OBJECTIVES: This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group. METHODS: PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis. RESULTS: Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group. CONCLUSIONS The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.
Humans ; Malocclusion, Angle Class II/therapy* ; Mandibular Advancement ; Orthodontics, Corrective ; Orthodontic Appliances, Functional ; Mandible ; Orthodontic Appliances, Removable ; Cephalometry

Objective: To compare the treatment effect of distraction osteogenesis (DO) and maxillomandibular advancement (MMA) for severe obstructive sleep apnea hypopnea syndrome (OSAHS) patients and to guide clinical decisions about treatment of OSAHS. Methods: Thirty-seven OSAHS patients which accepted maxillomandibular advancement (MMA) or distraction osteogenesis (DO) in Stomatological Hospital of the Department of Maxillofacial Trauma and Orthognathic Surgery, School of Stomatology, The Forth Military Medical University from June 2017 to June 2019 were collected. Their preoperative and postoperative data of cephalometry, polysomnography (PSG), Pittsburgh sleep quality index (PSQI) and Epworth sleepiness scale (ESS) scores were collected and analyzed. With propensity score matching method, the treatment effect of MMA and DO was analyzed and compared. Results: According to the statistics of MMA group, only AHI was correlated with operative successful rate and cure rate. With the increase of AHI, the treatment effect of MMA on OSAHS patients gradually decreased. The cut-off point of AHI as a predictor of MMA treatment failure was 78.2 n/h. All the matched cases were severe OSAHS patients. Statistical analysis showed that the mandibular elongation of DO patients[(24.00±4.39) mm] was significantly more than that of MMA group [(11.20±1.37) mm] (t=-6.11, P<0.001), the improvement of PSG index [including lowest oxygen saturation (LSpO₂), longest apnea (LA) and longest hypopnea (LH)] in DO group [LSpO₂=(93.40±1.82)%; LA=(18.28±8.32) s; LH=(61.84±32.94) s] was significantly higher than that in the MMA group [LSpO₂=(86.00±4.06)%, LA=(64.08±21.78) s, LH=(172.40±30.70) s](t=-3.72, P=0.005; t=4.39, P=0.003; t=5.49, P=0.004). The PSQI and the ESS scores of DO group (PSQI=4.20±0.83; ESS=3.40±1.52) were also significantly better than that of MMA group (PSQI=8.80±2.39, ESS=9.40±2.88)(t=4.07, P=0.001; t=4.12, P=0.002). Conclusions: For severe OSAHS patients, the objective and subjective indicators of DO treatment group showed a better therapeutic effect than that of MMA.
Humans ; Mandibular Advancement ; Osteogenesis, Distraction ; Retrospective Studies ; Sleep Apnea, Obstructive/surgery* ; Treatment Outcome

BACKGROUND AND OBJECTIVES: The clinical significance and need for the treatment of primary snoring and mild obstructive sleep apnea have been recently questioned. In this study, we analyzed therapeutic outcome and the methods of treatment of such diseases. SUBJECTS AND METHOD: A retrospective review was conducted using the medical records of patients diagnosed with primary snoring or mild obstructive sleep apnea at a single institution from 2013 to 2015 through polysomnography or WATCHPAT. RESULTS: Of the 18 patients (37%) with primary snoring, 13 patients (72.2%) underwent surgery, four patients (22.2%) were treated with surgery and mandibular advancement device, and one patient (5.6%) underwent automatic positive airway pressure therapy. Of the 78 patients (61%) with mild obstructive sleep apnea, 35 patients (44.8%) had surgery, 24 patients (30.8%) were treated with mandibular advancement device, 13 patients (16.7%) were treated with surgery and mandibular advancement device and 6 patients (7.7%) received automatic positive airway pressure therapy. For primary snoring, while Epworth Sleepiness Scale and Pittsburg Sleep Quality Index did not improve, the snoring visual analog scale decreased significantly. In patients with mild obstructive sleep apnea, Apnea-Hypopnea Index, snoring decibel, Epworth Sleepiness Scale, and Pittsburg Sleep Quality Index were significantly decreased after treatment and the lowest oxygen saturation was significantly increased after treatment. CONCLUSION: For primary snoring, the direction of treatment should be determined in accordance with the presence of associated diseases related to sleep disturbance breathing. For mild obstructive sleep apnea, active treatment may be helpful.
Humans ; Mandibular Advancement ; Medical Records ; Methods ; Oxygen ; Polysomnography ; Respiration ; Retrospective Studies ; Sleep Apnea, Obstructive ; Snoring ; Visual Analog Scale

OBJECTIVES: The aim of this study was to investigate the effects of advancement magnitude and changes in mandibular plane angle on the stability of mandibular advancement. MATERIALS AND METHODS: This retrospective cohort study evaluated the postoperative stability of mandibular advancement in class II skeletal subjects who underwent bilateral sagittal split osteotomy. Radiographs taken preoperatively, immediately postoperatively and 1 year postoperatively were traced and analyzed using linear and angular measurements. To determine horizontal and vertical relapse, an X-Y coordinate system was established in which the X-axis was constructed by rotating S-N downward by 7° (approximation of the Frankfort horizontal plane) and the Y-axis was defined as a line perpendicular to the X-axis and passing through the point Sella. For certain reference points including point A, point B, pogonion and menton, the perpendicular distance between each point and both axes was determined and cephalometric variables were recorded as X and Y coordinates. RESULTS: Twenty-five subjects were studied. A significant correlation between the amount of mandibular advancement and relapse in the B point (vertical and horizontal) and the pogonion point was observed (vertical and horizontal, P<0.001). Evaluation of data demonstrated a positive correlation between the mandibular plane angle (SN/ML) change and vertical relapse in the B point (P<0.05). A simple regression model demonstrated that 74% of horizontal relapse and 42.3% of vertical relapse in the B point was related to the amount of mandibular advancement. The receiver operating characteristic test showed that 8.5 mm mandibular advancement is related to a relapse rate of 1 mm or more in the pogonion, vertically or horizontally. CONCLUSION: The magnitude of mandibular advancement is a stronger surgical predictor for horizontal rather than vertical relapse at the B point. Changes in mandibular plane angle (SN/ML) during surgery affect vertical, but not horizontal relapse at the B point.
Cohort Studies ; Mandible ; Mandibular Advancement* ; Orthognathic Surgery ; Osteotomy ; Recurrence ; Retrospective Studies ; ROC Curve

BACKGROUND AND OBJECTIVES: Recently, mandibular advancement device (MAD) has been used widely used for the treatment of obstructive sleep apnea (OSA) because it can effectively reduce the collapsibility of upper airway during sleep. Although MAD is widely prescribed by otorhinolaryngologists, several studies described its complications arising from the anterior placement of the mandible with long-term use. However, there is still a lack of studies on long-term complications in Korean patients. SUBJECTS AND METHOD: Retrospectively, we included a total of 57 OSA patients in the study. In this study, all enrolled OSA patients had used MAD over two years with more than 4 hours/day. Dental consulting and cephalometric analysis were conducted to identify the change of dental and skeletal findings at two different times (baseline and after 2 year). RESULTS: The dental findings showed that the overbite and overjet were significantly decreased. Additionally, the proclination of the lower incisors were increased significantly, whereas there was no significant change on the retroclination of the upper incisors. Three patients showed a change of malocclusion type. On the analysis of skeletal findings, we found a significant increase in the sella turcica central point-nasion-supramental point angle and a decrease in the subspinal point-nasion-supramental point angle. Moreover, the anterior lower facial height and anterior facial height were significant increased. CONCLUSION: Consistent with Western studies, our findings suggest that the long-term use of MAD could induce changes in dental and skeletal morphologies in Korean OSA patients. Therefore, clinicians should thoroughly evaluate potential changes in dental and skeletal morphologies when they prescribe MAD to patients with OSA.
Humans ; Incisor ; Malocclusion ; Mandible ; Mandibular Advancement* ; Methods ; Overbite ; Retrospective Studies ; Sella Turcica ; Sleep Apnea, Obstructive*

OBJECTIVEThis study investigated the reconstructed mandibular condylar cartilage and the ultrastructural variations in mandibular condylar cartilage in adult rats as a result of mandibular advancement.

METHODSThirty 9-week-old male Sprague-Dawley rats were randomly divided into experimental and control groups. Rats in the experimental group were subjected to mandibular advancement. Rats were sacrificed on days 3, 7, 14, 21, 30. Sections were cut from condyles, and bone morphogenetic protein-2 (BMP-2) expression in condylar cartilage was examined through immunohistochemical analysis. Condylar cartilage samples were harvested, and ultrastructural changes in these samples were observed under Micro-CT and transmission electron microscope.

RESULTSCompared with the control group, the experimental group obviously displayed cartilage hyperplasia in the middle and rear of the condyle. Moreover, the number of BMP-2-positive cells in condylar cartilage and the gray value gradually increased in the experimental group on day 7 of the intervention. Ultrastructural changes, such as karyopyknosis, reduced microfilaments around the nucleus, reduction in size or even disappearance of lipid droplets, swelling of endoplasmic reticulum compartments, broadened and increased extracellular matrix, were observed in the condylar hypertrophic chondrocytes. Micro-CT revealed that the trabecula and the newly formed bone gradually thickened.

CONCLUSIONSHypertrophic remodeling of the condylar cartilage and high BMP-2 expression are observed in adult rats as a result of continuous mandibular advancement.

OBJECTIVES: The purpose of this study was to estimate the safety and efficacy of a mandibular advancement device (MAD), 'Bioguard,' for the treatment of obstructive sleep apnea (OSA). METHODS: In this 5-week prospective, multi-center, single group, and non-inferiority trial, patients who chose 'Bioguard' as their treatment option were evaluated using both questionnaires (Pittsburgh Sleep Quality Index (PSQI), Epworth sleepiness scale (ESS)) and polysomonography (PSG) (apnea hypopnea index (AHI), oxygen saturation). All patient data, including clinical records, PSG studies (both pre- and post-treatment), and adverse events (AEs), were reviewed and analyzed. RESULTS: Results were obtained for 59 of 62 patients (95.16%). No significant difference in success rate was found between the MAD treatment and surgical treatment (95% CI). AHI, PSQI, ESS and oxygen saturation demonstrated significant improvement (p < 0.001) after MAD treatment, and 39 of 62 patients (62.9%) reported 85 AEs. 79 of the 85 AEs (91.8%) were mild cases, and there were no severe AEs related to the MAD treatment. CONCLUSION: The MAD 'Bioguard' should be considered as an alternative treatment option for OSA patients.
Humans ; Mandibular Advancement* ; Oxygen ; Prospective Studies* ; Sleep Apnea, Obstructive*

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.
Cleft Lip ; Congenital Abnormalities* ; Female ; Follow-Up Studies ; Genioplasty* ; Humans ; Hyoid Bone ; Incisor ; Jaw ; Malocclusion ; Malocclusion, Angle Class III ; Mandible ; Mandibular Advancement ; Mandibular Condyle ; Maxilla ; Molar ; Orthognathic Surgery ; Osteotomy* ; Palate ; Polymerase Chain Reaction ; Retrognathia* ; Tooth

OBJECTIVE: The efficacy of mandibular advancement devices (MADs) in the treatment of obstructive sleep apnea (OSA) ranges between 42% and 65%. However, it is still unclear which predictive factors can be used to select suitable patients for MAD treatment. This study aimed to systematically review the literature on the predictive value of cephalometric analysis for MAD treatment outcomes in adult OSA patients. METHODS: The MEDLINE, Google Scholar, Scopus, and Cochrane Library databases were searched through December 2014. Reference lists from the retrieved publications were also examined. English language studies published in international peer-reviewed journals concerning the predictive value of cephalometric analysis for MAD treatment outcome were considered for inclusion. Two review authors independently assessed eligibility, extracted data, and ascertained the quality of the studies. RESULTS: Fifteen eligible studies were identified. Most of the skeletal, dental, and soft tissue cephalometric measurements examined were widely recognized as not prognostic for MAD treatment outcome; however, controversial and limited data were found on the predictive role of certain cephalometric measurements including cranial base angle, mandibular plane angle, hyoid to mandibular plane distance, posterior nasal spine to soft-palate tip distance, anterior nasal spine to epiglottis base distance, and tongue/oral cross sectional area ratio thus justifying additional studies on these parameters. CONCLUSIONS: Currently available evidence is inadequate for identification of cephalometric parameters capable of reliably discriminating between poor and good responders to MAD treatment. To guide further research, methodological weaknesses of the currently available studies were highlighted and possible reasons for their discordant results were analyzed.
Adult* ; Epiglottis ; Humans ; Mandibular Advancement* ; Skull Base ; Sleep Apnea, Obstructive* ; Spine ; Treatment Outcome*

A Brazilian girl aged 14 years and 9 months presented with a chief complaint of protrusive teeth. She had a convex facial profile, extreme overjet, deep bite, lack of passive lip seal, acute nasolabial angle, and retrognathic mandible. Intraorally, she showed maxillary diastemas, slight mandibular incisor crowding, a small maxillary arch, 13-mm overjet, and 4-mm overbite. After the diagnosis of severe Angle Class II division 1 malocclusion, a mandibular protraction appliance was placed to correct the Class II relationships and multiloop edgewise archwires were used for finishing. Follow-up examinations revealed an improved facial profile, normal overjet and overbite, and good intercuspation. The patient was satisfied with her occlusion, smile, and facial appearance. The excellent results suggest that orthodontic camouflage by using a mandibular protraction appliance in combination with the multiloop edgewise archwire technique is an effective option for correcting Class II malocclusions in patients who refuse orthognathic surgery.
Crowding ; Diagnosis ; Diastema ; Female ; Follow-Up Studies ; Humans ; Incisor ; Lip ; Malocclusion* ; Malocclusion, Angle Class II* ; Mandible ; Mandibular Advancement ; Orthognathic Surgery ; Overbite ; Tooth