Dentoskeletal effects of rapid maxillary expander therapy in early mixed dentition patients with different vertical growing patterns without posterior crossbite: A retrospective study.

INTRODUCTION: This study aimed to analyze the variation of dentoskeletal effects after rapid maxillary expander therapy in subjects with different vertical growth patterns. METHODS: The study sample consisted of 94 patients (32 males, 62 females; mean age 8.9 ± 1.5 years) treated with rapid maxillary expander (RME) anchored on first permanent molars. For each subject, lateral cephalograms and maxillary digital dental casts were available before RME, immediately after appliance removal, and 1 year after appliance removal. All the subjects were divided into 3 groups according to their vertical facial patterns (low-angle, normal-angle, and high-angle). Cephalometric analysis was conducted on lateral cephalograms. The virtual 3-dimensional models were used to analyze the torque of the first permanent molars and intercanine and intermolar width. The differences between the vertical facial subgroups were contrasted by analysis of variance multicomparison test (P <0.05). RESULTS: In the short-term (from before to immediately after RME removal), high-angle subjects showed a mandibular clockwise rotation compared with other groups. No significant long-term vertical and sagittal skeletal changes (from before to 1 year after RME removal) were found between the groups. A greater increase in maxillary molar torque was observed in high-angle subjects than in the other groups. The low-angle patients showed a greater increase in the intercanine diameter. CONCLUSIONS: Hyperdivergent subjects showed increased buccal tipping of the anchor molars after the expansion. Hypodivergent and normodivergent subjects showed lower buccal tipping after the expansion and an increased expansion effect in the anterior region.

Leveling the curve of Spee: Comparison between continuous archwire treatment and Invisalign system: A retrospective study.

INTRODUCTION: The purpose of this study was to evaluate and compare leveling of the curve of Spee (COS) achieved by traditional fixed appliances and Invisalign clear aligners (Align Technology, Santa Clara, Calif). METHODS: This retrospective study involved 2 groups of subjects with an increased COS depth. Patients treated with the Invisalign system (I group) and patients treated with the standard edgewise full-fixed appliance (F group). The I group included 30 subjects (13 males, 17 females; mean age, 24 years 5 months ± 19 months). The F group included 32 subjects (12 males, 20 females; mean age, 22 years 4 months ± 21 months). The 2 groups were matched for sex, age, vertical pattern, and observation period. Pretreatment (T0) and posttreatment (T1) lateral cephalograms were analyzed. COS depth was measured on digital dental casts. The intragroup variation between T0 and T1 was analyzed with a paired t test. The intergroup variation was evaluated using an unpaired t test. RESULTS: The leveling of COS was statistically significant, comparing T0 and T1 within the groups. The F group presented a statistically significant extrusion of posterior teeth, with a flaring of the mandibular incisors. The I group showed a statistically significant intrusion of the mandibular incisors, with excellent control in the proclination of incisors during the intrusion movement. CONCLUSIONS: Traditional continuous archwire treatment and the Invisalign system effectively level the COS.

Dento-skeletal response to three different protocols of rapid maxillary expansion in hyperdivergent growing subjects: a longitudinal retrospective study.

BACKGROUND: The aim of this study was to evaluate the dento-skeletal response in hyperdivergent growing patients comparing Rapid Maxillary Expansion (RME) using three different protocols. MATERIALS AND METHODS: Three groups of hyperdivergent subjects treated with RME were analyzed. In 41 patients (23F, 18M) the RME was bonded on the maxillary deciduous second molars (E-RME group); in 40 patients (24F, 16M) the RME was bonded on the first permanent maxillary molars (6-RME group); in 45 patients (26F,19M) the RME was bonded on the first permanent maxillary molars with a removable mandibular Bite-Block (6-RME/BB group). Lateral cephalograms and dental casts were scanned and digitally measured before treatment (T1), at the appliance removal (T2) and at least 1 year after the appliance removal (T3). The comparison was made within the same group and between the groups. Statistical comparisons were assessed with analysis of variance multi-comparison test (*P = 0.05). RESULTS: A significant increase of upper molars buccal tipping was observed in 6-RME group when compared with E-RME and 6-RME/BB groups in the short-term (T2-T1) and long-term (T3-T1); a significant intercanine width increase was observed in E-RME group at the same times. No significant differences in dentoalveolar variables were observed comparing E-RME group versus 6-RME/BB group. CONCLUSIONS: The E-RME protocol allows for a greater skeletal expansion and produces a lower buccal tipping of the first permanent upper molars. The use of the BB in 6-RME/BB group shows a similar attitude to the E-RME protocol then can be considered an effective therapeutic alternative.

Palatal vault morphometric analysis of the effects of two early orthodontic treatments in anterior open bite growing subjects: a controlled clinical study.

BACKGROUND: The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM). METHODS: AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. RESULTS: At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs. CG demonstrated a slight transversal maxillary expansion. CONCLUSIONS: RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Changes in mandibular shape after early treatment in subjects with open bite: a geometric morphometric analysis.

OBJECTIVES: To evaluate the mandibular modifications in anterior open bite (OB) growing subjects treated with Rapid Maxillary Expansion and bite block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Method (GMM) and conventional cephalometric. MATERIALS: The OB group comprised 34 subjects (26 girls, 8 boys) with dentoskeletal OB and a mean age of 8.0 ± 1.0 years. OB group was divided in two subgroups: RME/BB group comprised 17 subjects (13 girls, 4 boys), while QH/C group included 17 subjects (13 girls, 4 boys). The two subgroups were compared with a CG of 17 subjects (13 girls, 4 boys) matched for sex, age, vertical pattern, and observation periods. Two consecutives lateral cephalograms were available: the first one was taken before treatment (T1), and the second one was acquired at a follow-up observation at least 4 years after the completion of treatment (T2). Landmarks and semilandmarks were digitized on lateral cephalograms and GMM was applied. Procrustes analysis and principal component analysis were performed. Analysis of variance (ANOVA) with Tukey post hoc tests was used to compare the T2-T1 cephalometric changes between the RME/BB, QH/C, and CG. RESULTS: In the long term, RME/BB showed a significantly greater decrease of the Condylar axis to mandibular plane angle when compared to CG and QH/C. GMM showed an increased in height of the mandibular ramus in RME/BB group with tendency to counterclockwise rotation of the mandible when compared with QH/C and CG groups. CONCLUSIONS: RME/BB subjects showed significant changes in the shape of the mandibular ramus with a counterclockwise rotation tendency when compared with QH/C and CG subjects.

Morphometric analysis of the palatal shape and arch dimension in subjects with buccally displaced canine.

OBJECTIVES: To analyse morphological variations of the palate shape and maxillary arch dimension between a group of subjects with unilaterally or bilaterally buccally impacted maxillary canines and a control group (CG) by means of 3D geometric morphometric (GMM). MATERIALS: Pre-treatment records of 50 subjects (16 males and 34 females; mean age 13.9 years ± 1.8) with one or both canines buccally displaced were collected retrospectively. A CG of 50 subjects was selected from a list of orthodontic patients at the same dental hospital. The experimental group, buccally displaced canine (BDC) was divided in two groups: unilateral buccally displaced canine (UBDC) and bilateral buccally displaced canine (BBDC). To analyse the palate's shape and maxillary arch dimension, study casts were scanned. To study the entirety of the palatal shape, 3D GMM analysis was used. To analyse the maxillary arch dimension, the virtual three-dimensional models were measured with a specific software (VAM, Vectra, Canfield Scientific, Fairfield, New Jersey, USA). RESULTS: When comparing the groups with the GMM analysis, patients with BDC showed a statistically significant narrower and higher palatal vault. About the analysis of linear measurements, the intercanine width, the anterior and posterior segment length were significantly smaller in BDC, UBDC, and BBDC subjects when compared with the controls and there were no differences between UBDC versus BBDC groups. CONCLUSIONS: Patients with buccally displaced permanent canine tended to have maxillary transverse constriction and variation in palatal vault morphology. The morphometric variation of the palatine vault and arch dimensions can be considered a clinical factor associated with the presence of BDC.

Morphometric analysis of the palatal shape and arch dimension in subjects with palatally displaced canine.

OBJECTIVES: The aim of this study is to analyse the morphological variations of the palate shape and maxillary arch dimension in a group of subjects with unilaterally or bilaterally impacted maxillary canines compared with a control group, using three-dimensional (3D) geometric morphometric. MATERIALS: The subject of this study consisted of pre-treatment records of 46 (18 males and 28 females) patients with one or both canines palatally displaced. A control group of 26 subjects was selected from a list of orthodontic patients at the same dental hospital. The subjects were divided in two study groups: unilateral palatally displaced canine (UPDC) and bilateral palatally displaced canine (BPDC). Study casts were scanned to analyse the palate's shape and maxillary arch dimension. The 3D geometric morphometric analysis was used to study the entirety of the shape of the palate. The virtual 3D models were measured with a specific software to analyse the maxillary arch dimension. (VAM, Vectra; Canfield Scientific, Fairfield, New Jersey, USA). RESULTS: When comparing the groups with the geometric morphometrics analysis, no significant palatal shape change was found. For the analysis of linear measurements, only a significant reduction of intercanine width was found in the UPDC and BPDC groups when compared with the control subjects. CONCLUSIONS: Patients with palatally displaced permanent canine showed no maxillary transverse constriction or variation in palatal vault morphology but the absence of permanent teeth was associated with a reduction in the intercanine width.

Long-term stability of curve of Spee levelled with continuous archwires in subjects with different vertical patterns: a retrospective study.

OBJECTIVES: The aim of the study was to evaluate the curve of Spee (COS) stability in patients treated with continuous archwires with different vertical patterns. METHODS: The study sample consisted of 60 patients (28 males, 32 females; mean age 19.8 ± 1.4 years) presenting with COS depth of at least2 mm at baseline. For each subject, lateral cephalograms and dental casts were available before treatment (T1), at the end of orthodontic therapy (T2), and 2 years after the end of treatment (T3). All subjects were divided into three groups according to vertical facial patterns. Cephalometric parameters were used to evaluate the dental movements after treatment. COS depth was measured on digital casts. Mean differences between vertical facial subgroups were contrasted by means of analysis of variance test (P < 0.01). RESULTS: In low-angle subjects, COS levelling occurred through advancement and intrusion of lower incisors, whereas in high-angle patients, the COS was flattened through extrusion and uprighting of lower posterior teeth. In the low-angle group, a significant relapse of lower incisors inclination was observed. Differently, the high-angle group exhibited a greater stability of COS obtained by stable extrusion of posterior teeth. CONCLUSIONS: The long-term instability of flared incisors determined the relapse of overbite and COS depth in the low-angle group.

Long-term evaluation of rapid maxillary expansion and bite-block therapy in open bite growing subjects: A controlled clinical study.

OBJECTIVE: To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite. MATERIALS AND METHODS: The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG. RESULTS: In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (-3.3 mm), and, consequently, a significant decrease in facial divergence (-2.8°) when compared with untreated subjects. CONCLUSIONS: The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.

Leveling the curve of Spee with continuous archwire appliances in different vertical skeletal patterns: A retrospective study.

INTRODUCTION: The aim of this study was to determine the effects of the leveling of the curve of Spee in subjects treated with preadjusted appliances in different skeletal vertical patterns. METHODS: The study sample consisted of 90 white patients (39 male, 51 female; age, 19 years 4 months ± 1 year 9 months), with a curve of Spee of 2 mm or greater before treatment. They were categorized into 3 groups: low-angle group (30 subjects; 12 male, 18 female; age, 19 years 1 month ± 1 year 4 months), normal-angle group (30 subjects; 14 male, 16 female; age, 19 years 6 months ± 2 years 1 month), and high-angle group (30 subjects; 13 male, 17 female; age, 19 years 7 months ± 1 year 5 months) by their vertical facial types. Cephalometric parameters were used to evaluate the different dental movements after treatment. The curve of Spee was measured on digital dental casts. Analysis of variance was used to determine any differences between the changes in the groups with time. RESULTS: For the skeletal variables, no significant modifications were found in the 3 groups. For the dentoalveolar variables, the low-angle group showed significant buccal movements and intrusion of the mandibular incisors. The high-angle group had greater extrusion of the posterior teeth associated with uprighting of the first and second molars. CONCLUSIONS: In low-angle subjects, leveling of the curve of Spee occurs through buccal movement and intrusion of the mandibular incisors; in high-angle subjects, it occurs through extrusion and uprighting of the posterior teeth.

Comparisons of two protocols for early treatment of anterior open bite.

Aim: The purpose of this study was to compare the outcomes of the treatment with the quad-helix/crib (Q-H/C) appliance with those of a combination of transpalatal arch, high-pull headgear, and lip bumper (TPA/HG/LB) in growing patients with anterior open bite malocclusion. Methods: The TPA/HG/LB sample consisted of 22 subjects, 16 girls and 6 boys (mean age 7.5±1.4 years at the start of treatment, T1, and 8.7±1.5 years at the end of active treatment, T2). The Q-H/C sample consisted of 28 subjects, 17 girls and 11 boys (mean age 8.2±1.3 years at T1, and 8.7±1.6 years at T2). Both treated groups were compared with a control group of 20 untreated subjects matched for dentoskeletal disharmony and observation interval. The changes from T2 to T1 between the three groups were compared with the analysis of variance. Results: Both TPA/HG/LB and Q-H/C groups exhibited greater reduction of the palatal plane to mandibular plane angle (-1.7° and -1.9°, respectively) and a significantly greater increase in overbite (2.2 and 2.3mm, respectively) with respect to controls. Conclusions: Q-H/C and TPA/HG/LB protocols were equally effective in correcting the anterior open bite.

Dentoskeletal features in individuals with ectopic eruption of the permanent maxillary first molar.

OBJECTIVE: The aim of the study was to analyze the prevalence and distribution of ectopic eruption of the permanent maxillary first molar (EEM) in individuals scheduled for orthodontic treatment and to investigate the association of EEM with dental characteristics, maxillary skeletal features, crowding, and other dental anomalies. METHODS: A total of 1,317 individuals were included and randomly divided into two groups. The first 265 subjects were included as controls, while the remaining 1,052 subjects included the sample from which the final experimental EEM group was derived. The mesiodistal (M-D) crown width of the deciduous maxillary second molar and permanent maxillary first molar, maxillary arch length (A-PML), maxillomandibular transverse skeletal relationships (anterior and posterior transverse interarch discrepancies, ATID and PTID), maxillary and mandibular tooth crowding, and the presence of dental anomalies were recorded for each subject, and the statistical significance of differences in these parameters between the EEM and control groups was determined using independent sample t-tests. Chi-square tests were used to compare the prevalence of other dental anomalies between the two groups. RESULTS: The prevalence of maxillary EEM was 2.5%. The M-D crown widths, ATID and PTID, and tooth crowding were significantly greater, while A-PML was significantly smaller, in the EEM group than in the control group. Only two subjects showed an association between EEM and maxillary lateral incisor anomalies, which included agenesis in one and microdontia in the other. CONCLUSIONS: EEM may be a risk factor for maxillary arch constriction and severe tooth crowding.

Post-traumatic impaction of maxillary incisors: diagnosis and treatment.

AIM: To provide clinicians with useful information for immediate diagnosis and management of impacted maxillary incisors due to trauma. METHODS: We present a case of post-traumatic impaction of a central right maxillary incisor in a young patient. The treatment plan consisted in the interceptive management (surgical and orthodontic), the valuation of the necessary space to move the impacted tooth in the normal position and the biomechanical approach for anchorage, avoiding prosthetic/implants replacement. RESULTS: THE THERAPY OF AN IMPACTED MAXILLARY INCISOR DUE TO TRAUMA REQUIRES A MULTIDISCIPLINARY APPROACH: orthodontic, surgical, endodontic and periodontal considerations are essential for successful treatment. CONCLUSIONS: SURGICAL EXPOSURE AND ORTHODONTIC TRACTION IS THE TREATMENT MOST OFTEN USED IN CASE OF POSTTRAUMATIC IMPACTED INCISOR: this technique in fact can lead to suitable results at the periodontal, occlusal and esthetics levels at an early stage and more definitively than with other treatment options.

Stability of quad-helix/crib therapy in dentoskeletal open bite: a long-term controlled study.

INTRODUCTION: The purpose of this study was to evaluate the long-term stability of quad-helix/crib treatment in subjects with dentoskeletal open bite. METHODS: Twenty-eight subjects (11 boys, 17 girls; mean age, 8.2 ± 1.3 years) were treated consecutively with quad-helix/crib appliances. The patients were reevaluated at the end of active treatment with the quad-helix/crib (mean age, 9.7 ± 1.6 years) and at least 5 years after the completion of treatment (mean age, 14.6 ± 1.9 years). A control group of 20 untreated subjects with the same dentoskeletal disharmony was used for the statistical comparison (Mann-Whitney U test). RESULTS: In the long term, the quad-helix/crib group showed a significant reduction in the ANB angle (-1.3°), a downward rotation of the palatal plane (1.8°), a greater increase in overbite (2.1 mm), and a decrease in overjet (-1.5 mm) when compared with the controls. CONCLUSIONS: In the long term, the use of the quad-helix/crib appliance led to successful outcomes in about 93% of the patients considered. Correction of dentoskeletal open bite was associated with a clinically significant downward rotation of the palatal plane.

Prevalence rate and dentoskeletal features associated with buccally displaced maxillary canines.

The aim of the study was to analyse the prevalence and distribution of buccally displaced canines (BDCs) in subjects scheduled for orthodontic treatment and to investigate the association between BDC and sagittal, vertical, and transverse dentoskeletal relationships. A study sample of 1852 subjects was examined, and it was divided randomly into two groups. A first group of 252 subjects served as control group: the 'reference' prevalence rates for the examined parameters were calculated in this group. The remaining 1600 subjects comprised the sample from which the experimental BDC group was derived. Presence of unilateral or bilateral maxillary BDC, ANB, and SN GOGn angles for sagittal and vertical skeletal relationships, intercanine and intermolar distances, and tooth crowding at the maxillary arch were recorded for each subject. The statistical significance of differences between the BDC and the control groups in transverse relations and tooth crowding at the upper arch was tested by means of independent sample t-tests. Chi-square tests were performed to compare the prevalence rates of BDC and also sagittal and vertical skeletal features in the two groups. The prevalence rate of BDC was 3.06 per cent with a male-to-female ratio of 1:1. BDC subjects exhibited a significant association with hyperdivergent skeletal relationships (38.8%), reduced maxillary intercanine width, and crowding in the upper arch. The presence of specific dentoskeletal characteristics can be considered as a risk indicator for developing a buccal displacement of upper permanent canines.

Impacted maxillary incisors: diagnosis and predictive measurements.

BACKGROUND: When the incisors do not erupt at the expected time, it is crucial for the clinician to determine the etiology and formulate an appropriate treatment plan. AIM: THE AIM OF THIS REPORT IS TO PROVIDE USEFUL INFORMATION FOR IMMEDIATE DIAGNOSIS AND MANAGEMENT OF IMPACTED MAXILLARY INCISORS USING THE INTERCEPTIVE TREATMENT: removal of obstacles and rapid maxillary expansion (RME). DESIGN: An accurate diagnosis may be obtained with clinical and radiographic exam such as panoramic radiograph, computerized tomography (CT) and cone beam computerized tomography (CBCT). It's important to know the predictive measurements of eruption evaluated on panoramic radiograph: distance from the occlusal plane, maturity, angulation and vertical position of the unerupted incisors. Early diagnosis is important and interceptive orthodontic treatment, such as removal of obstacles and orthopedic rapid maxillary expansion (RME), may correct disturbances during the eruption through recovering space for the incisors and improving the intraosseus position of delayed teeth. RESULTS: RME treatment following the surgical removal of the obstacle to the eruption of maxillary incisors leads to an improvement of the intraosseus position of the tooth. CONCLUSIONS: The angulation and the vertical position of the delayed tooth appear to be important in trying to predict eruption. The improvement of the intraosseus position of the unerupted incisor, obtained by removal of the odontoma and rapid maxillary expansion, permits a conservative surgery and the achievement of an excellent esthetics and periodontal result.

Stability of rapid maxillary expansion and facemask therapy: a long-term controlled study.

INTRODUCTION: The aim of this prospective controlled study was to evaluate the long-term effects of rapid maxillary expansion and facemask therapy in Class III subjects. METHODS: Twenty-two subjects (9 boys, 13 girls; mean age, 9.2 years ± 1.6) with Class III disharmony were treated consecutively with rapid maxillary expansion and facemask therapy followed by fixed appliances. The patients were reevaluated at the end of the 2-phase treatment (mean age, 14.5 years ± 1.9) and then recalled about 8.5 years after the end of rapid maxillary expansion and facemask treatment (mean age, 18.7 years ± 2.1). Two groups of controls with untreated Class III malocclusion were used for statistical comparisons of the short-term and long-term intervals. Statistical comparisons were performed with the Mann-Whitney U test. RESULTS: In the long term, no significant differences in maxillary changes were recorded, whereas the treatment group showed significantly smaller increases in mandibular protrusion. The sagittal maxillomandibular skeletal variables maintained significant improvements in the treatment group vs the control groups. CONCLUSIONS: In the long term, rapid maxillary expansion and facemask therapy led to successful outcomes in about 73% of the Class III patients. Favorable skeletal changes were mainly due to significant improvements in the sagittal position of the mandible.

Treatment and posttreatment effects of a facial mask combined with a bite-block appliance in Class III malocclusion.

INTRODUCTION: In this cephalometric investigation, we analyzed the treatment and posttreatment effects of an orthopedic protocol for Class III malocclusion consisting of a facial mask combined with a removable bite-block appliance. METHODS: The treated sample consisted of 22 Class III patients treated with the facial mask and bite-block protocol before the pubertal growth spurt (mean age, 8.9 +/- 1.5 years). Treated subjects were evaluated after facial mask and bite-block therapy and at a posttreatment observation in absence of retention. The treated group was compared with a matched control group of 12 untreated Class III subjects. All treated and control subjects were postpubertal at the final observation. Significant differences between the treated and control groups were assessed with the Mann-Whitney U test (P <0.05). RESULTS: Both angular and linear sagittal measurements of the maxilla showed significant improvements during active treatment. Significant improvements of SNA angle, ANB angle, overjet, and molar relationship remained stable during the posttreatment period. No significant effect was found in the mandibular skeletal measures. No significant protraction of the maxillary incisors or retraction of the mandibular incisors was observed. CONCLUSIONS: A bite-block appliance in the mandibular arch with a facial mask enabled effective control of mandibular rotation with progressive closure of the gonial angle. This added to the favorable maxillary outcomes of the treatment protocol.

Treatment and post-treatment effects of facemask therapy on the sagittal pharyngeal dimensions in Class III subjects.

The purpose of this cephalometric study was to analyse the treatment and post-treatment craniofacial effects of a facemask (FM) combined with a bite block (BB) with specific regard to the sagittal pharyngeal dimensions in subjects with a Class III malocclusion when compared with an untreated Class III control group. The FM/BB group (22 subjects, 12 females and 10 males) had a mean age pre-treatment (T1) of 8.9 +/- 1.5 years, at the end of active treatment (T2) of 10.5 +/- 1.3 years, and post-treatment (T3) of 12.6 +/- 1.9 years. The treated group was compared with a control group of 14 subjects (6 females and 8 males) with untreated Class III malocclusions that matched the FM/BB group as to age at T1, T2, and T3, observation periods and skeletal maturation. Comparisons of the T2-T1 and T3-T1 changes between the two groups were analysed with the Mann-Whitney test. Significant favourable skeletal changes in the maxilla and mandible were observed in the treated group both after Ts2 and T3. No significant short- or long-term changes in the sagittal oropharyngeal and nasopharyngeal airway dimensions were induced by maxillary protraction in subjects with a Class III malocclusion when compared with untreated controls.