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Class III malocclusion due to a retrognathic maxilla is common in patients with cleft lip and palate. Skeletally anchored maxillary protraction using screw-anchored mini-plates combined with intraoral elastics has shown promising results in achieving orthopedic changes and maintaining the outcome until the completion of the growth. This case report presents the course of treatment in a patient with unilateral cleft lip and palate and multiple congenitally missing teeth treated with bone-anchored maxillary protraction until the end of growth. Four mini-plates (Bollard plates) were used during comprehensive fixed orthodontic treatment to protract the dentition and close the space where teeth were missing, extrude the canine, and force eruption of the second premolar using extension arms and cantilevers. A 2-year follow-up at age 17 showed stable occlusion and maintenance of soft tissue results. Bone-anchored maxillary protraction treatment in a patient with cleft lip and palate demonstrates proper orthopedic results and could be a viable alternative to orthognathic surgery., (© 0000 by The EH Angle Education and Research Foundation, Inc.)

To investigate the hypothesis that there is difference in the treatment outcomes of milder skeletal Class III malocclusion between facemask and facemask in combination with a miniscrew in growing patients. Patients were randomly divided into two groups. In one group, the patients were treated with facemask therapy (FM group: 12 males, eight females, average age: 10 years, 5 months ± 1 year, 8 months). In the other group, patients were treated with facemask therapy along with a miniscrew (FM+MS group: 12 males, seven females, average age: 11 years, 1 month ± 1 year, 3 months). A lingual arch with hooks was fixed to the maxillary arch in both groups and a protractive force of 500 g was applied from the facemask to the hooks. The patients were instructed to use the facemask for 12 hours per day. In the FM+MS group, a miniscrew was inserted into the palate and fixed to the lingual arch. Mobility and loosening of the miniscrew were not observed during treatment. Lateral cephalometric analysis showed that SNA, SN-ANS, and ANB values were significantly increased in the FM+MS group compared with those for the FM group (SNA, 1.1° SN-ANS, 1.3° ANB, 0.8°). Increase in proclination of maxillary incisors was significantly greater in the FM group than in the FM+MS group (U1-SN, 5.0°). During treatment of milder skeletal Class III malocclusion, facemask therapy along with a miniscrew exhibits fewer negative side effects and delivers orthopedic forces more efficiently to the maxillary complex than facemask therapy alone. [ABSTRACT FROM AUTHOR]

This study evaluated the long-term stability of maxillary protraction (MP) in patients with complete unilateral cleft lip and palate (UCLP) and identified factors influencing relapse and long-term outcomes. Twenty-three adolescents with UCLP who underwent MP therapy were recalled when craniofacial growth was close to completion. Subjects exhibiting reverse/positive overjets were assigned to unstable/stable groups. Lateral cephalometric measurements were made before treatment (T0), after active treatment (T1), and at the end of the growth spurt (T2). About 63% of the subjects exhibited positive overjets during follow-up. The unstable group demonstrated higher B–x and Co–Gn distances than the stable group (both P <.05) at T0. More short-term (T0–T1) sagittal advancement of point A (A–y) was evident in the unstable group than in the stable group (P <.05), but no long-term difference was apparent between the two groups (P =.481). During the posttreatment period (T1–T2), the SNA angle and maxillary incisor protrusion (U1–SN angle) were considerably lower in the unstable group than in the stable group (both P <.05). Overall, the unstable group exhibited a lower increase in the vertical extent of point A (A–x) than the stable group from T0 to T2 (P <.05). In the long term, MP affords favorable maxillary advancement in patients with UCLP. A mandibular excess at T0 and vertical maxillary hypoplasia may contribute to the long-term relapse of a reverse overjet. [ABSTRACT FROM AUTHOR]

Objectives: The present study aimed to compare the amount of incisal tooth wear in the maxillary central incisors of patients with skeletal Class III malocclusion and anterior crossbite receiving onephase or two-phase treatment. The hypothesis was that tooth wear would differ according to treatment modalities. Materials and Methods: Maxillary dental casts obtained before (T1) and after (T2) orthodontic treatment were divided into three groups. Group I consisted of casts from 21 patients (7 males, 14 females; mean age 9.8 years) who received two-phase treatment (maxillary protraction followed by fixed appliance therapy). Group II comprised casts from 37 patients who underwent orthodontic camouflage treatment for crossbite, subdivided according to age. Group IIa consisted of casts from 15 adolescents (8 males, 7 females; mean age 13.5 years), and group IIb consisted of casts from 22 adults (13 males, 9 females; mean age 24.5 years). Maxillary dental casts obtained at T1 and T2 were scanned. For each pair of digital images, T2 was superimposed on T1 using the best-fit method. Tooth wear was quantified and compared among groups. Results: Significantly less tooth wear was observed in group I compared to groups IIa and IIb, but no difference was found between groups IIa and IIb. Spearman correlation analysis revealed no significant correlation between tooth wear and age, treatment duration, or craniofacial morphology. Conclusions: Despite the long duration of early treatment, it caused less wear of the maxillary central incisors than did orthodontic camouflage treatment. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the changes in pharyngeal airway dimensions and the position of the hyoid bone after maxillary protraction with different alternate rapid maxillary expansion and construction (Alt-RAMEC) protocols in patients with skeletal class III malocclusion as a result of maxillary retrusion. Material and Methods: The patients with skeletal class III malocclusions were consecutively divided into two groups. Group 1 consisted of 17 patients (11 boys and 6 girls, mean age 11.31 6 1.71 years) who had the Alt-RAMEC protocol for 5 weeks, and group 2 consisted of 17 patients (10 boys and 7 girls, mean age 11.64 6 1.24 years) who had the Alt-RAMEC procedure for 9 weeks. In this study, 4 angular and 13 linear measurements were performed to evaluate the skeletal and pharyngeal airway changes that occurred after maxillary protraction. Results: A significant increase in the maxillary growth, inhabitation of mandibular growth, and clockwise rotation of the mandible caused the improvement of the maxillo-mandibular relationship in both groups. Those changes caused a significant increase in the upper pharyngeal airway dimension (P , .01) and affected the vertical position of the hyoid bone in both groups (P , .05 and P , .01, respectively). However, changes that occurred in both groups were found to be similar for all airway variables (P . .05). Conclusion: Upper pharyngeal dimension and vertical position of the hyoid bone were affected by the maxillary protraction with different Alt-RAMEC protocols. There were no statistically significant differences between the groups. [ABSTRACT FROM AUTHOR]

Objective: To test the null hypothesis that there were significant differences for skeletal, dentoalveolar, and soft tissue changes induced by face mask (FM) started simultaneously and after an alternate rapid maxillary expansion and constriction (Alt-RAMEC) procedure. Materials and Methods: Thirty-six patients with Class III malocclusion due to maxillary deficiency were randomly assigned to Group I (FM started after the completion of the Alt-RAMEC) and Group II (FM started simultaneously with the Alt-RAMEC). The screw of the RME appliance was alternately activated and deactivated twice daily (0.20 mm per turn) for 1 week over the course of 8 weeks. The changes observed in both groups were assessed using the cephalometric lateral films and statistically evaluated using the paired t-test and Student's t-test. Results: Thirty patients completed the present prospective study. No significant differences were observed between the groups. Class III malocclusion and negative overjet were improved by means of skeletal changes in conjunction with upper incisor proclination in both groups. Skeletal contribution to overjet correction in Groups I and II was 91.70% and 86.10%, respectively. Maxilla showed a forward movement of 3.84 mm and 3.02 mm in Groups I and II, respectively. Conclusions: The null hypothesis was rejected. Both groups showed similar results, and, thus, waiting until completion of the Alt-RAMEC procedure for the FM treatment is not necessary. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To analyze the long-term stability of rapid maxillary expansion (RME) and protraction from chincup therapy in girls with Class III malocclusion. MATERIALS AND METHODS: Twenty-two girls (mean age = 9.1 ± 0.6 years) with Class III malocclusion were treated with combined RME and protraction from a chincup, followed by fixed appliances. Lateral cephalograms were evaluated before treatment, at the end of a two-phase treatment protocol (mean age = 15.1 ± 1.1 years), and 10.9 ± 0.5 years after the end of treatment (mean age = 27.5 ± 0.5 years). The control group consisted of 22 matched girls with skeletal Class I malocclusion. RESULTS: After treatment, the Class III group showed significant improvement of the Class III malocclusion, mainly due to changes in the mandible (ie, SNB angle decreased 1.8 ± 1.6°) and significant improvement of the sagittal maxillomandibular relationship (Wits appraisal increased 2.6 ± 2.1 mm; ANB angle increased 1.0 ± 0.3 mm). These changes remained stable for an average of 10 years after the end of therapy. No tendency toward relapse was detected, and the mandibular position showed favorable outcomes. CONCLUSIONS: RME and protraction from chincup therapy led to successful long-term outcomes in 18 of 22 patients (81.8%). This treatment approach can be considered an efficient therapy in growing girls with mild skeletal Class III malocclusion caused by maxillary retrusion and mandibular protrusion. [ABSTRACT FROM AUTHOR]

Objective: To analyze the treatment effects of corticotomy-assisted maxillary protraction with skeletal anchorage and Class III elastics in patients with Class III malocclusions. Materials and Methods: The study group consisted of 19 patients with a mean age of 13.12 ± 1.28 years. Initially, patients were monitored for 5 months before treatment to evaluate growth changes. Changes during control, protraction and fixed orthodontic treatment periods were compared with the cephalometric radiographs taken initially, before protraction, after protraction, and after fixed orthodontic treatment. Treatment outcomes also were compared with the growth effects. Results: Sagittal measurements of maxilla showed significant improvements (3.59 ± 1.32 mm) during the protraction period (3.85 ± 1.12 months) whereas no significant changes were seen during the control period. Upper and lower incisor inclinations were increased, and the upper occlusal plane angle showed significant counterclockwise rotation during protraction. Significant soft-tissue changes also reflected the underlying skeletal changes. Maxillary advancement was stable during fixed orthodontic treatment. Conclusion: Compared with control period of the patients, this protocol produced significant improvements in skeletal and soft-tissue structures. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effectiveness of temporary anchorage device (TAD)-anchored maxillary protraction (MP) in terms of the skeletal and dentoalveolar changes and to compare it with traditional tooth-anchored MP. Materials and Methods: A computerized literature search for relative randomized controlled trials and prospective controlled trials was performed in PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Embase, CNKI, and Google Scholar, complemented with manual search. Data extraction and quality assessment were carried out by two reviewers independently. Meta-analysis was followed when possible; otherwise, description was done. Results: Forty articles were found, among which four trials were qualified for meta-analysis. The results showed that there was significant difference between TAD-anchored MP and untreated control in terms of maxillary advancement (weighted mean differences (WMD) 3.08 mm; 95% CI: 1.61 to approximately 4.56; P < .0001), but there were no consistent points in terms of mandibular rotation. Also, there were significant differences between both treatment patterns regarding maxillary advancement (WMD 1.41 mm; 95% CI: 0.47 to approximately 2.35; P = .003), mandibular rotation (WMD -1.39°, 95% CI: -2.47 to approximately -0.31; P = .01), proclination of maxillary incisors (WMD -2.29°; 95% CI: -4.41 to approximately -0.17; P = .03), and extrusion of maxillary molars (WMD 21.68 mm; 95% CI: -2.51 to approximately 20.85; P < .0001). Conclusions: According to the present results, TAD-anchored MP might have a greater maxillary advancement effect and might reduce skeletal and dental side effects, compared with toothanchored MP. [ABSTRACT FROM AUTHOR]

Objective: To compare the dentofacial effects of maxillary protraction with two facemask therapies in growing Class III patients: facemask in association with miniscrew implants (MSI/FM) and facemask with rapid maxillary expanders (RME/FM). Materials and Methods: Forty-three Chinese patients with Class III malocclusion and maxillary deficiency were randomly assigned to a MSI/FM sample of 20 patients and a RME/FM sample of 23 subjects. The changes in dentofacial cephalometric variables from the beginning (T1) to the end of treatment (T2) were compared with t-test for paired samples in both groups and for independent samples between the two groups. Results: No significant cephalometric differences were observed between the two groups in active treatment effects except for maxillary dental variables. However, significant favorable changes in both maxillary and mandibular skeletal components were noted in two groups after treatment. Sagittal measurements showed the maxilla was advanced, mandibular projection was reduced, and the relative sagittal intermaxillary discrepancy improved. Patients experienced additional unfavorable outcomes of clockwise rotation of the mandible as well as retroclination of the lower incisors. The soft tissue profile was improved remarkably in both groups. Proclination of the maxillary incisors and mesialization of the maxillary dentition were significantly different between the two groups. The increases in U1-SN, U1-VR, and U6-VR were 6.41u, 2.78 mm, and 1.24 mm less in the MSI/FM group than in the RME/FM group, respectively. Conclusions: Compared with the RME/FM therapy, the MSI/FM protocol using a smaller magnitude of protraction force improves skeletal relationships and soft tissue profile and reduces the undesired dentoalveolar effects. [ABSTRACT FROM AUTHOR]

Objective: To describe the correlation between the skeletal changes induced by maxillary protraction treatment and the sagittal airway dimension associated with tongue, soft palate, and hyoid bone position in skeletal Class III children. Materials and Methods: Twenty Class III patients (5 boys, 15 girls; mean age, 9.4 6 1.8 years) treated with a maxillary protraction appliance were included in this study. Pretreatment and posttreatment cephalometric radiographs were analyzed; linear and angular measurements were performed by an expert orthodontist. The correlation between treatment changes in craniofacial morphology and those in upper airway, tongue, soft palate, and hyoid position was evaluated by Pearson's correlation analysis. Results: A significant increase in maxillary forward displacement, inhibition of mandibular forward growth, and clockwise rotation of the mandible were observed. Simultaneously, nasopharyngeal airway measurements PNS-ad1 and PNS-ad2 significantly increased by 1.4 mm and 1.9 mm, respectively. A correlation analysis revealed that maxillary protraction had a positive relationship with PNS-ad1 and PNS-ad2. Conclusions: The nasopharyngeal airway dimensions can be improved in the short term with maxillary protraction in skeletal Class III children. (Angle Orthod. 2011;81:426-432.) [ABSTRACT FROM AUTHOR]

Objective: To compare the treatment outcomes of rapid maxillary expansion (RME) plus face mask (FM) and LeFort 1 osteotomy + FM during maxillary protraction. Materials and Methods: This study was carried on 34 patients all having maxillary retrognathic, anterior cross-bite, Class III skeletal and dental malocclusion characteristics and a concave profile. Eighteen patients with milder maxillary retrognathism were treated with RME + FM. Sixteen other patients with moderate to severe maxillary retrognathism were treated with an incomplete LeFort 1 osteotomy + FM therapy. Cephalometric data were evaluated statistically. Results: Significantly higher values of maxillary advancement and reduced treatment time were achieved with surgically assisted FM therapy. Conclusions: The surgically assisted FM treatment was more rapid and effective in maxillary protraction compared to the RME + FM treatment. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference in the active treatment effects for maxillary advancement induced by bone-anchored maxillary protraction (BAMP) and the active treatment effects for face mask in association with rapid maxillary expansion (RME/FM). Materials and Methods: This is a study on consecutively treated patients. The changes in dentoskeletal cephalometric variables from start of treatment (T1) to end of active treatment (T2) with an average T1-T2 interval of about 1 year were contrasted in a BAMP sample of 21 subjects with a RME/FM sample of 34 patients. All subjects were prepubertal at T1. Statistical comparison was performed with t-tests for independent samples. Results: The BAMP protocol produced significantly larger maxillary advancement than the RME/FM therapy (with a difference of 2 mm to 3 mm). Mandibular sagittal changes were similar, while vertical changes were better controlled with BAMP. The sagittal intermaxillary relationships improved 2.5 mm more in the BAMP patients. Additional favorable outcomes of BAMP treatment were the lack of clockwise rotation of the mandible as well as a lack of retroclination of the lower incisors. Conclusions: The hypothesis is rejected. The BAMP protocol produced significantly larger maxillary advancement than the RME/FM therapy. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that there is no difference between the effects of maxillary protraction on anterior crossbites in repaired unilateral cleft lip and palate (UCLP) and noncleft prepubertal boys. Materials and Methods: Eighteen operated UCLP boys with anterior crossbite (aged 9.54 ± 1.21 years) were the experimental subjects. Eighteen noncleft boys with similar malocclusion (aged 9.75 ± 1.46 years) were selected as a control group. A Hyrax appliance and reverse headgear were applied. Lateral cephalometric radiographs were taken before and after the treatment. Computerized cephalometric analysis and statistics were carried out. Results: There were no significant differences in anterior movement of point A between the two groups (P > .05). ANB increased by 3.82° and A-Pg (FH) increased by 5.89 mm in the UCLP group. ANB increased by 2.68° and A-Pg (FH) increased by 3.66 mm in the noncleft group. The change of sagittal skeletal intermaxillary relationships was significantly larger in the UCLP group than in the noncleft group (P < .05). The change of lower lip in the UCLP group was less than in the noncleft group (P < .05). Conclusions: The hypothesis is rejected. The changes of sagittal skeletal intermaxillary relationship and mandibular clockwise rotation were larger in the operated UCLP patients than in the noncleft subjects. The amount of the lower lip retrusion was significantly less in the UCLP patients. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that maxillary protraction appliances (MPA) have no effect on the size of the upper airway passage and craniofacial structures in adolescent patients. Materials and Methods: Twenty patients (5 male and 15 female; mean age 11.5 years) with skeletal Class III malocclusion were included in this study. The records of all patients who had maxillary protraction treatment and had lateral head radiographs taken before and after their protraction treatments were obtained from the files of treated cases. Treatment changes were determined by means of linear, angular, and area measurements. Data were analyzed statistically by means of paired t-test and correlation analysis. Results: Significant increases were observed in the width and area of the pharyngeal airway. Significant increases also occurred in the sagittal growth of the maxilla, while a clockwise rotation and inhibition of sagittal growth were observed in the mandible. Conclusions: The hypothesis was rejected. The size of the upper airway can be increased by means of MPA application. [ABSTRACT FROM AUTHOR]

Objective: The goal of the study was to examine the strain in the sutures of the midface and the cranial base with maxillary protraction therapy and to clarify whether such stretching suggests a skeletal effect of the apparatus employed for that purpose. Materials and Methods: Using a finite elements model, a maxillary protraction therapy was simulated with various force levels and vectors, and the strains appearing at the sutures (in µstrain) were measured at the midface and the cranial base. The simulation model we employed consisted of 53,555 individual elements; the simulated forces were 2 x 3 N and 2 x 5 N, while the vectors of the applied forces were in the anterior and anterior caudal direction. Results: The maximum measured strains were on average below 10 µstrain, while higher values were measured only at the nasal bone and at the cranial base at the oval and spinous foramina with anterior directed force vectors (26.4 µstrain). With an anterior-caudal force vector, the measured values were usually lower. Discussion: The measured strains were on average about hundredfold lower than the Frost thresholds (2000 µstrain). It does not seem probable that the strains occurring upon maxillary protraction therapy suffice to stimulate any additional bone growth. Conclusion: The good clinical efficacy of maxillary protraction therapy is apparently based, for the most part, on dental effects, while its skeletal effects still remain doubtful. [ABSTRACT FROM AUTHOR]

Multipurpose titanium miniplates were placed on the lateral nasal wall of the maxilla as anchorage for face mask protraction in an 11-year-old girl presenting with severe maxillary hypoplasia and hypodontia. Applying orthopedic forces directly to the maxilla resulted in an eight mm maxillary advancement. Intraosseous titanium screws were also placed on the palatal bone, near the alveolar crests, to provide anchorage for the expansion appliance. The maxilla was expanded from the median palatal suture, and seven mm of expansion was achieved across the buccal segments. No other tooth support was used for the expansion or the protraction of the maxilla. [ABSTRACT FROM AUTHOR]

A hexagonal onplant of 7.7 mm diameter was placed on the palatal bone of the maxilla in an 11-year five-month-old female patient with a Class III malocclusion and midface deficiency. Elastic traction (400 g per side) was applied from a facemask to the onplant at 30° to the occlusal plane 12 hours per day for 12 months. The maxilla was found to have displaced forward and downward by 2.9 mm. The mandible was rotated downward and backward. There was a 3° increase in mandibular plane angle and an increase in the lower face height. Clinically, there was a significant improvement in midface esthetics, noted by an increase in fullness of the infraorbital region and correction of the skeletal discrepancy between the maxillary and mandibular jaw relationship. Contrary to the reports that use teeth rather than onplants as anchorage, there was no forward movement of the maxillary molars and minimal extrusion of the maxillary molars. These results suggest that onplants can be used as an extremely stable anchorage for maxillary orthopedic facemask treatment. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate and compare the soft tissue effects of chincup (CC), chincup plus bite plate (CC+P), and reverse headgear (RHg) therapies with each other and with an untreated control group (C). The material consisted of lateral cephalometric and hand-wrist films of 59 Class III cases and 20 nontreated control subjects. Thirty-one cases were treated with CC, 14 with CC+P, and 14 with RHg, and Class I relation was achieved. The mean pretreatment ages were approximately 11 years and the observation period was one year. The cephalometric films were analyzed according to the structural superimposition method of Björk. All tracings were double digitized, and the measurements were calculated by a computer program (PORDIOS). Treatment and control changes within the groups and the differences between the groups were analyzed statistically. Forward positioning of the maxilla was significant in the RHg group, whereas the mandible was positioned backward significantly in all the treatment groups. Posterior rotation of the mandible was significant in the CC+P and RHg groups. The overjet increased and the overbite decreased significantly in all the treatment groups. Forward movement of soft tissue A and upper lip was significant in all groups, whereas more pronounced in the CC+P group. The soft tissue changes in the mandibular region were significant in the CC and CC+P groups, whereas in the maxillary region more significant and similar improvements were obtained by CC+P and RHg treatments. Long-term studies are required to confirm the stability of these changes. [ABSTRACT FROM AUTHOR]

This cephalometric study evaluated skeletal and dentoalveolar changes produced by rapid maxillary expansion and facial mask therapy in 85 subjects exhibiting a Class III malocclusion with a retruded maxilla. The skeletal maturity of individual patients was assessed on the basis of Fishman's skeletal maturity indicator (SMI), using hand-wrist radiographs at the initiation of treatment, to determine the relationship between the effect of maxillary protraction and skeletal age. Patients were divided into three groups: prepubertal growth peak group (SMI 1-3), pubertal growth peak group (SMI 4-7), and postpubertal growth peak group (SMI 8-11). The major findings of this cephalometric study were as follows: (1) there was no difference in the effects of maxillary advancement after maxillary protraction between the prepubertal growth peak and the pubertal growth peak group, but there was a decrease in the postpubertal growth peak group; (2) in the postpubertal growth peak group, there was a decrease in maxillary skeletal advancement, whereas the dentoalveolar effect was increased; (3) the posteroinferior rotation of mandible, the increase of lower facial height, and the eruption of maxillary molars showed no correlation with skeletal age. The results of our study emphasize the importance of performing a biologic evaluation of skeletal maturity and pubertal growth peak in individual patients in the diagnosis and treatment planning of Class III malocclusions. [ABSTRACT FROM AUTHOR]

A 7-year-old girl with a cleft lip and palate had a midface retrusion due to growth inhibition of the maxillary complex. She presented for correction of a severe total crossbite with a Class III skeletal pattern. Initially, maxillary expansion was provided to widen the maxilla and then maxillary protraction headgear was worn to improve the sagittal skeletal relation. Fixed orthodontic appliances were placed to align the dentition and Class III elastics were used to establish intercuspation and stability. The maxillary expansion and protraction usually provide effective improvement in skeletal Class III patients with repaired cleft lip and palate patients. The success of the orthopedic procedure essentially depends on the individual growth of the maxilla and the mandible. This case report shows the significant growth of the mandible after maxillary expansion and protraction in late adolescence. [ABSTRACT FROM AUTHOR]

This study was conducted to examine the effect of treatment with a maxillary protraction appliance on the development of the craniofacial structures and upper-airway dimensions. A total of 25 patients (mean age: 9.8 years) with Class III malocclusions were evaluated by the use of lateral cephalograms. A significant increase in maxillary forward growth, inhibition of mandibular forward growth, and clockwise rotation of the mandible were observed. The maxillary incisors were significantly proclined and the mandibular incisors significantly retroclined. A multiple-regression analysis revealed that maxillary growth had a significant positive effect on the superior upper-airway dimension. These findings indicate that the superior upper-airway dimension can be altered during maxillary protraction. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effects of very early face mask therapy in children with Class III malocclusion. At pretreatment (T0), 40 female subjects who were eventually treated showed a more severe Class III pattern (ANB 0.1°) than did 28 skeletal Class III female subjects who remained untreated (ANB 0.4°), as observed in the Wits analysis. Posttreatment results (T1) showed significant (p<0.01) anterior advancement of the maxillary components, backward rotation of the mandible without increased lower anterior facial height, and an improved incisor relationship. Comparison of posttreatment (T1) and postretention (T2) records, however, revealed no increase in SNA in the treated group. SNA did increase in the untreated group, with no significant difference in ANB angle. The x-components of B-point and Me showed a significant (p<0.05) difference between the two groups. At postretention (T2), N-S-Ba, N-S-Ar, and CC-Ba tended to increase more in the treated group than in the untreated group. [ABSTRACT FROM AUTHOR]

Objectives: The present study aimed to compare the amount of incisal tooth wear in the maxillary central incisors of patients with skeletal Class III malocclusion and anterior crossbite receiving one-phase or two-phase treatment. The hypothesis was that tooth wear would differ according to treatment modalities., Materials and Methods: Maxillary dental casts obtained before (T1) and after (T2) orthodontic treatment were divided into three groups. Group I consisted of casts from 21 patients (7 males, 14 females; mean age 9.8 years) who received two-phase treatment (maxillary protraction followed by fixed appliance therapy). Group II comprised casts from 37 patients who underwent orthodontic camouflage treatment for crossbite, subdivided according to age. Group IIa consisted of casts from 15 adolescents (8 males, 7 females; mean age 13.5 years), and group IIb consisted of casts from 22 adults (13 males, 9 females; mean age 24.5 years). Maxillary dental casts obtained at T1 and T2 were scanned. For each pair of digital images, T2 was superimposed on T1 using the best-fit method. Tooth wear was quantified and compared among groups., Results: Significantly less tooth wear was observed in group I compared to groups IIa and IIb, but no difference was found between groups IIa and IIb. Spearman correlation analysis revealed no significant correlation between tooth wear and age, treatment duration, or craniofacial morphology., Conclusions: Despite the long duration of early treatment, it caused less wear of the maxillary central incisors than did orthodontic camouflage treatment.