. Inclusion criteri for CLP subjects were unilterl (left- or right-sided) or bilterl, full or prtil presurgicl CLP. They were excluded for isolted cleft lip or plte, common colds, or generl diseses tht would restrict nose or mouth brething. Therefore, of 23 eligible CLP subjects, 6 were excluded for the following resons: 2 hd isolted cleft lip, 3 hd isolted cleft plte, nd 1 ws in poor generl stte of helth, long with hving dyspne. Inclusion criteri for noncleft control subjects were bsence of CLP, common colds, nd generl diseses. MATERIALS AND METHODS Introrl tmospheric pressure chrcteristics were recorded simultneously in the VS nd SPS using prepred pcifier (Nuk, size 1, Mp GmbH, Zeven, Germny) connected to digitl mnometer (GMH3156, with sensor GMSD350MR, resolution of 0.1 mbr rel.; softwre GSOFT3050; Greisinger, Regenstuf, Germny) vi two cnnuls (Vsofix-Sfety 1.3G18, Brun, Melsungen, Germny) (Figure 1). The durtion of ech mesurement intervl ws 200 seconds. The first nd lst 10 of ech recording were discrded in order to nlyze deglutition chrcteristics t rest, following fmiliriztion only. There were singulr ssessments in the control subjects, while the CLP subjects were mesured t first with their PSO plte nd subsequently fter brek of 2 minutes,

3 IMPACT OF DRINK PLATES ON CLP DEGLUTITION 317 Figure 1. Atmospheric pressure ssessments were performed simultneously in the vestibulr spce (VS) nd subpltl spce (SPS) using prepred pcifier with two internl cnnuls connected to digitl mnometer. Pltl perfortions prevent blocking of the internl pltl cnnul by the tongue nd solely llow for SPS recordings. The perforted VS cnnul diverges lterlly from the pcifier. without the PSO. All mesurements were mde by the sme opertor. Sttisticl Anlysis Introrl pressure chrcteristics were prmeterized by the following fetures of the pressure curves: The res under the pressure curves (AUC), frequencies, nd medin mgnitudes of swllowing peks (mbr) nd durtion (seconds), frequencies, nd medin mgnitudes (mbr) of pressure resting plteus.5 seconds. Signl extrction ws crried out ccording to the methods described by Jung et l. 19 For ech feture, differences between study groups (CLP, CLP-PSO, control), loctions (VS, SPS) s well s their interction, were nlyzed by nonprmetric, two-fctor nlysis of vrince (ANOVA) for repeted mesures. 20 Globl group comprisons of ech loction were performed using the Kruskl-Wllis test, followed by pirwise comprisons with the Mnn- Whitney U-test. All tests were performed t significnce level of 5 5%, ccording to the closed testing procedure. Sttisticl nlyses were done with the softwre R (version 3.0, nd the R-pckge MALDIqunt for pek detection. Method Error Repeted introrl pressure mesurements hve been reported to be subject to vrition. 17,21 23 In order to chrcterize the robustness of the distinctive prmeters, the vrition of mesurements ws nlyzed on the bsis of series of three-time repeted pressure monitoring of three subjects of the control group (Tble 1). Tble 1. Three Time-Repeted Mesurement Intervls: Robustness of the Distinctive Curve Prmeters Ws Described Within Ech Ptient By Mens (m), 6 Stndrd Devitions (s), nd by the Coefficients of Vrition (c v 5 m/s) s Stndrdized Mesure of Vrition Subject 1 Subject 2 Subject 3 Are Prmeter (unit) Men 6 SD SD/Men (%) Men 6 SD SD/Men (%) Men 6 SD SD/Men (%) VS Pek frequency (n) VS Medin pek height (mbr) VS Plteu frequency (n) VS Medin plteu height (mbr) VS Medin plteu durtion (s) VS AUC SPS Pek frequency (n) SPS Medin pek height (mbr) SPS Plteu frequency (n) SPS Medin plteu height (mbr) SPS Medin plteu durtion (s) SPS AUC VS indictes vestibulr spce; SPS, subpltl spce. b AUC indictes res under the pressure curves.

4 318 KNÖSEL, FENDEL, JUNG, SANDOVAL, ENGELKE Tble 2. Results of Two-wy Anlysis of Vrince of Effects Between Groups (CLP, CLP-PSO, Control), Loctions of Pressure Recordings (Vestibulr Spce [VS] or Subpltl Spce [SPS]), s Well s Their Interction Prmeter Group Effect (CLP, CLP-PSO, Control) Effect of Loction (VS; SPS) Interction Group X Loction AUC,0.01,0.01,0.01 Frequencies of peks (n),0.01, Medin pek height (mbr),0.01, Frequencies of plteus (n),0.01, Medin plteu height (mbr),0.01,0.01,0.01 Medin plteu durtion (s),0.01, CLP indictes cleft lip nd plte; PSO, presurgicl orthopedic(s). RESULTS For ll prmeters, two-wy ANOVA yielded significnt differences between the groups s well s significnt interctions between group nd loction of pressure recording (Tble 2). Furthermore, loction effects were lso significnt for ll prmeters. Becuse of the significnt interctions, nlyses were further split by loction, yielding sttisticlly significnt differences in introrl pressure chrcteristics between the three groups, with significntly higher negtive pressures by AUC in the control subjects compred with CLP nd CLP-PSO (P,.01; Tbles 2 nd 3). Ares Under the Pressure Curves In the SPS, there were significnt differences in AUC dimensions between noncleft controls nd CLPs, lso between controls nd CLP-PSO (Tble 4), while there ws no significnt difference between CLP-PSO nd CLP (P 5.15; Tble 4). There ws similr pttern t the VS compred with the SPS (Tble 5), lthough there were much greter differences between noncleft control subjects nd CLP or CLP-PSO (Tble 3). Accordingly, there ws significnt interction between group nd introrl loction of recording (P,.05; Tble 2). Frequencies of Peks There ws significnt interction between group nd introrl loction of recording (P,.01; Tble 2), with significnt differences between noncleft controls nd CLP or CLP-PSO in the VS (Tble 5), but not in the SPS (P 5.29; Tble 4). Medin Pek Height Medin pek height ws highest in the noncleft control group (Tble 3), nd the difference in pek height compred with the CLP nd CLP-PSO groups ws even more pronounced in the VS thn in the SPS: There ws significnt interction between group nd introrl loction of recording (P,.05; Tble 2). There were no significnt differences between CLP nd CLP-PSO when compring recordings tken t the SPS or VS (Tbles 4 nd 5). Frequencies of Plteus In terms of plteu frequencies recorded t the VS, there were significnt group-specific differences between CLP-PSO or CLP nd noncleft control subjects, but not between SPS recordings (Tble 3). Also t the VS, there ws no significnt difference when compring CLP-PSO nd CLP directly (Tble 5). Medin Plteu Height Likewise, there were significnt differences between control subjects nd CLP or CLP-PSO tht were more pronounced t the VS thn t the SPS (Tble 3). Medin Plteu Durtion The durtion of SPS plteus did not differ significntly between groups (P 5.47; Tble 3); however, VS plteu durtion did: There ws significnt interction between the group nd the introrl loction of recording (Tble 2). DISCUSSION While singulr pressure ssessments during sucking in infnts hve been performed previously, 4,13,24 this is, to the best of our knowledge, the first ttempt to provide introrl difference pressure recordings simultneously in two functionl comprtments (SPS nd VS) in noncleft nd CLP bbies. Min Outcomes While negtive introrl pressure levels hve been described erlier s being norml feture in newborns, 13 the new nd striking result of this study goes beyond this knowledge in tht there is formtion of two seprte comprtments (SPS, VS) creted by introrl soft tissue ctivity during swllowing nd suction, especilly in helthy, noncleft newborns, but lso, to minor degree, in CLP infnts (Tble 2). However, in contrst to the pttern of introrl comprtment formtion seen in subjects with norml occlusion permnent dentition, 17 with higher negtive pressures t the SPS thn t the vestibulum (VS), this

5 IMPACT OF DRINK PLATES ON CLP DEGLUTITION 319 Tble 3. Descriptive Anlysis of Single Pressure Curve Prmeters Recorded t the SPS nd VS Subpltl Spce (SPS) Vestibulr Spce (VS) Prmeter Control CLP CLP-PSO P Control CLP CLP-PSO P AUC Men , ,.01 SD Min Medin Mx IQR b Frequencies of peks (n) Men ,.01 SD Min Medin Mx IQR Medin pek height (mbr) Men , ,.01 SD Min Medin Mx IQR Frequencies of plteus (n) Men ,.01 SD Min Medin Mx IQR Medin plteu height (mbr) Men , ,.01 SD Min Medin Mx IQR Medin plteu durtion (s) Men ,.01 SD Min Medin Mx IQR Ech of the lst columns indictes the P vlues of globl group comprison. b Indictes interqurtile rnge. Tble 4. Subpltl Spce (SPS) Recordings: Pirwise Comprisons nd P Vlues of Those Prmeters Found to be Significnt in Globl Group Comprisons Prmeter CLP vs Control CLP-PSO vs Control CLP-PSO vs CLP AUC,.01, Medin pek height (mbr),.01, Medin plteu height (mbr),.01, Tble 5. Vestibulr Spce (VS) Recordings: Pirwise Comprisons nd P Vlues of Those Prmeters Found To Be Significnt in Globl Group Comprisons Prmeter CLP vs Control CLP-PSO vs Control CLP-PSO vs CLP AUC,.01, Frequencies of peks (n),.01, Medin pek height (mbr),.01, Frequencies of plteus (n),.01, Medin plteu height (mbr),.01, Medin plteu durtion (s),.01, There ws no significnt effect by PSO on ssessed pressure curve chrcteristics of CLP subjects.

6 320 KNÖSEL, FENDEL, JUNG, SANDOVAL, ENGELKE study found n infntile pttern of comprtment formtion tht ws inverted (Tble 3). Positive pressures were detected only on rre occsions nd on smll scle (Tble 3; Figure 3; wherein dt below 0 indicte positive pressures). This is likely due to the fct tht subjects were given pcifier, which triggers suction reflex, ie, genertion of negtive pressures. Null Hypothesis The null hypothesis of no significnt differences between introrl pressure chrcteristics ssessed t the VS nd t the SPS between groups CLP, CLP- PSO, nd non-clp control infnts ws rejected: Noncleft infnts were ble to generte significntly higher negtive pressures in both comprtments VS nd SPS compred with the mtched CLP group, nd there ws no significnt effect of PSO by drink pltes on the normliztion of deglutition in those subjects (Tbles 2 5). Inbility to generte negtive pressures is believed to be cused by n extrorl/introrl irwy shunt, nd the fct tht there ws no significnt difference following incorportion of drink plte my be simply tht those pltes do not sufficiently close this irregulr irwy gp, thereby preventing the genertion of negtive pressure in the SPS. However, genertion of negtive pressures t the pltl vult hs been demonstrted to be prerequisite both for stbilizing the tongue in physiologic position t rest nd for inititing physiologic sequence of deglutition in dolescents nd dults. 17,18 However, lthough we detected ptterns of comprtment formtion in helthy, non-clp infnts lthough t lower pressure levels (Tbles 2 nd 3; Figures 2 nd 3) negtive pressures were higher in the vestibulum thn in the pltl vult, hinting t potentil development nd inversion of ptterns of comprtment formtion following infncy, during childhood. Subjects All CLP subjects included in the study hd t lest cleft lip nd cleft plte. Tht is, lso during deglutition nd in contrst to noncleft peers (where there is posterior closure of the orl cvity by the bck of the tongue nd the soft plte during deglutition), there hve been bnorml extr-/introrl shunts between the orl cvity nd the nose in ll the CLP subjects. The first surgicl intervention in CLP infnts is usully t 6 months. Therefore, study subjects were between 4 nd 6months of ge, nd t the time of recording, they hd become ccustomed to PSOtherpy by pltes for bout 3 4 months. Tking into considertion tht the subjects did not yet hve teeth, differences in deglutition ptterns compred with subjects with developed dentition would hve been conceivble. 17,18 Nonetheless, functionl comprtment formtion s prmeterized by significntly different pressure recordings (SPS, VS) ws observed (Tble 2). Potentil Benefits of PSO The benefits of PSO in CLP therpy re subject to controversy. 12 Bsed on findings by retrospective studies, some uthors see dvntges of PSO therpy in terms of nrrowing the cleft width, thereby fcilitting subsequent surgery. 8 In contrst, other uthors found no ltertion of mxillry lveolr ridge shpe in CLP subjects treted with PSO compred with nontreted control group, while surgicl correction of cleft lips seemed to hve greter impct on rch dimensions thn did PSO. 12 PSO is often resoned by the postulte tht the tongue of CLP newborns needs to be trined to mintin posture considered to be physiologicl in order to support norml lnguge development: Bsed on sonogrphy nlyses of tongue movements nd postopertive rticultory function in CLP children ged bout 5 yers, Suzuki et l. concluded tht those subjects could not crete negtive pressure in the orl cvity, regrdless of previous presence or bsence of n orthopedic plte. 25 This finding is confirmed by the results of our study (Tble 3). However, they lso reported n improvement in tongue dynmics during sucking nd rticultion in subjects treted by PSO, which ws not substntited by our results (Tble 2 5). Likewise, other uthors found tht ingestion is not fcilitted or improved by PSO. 26 However, the bility to ingest food my vry s function of cleft plte extension nd loction. 14 Study Limittions CLP morphologies re subject to brod vrition. Therefore, generlizbility of single studies nd comprisons of study findings re impeded, eg, infnts with smller cleft pltes were ble to generte higher pressures during suction nd food intke compred with newborns with lrger clefts. 14 Hence, CLP vritions nd loctions my constitute sources of devition in pressure levels. In the present study, morphologicl differences between mlformtions were not considered seprtely during nlysis due to scrceness of the subjects. Although tril smple of 17 subjects with differently expressed CLPs could be collected within recruitment period of lmost 5 yers, this fctor needs to be considered s potentilly ffecting pressure levels.

7 IMPACT OF DRINK PLATES ON CLP DEGLUTITION 321 Figure 2. Introrl ctivity within the respective comprtments (SPS nd VS) is chrcterized by the qulity of pressure plteus (medin height, durtion, nd frequencies) nd by negtive pressure levels (re under the pressure curves) in the distinctive study groups.

8 322 KNÖSEL, FENDEL, JUNG, SANDOVAL, ENGELKE Figure 3. Exmples of pressure curves in the SPS nd VS in groups CLP, CLP-PSO, nd control. Although gret cre ws tken to ensure tht the children were sucking normlly, repeted introrl pressure recordings showed tht single pressure curve chrcteristics were subject to vrition (Tble 1), s lso reported previously by others. 17,21 23 Although sttisticl nlyses yielded significnt differences between pressure chrcteristics of the groups, the robustness of pressure prmeters needs to be considered in interpreting the dt. There is limittion in tht the CLP subjects were ccustomed to PSO therpy, nd the pttern of deglutition without the drink plte they were used to might be different from the swllowing pttern tht would hve developed in the bsence of PSO therpy. However, s PSO therpy in CLP subjects is stndrd in developed countries, further studies using CLP smple without PSO pretretment re needed to corroborte the findings of this study. CONCLUSIONS N Both noncleft nd CLP infnts generted negtive introrl pressures during suction, but pressure levels in the ltter were significntly lower. N Two seprte functionl comprtments (SPS nd VS) were formed by introrl soft tissues during swllowing nd suction, especilly in noncleft newborns, but lso, to minor degree, in CLP infnts. N Differences in pressure levels between noncleft nd CLP infnts were even more pronounced in the vestibulum thn in the SPS. N There ws no significnt effect of PSO by drink pltes on the normliztion of deglutition in CLP subjects. N In contrst to the pttern of introrl comprtment formtion seen in subjects hving normlly occluded permnent dentition with higher subpltl thn

9 IMPACT OF DRINK PLATES ON CLP DEGLUTITION 323 vestibulr negtive pressures, we found n inverted infntile pttern of comprtment formtion. N In terms of improving swllowing chrcteristics nd chieving physiologicl deglutition in CLP infnts, the use of drink pltes seems questionble. ACKNOWLEDGMENT We thnk Dr Nikolos Drtsinos, Dentistry Center, University of Bonn, Bonn, Germny, for providing us with the opportunity of crrying out mesurements during his CLP consulttion hour. REFERENCES 1. Melsen B, Stensgrd K, Pedersen J. Sucking hbits nd their influence on swllowing pttern nd prevlence of mlocclusion. Eur J Orthod. 1979;1: Melsen B, Attin L, Snturi M, Attin A. Reltionships between swllowing pttern, mode of respirtion, nd development of mlocclusion. Angle Orthod. 1987;57: Modéer T, Odenrick L, Lindner A. Sucking hbits nd their reltion to posterior cross-bite in 4-yer-old children. Scnd J Dent Res. 1982;90: Lindner A, Modéer T. Reltion between sucking hbits nd dentl chrcteristics in preschool children with unilterl cross-bite. Scnd J Dent Res. 1989;97: Shpir Y, Lubit E, Kuftinec MM, Borell G. The distribution of clefts of the primry nd secondry pltes by sex, type, nd loction. Angle Orthod. 1999;69: Vnders AP. Incidence of cleft lip, cleft plte, nd cleft lip nd plte mong rces: review. Cleft Plte J. 1987;24: Zeiger JS, Bety TH, Ling KY. Orl clefts, mternl smoking, nd TGFA: met-nlysis of gene-environment interction. Cleft Plte Crniofc J. 2005;42: Grcí Abubr AN, Drescher D. Development on the mxillry of ptients with unilterl totl cleft with the use of orthopedic plte. Two-dimensionl cst nlysis. Revist Colombin de Investigción en Odontologí. 2010;1: Prhl C, Kuijpers-Jgtmn AM, Vn t Hof MA, Prhl-Andersen B. Infnt orthopedics in UCLP: effect on feeding, weight, nd length: A rndomized clinicl tril (Dutchcleft). Cleft Plte Crniofc J. 2005;42: Kryzgn B, Guny Y, Gurbuzer B, Erkn M, Aty A. A preopertive pplince for newborn with cleft plte. Cleft Plte Crniofc J. 2009;46: Uzel A, Alprsln ZN. Long term effects of presurgicl infnt orthopedics in ptients with cleft lip nd plte: systemtic review. Cleft Plte Crniofc J. 2011;48: Adli N, Mrs M, Petrie A, Nor J, Sommerld B. Presurgicl orthopedics hs no effect on rchform in unilterl cleft lip nd plte. Cleft Plte Crniofc J. 2012;49: Lindner A. Mesurement of intr-orl negtive ir pressure during dummy sucking in humn newborn. Eur J Orthod. 1991;13: Reid J, Reilly S, Kilptrick N. Sucking performnce of bbies with cleft conditions. Cleft Plte Crniofc J. 2007;44: Lzrus DD, Hudson DA, Fleming AN, Goddrd EA, Fernndes DB. Are children with clefts underweight for ge t the time of primry surgery? Plst Reconstr Surg. 1999;103: Mew JRC. The posturl bsis of mlocclusion: philosophicl overview. Am J Orthod Dentofcil Orthop. 2004;126: Engelke W, Jung K, Knösel M. Intr-orl comprtment pressures: biofunctionl model nd experimentl mesurements under different conditions of posture. Clin Orl Invest. 2011;15: Fränkel R. Die Dynmik des interokkluslen Unterdruckes. Dtsch Zhnrztl Z. 1967;22: Jung K, Engelke W, Knösel M. Sttisticl signl processing methods for intr-orl pressure curve nlysis in orthodontics. Eur J Orthod. 2011;34: Brunner E, Domhof S, Lnger F. Nonprmetric Anlysis of Longitudinl Dt in Fctoril Experiments. New York:Wiley; 2002: Dy AJ, Foster TD. The mesurement of vritions in introrl ir pressure. Angle Orthod. 1970;40: Thüer U, Sieber R, Ingervll B. Cheek nd tongue pressures in the molr res nd the tmospheric pressure in the pltl vult in young dults. Eur J Orthod. 1999;21: Kieser J, Singh B, Swin M, et l. Mesuring introrl pressure: dpttion of dentl pplince llows mesurement during function. Dysphgi. 2008;23: Lindner A, Hellsing E. Cheek nd lip pressure ginst mxillry dentl rch during dummy sucking. Eur J Orthod. 1991;13: Suzuki K, Ymzki Y, Sezki K, Nkkit N. The effect of preopertive use of n orthopedic plte on rticultory function in children with cleft lip nd plte. Cleft Plte Crniofc J. 2006;43: Msrei AG, Wde A, Mrs M, Sommerld BC, Sell D. A rndomized control tril investigting the effect of presurgicl orthopedics on feeding in infnts with cleft lip nd/or plte. Cleft Plte Crniofc J. 2007;44: