Originl Article Interction between deglutition, tongue posture, nd mlocclusion: A comprison of introrl comprtment formtion in subjects with neutrl occlusion or different types of mlocclusion Michel Knösel ; Crolin Nüser b ; Klus Jung c ; Hns-Jochim Helms d ; Wilfried Engelke e ; Pulo Sndovl f ABSTRACT Objective: To test the null hypothesis of no significnt difference in terms of introrl pressure curve chrcteristics ssessed simultneously t the subpltl spce (SPS) nd the vestibulr spce (VS), during different orl postures, between four groups with either n Angle Clss II/1 (II1), Angle Clss II/2 (II2), nterior open bite (O) mlocclusion, or neutrl occlusion control group (I). Mterils nd Methods: Introrl pressure recordings were performed simultneously in the VS nd SPS of 69 consecutive subjects (n II1 5 15; n II2 5 17; n O 5 17; n I 5 20; men ge/stndrd devition 18.43/6.60 yers). Assessments included defined sections of open mouth posture (OMP, 30 seconds), nteriorly closed mouth condition (60 seconds), dynmics by tongue-repositioning mneuver (TRM, 60 seconds), swllowing, nd positive pressure genertion (, 10 seconds). Interctions of mlocclusion, comprtment loction, nd posture on pressure curve chrcteristics were nlyzed by Kruskl-Wllis nd Mnn-Whitney U-tests, dopting n level of 5%. Results: Globlly significnt group differences were detected t the VS (plteu durtion nd medin pek heights during TRM; re under pressure curve [AUC] during ) nd SPS (AUC during TRM nd ). Subjects with nteriorly nonopen dentl configurtions (groups I nd II2) were ble to keep negtive pressure levels t the VS for longer time periods during TRM, compred to groups O nd II1. Conclusions: The null hypothesis ws rejected for men VS plteu durtions nd pek heights nd for SPS AUC. Negtive pressures t the VS my stbilize outer soft tissues pssively nd my explin the dentl rch form shping effect by mimic muscles. (Angle Orthod. 2016;86:697 705.) KEY WORDS: Tongue posture; Deglutition; Norm-occlusion; Mlocclusion; Introrl pressure; Orl posture Professor, Deprtment of Orthodontics, University Medicl Center Göttingen, Göttingen, nd Privte Prctice, Hmburg, Germny; nd Visiting Professor, Deprtment of Orthodontics, Universidd de L Fronter, Temuco, Chile. b Reserch Fellow, Dentist, Privte Prctice, Itzehoe, Germny. c Biosttisticin, Professor, Deprtment of Medicl Sttistics, University Medicl Center Göttingen, Göttingen, Germny; nd Institute for Animl Breeding nd Genetics, University of Veterinry Medicine Hnnover, Hnnover, Germny. d Biosttisticin, Reserch Assistnt, Deprtment of Medicl Sttistics, University Medicl Center Göttingen, Göttingen, Germny. e Professor, Deprtment of Mxillofcil Surgery, Universidd de L Fronter, Temuco, Chile. f Professor, Deprtment of Peditrics nd Orthodontics, Universidd de L Fronter, Temuco, Chile. Corresponding uthor: Professor Dr Michel Knösel, Lübecker Str. 128, 22087 Hmburg, Germny (e-mil: mknoesel@yhoo.de) INTRODUCTION The cuse of mlocclusion is widely ccepted to be multifctoril nd includes genetic fctors s well s hbits, dietry preferences, hbitul orl or tongue posture, nd swllowing chrcteristics. 1 4 While most of the theories ccept genetics s the min or underlying cuse, the importnce of locl or environmentl fctors, such s orl posture nd orl soft tissue chrcteristics, is lso widely ccepted, s these fctors cn hve both deteriorting nd enhncing influence. The fct tht muscle wekness Accepted: December 2015. Submitted: October 2015. Published Online: Februry 24, 2016 G 2016 by The EH Angle Eduction nd Reserch Foundtion, Inc. DOI: 10.2319/101615-699.1 697
698 KNÖSEL, NÜSER, JUNG, HELMS, ENGELKE, SANDOVAL is connected with the increse of verticl growth is generlly greed upon. 4 In ddition, ptients with hbitul open mouth posture were identified s hving significntly reduced growth of the mxillry rch. 5 The detrimentl influence of deviting tongue posture on the formtion of mlocclusion hs been underlined by Hrvold et l., 6 who displced the tongue of rhesus monkeys from its norml posture nd subsequently recognized extensive occlusl nd skeletl chnges. Another study 7 in children with unilterl posterior crossbite lso showed, using three-dimensionl ultrsound, tht tongue posture is n importnt fctor in the development of mlocclusions. However, evidence tht tongue dynmics nd resting postures re functionl fctors is still scrce, s it is difficult to chieve rel-time prmeteriztion of introrl soft tissues. 4 Approches involving the use of mgnetic resonnce imging, or even rdiogrphic methods, involve ethicl issues. 8 A noninvsive method of ssessing tongue posture during function is the use of the introrl mnometry technique. 9 12 This technique is bsed on the concept of the biofunctionl model of the orl cvity, combining spects from ntomy, dentistry, nd otorhinolryngology. 13 It describes biofunctionl comprtments or spces tht typiclly form during deglutition, speech, nd t respirtory resting posture in norm-occlusion subjects: These re the vestibulr spce (VS) nd the subpltl spce (SPS). 14 The first spce (VS) is limited by the cheeks, lips, nd the lterl nd bse of the tongue nd is defined s the spce surrounding the dentl rches. The ltter spce (SPS) is limited by the dorsum of the tongue nd the center of the hrd plte. Formtion of negtive pressure t the SPS s well s differentition of the two functionl introrl soft tissue comprtments hve been reported 11,13 to be prerequisite for the initition of the physiologicl ct of degluttion. The type of swllowing hs been shown 1 4 to hve n impct on norml or deviting occlusl nd dentofcil development. In order to chieve deeper understnding of orofcil biofunctions nd to better explin previously detected significnt interctions between deglutition, orl posture, nd mlocclusions, the im of the present study ws to ssess the introrl pressure curve chrcteristics t the VS nd SPS of groups of subjects with different occlusl trits (neutrl occlusion, Angle Clss II/1, Angle Clss II/2, nd open bite mlocclusion), t rest nd during different orl postures nd functionl mneuvers. We tested the null hypothesis tht there is no significnt difference in terms of pressure curve chrcteristics t the VS nd SPS during functioning between them. MATERIALS AND METHODS Subjects The study received the full pprovl of the locl ethics committee (No. 27/7/09). Sixty-nine subjects (mle/femle 5 29/40; men ge/stndrd devition [SD] 5 18.43/6.60 yers; Tble 1) were consecutively recruited by one ssessor t two centers (University of Göttingen, Germny; Privte Prctice, Itzehoe, Germny), ccording to the inclusion nd exclusion criteri presented in Tble 1. Within the time period of July 1, 2009, to October 31, 2012, initil dignostic plster csts of ll new ptients were screened. Bsed on their occlusl trits, subjects were ssigned to one of four mlocclusion groups. The definitions nd compositions of those groups re provided in Tble 1, s follows: group l, normocclusion subjects; groups II1 nd II2, subjects chrcterized by n Angle Clss II/1 or II/2 mlocclusion nd cliniclly proclined (II1) or reclined incisors (II2); nd group O, subjects chrcterized by n nterior open bite of lest of 1 mm. Mterils nd Methods Recordings of different pressures t the interocclusl or VS nd t the SPS were performed chirside, with the hed in the nturl position, by single opertor (C.N.). A digitl precision pressure meter (GMH3156; with two piezo-resistnt reltive pressure sensors GMSD350MR; mesuring rnge/resolution 500/0.1 mbr (rel); softwre: GSOFT3050; Greisinger, Regenstuf, Germny) ws connected by flexible polyvinyl chloride tubes (4-mm inside dimeter) to the VS nd SPS. A thin flexible cp of venous ctheter (Brun, Melsungen, Germny) served s the end piece t the SPS; it ws threded through the dentl rches. A dentl suctor s end cp ws ttched to the VS tube nd plced lterl to the premolr region (VS) in order to void blocking by soft tissues (Figure 1). Definition of Orl Postures During Recordings Mesurements were repeted three times with ech prticipnt. Ech pressure recording cycle lsted for 3 minutes nd ws divided into six sections or stges: Prticipnts were instructed to perform different mneuvers or to dopt defined orl postures (Tble 2). Ech prticipnt ws crefully instructed nd trined prior to inititions of the recordings. Sttisticl Anlysis The first nd the lst 5 seconds of ech ssessment intervl were cut in order to receive mesurements t
ORAL POSTURE AND MALOCCLUSION 699 Tble 1. Definition of Inclusion Criteri, Subject nd Group Chrcteristics, nd Numbers of Included nd Excluded Subjects, With Resons Group I II1 II2 O All Generl inclusion Absence of gps in upper or lower dentl rches criteri N Absence of common colds, cough, coryz, or ny other helth conditions tht would ffect or impede nsl respirtion or mouth brething N Willingness nd bility to comply with nd follow instructions during pressure ssessments N Completed mixed dentition stge 1 (full eruption of ll permnent incisors nd first molrs) or complete permnent dentition Generl exclusion N Gps within either of the dentl rches (eg, by missing deciduous teeth) criteri N Orthodontic tretment history Group-specific inclusion criteri Men ge, y (SD) [minimum; mximum] Potentilly eligible subjects (n) Excluded subjects (n), with resons Included subjects (n) Norm-occlusion without side shift or crossbites nd with verticlly nd sgittlly wellsupported incisors without mjor crowding.2 mm 26.93 (7.51) [23.2; 57.8] Angle Clss II mlocclusion of lest of ½ cusp of distl molr nd cnine reltion nd cliniclly proclined incisors 11.41 (1.54) [8.1; 14.3] Angle Clss II mlocclusion of lest of ½ cusp of distl molr nd cnine reltion nd cliniclly reclined incisors 19.82 (9.55) [10.1; 35.5] Negtive overbite (open bite) of lest of 21 mm; 15.56 (7.79) [8.4; 37.6] 20 19 19 21 79 0 Gps in dentl rch: n 5 2 Unwilling to cooperte n 5 2 20 (mles/femles: n 5 9/11) 15 (mles/femles: n 5 8/7) Gps in dentl rch: n 5 2 17 (mles/femles: n 5 6/11) Gps in dentl rch: n 5 4 17 (mles/femles: n 5 6/11) (Angle Clss I: n 5 5 Angle Clss II: n 5 11 Angle Clss III: n 5 1) 18.43 (6.60) [8.1; 57.8] 10 69 (mles/femles: n 5 29/40) rest. Different prmeters were extrcted from the recorded pressure curves in order to ssess the influence of the fctors of mlocclusion (groups I, II1, II2, nd O) nd locliztion of introrl comprtment (VS, SPS) seprted by six sections. These were the re under the curve (AUC), frequencies nd medin heights (mbr) of swllowing peks (defined s chnge of pressure of 5 or more mbr in less thn 1 second nd second chnge [decrese] within 5 seconds), pressure plteus of.5 seconds, nd medin plteu durtion (seconds). Signl extrction ws implemented using methodology proposed previously. 14 Extrcted curve prmeters of ll mlocclusion groups were globlly compred by ssessment section nd comprtment loction using the Kruskl- Wllis test. In cse of significnt differences, pirwise comprisons of mlocclusion groups nd ssessment sections were implemented, seprtely for the VS or SPS comprtment, using Mnn-Whitney U-tests. All nlyses were performed using the softwre R (www.r-project.org), dopting n level of.05. Method Error Repeted introrl pressure mesurements hve been reported 10,12,13,15 to be subject to vrition. Therefore, introrl mesurements were repeted three times with ech prticipnt in order to test the robustness of the distinctive prmeters. Repetedmesures nlysis of vrince ws used per curve chrcteristic to evlute whether there ws significnt effect of the replictes or n individul 3 replicte interction. No significnt effects were detected by the mesurement replictes (P..05 for ech curve chrcteristic). Therefore, the three replictes per individul were verged prior to further nlysis. RESULTS Mens nd stndrd devitions of ll extrcted curve prmeters re given seprtely for the VS nd the SPS comprtment mesurements in Tble 3. Subjects with nteriorly nonopen dentl configurtions (groups I nd II2) were ble to keep negtive pressure levels t the VS for longer time periods during the tongue-repositioning mneuver (TRM), compred to
700 KNÖSEL, NÜSER, JUNG, HELMS, ENGELKE, SANDOVAL Figure 1. Schemtic of the experimentl setup. groups O nd II1. Globl comprisons of ll four mlocclusion groups yielded the result of significnt differences in terms of SPS vs plteu durtion during TRM; these were due to differences between the subjects of groups I nd II2 nd those of group O (Tbles 4 nd 5). Tble 6 depicts results of comprisons of VS nd SPS mesurements. DISCUSSION Successful correction of mlocclusion nd long-term stbility of chieved occlusions is widely ccepted to be enhnced by the bsence of orl dysfunction nd posturl hbits, such s hbitul open mouth postures, or swllowing ptterns chrcterized by tongue thrust movements. 2,4,5,11,16 The objective of the present study ws therefore to screen introrl soft tissue dynmics nd prmeterize tongue posture during swllowing considered to be norml. 13 Tht is, in terms of the presence or bsence of incisor contct during occlusion, two of the groups (II1 nd O) were chrcterized by either verticlly or sgittlly open incisor sitution, while the two other groups (I nd II2) were not. The null hypothesis tht there is no significnt difference in terms of introrl pressure curve chrcteristics ssessed t the VS nd SPS during function between the groups with different occlusl trits ws thus rejected for men plteu durtions ssessed t the VS (groups I nd II2 compred to group O) during section TRM (Tble 3) nd for AUC ssessed t the SPS during TRM (Tble 4; group I significntly incresed compred to group II2 [Tble 5]). Robustness of the Method Some vrition in repeted, intrindividul, introrl pressure recordings hs been previously reported by severl groups. 10,12,13,15 Three-time repeted ssessments yielded no significnt intrindividul differences, nd the replictes were Tble 2. Definition nd Durtions of Sections of Pressure Recordings Section No. Description (Abbrevition) Durtion (s) Instruction Given to Subjects During Recording 1 Open mouth condition (OMP) 0 30 To slightly open the lips nd to brethe normlly 2 Anteriorly closed condition (ACC) 31 90 To gently close their lips nd to continue brething normlly 3 Tongue-repositioning mneuver (TRM) 13 91 150 To collect sliv, then to swllow nd to subsequently keep on brething normlly for 60 s 4 Swllowing (SW) 151 155 To swllow sliv nd keep on brething normlly for nother 5 s 5 Positive pressure condition () 156 160 To crete positive introrl ir pressure by inflting cheeks 6 Testing for sliv-blocked cnnuls: relpse to environmentl pressure? (T) 161 165 To remove introrl cnnuls/sensors; recordings proceeded for 5 s
ORAL POSTURE AND MALOCCLUSION 701 verged for further nlysis in order to improve the robustness of pressure prmeters. Furthermore, section T ssessments were used s n dditionl control in terms of ssessing potentil blocking of the cnnule by sliv: There ws relpse to tmospheric mbient pressure following removl of the cnnule from the orl cvity (Tble 3), indicting the presence of no or only few sliv, with no significnt differences between the test groups nd cnnule (Tbles 4 nd 5). Are Under the Curve Considering the overll generted negtive pressure, s represented by the AUC, more negtive pressure ws noted for the SPS compred to the VS (Tble 3). This feture pplied to both norm-occlusion nd mlocclusion subjects nd thereby prtilly confirms the outcome of previous study 13 on introrl comprtment formtion in norm-occlusl subjects. The globl comprison of the AUC vlues between the four study groups yielded significnt differences for the positive pressure () section, seprtely for comprtments SPS nd VS (Tble 4). In both comprtments, these globl group differences were due to significnt differences during between the subjects of groups I nd II1 nd those of the open bite group O (Tbles 3 nd 5). Also, AUC t the SPS ws globlly significnt during section TRM (Tble 4), nd this ws due to formtion of significntly more negtive SPS pressures in group I, compred to ssessments in group II2 (Tble 5). Frequencies of Peks nd Plteus Frequencies of peks nd plteus nd the medin plteu durtion cn be considered representtive fetures of introrl soft tissue dynmics of the two functionl comprtments. However, we did not detect significnt differences in the globl comprison of mesurements mde t the cheek (VS) or t the SPS for frequencies of peks or plteus (Tble 4). Tht is, quntities of swllowing ctivities re similr for subjects with norm-occlusion nd mlocclusion nd do not seem to interct with presence of mlocclusion. Medin Pek Height Globl comprison of VS mesurements yielded significnt results for the TRM (Tble 4). Further splitting by intergroup comprisons in section TRM yielded significnt differences for group I (Figure 2) compred to group O nd for group II1 compred to group O (Tble 5). Averge negtive swllowing peks t the VS were significntly higher in subjects of groups I nd II1 (234.5 to 239.6 mbr) compred to those of group O (224.4 mbr; Tble 5). Thus, medin swllowing pek height is not seen s feture tht is clerly ssocited with the presence or bsence of mlocclusion. Compring pressures levels in both comprtments, medin pek height ws, in generl, more negtive t the SPS compred to the VS, with exceptions mde for group I (sections open mouth condition [OMP] nd nteriorly closed condition [ACC]) nd group O (section OMP; Tble 3). Tht is, in terms of qulity of swllowing ctivities, the typicl pttern of more negtive pressures t the SPS seen in normocclusion subjects 13 is lso seen in mjority of mlocclusion subjects. Medin Plteu Height nd Durtion No significnt differences were seen for globl comprisons between medin plteu heights t the VS or SPS of the vrious groups (Tble 4). However, globl, seprte considertion of VS pressures did yield significnt differences in terms of medin plteu durtion yielded during section TRM (Tble 4), nd these were due to differences between norm-occlusion nd open bite subjects nd were lso due (Figure 2) to those differences between group II2 nd group O (Tble 5). Men VS plteu durtions of groups I nd II2 were distinctively longer (37.6 38.5 seconds) compred to those of group O (23.2 seconds), nd, though not significnt, were lso longer in comprison to those of group II1 (25 seconds; Tble 3). This seems to confirm the results of previous study, 17 in which single mesurements t the vestibule yielded the result of longer plteu durtions for subjects with Angle Clss II/2 mlocclusion, compred to normocclusion subjects. The formtion of negtive pressures t the SPS hs been shown erlier to be prerequisite for the initition of deglutition. Thus, we interpreted our findings to indicte tht SPS negtive pressures re comprble for the vrious groups with different occlusl trits nd do not seem to be ffected by the presence or bsence of mlocclusion. However, significnt differences in terms of negtive pressures ssessed t the VS indicte cler tendency tht subjects with nteriorly nonopen dentl configurtions (groups I nd II2), in contrst to verticlly or sgittlly open incisor configurtions (s in groups O nd II1) re ble to keep negtive pressure levels t the VS for longer time periods. These negtive VS pressures re ssumed to stbilize the soft tissues of the cheeks nd lips physiclly nd pssively, especilly during bsence of neuromusculr ctivity. This type of pssive stbiliztion my, in turn, contribute to the explntion of the dentl rch form shping effect of soft tissues.
702 KNÖSEL, NÜSER, JUNG, HELMS, ENGELKE, SANDOVAL Tble 3. Men 6 Stndrd Devition of Negtive Pressure Chrcteristics, Seprtely for Section nd Group, in the Mesurements t the Vestibulr Spce (VS; Cheek) nd Subpltl Spce (SPS). Durtion of Stges 4, 5, nd 6 (Swllowing [SW], Positive Pressure [], nd Test Stge [T]) Did Not Allow for n Assessment of Pek nd Plteu Fetures Peks (n) Medin Pek Height (mbr) Plteu Frequencies (n) Section Group VS SPS VS SPS VS SPS OMP I 0.1 6 0.2 0.2 6 0.4 25.3 6 23.9 16.3 6 16.6 0 6 0.1 0 6 0 OMP II1 0.3 6 0.4 0.3 6 0.3 14.5 6 10.6 20.6 6 15.1 0 6 0.2 0.1 6 0.3 OMP II2 0.2 6 0.3 0.3 6 0.4 12.9 6 9.8 39 6 31.8 0 6 0.1 0.2 6 0.4 OMP O 0.2 6 0.4 0.3 6 0.7 13.1 6 4.1 12.9 6 4.4 0 6 0 0.1 6 0.3 ACC I 1 6 0.7 1.1 6 0.9 28.7 6 20.9 25.8 6 11.9 0.2 6 0.4 0.1 6 0.3 ACC II1 1.7 6 1.1 1.8 6 0.9 31.3 6 14.4 37 6 21.3 0.6 6 0.7 0.6 6 0.9 ACC II2 1.1 6 1 1.2 6 0.9 19.6 6 8.8 28.4 6 27.2 0.4 6 0.8 0.5 6 0.6 ACC O 1 6 0.9 1.3 6 1 19.3 6 13.5 35 6 32.9 0.4 6 0.8 0.6 6 0.9 TRM I 1.7 6 0.6 1.8 6 0.6 34.5 6 23.3 50 6 30.1 1 6 0.6 1.3 6 1 TRM II1 2 6 1.1 2.1 6 0.8 39.6 6 22.6 46.2 6 34.8 1.4 6 1.2 1.3 6 1.1 TRM II2 1.5 6 1 1.6 6 0.9 24.6 6 17.5 32.2 6 30.8 0.7 6 0.9 0.8 6 0.8 TRM O 1.4 6 0.8 1.6 6 0.9 24.4 6 25.5 40.2 6 51.1 0.8 6 0.9 1.1 6 0.9 SW I SW II1 SW II2 SW O I II1 II2 O T I T II1 T II2 T O OMP indictes open mouth condition; ACC, nteriorly closed condition; TRM, tongue-repositioning mneuver; O, nterior open bite occlusion; nd I, neutrl occlusion (control). Differentition of Comprtments VS nd SPS The use of two different end pieces for VS nd SPS hs been proved previously to not hve n influence on enbling pressure mesurements. 17 The dimeter of the tube hs no influence on ssessed pressures nd is owed insted to the ntomicl sitution (ie, prevention of blocking of soft tissues by the suctor end cp nd smll dimensions of the SPS cnul to enble teeth contcts during mesurements). In section OMP, ll groups showed differentition of comprtments, s evident by significnt differences in the AUC ssessed t the VS nd SPS (Tble 6). The negtive pressure in the VS cn be explined by subjects subconsciously sucking on the dentl suctor cp, perhps including some buccintor ctivity. In ddition, norm-occlusion subjects showed differentition of comprtments in section ACC, s evident by the significntly different VS SPS pressure plteu durtions in contrst to those of subjects with ny type of mlocclusion. Limittions The inclusion criterion of no orthodontic tretment history my hve contributed to decresed men ge of group II1 subjects, compred to those of the other groups. This ws due to the difficulties in finding Tble 4. P-Vlues for the Globl Comprison (All Four Mlocclusion Groups), Seprted by Section, in the Mesurements t the Vestibulr Spce (VS) nd Subpltl Spce (SPS). Bold Vlues Indicte Significnce Peks (n) Medin Pek Height (mbr) Plteus (n) Medin Plteu Height (mbr) Durtion of Plteus (s) Are Under the Curve Stge VS SPS VS SPS VS SPS VS SPS VS SPS VS SPS OMP.07.3.9.4.6.2.41.09.3.7.06.4 ACC.2.2.1.5.3.09.45.48.9.1.5.3 TRM.4.2.045.1.1.3.77.058.039.2.06.049 SW.9.9.04.0015 T.3.4 OMP indictes open mouth condition; ACC, nteriorly closed condition; TRM, tongue-repositioning mneuver; SW, swllowing;, positive pressure; nd T, test stge.
ORAL POSTURE AND MALOCCLUSION 703 Tble 3. Extended. Medin Plteu Height (mbr) Durtion of Plteus (s) Are Under the Curve VS SPS VS SPS VS SPS 5.9 6 NA 11.5 6 NA 9.1 6 14.9 14.2 6 12.1 9.6 6 NA 14.1 6 13 14.5 6 NA 14.7 6 11.5 11.9 6 13.5 33.5 6 73.2 11.8 6 8 37.9 6 23 17 6 2.8 20.8 6 9.5 15.3 6 25.7 96.6 6 245.7 9.8 6 3.9 18.6 6 9.1 7.5 6 7.6 25.8 6 34.3 9.6 6 4.6 7.7 6 3 20.1 6 2.5 13.9 6 2.1 73.1 6 61.1 67.9 6 43.7 14.5 6 7.5 17.3 6 14.5 24 6 12.8 24.3 6 5.2 180.2 6 199 219.8 6 256.4 10.7 6 4.5 19.6 6 27.2 20.9 6 9.6 19 6 8.6 105.8 6 137.9 256.2 6 585.8 15.9 6 9.5 12.3 6 6.9 22.7 6 6.2 21.8 6 10.2 127.9 6 198.4 179.7 6 247.2 20.9 6 17.6 34.7 6 24.4 38.5 6 17.6 35.4 6 16.4 539 6 483.3 871.8 6 810.7 21.1 6 11 29.4 6 18.3 25 6 14.4 22.1 6 9.1 444.1 6 387.8 637 6 619.5 15.9 6 9.1 18.4 6 24.6 37.6 6 16.2 28.1 6 18.2 249 6 304.5 342.1 6 666.3 21.6 6 21.3 31.1 6 44.4 23.2 6 9.3 28.6 6 15.5 349.2 6 592.1 678.2 6 1285.8 45.1 6 49.3 49.2 6 45.3 57.4 6 58.5 72.2 6 88.2 34.9 6 29 48.4 6 59.5 48.8 6 54.1 63.4 6 95 0.2 6 0.7 0.1 6 0.2 6.7 6 19.5 3.8 6 6.3 1.3 6 3.1 1.9 6 3.7 3.3 6 9.2 4.1 6 13.8 0.9 6 0.4 1.2 6 0.7 1 6 1.3 1 6 1.3 0.7 6 0.6 1.5 6 3.1 1.6 6 2.2 1.4 6 2 sufficient numbers of untreted Angle Clss II/1 dolescents or dults within the recruitment period who were lso willing to prticipte in the study. In ddition, the incresed ge rnge of group I subjects compred to those of the mlocclusion groups my explin some of the results tht were found to be chrcteristic in tht group. Although there seems to be controversy in the literture regrding whether there re 18,19 or re not 20 ge-relted chnges in terms of lip nd tongue pressuresor not, no relible dt seem to be vilble on potentil ge-relted chnges in introrl comprtment formtion between predolescents, dolescents, nd dults. However, the swllowing pttern my be subject to chnge within this time period, nd this needs to be considered s possible limittion to the generlizbility of our study findings. With regrd to the testing procedures, we omitted multiple testing corrections delibertely in order to void flse negtives. This study ims t generting Tble 5. P-Vlues for Pirwise Comprisons of All Four Groups, Seprted by Section, for Mesurements t the Vestibulr Spce (VS) nd Subpltl Spce (SPS). Only Those Sections Tht Hve Been Identified s Being Significnt in Globl Comprisons Hve Been Given (See Tble 4). Bold Vlues Indicte Significnce Peks Medin Pek Height Plteus Medin Plteu Height Durtion of Plteus Are Under the Curve Section Group VS SPS VS SPS VS SPS VS SPS VS SPS VS SPS TRM I vs II1.5.2.5.6.4.97.4.8.06.03.5.4 TRM I vs II2.2.3.2.03.03.09.9.02.81.2.02.006 TRM I vs O.3.5.04.045.3.6.9.11.0196.3.02.07 TRM II1 vs II2.17.07.06.3.06.2.3.049.09.7.18.2 TRM II1 vs O.2.1.02.3.2.8.5.1.95.3.28.6 TRM II2 vs O.97 0.9.5.9.5.2.9.5.038.7.7.4 I vs II1.017.001 I vs II2.14.003 I vs O.01.0003 II1 vs II2.3.5 II1 vs O.9.8 II2 vs O.3.9 TRM indictes tongue-repositioning mneuver;, positive pressure; O, nterior open bite occlusion; nd I, neutrl occlusion (control).
704 KNÖSEL, NÜSER, JUNG, HELMS, ENGELKE, SANDOVAL Tble 6. P-Vlues for Comprison of Mesurements t the VS nd SPS, Seprtely for Section nd Group Section Group Peks (n) Medin Pek Height (mbr) Plteus (n) Medin Plteu Height (mbr) Durtion of Plteus (s) Are Under the Curve OMP I.3.6.3.002 OMP II1.8.3.3.6.6.04 OMP II2.5.08.4.06.5.03 OMP O.4.9.07.004 ACC I.9.9.7.6.01.9 ACC II1.7.5.7.8.3.5 ACC II2.58.9.5.6.7.3 ACC O.4.1.4.7.6.1 TRM I.6.09.5.06.8.3 TRM II1.6.8.8.3.8.4 TRM II2.6.7..4.2.4 TRM O.6.2.3.9.5.2 SW I.8 SW II1.7 SW II2.8 SW O.8 I.8 II1.7 II2.3 O.8 T I.05 T II1.98 T II2.96 T O.6 OMP indictes open mouth condition; ACC, nteriorly closed condition; TRM, tongue-repositioning mneuver; SW, swllowing;, positive pressure; O, nterior open bite occlusion; nd T, test stge. pool of importnt findings tht might help us to design further studies. Thus, we ccept flse-positive findings, with which we cn better cope (compred with flse-negtives). Sttisticl testing ws pplied to chieve rnking vi P-vlues for individul curve prmeters nd findings. Clinicl Implictions Formtion of introrl negtive pressure is essentil for swllowing. 11,13 This study tried to ddress the question of how this pressure cn be chieved in the presence of mlocclusions tht re typiclly ccompnied by tongue posture between the teeth rther thn ginst the plte, such s in the cse of nterior open bites or Angle Clss II/1 mlocclusions. The men VS plteu durtions of groups I nd II2 were distinctively longer thn those of groups O nd II1. The fct tht there were no significnt differences in terms of negtive SPS pressure formtion between the different occlusion groups my be interpreted to Figure 2. A C. Distribution of medin pressure plteu durtion t the VS nd SPS during ACC (A) nd t the VS during TRM (B) nd medin pek heights t the VS during TRM (C).
ORAL POSTURE AND MALOCCLUSION 705 represent the effect tht occurs when subjects of groups O nd II1 crete sel by pressing the mrgins of their tongues ginst their teeth during suction, potentilly supported by n dditionl contrction of the buccintor ginst the teeth, in order to prevent n ingress of ir between the teeth. 20,21 It is suggested tht the development of correct tongue-to-plte swllowing pttern my form nd widen the dentl rches during crniofcil development to suit the tongue, while persistence of swllowing pttern tht includes pressing of the tongue between the teeth my not. 3 This would explin the triggering of the development nd persistence of open bites nd Angle Clss II/1 mlocclusions in some subjects nd would be substntited by our finding tht subjects with the verticlly or sgittlly open incisor configurtions in groups O nd II1 seem to be unble to keep negtive pressure levels t the VS for longer time periods. Therefore, our findings seem to support the point of view tht trining of tongue postures my be promising bsis for the correction of mlocclusions. Future reserch will ddress differences in comprtment formtion between low nd high muscle tone groups. Introrl pressure recordings re considered useful dignostic tool in the screening for the progression of such preorthodontic exercises. CONCLUSIONS N The null hypothesis ws rejected for men VS plteu durtions nd pek heights nd for SPS AUC. N Nonopen dentl configurtions (groups I nd II2) seem to enble longer negtive pressure levels t the VS, in contrst to verticlly or sgittlly open incisor configurtions (groups O nd II1). REFERENCES 1. Melsen B, Stensgrd K, Pedersen J. Sucking hbits nd their influence on swllowing pttern nd prevlence of mlocclusion. Eur J Orthod. 1979;1:271 280. 2. Melsen B, Attin L, Snturi M, Attin A. Reltionships between swllowing pttern, mode of respirtion, nd development of mlocclusion. Angle Orthod. 1987;57:113 120. 3. Fujiki T, Inoue M, Miywki S, Ngski T, Tnimoto K, Tkno-Ymmoto T. Reltionship between mxillofcil morphology nd deglutitive tongue movement in ptients with nterior open bite. Am J Orthod Dentofcil Orthop. 2004;125:160 167. 4. Mew JRC. The posturl bsis of mlocclusion: philosophicl overview. Am J Orthod Dentofcil Orthop. 2004;126: 729 738. 5. Kiliridis S, Mejersjo C, Thilnder B. Muscle function nd crnio-fcil morphology: clinicl study in ptients with myotonic dystrophy. Eur J Orthod. 1989;11:131 138. 6. Hrvold EP, Chierier G, Vrgervik K. Experiments on the development of dentl mlocclusion. Am J Orthod. 1972;61: 38 44. 7. Volk J, Kdivec M, Music MM, Ovsenik M. Three-dimensionl ultrsound dignostics of tongue posture in children with unilterl posterior crossbite. Am J Orthod Dentofcil Orthop. 2010;138:608 612. 8. Engelke W, Glombek J, Psychogios M, Schneider S, Ellenberger D, Sntnder P. Displcement of orophryngel structures during suction-swllowing cycles. Eur Arch Otorhinolryngol. 2014;271:1987 1997. 9. Knösel M, Fendel C, Jung K, Sndovl P, Engelke W. Presurgicl orthopedics by drink pltes does not significntly normlize deglutition in infnts with cleft lip nd plte. Angle Orthod. 2015;[Epub hed of print]. 10. 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: 299 309. 11. Fränkel R. Die dynmik des interokkluslen unterdruckes. Dtsch Zhnrztl Z. 1967;22:282 290. 12. Kieser J, Singh B, Swin M, et l. Mesuring introrl pressure: dpttion of dentl pplince llows mesurement during function. Dysphgi. 2008;23:237 243. 13. Engelke W, Jung K, Knösel M. Intr-orl comprtment pressures: biofunctionl model nd experimentl mesurements under different conditions of posture. Clin Orl Investig. 2011;15:165 176. 14. Jung K, Engelke W, Knösel M. Sttisticl signl processing methods for intr-orl pressure curve nlysis in orthodontics. Eur J Orthod. 2011;34:574 582. 15. Dy AJ, Foster TD. The mesurement of vritions in introrl ir pressure. Angle Orthod. 1970;40:45 50. 16. Proffit W. Equilibrium theory revisited: fctors influencing position of the teeth. Angle Orthod. 1987;48:175 185. 17. Knösel M, Jung K, Kinzinger G, Buss O, Engelke W. A controlled evlution of orl screen effects on intr-orl pressure curve chrcteristics. Eur J Orthod. 2010;32: 535 541. 18. Posen AL. The influence of mximum periorl nd tongue force on the incisor teeth. Angle Orthod. 1972;42: 285 309. 19. Mitchell JI, Willimson EH. A comprison of mximum periorl muscle forces in North Americn blcks nd whites. Angle Orthod. 1978;48:126 131. 20. Lmbrecht H, De Bets E, Fieuws S, Willems G. Lip nd tongue pressure in orthodontic ptients. Eur J Orthod. 2010; 32:466 471. 21. Mew J. The influence of the tongue on dentofcil growth. Angle Orthod. 2015;85:715 716.