Table 2. Data extraction sheet.
OSA: Obstructive sleep apnoea; AHI: apnoea-hypopnoea index; OHI: oral hygiene index; REM: rapid eye movement; NREM: non-rapid eye movement; RME: rapid maxillary expansion; ENT: ear, nose and throat; AI: apnoea index; PSG: polysomnography; RDI: respiratory disturbance index; SaO2: oxygen saturation; Epworth sleepiness scale (ESS); CT imaging: computed tomography imaging; NMSE: naso-maxillary skeletal expansion
| Study | Population | Type of study | Mean age of the patients | Parameters checked | Intervention | Comparison | Outcome | Time period |
| Villa et al., 2007 [12] | Children aged 4-11 years with clinical signs of malocclusion, symptoms of OSA, and AHI >1 | Prospective clinical trial | 6.9 ± 2.2 years | Clinical score of OSA symptoms, AHI, OHI, arousal index, mean SaO2, REM, NREM, tonsillar hypertrophy, maxillary expansion | Orthodontic treatment with rapid maxillary expansion (RME) | Pre-treatment vs. post-treatment (baseline, 6 months, and 12 months) | Significant improvement in clinical score, AHI, OHI, and arousal index | November 2004 to April 2005 |
| Pirelli et al., 2004 [13] | 31 children with maxillary constriction, no adenotonsillar hypertrophy, BMI < 24 kg/m2, presence of OSAS, parents signed informed consent | Prospective trial | 8.7 years (range: 6-12 years) | ENT evaluations, anterior rhinomanometry, nasal fibroscopy, panoramic radiographs, cephalometric radiographs, polysomnography, paediatric sleep questionnaire | Rapid maxillary expansion (RME) | Evaluations conducted at T0 (before orthodontic therapy), T1 (after 4 to 6 weeks with the device), T2 (4 months after end of treatment) | Significant improvement in nasal resistance, reduction in AHI, increased cross-sectional expansion of the maxilla, increased pyriform opening, improved sleep parameters | Initial examination, after four to six weeks with the device, and four months after the end of orthodontic treatment |
| Villa et al., 2002 [14] | 32 children (20 males), age range: 4-10 years, mean age 7.1 ± 2.6 years | Randomized controlled study | 7.1 ± 2.6 years (Overall), 6.86 ± 2.34 years (Intervention group), 7.34 ± 3.10 years (Control group) | Apnoea Index (AI), daytime symptoms like sleepiness, irritability, and tiredness; nighttime symptoms like habitual snoring, restless sleep, tonsillar hypertrophy, polysomnography | Personalized oral appliance for mandibular positioning, worn continuously except at mealtimes | Control group did not undergo therapy | Significant reduction in tonsillar hypertrophy in the treated group (66.7% vs. 14.3% in controls) and improvement in daytime and nighttime symptoms in the treated subjects. 64.2% of the treated subjects experienced a ≥50% reduction in AHI | Six-month trial period |
| Guilleminault et al., 2011 [15] | 31 pre-pubertal children with OSA | Randomized controlled trial | 6.5 ± 0.2 years | Clinical symptoms, polysomnography (PSG), apnoea-hypopnea index (AHI), respiratory disturbance index (RDI), lowest oxygen saturation (SaO2), tonsil and tongue position, nasal turbinates, nasal septum deviation, dental and orthodontic evaluations | Group 1: Adeno-tonsillectomy followed by orthodontics (rapid maxillary expansion) Group 2: Orthodontics (rapid maxillary expansion) followed by adeno-tonsillectomy | Pre-treatment vs. post-treatment 1 vs. post-treatment 2 | Reduction in AHI and RDI, improvement in SaO2, clinical symptom improvement | Follow-up four weeks post-ENT surgery and three months post-orthodontic expansion |
| Marino et al., 2012 [16] | 15 OSA syndrome children (eight boys and seven girls) | Longitudinal observational study | 5.94 ± 1.64 years | Cephalometric variables (SNA, SNB, skeletal divergence, total facial height), respiratory disturbance index (RDI) | Rapid maxillary expansion (RME) | Baseline (T0) vs. post-treatment (T1) | Improvement in SNA and SNB angles in the improved (I) group compared to the stationary/worsened (SW) group | Mean follow-up period of 1.57 ± 0.58 years |
| Pirelli et al., 2012 [17] | 80 children (43 boys and 37 girls) with OSAS, BMI <24 kg/m² | Longitudinal observational study | 6–13 years (average 7.3 years) | Cephalometric variables, respiratory disturbance index, apnoea-hypoponea index (AHI), SpO2, polygraphic variables | Rapid maxillary expansion (RME) and adenotonsillectomy (AT) | Baseline (T0) vs. post-treatment (T1) and second phase evaluation (T2) | Improvements in cephalometric parameters, reduction in AHI, increase in maxillary width, normalization of SpO2 | T1 - four months after treatment; T2 - after the completion of both RME and AT treatments, study conducted over eight years |
| Cozza et al., 2004 [18] | 20 Caucasian children (10 boys and 10 girls) with OSA | Longitudinal observational study | Four to eight years (mean age 5.91) | Polysomnographic variables, obstructive apnoea-hypopnea index (AHI), minimum arterial oxygen saturation (min SaO2), arousal index, Epworth sleepiness scale (ESS) | Modified monobloc device worn nightly for six months | Baseline polysomnography vs. post-therapy polysomnography after six months | Decrease in median obstructive apnoea-hypopnoea index: from 7.88±1.81 episodes before treatment to 3.66±1.70 episodes after 6 months (p<0.001). ESS score reduced from 15.2±4.9 to 7.1±2.0. Arousal index and min SaO2 showed no significant change. | Six months |
| Caruso et al., 2023 [19] | 14 paediatric patients (six males and eight females) aged between 6 and 10 years with mixed dentition and class III malocclusion associated with OSAS | Prospective cohort study | Median age: eight years | Skeletal variables, dental variables, upper airway space dimensions like nasopharynx, oropharynx, hypopharynx | Rapid maxillary expansion (RME) followed by Delaire mask treatment | Cephalometric variables measured before treatment (T0) and after treatment (T1) | Significant changes in dental variables, a skeletal variable (SNA), and upper airway space dimensions (nasopharynx and oropharynx) with p ≤ 0.05. | Orthodontic treatment duration: 18 months - RME activation: two rounds/day for 15 days - RME retained in mouth for 12 months |
| Pirelli et al., 2015 [20] | 31 Caucasian children (19 boys) | Retrospective study | 8.68 years | Clinical evaluation (Tanner stage, maxillary deficiency, cross-bites), otolaryngologic and orthodontic evaluation, PDSS, ESS, PSG, CT imaging | Rapid palatal expansion (RPE) | No control group specified | Significant reduction in AHI, improved oxygen saturation, stable anatomical changes, absence of OSA recurrence at final follow-up | 12.3 ± 1.5 years (total), 12.0 ± 0.5 years (posttreatment follow-up) |
| Villa et al., 2015 [21] | Children aged 4-10 years referred to Paediatric Sleep Center, Sant’Andrea Hospital, Rome, Italy | Prospective longitudinal study | 4-10 years | Clinical signs of malocclusion, tonsillar grading I-III, signs and symptoms of OSA, AHI > 1 as defined by PSG recording, parental written informed consent | Evaluation of RME | Baseline vs T1 | Significant decrease in AHI (AHI T0: 4.7 ± 4.4 events/h vs AHI T1: 1.6 ± 1.4 events/h, p < 0.001) | Before and after treatment |
| Pirelli e al., 2019 [22] | Children presenting with snoring and clinical symptoms suggestive of abnormal breathing during sleep | Prospective observational study | 10.5 years (range: 9–12 years) | PSG, CT imaging | Rapid maxillary expansion (RME) therapy | Pre-RME vs post-RME | Improvement in mid-palatal suture opening, maxillary width, nasal cavity width, first molar angulation, and pterygoid process distance | Pre-treatment (T0) and post-treatment (T1) |
| Pirelli et al., 2021 [23] | 78 children with malocclusion | Prospective cohort study | 8.5 years (range: 5-12 years) | Maxillary suture width, nasal width, molar angulation, pterygoid processes distance, nasal cavity dimensions, pharyngeal airway volume | Rapid maxillary expansion (RME) | Comparison between pre- and post-treatment measurements | Increase in mid-palatal suture opening, maxillary width, pterygoid processes distance, nasal cavity dimensions, and pharyngeal airway volume | Before orthodontic therapy (T0), after two months (T1) with device on, and four months after the end of orthodontic treatment (T2) |
| Kim et al., 2022 [24] | 26 patients with OSA | Retrospective record-based study | 13.6 ± 2.9 years (range: 9-18 years) | Transverse nasomaxillary dimensions, UA dimensions, HST parameters | Nasomaxillary skeletal expansion (NMSE) | Comparison between pre-treatment (T0) and post-treatment (T1) measurements | Significant expansion of nasal and upper airway dimensions, improved sleep parameters, and reduced symptoms | May 2016 to June 2019 |
| Li et al., 2022 [25] | 25 children aged 10-16 years who completed pre- and post-operative evaluations. | Observational study | 10-16 years | Improvement in PSG metrics (AHI), clinical symptoms (OSA-18 scores), mid-palatal suture separation, nasal sidewall widening, dental expansion, nasal airflow pressure, and velocity | Treatment by transpalatal distraction (TPD) for nasomaxillary expansion | Comparison of pre- and post-operative data | Improvement in PSG metrics, clinical symptoms, successful mid-palatal suture separation, nasal sidewall widening, dental expansion, and reduced nasal airflow pressure and velocity | Until completion of orthodontic treatment |
| Chuang et al., 2019 [26] | Children suspected of pediatric OSA | Observational study | 4-14 years | Clinical symptoms, AHI, RDI, BMI, age, sex, body weight, height, gestational age, birth body weight, OSA-18 scores, cephalometric data, upper airway morphology, PSG metrics, quality of life questionnaire | Treatment with a custom-designed oral appliance with built-in tongue bead (passive MFT) or no further treatment | Pre- and post-operative evaluations, PSG, lateral cephalometric X-ray | Significant improvement in PSG metrics, clinical symptoms, upper airway morphology, and quality of life survey scores; statistical analyses included Chi-square test, Mann-Whitney U test, and Wilcoxon signed-rank test | Before and after one year |
| Ghodke et al., 2014 [27] | Growing subjects with skeletal class II malocclusion | Prospective longitudinal study | 8-14 years | Skeletal changes (SNA, SNB, FMA), PAP dimension changes (DOP, DHP, SPL, SPT, SPI), posterior pharyngeal wall thickness changes, age, sex, BMI, occlusion, crowding, rotations, follow-up duration | Correction with standard twin-block appliance, one-step mandibular advancement | Phase of pre-functional therapy with sectional fixed orthodontic appliance | Significant skeletal and PAP dimension changes. Maintenance of PPWT in treatment group. Different PPWT changes in control group | Before treatment (T0) and after approximately six months (T1) |
| Machado-Júnior et al., 2016 [28] | Children from Campinas at the physiological stage of mixed dentition | Prospective longitudinal study | Mean age: 8.13 years (experimental group) and 8.39 years (control group) | Clinical diagnosis of mandibular retrusion, symptoms of obstructive sleep apnoea (OSA), apnoea-hypopnoea index (AHI), sex distribution | Experimental subgroup: Mandibular advancement devices constructed based on neuro-occlusal rehabilitation principles and Pedro Planas' device, modified for the study | Control subgroup: No intraoral device or OSA treatment | Decrease in AHI in the experimental group, increase in the control group | Initial examination and after 12 months |
| Concepción Medina et al., 2022 [29] | 39 children: 20 in activator group, 19 control | Prospective longitudinal study | 10.9±0.9 years (activator group), 9.8±1.4 years (control group) | Skeletal pattern, SNA angle, SNB angle, ANB angle, BMI, sleep-related breathing disorder symptoms, upper airway linear width, cephalometric measurements, at-home sleep-breathing monitoring indicators | Activator group: Wore Andresen functional activator appliance | Control group: No activator appliance | Improved sleep breathing patterns, widened upper airway, decreased severity of sleep breathing disturbances | Initial assessment and after functional therapy |
| Zhang et al., 2013 [30] | 46 patients from the Department of Orthodontics, Wuhan University | Prospective longitudinal study | 9.7±1.5 years | Cervical vertebrae maturation indices, mandibular retrognathia (ANB, SNB, incisor overjet), snoring habit, OSA (AHI), BMI | Customized twin block appliances | Pre-treatment vs post-treatment | Improved airway, reduced AHI, increased lowest SaO2, No significant change in mean SaO2, forward movement of mandible, improved facial convexity | Before and after TB treatment |
| Zhao et al., 2018 [31] | Patients aged 12-14 years from the Department of Orthodontics, Wuhan University | Retrospective comparative study | 12.3 ± 1.2 years | Full permanent dentition, distal molar relationship (ANB ≥ 4), hyperdivergent skeletal growth (SNGoMe ≥ 36), crowding ≤ 3 mm, PSG findings, lateral cephalometric radiograph | Comprehensive orthodontic treatment protocol by same orthodontist | OSAHS group vs control group | Improved craniofacial structures, changes in cephalometric measurements, normalized overbite and overjet | Before and after treatment |
| Zreaqat et al., 2023 [32] | 34 polysomnography - proven OSA children with class II mandibular retrognathic skeletal malocclusion | Interventional | 8-12 years | Upper airway parameters/dimensions, apnoea-hypopnoea indexes (AHIs) | Myofunctional twin-block therapy | Treatment vs control group | Increase in upper airway volume, increase in minimal cross-sectional area (MCA), decrease in AHI | Pre- and posttreatment |