Prevalence of sleep-disordered breathing in children and adolescents with large horizontal maxillary overjet due to mandibular retrognathia: a case control study.

STUDY OBJECTIVES: The aim of the study was to examine the prevalence of sleep-disordered breathing (SDB) in children and adolescents with large overjet due to mandibular retrognathia compared to a control group. METHODS: In this case-control study children with large overjet ≥ 6 mm due to mandibular retrognathia (study group) were compared to a group with neutral occlusion (controls). All participants underwent respiratory polygraphy (PG) and questionnaires regarding sleepiness and snoring. Differences across groups were tested by: Chi-square, general linear model adjusted for age, sex, and body mass index (BMI), and Mann-Whitney test. Differences in results of PG were also tested by general linear model adjusted for age, sex, and BMI according to severity of mandibular retrognathia. RESULTS: Thirty-seven (19 male;18 female, median age 12.3 years) participants were included in the study group and 32 (16 male;16 female, median age 12.2 years) in the control group. No significant difference in SDB assessed by PG or questionnaires between the groups was found even though the snore index was higher in the study group (p=0.051). The snore index was higher than the parent-reported snoring. Respiration rate was significantly reduced in the study group (p=0.043), and estimated sleep time efficiency was significantly reduced in males compared to females (p<0.001). CONCLUSIONS: No significant differences in SDB were found between the groups even though the snore index was higher in the study group. The snore index of the PG was higher than the parent-reported snoring. Estimated sleep time efficiency was reduced in males. The study improves the understanding of risk of SDB in non-obese children with large overjet due to mandibular retrognathia and may contribute to an interdisciplinary approach of risk assessment of SDB in children with malocclusion. CLINICAL TRIAL REGISTRATION: NCT04964830.

Association between orthodontic treatment and upper airway changes in children assessed with cone-beam computed tomography (CBCT): A systematic review.

BACKGROUND: Some orthodontic devices used in children share similar design principles to appliances used to treat obstructive sleep apnoea in adults. As well as treating malocclusion, orthodontic appliances used in children may therefore also have effects on the upper airway. OBJECTIVE: A review of the literature to assess the effects of orthodontic treatment on the upper airway dimensions in children assessed on CBCT. MATERIALS AND METHODS: Following registration of the protocol (PROSPERO CRD42023439056), a systematic electronic search of published studies was performed using several databases (PubMed; Scopus, Web of Science and Science Direct) in accordance with the PRISMA guidelines. Inclusion criteria were as follows: age under 18 years, orthodontic treatment with any appliance, a control group who received no treatment or a non-active alternative treatment and airway measurement using CBCT. RoB-2 and ROBINS-I tools were used to assess risk of bias and quality of the evidence. RESULTS: In total, 341 studies were identified following the initial search. Title and abstract screening resulted in 45 studies for further full-text analysis. On completion of the screening process, a total of 23 studies met the inclusion criteria. Study interventions included functional appliances (10 studies), rapid maxillary expansion (RME) (9 studies), reverse-pull headgear (1 study) and 4 premolar dental extractions (3 studies). The included studies had moderate to high risk of bias, and the quality of evidence was low. CONCLUSION: The scientific evidence shows that functional appliances are associated with significant improvements in both upper airway volume and constriction when used in children however, the effects on the nasal cavity are limited. RME was associated with a significant increase in nasal cavity and nasopharyngeal dimensions, but not the upper pharyngeal airway. Neither reverse-pull headgear nor dental extractions were associated with any change in airway dimensions; however, the evidence is limited. Functional appliances may reduce the severity of obstructive sleep apnoea (OSA) in children.

Sleepiness in children with severe malocclusion compared with in children with neutral occlusion.

INTRODUCTION: The study aimed to compare daytime sleepiness in children with severe malocclusion with healthy children with neutral occlusion (controls) and to analyze associations between daytime sleepiness and craniofacial morphology in children with severe malocclusion. METHODS: In 120 children with severe malocclusion (73 girls, 47 boys; mean age, 11.96 years; mean body mass index [BMI] score, 18.97 kg/m2) and 35 controls (18 girls, 17 boys; mean age, 11.97 years; mean BMI score, 20.28 kg/m2), sleep and daytime sleepiness were recorded using Epworth Sleepiness Scale and Berlin Questionnaire. Occlusion was registered clinically, and craniofacial morphology was assessed on lateral cephalograms. Differences in daytime sleepiness and sleep between the groups and associations between daytime sleepiness and sleep and craniofacial morphology were analyzed by a general linear model adjusted for age, gender, and BMI score. RESULTS: Daytime sleepiness occurred significantly more often in children with malocclusion than in control subjects (P = 0.015). There was a tendency for children with malocclusion to feel extremely tired during the day more often than controls (P = 0.054). There was no significant difference between the groups in sleeping hours during night-time, but the amount of sleep was negatively associated with age (P <0.001) and BMI score (P = 0.004). Only maxillary inclination was significantly associated with daytime sleepiness (P = 0.043). CONCLUSIONS: Daytime sleepiness occurred significantly more often in children with severe malocclusion than in those with neutral occlusion, and the association between daytime sleepiness and craniofacial morphology may exist. The results might prove valuable in interdisciplinary collaboration between medical doctors and orthodontists in diagnostics, prevention, and treatment of children at risk for sleep-disordered breathing.

Oro-facial function and quality of life in children and adolescents with large horizontal maxillary overjet-A case-control study.

BACKGROUND: Large horizontal maxillary overjet (overjet) is associated with reduced bite force (BF) and number of contacts, which influence the chewing effectivity (CE). Oral health, oro-facial function (OF) and malocclusion have great impact on psychological well-being and quality of life (QoL). OBJECTIVES: The aims of the study were to examine OF, temporomandibular disorders (TMD), BF, CE, QoL and well-being in children and adolescents with large overjet. METHODS: The study was a case-control study including healthy children with large overjet in the study group compared to a control group of healthy children with neutral occlusion, all 9-14 years old. OF was examined by use of Nordic Orofacial Test-Screening (NOT-S), Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and registration of morphological and functional occlusion. QoL and well-being were examined using KIDSCREEN-10 and Strengths and Difficulties Questionnaire. RESULTS: The study and control groups included 37 and 32 participants, respectively. Significantly increased NOT-S score (p < .001) and reduced BF (p = .011), numbers of contacts (p < .001) and CE (p = .005) were found in the study group. BF, numbers of contacts and CE were negatively associated with erupting canines and premolars. No significant difference was found in age, gender, dental eruption, TMD diagnosis or QoL between the groups. Significantly increased emotional symptoms (p = .007), hyperactivity (p = .043) and total difficulties score (p = .009) were found in the study group. CONCLUSION: The study group showed higher NOT-S score and reduced BF, number of contacts and CE. No difference in QoL were found between the groups, although reduced well-being and increased emotional symptoms, hyperactivity and total difficulties were found in the study group.

Clinical and digital assessment of tooth wear.

The aim of this study was to compare the assessment of tooth wear performed on digital models with the one conducted at the clinical examination. Seventy-eight volunteers (29 males and 49 females, age range 20-30 years) with at least 24 teeth, normal oral function, and a neutral transverse relationship were examined. During the clinical examination, dental wear was registered according to the Basic Erosive Wear Examination (BEWE) index. Subsequently, the BEWE index was blindly applied by two examiners on digital models obtained from the volunteers. Data were analyzed using weighted Cohen's kappa coefficient and correlation tests with a confidence interval of 95%. All volunteers showed signs of tooth wear. Anterior teeth showed increased severity of tooth wear than first molars. Early loss of tooth substance could be identified on the digital models, including in areas with challenging direct intraoral visual access. Approximately 50% of the scores based on clinical examination agreed with those based on examination of digital models (k = 0.543, p < 0.01). A moderate, positive correlation was observed between scores registered clinically and on digital models (Spearman's rho = 0.560, p < 0.001). Considering the rather low agreement between the clinical and digital scores, alternatives to using BEWE on digital models are needed.

Dental Maturation in Two Groups of Children Born in 1969-1973 and 2005-2010.

This study compared differences in dental maturation and dental age in Scandinavian children born in 1969-1973 and 2005-2010. The study was based on 130 ethnic Scandinavian children, who were divided in two groups corresponding to the time periods and matched on age and sex. Each group consisted of 65 children (30 girls, 35 boys, mean age 9.29 years and 9.30 years, respectively). Dental maturation was analysed by orthopantomographs, in accordance with Demirjian and Haavikko. Dental age was analysed by orthopantomographs in accordance with Demirjian. Boys and girls were analysed separately by linear regression analysis adjusted for age. For the children born in 2005-2010, teeth matured significantly earlier (Demirjian: 0.21 maturities, CI 95% 0.11-0.31, p < 0.000. Haavikko: maxilla: 0.39 maturities, CI 95% 0.21-0.56, p < 0.000. Mandible: 0.42 maturities, CI 95% 0.17-0.67, p = 0.001) and the dental age was significantly higher (Demirjian: 6.04 months, CI 95% 0.23-0.77, p < 0.000) in comparison with the children born in 1969-1973. In conclusion, the teeth of Scandinavian children born 2005-2010 matured significantly earlier than those of children born in 1969-1973. The results may prove valuable in forensic dentistry, pedodontics, and for the timing of pedodontic and orthodontic treatment.

Signal quality of home polygraphy in children and adolescents.

AIM: The aims of the study were to examine the signal quality (SQ) of home polygraphy (PG) in children and adolescents and to compare automatic and manual scoring of the PGs. METHODS: Clinical Trials Registration: NCT04964830. Participants and caregivers were instructed to set up the equipment and perform home PGs themselves. The PGs were analysed according to SQ and their interpretability and differences in automatic vs. manual scoring regarding apnoea-hypopnoea index (AHI), apnoea index (AI), hypopnoea index (HI) and oxygen desaturation index (ODI) were examined. RESULTS: 54 healthy children aged 9-14 years participated in the study. 86% of the PGs were interpretable with mean SQ of 79.1% (CI 95%: 73.5%; 84.8%). Significant differences between the automatic and manual scoring were found for AHI, AI, HI and ODI (p < 0.0001). CONCLUSION: Home PGs of children and adolescents are feasible to be performed with good SQ. Significantly higher markers of sleep-disordered breathing were achieved in the automatic scoring in comparison with the manual scoring.

Association between dental and skeletal maturation in Scandinavian children born between 2005 and 2010.

OBJECTIVE: The aim of this cross-sectional study was to analyse the association between dental and skeletal maturation in children born between 2005 and 2010. MATERIALS AND METHODS: Dental and skeletal maturation of 117 ethnic Scandinavian children born between 2005 and 2010 (70 girls, 47 boys, mean age 11.48 years) was analysed. Dental maturation (DM) was assessed on orthopantomographs (OPs) by using Demirjian's and Haavikko's methods while skeletal maturation was assessed on hand-wrist radiographs by use of Helm's method. The correlation between skeletal and DM was analysed using Spearman's rho (Rs). Additionally, the most frequent DM stage in relation to the skeletal maturation stage was analysed by logistic regression adjusted for age and sex. RESULTS: The correlation between dental and skeletal maturation was significant for all teeth (Rs = 0.071-0.562; p < .000-p = .035) except for the first incisor and the first molar. Logistic regression analysis showed that when the mandibular and maxillary canines are ¾ mineralized, this is significantly associated with the beginning of the adolescent period before peak height velocity (PHV) (PP2= p < .005-< .05). Likewise, when the mandibular second premolars are ¾ mineralized, this is significantly associated with the maturation stage PP2= or S (PP2= p < .05, S: p < .005-< .05), both of which are before PHV at the beginning of the adolescent period. LIMITATIONS: Limited sample size and the X-rays were taken before orthodontic treatment, which may have introduced a selection bias. CONCLUSIONS: When the root of the canines or second premolars is ¾ mineralized, it may indicate the beginning of the adolescent period with increased skeletal growth intensity.

Daytime Sleepiness and Quality of Life in Obstructive Sleep Apnoea Patients before and after Long-Term Mandibular Advancement Device Treatment.

This study compared daytime sleepiness and quality of life in OSA patients with healthy controls and compared sleepiness and quality of life in OSA patients before and after long-term treatment with a mandibular advancement device (MAD). A total of 27 OSA patients (18 men, 9 women, mean age 52.3 years) and 32 healthy age- and sex-matched controls (20 men, 12 women, mean age 51.1 years) were included. At baseline and after MAD treatment, daytime sleepiness and quality of life were recorded by the Epworth Sleepiness Scale (ESS) and Short Form-36 questionnaires (SF-36). Daytime sleepiness occurred significantly more often in OSA patients compared to controls at baseline (p = 0.01). The quality of life domains Energy and vitality (p < 0.0001), General perception of health (p = 0.0002), Mental health (p = 0.0031), Social functioning (p = 0.0119), Role limitations due to emotional problems (p = 0.0173) and Physical functioning (p = 0.0226) were significantly poorer in OSA patients compared to controls at baseline. After long-term MAD treatment, daytime sleepiness decreased (p < 0.01) and the quality of life domain Energy and Vitality increased (p < 0.01) in OSA patients compared to baseline. The results of the present study support the relevance of MAD treatment as an effective tool for decreasing daytime sleepiness and increasing the quality of life in OSA patients­also in the long term.

Reliability of Acoustic Pharyngometry and Rhinometry Examination in Children and Adolescents.

Objectives: The aim of this cross-sectional study was to examine the method error and reliability of acoustic pharyngometry and rhinometry in children and adolescents and to describe the feasibility of these methods in a young population. Material and Methods: The study sample included 35 healthy subjects in the age of 9 to 14 years. The subjects were randomly recruited for the present project in the period from June 2021 to February 2022. Repeated measurements of the upper airway dimensions in standing mirror position were performed by the use of Acoustic Pharyngometer and Rhinometer. Volume (cm3), calculated resistance (cm H2O/L/min), mean area (cm2), minimum cross-sectional area (MCA, cm2) and distance to MCA (cm) were examined. Method errors and reliability coefficients were evaluated using Dahlberg's formula and the Houston reliability coefficient. The feasibility of the methods were analysed using paired t-test and estimated by difference in drop-out rates. Results: No systematic error exhibited in the repeated measurements except volume in the left nostril (P = 0.017). The method errors of the acoustic pharyngometry and rhinometry were betweeen 0.0002 to 0.069 and 0.001 to 0.082 respectively. The Houston reliability coefficient for both methods were between 0.952 to 0.999. The acoustic pharyngometry was significantly more feasible compared to rhinometry (P < 0.001). Conclusions: The study shows that acoustic pharyngometry and rhinometry in the standing mirror position are reliable methods, with acoustic pharyngometry being even more feasible than rhinometry, which is why it is recommended to practice the methods with children and ensure reliability of results before registering measurements.

Temporomandibular disorders, bite force and osseous changes of the temporomandibular joints in patients with hypermobile Ehlers-Danlos syndrome compared to a healthy control group.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a hereditary disorder that affects the connective tissue and collagen structures in the body characterised by joint hypermobility, skin hyperextensibility and tissue fragility. OBJECTIVE: The aim was to investigate temporomandibular disorders (TMD), bite force, teeth in occlusal contact and osseous changes of the temporomandibular joints (TMJs) in 26 patients with hypermobile EDS (hEDS), differentiated by a genetic test, compared to 39 healthy controls. METHODS: Clinical examination according to Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), radiological examinations of the TMJs by cone-beam-computed tomographic (CBCT) scans, registration of bite force and teeth in occlusal contact was performed. Statistical analyses included Fisher's Exact Test, multiple logistic and linear regression models adjusted for age, gender and Body Mass Index (BMI). RESULTS: Single symptoms and signs of TMD occurred significantly more often in hEDS (p = .002; p = .001; p = .003; p = <.0001; p = .012) and maximum mouth opening was significantly smaller in hEDS compared to controls (p = <.0001). The DC/TMD diagnosis myalgia, myofascial pain with referral, arthralgia, headache attributed to TMD, disc displacement disorders and degenerative joint disease occurred significantly more often in hEDS compared to controls (p = .000; p = .008; p = .003; p = .000; p = <.0001; p = .010, respectively). No significant differences were found in bite force and in teeth in occlusal contact between the groups (p > .05). On CBCT of the TMJs, subcortical sclerosis occurred significantly more often in hEDS compared to controls (p = .005). CONCLUSION: Symptoms and signs of TMD and osseous changes of the TMJs occurred significantly more often in hEDS. Bite force and teeth in occlusal contact were comparable to controls.

Bite Force, Occlusal Contact and Pain in Orthodontic Patients during Fixed-Appliance Treatment.

Previously, bite force, occlusal contact and pain were investigated in orthodontic patients with moderate-to-severe malocclusion, but not in patients with minor malocclusion. The purpose of this study was to investigate changes in bite force, teeth in occlusal contact and pain in orthodontic patients with minor crowding before orthodontic treatment (T0), after bonding (T1), during treatment (T2), post-treatment (T3) and during retention (T4). In total, 27 patients (21 females, 6 males, median age 15.3 years) with neutral occlusion and normal craniofacial morphology were treated with non-extractions and fixed appliances. Differences in the registered data were analysed by a mixed linear model with repeated measures. Bite force and teeth in occlusal contact significantly decreased between T0 and T1 (p < 0.0001, respectively) and between T0 and T2 (p < 0.01, respectively). Bite force and teeth in occlusal contact significantly increased between T1 and T4 (p < 0.05, p < 0.0001, p < 0.001, respectively) and between T2 and T4 (p < 0.05, p < 0.0001, p < 0.01, respectively). No significant difference in pain was found. The results indicate that bite force and teeth in occlusal contact significantly decreased during treatment and reached baseline level at retention. The findings may prove valuable for informing orthodontic patients with minor malocclusion.

Airway changes after fixed functional appliance treatment in children with and without morphologic deviations of the upper spine: A 3-dimensional CBCT study.

INTRODUCTION: Functional appliances (FA) have a positive effect on the upper airway volume and minimal cross-sectional area (MCA) in children. An association between morphologic deviations of the upper spine (MDUS) and reduced treatment response was found in appliances used to treat adults with obstructive sleep apnea. This study aimed to: (1) compare airway changes after FA treatment in children with and without MDUS and controls; (2) identify if MDUS causes a smaller upper airway. METHODS: Pretreatment and posttreatment cone-beam computed tomography scans were included from 21 children with MDUS and 42 without MDUS treated with a fixed FA, along with a pair-matched control group (matched for chronological age, skeletal age, gender, and mandibular inclination) who received orthodontic treatment for minor malocclusions without an FA. The influence of MDUS on changes in upper airway volume and MCA were evaluated with 3-dimensional cone-beam computed tomography scans using standardized, previously validated methods and mixed-effects linear regression. RESULTS: There was a significantly increased volume and MCA in the FA groups with and without MDUS compared with control (P = 0.003 and P = 0.049) and in the FA group without MDUS compared with the MDUS group (P = 0.008 and P = 0.011) after treatment. There was no significant pretreatment difference in airway dimensions between the MDUS and non-MDUS FA groups. CONCLUSIONS: The airway response with fixed FA is significantly reduced in MDUS children. MDUS caused no significant pretreatment airway differences in children. However, MDUS may be important in predicting airway changes in FA treatment.

Specific dento-craniofacial characteristics in non-syndromic children can predispose to sleep-disordered breathing.

AIM: To ascertain and illustrate specific clinical dento-craniofacial characteristics associated with sleep-disordered breathing (SDB) in non-syndromic children. METHODS: Narrative review of literature on SDB, dental occlusion and craniofacial morphology retrieved through online literature database search for these terms. The review focused on clinical examples and graphical illustrations in order to ascertain the association between dento-craniofacial characteristics and SDB. Only publications concerning healthy non-syndromic children without any somatic or psychological diagnosis were included. RESULTS: Dento-craniofacial characteristics such as anterior open bite, large overjet, cross bite and facial appearance such as convex profile due to mandibular retrognathia and inclination, narrow and high palate can predispose to SDB in non-syndromic children. Furthermore, extended head posture, mouth breathing and general adenoidal face may be symptoms or predisposing factors to SDB in non-syndromic children. CONCLUSION: Dento-craniofacial characteristics as anterior open bite, large overjet due to mandibular retrognathia, cross bite, and narrow and high palate can predispose to SDB in non-syndromic children. Facial characteristics predisposing to SDB can be a convex facial profile, extended head posture, mouth breathing and general adenoidal face. Interdisciplinary collaboration between medical doctors and dentists can prove valuable in diagnostics, prevention and treatment of SDB in non-syndromic children.

Sleep-disordered breathing and malocclusion in children and adolescents-a systematic review.

BACKGROUND: Sleep-disordered breathing (SDB) has negative influence on children's development and well-being. Malocclusion due to some craniofacial anatomical characteristics may be associated with SDB. OBJECTIVES: The aim of this paper is to ascertain whether SDB is associated with malocclusion in children/adolescents, aged 6-15 years compared to healthy controls. METHODS: Prospero ID: CRD42021232103. A systematic electronic literature search following PRISMA was performed in PubMed, Embase and Cochrane Library. Inclusion criteria were as follows: Healthy children/adolescents aged 6-15 years with malocclusion undergoing polysomnography (PSG) or polygraphy (PG) and/or sleep questionnaire and orthodontic screening; compared to a healthy age-matched control group with neutral or minor deviation in the occlusion without requirement for orthodontic treatment; publications in English, Danish, Norwegian or Swedish published until 23 March 2021. JBI Critical Appraisal Tools and GRADE were used to evaluate the risk of bias and level of evidence. RESULTS: The search resulted in 1996 records, 610 duplicates were removed, 1386 records were screened, and 1322 records were excluded. Sixty-four studies were selected for full-text reading, and four publications fulfilled the inclusion criteria. The included studies had moderate risk of bias, and the quality of evidence was low. CONCLUSION: No firm conclusion can be drawn regarding an association between specific malocclusion traits and SDB. Thus, the studies found no association between molar relationship and crowding and SDB symptoms in children. It may be recommended that future studies include objective PSG or PG in diagnosis of SDB and compare groups of children with skeletal malocclusion and controls with neutral malocclusion.

Craniofacial Morphology and Upper Airway Dimensions in Patients with Hypermobile Ehlers-Danlos Syndrome Compared to Healthy Controls.

OBJECTIVES: The aims of the present case-control study were to compare craniofacial morphology, airway minimum cross-sectional area and airway volume between patients with hypermobile Ehlers-Danlos syndrome and healthy controls. MATERIAL AND METHODS: The sample comprised 18 hypermobile Ehlers-Danlos syndrome (hEDS) patients (16 females, 2 males, mean age 34.1 [SD 10.35] years), clinically diagnosed and genetically tested in order to exclude other types of EDS, and 16 controls (14 females, 2 males, mean age 37.9 [SD 10.87] years) with neutral occlusion and normal craniofacial morphology. Craniofacial morphology was assessed on lateral cephalograms. Minimum cross-sectional area and upper airway volume were assessed on cone-beam computed tomography and analysed by standard and well-validated methods. Differences were tested by logistic regression analysis adjusted for age, gender and body mass index (BMI). RESULTS: No significant differences in craniofacial morphology were found between hEDS patients and controls. Airway minimum cross-sectional area (P = 0.019) and airway volume (P = 0.044) were significantly smaller in hEDS patients compared to controls. When adjusted for age, gender and BMI no significant differences were found. However, minimum cross-sectional area was almost significant (P = 0.077). CONCLUSIONS: The craniofacial morphology and airway dimensions of hypermobile Ehlers-Danlos syndrome patients were comparable to controls, with a tendency towards a smaller minimum cross-sectional area in the hypermobile Ehlers-Danlos syndrome group. The results may prove valuable for understanding the effect of hypermobile Ehlers-Danlos syndrome on craniofacial morphology and the upper airways.

Effects of Presurgical Mandibular Incisor Decompensation on Long-Term Outcomes of Class III Surgical Orthodontic Treatment.

This research aimed to evaluate the effects of presurgical mandibular incisor decompensation on long-term outcomes of Class III surgical orthodontic treatment. Thirty-five patients with skeletal Class III malocclusion who received conventional surgical orthodontic treatment were included. Mandibular incisor brackets with -6° of inclination were placed normally in 18 patients (NB group) and inversely in 17 patients (RB group). Between-group differences and relationships between incisal and skeletal variables were analyzed based on lateral cephalograms at pretreatment, presurgery, postsurgery, posttreatment, and retention. Mandibular incisors were more labially inclined in the RB group than in the NB group from presurgery to retention. No significant between-group differences were observed in presurgical and postsurgical skeletal relationships. The NB group exhibited a larger overjet with deficient interincisal contact at postsurgery than the RB group. Skeletal Class III relationship was also more severe in the NB group at retention. More lingually inclined mandibular incisors at presurgery and larger overjet at postsurgery were correlated with a more severe skeletal Class III relationship at retention. Thus, establishing appropriate postsurgical overjet by sufficient presurgical mandibular incisor decompensation may play a significant role in postsurgical stability of Class III surgical orthodontic treatment.

Treatment effects of functional appliances in children with Class II malocclusion with and without morphologic deviations in the upper spine.

INTRODUCTION: This research aimed to compare treatment effects of functional appliances between children with and without morphologic deviations in the upper spine and analyze associations between Atlas dimensions and the short- and long-term treatment effects. METHODS: Sixty-eight prepubertal or pubertal children (35 boys and 33 girls; mean age, 11.47 ± 1.39 years) treated with Class II functional appliances were included. Lateral cephalograms were taken at pretreatment (T1), postfunctional appliance treatment (T2), and after retention at postpuberty (T3). Upper spine morphology and Atlas dimensions were evaluated at T1. T1-T2 and T1-T3 lateral cephalograms were superimposed using a structural method. Changes in the jaws were compared with multiple linear regression analysis between children with and without deviations in the upper spine. Associations between the changes and Atlas dimensions were analyzed by partial correlation. RESULTS: Children with morphologic deviations in the upper spine showed significantly more backward rotation of the mandible (P <0.01) and increased inclination of the jaws (P <0.05, P <0.01) from T1-T2 and significantly smaller condylar growth (P <0.01) from T1-T3 compared with children without the deviations. Atlas height was significantly associated with vertical and rotational changes in the mandible (P <0.01) from T1-T2 and condylar growth (P <0.05) from T1-T2 and T1-T3. CONCLUSIONS: Morphologic deviations in the upper spine and low Atlas height were significantly associated with smaller condylar growth induced by functional appliances in the long term. Upper spine morphology and the Atlas dimension may be valuable in phenotypic differentiation in children with Class II malocclusion for optimal treatment outcome.

Evaluation of growth changes induced by functional appliances in children with Class II malocclusion: Superimposition of lateral cephalograms on stable structures.

OBJECTIVE: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. METHODS: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. RESULTS: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion- pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. CONCLUSIONS: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.