Association Between Pediatric Adenotonsillar Hypertrophy And Maxillofacial Development

Part ⅠAssociation between adenotonsillar hypertrophy and the dentofacial morphology of childrenObjective:The objective of this study was to compare the dentofacial morphology of children with and without adenoid or tonsillar hypertrophy using cephalometric analysis.Methods:Children between the ages of 6 and 12 years old who visited the Department of Orthodontics,Hospital of Stomatology,Wuhan University,China,during April 1 to August 30 were included.Patients with craniofacial syndrome,poor quality images,incomplete information,or history of orthodontics,tonsillectomy or injury were excluded.Patients were divided into four groups according to Baroni’s methods:1)Adenoid hypertrophy only(AH);2)Tonsillar hypertrophy only(TH);3)Adenoid and tonsillar hypertrophy(ATH);and 4)No adenoid or tonsillar hypertrophy(NH).Cephalometric measurements were used for sagittal and vertical skeletal analysis,as well as dental analysis.Data were analyzed using one-way ANOVA and LSD post hoc tests.Results:A total of 599 patients were included,among which 88 had isolated adenoid hypertrophy,124 had isolated tonsillar hypertrophy,275 had both adenoid and tonsillar hypertrophy,and 112 had no adenoid or tonsillar hypertrophy.In one-way ANOVA analysis,interincisal angle(P=0.007);L1(P=0.008),SNB(P<0.001),ANB(P<0.001),NSAr(P=0.019)and Wits(P<0.001)were significantly different among four groups;whereas for U1,SNA,SArGo,ArGoMe,NGoAr,NGoMe,SUM and mandibular plane angle no significant difference was found.According to pairwise comparisons,the SNB values of TH(P<0.001)were significantly larger than the NH group,and ANB values(P<0.001)and Wits values(P=0.001)of TH groups were significantly lower than the NH group.U1L1 values of AH were significantly smaller than NH(P=0.035).Conclusion:Almost 81.3%children seeking orthodontic treatment in China had either adenoid or tonsillar hypertrophy.Tonsillar hypertrophy may be an important risk factor for Class Ⅲ malocclusion.Part ⅡThe prevalence of tonsillar hypertrophy in adults with different types of malocclusionObjective:The relationship between upper airway obstruction and malocclusion has been explored by several studies.However,whether the sites of pharyngeal obstruction are associated with certain patterns of malocclusion is still unknown.The objective of this study was to investigate the correlation between tonsil hypertrophy and types of malocclusion.Methods:We collected the lateral cephalograms of all adult patients who visited the Department of Orthodontics,Hospital of Stomatology,Wuhan University,China,during April 1 to August 30,2019.Patients with craniofacial syndrome,poor quality lateral cephalograms,incomplete information,or treatment history of orthodontics or tonsillectomy were excluded.Patients were divided into three groups according to the ANB angle:Class Ⅰ group(0<ANB<4);Class Ⅱ group(ANB≤0);Class Ⅲ group(ANB≥4).Tonsil hypertrophy was diagnosed with the lateral cephalogram by two authors independently according to Baroni’s methods.Data were analyzed using chi square tests(with Bonferroni correction).Results:A total of 1316 patients were included,among which 630(47.8%)were Class Ⅰ,359(27.28%)were Class Ⅱ,and 327(24.85%)were Class Ⅲ.The prevalence of tonsillar hypertrophy was 21.3%,12.5%and 41.9%in Class Ⅰ,Class Ⅱ and Class Ⅲpatients,respectively(X2=45.226,P<0.001).According to Bonferroni correction chisquare tests,the number of patients with tonsillar hypertrophy was significantly higher in Class Ⅲ group than Class Ⅰ(P<0.001)and Class Ⅱ(P<0.001)groups.Conclusion:Tonsil hypertrophy is associated with Class Ⅲ malocclusion in adult patients.Part ⅢEffects of maxillary miniscrew assisted rapid palatal expansion on upper airway airflow:a computational fluid dynamics analysisObjective:Recent evidence suggests that Maxillary Skeletal Expander(MSE)is helpful for correcting maxillary deficiency and relieving the symptoms of Obstructive Sleep Apnea(OSAHS)in adult patients.However,the effect of MSE on upper airway in adolescent patients is not clear.The purpose of the study was to investigate the upper airway response in an adolescent patient to MSE treatment using computational fluid dynamics analysis(CFD).Methods:Three-dimensional upper airway finite element models fabricated from cone beam computed tomography images were obtained before and after treatment with MSE in an adolescent patient.Turbulent analyses were applied for computational fluid dynamics analysis.The nasal cavity(NC)was divided into 6 planes along the Y-axis and the pharynx was divided into 7 planes in the z-axis.Changes in cross sectional area,airflow velocity,pressure and total resistance at maximum expiration and maximum inspiration were investigated at each plane after MSE treatment.Results:Six mm of maxillary expansion was obtained.The cross-sectional areas at 12 of the 13 planes showed significant increase after maxillary expansion.The greatest increase in area occurred in the oropharynx at the Z-5 plane which was around 40.65%.During both inspiration and expiration,airflow pressure decreased in both the NC and pharynx,which ranged from-11.34%to-23.68%.The airflow velocity showed no significant variance in both maximum expiration(ME)and maximum inspiration(MI).In the NC,the average velocity decrease was-0.18 m/s at ME and-0.13 m/s at MI.In the pharynx,the average velocity decrease was-0.07 m/s for both ME and MI.Conclusions:Treatment of patients with maxillary constriction using the MSE appliance shows positive effects in improvement of cross-sectional areas along the nasal and pharyngeal airway and reduction of upper airway resistance and velocity.The subject in the present study showed significant increase in the pharyngeal crosssectional area together with reduction in upper airway resistance in the nasal cavity.Part ⅣImpact of adenotonsillectomy on the dentofacial development of children:a systematic review and meta-analysisObjective:The aim of this systematic review was to investigate the dentofacial development changes of children after adenotonsillectomy and to further determine whether adenoid and tonsillar hypertrophy is a risk factor of the malocclusion.Methods:We searched PubMed,Embase,The Cochrane Library,CNKI and WanFang databases to collect studies on the impact of adenotonsillectomy on children’s dentofacial development.Two reviewers independently screened literature,extracted data and evaluated the risk of bias of the included studies.Then heterogeneity analysis and meta-analysis were conducted using RevMan 5.3 software.Results:A total of 2 prospective and 1 retrospective cohort studies involving 189 mouth breathing children were identified.A descriptive and quantitative synthesis of detofaical changes postoperatively is presented.The results of meta-analysis showed that the maxillary second molar width increase significantly greater than the control group[MD=0.28,95%CI(0.09,0.47),P=0.005].The increase of upper arch perimeter in surgery group was significantly less than the control group[MD=-1.4,95%CI(-0.27,-0.09),P=0.04]as well as palatal depth[MD=-0.28,95%CI(-0.52,-0.03),P=0.03].Conclusion:There is low evidence that adenotonsillectomy group showed greater maxillary transverse development than did the controls.Well-designed high quality studies are needed to confirm whether children dentofacial growth will benefit from adenotonsillectomy.Part ⅤEffects of adenotonsillectomy on the growth of children with obstructive sleep apnoea-hypopnea syndrome(OSAHS):a systematic reviewObjective:The aim of this systematic review was to investigate the growth changes of children after adenotonsillectomy and to further determine whether adenoid and tonsillar hypertrophy is a risk factor of the growth failure.Methods:We searched PubMed,Embase,The Cochrane Library,and Google Scholar databases to collect studies on the impact of adenotonsillectomy on children’s growth.Two reviewers independently screened literature,extracted data and evaluated the risk of bias of the included studies.Then qualitative analysis was applied.Results:According to the inclusion criteria,one randomized controlled trial and one prospective cohort study involving 418 OSAHS children were included.The results of qualitative analysis showed that after adenotonsillectomy children’s height and weight were significantly increased than the controls.Conclusion:Adenotonsillectomy may help the growth of children with OSAHS.However,due to limited number and quantity of the included studies,more evidence is needed to verify the conclusion.