Relationship between bite force, occlusal contact area, and three-dimensional facial soft tissue in dentofacial deformities.

PURPOSE: This study aimed to investigate three-dimensional facial soft tissue dimensions, maximum bite force (MBF), and occlusal contact area in patients with DFD. In addition, we analyzed the relationship between MBF and the three-dimensional facial measurements. METHODS: Thirty-two patients with skeletal Class III DFD and 20 patients with Class II DFD underwent a soft tissue evaluation using surface laser scanning, as well as MBF and occlusal contact area assessments. The DFD groups were compared with each other and with 25 healthy subjects. RESULTS: Significant morphological differences were found in the transversal, vertical, and anteroposterior dimensions between Class II DFD and Class III DFD. Both DFD groups presented an increased linear distance of chin height, which was strongly related with decreased MBF magnitude. The DFD groups exhibited lower MBF and occlusal contact area, with no significant differences between Class II and Class III DFD. CONCLUSION: The presence of DFD affected 3D measurements of facial soft tissue, causing variations beyond normal limits, lower MBF, and occlusal contact area in both Class II and Class III DFD patients. The vertical dimension might have influenced the lower MBF magnitude in the studied skeletal deformities.

Morphometric analysis of sella turcica in growing patients: an observational study on shape and dimensions in different sagittal craniofacial patterns.

The aim of this study was to evaluate the differences in sella dimensions and shape between growing patients with Class I, Class II, and Class III skeletal malocclusions, evaluated through morphometric analysis. Seventy-eight subjects aged between 9 and 13 years were selected and assigned to either the Class I, Class II, or Class III groups according to the measured ANB angle (the angle between the Nasion, skeletal A-point and skeletal B-point). Six landmarks were digitised to outline the shape of the sella turcica. Linear measurements of the sella length and depth were also performed. Procrustes superimposition, principal component analysis, and canonical variate analysis were used to evaluate the differences in sella shape between the three groups. A one-way MANOVA and Tukey's or Games-Howell tests were used to evaluate the presence of differences in sella dimensions between the three groups, gender, and age. The canonical variate analysis revealed a statistically significant difference in sella shape between the Class I and the Class II groups, mostly explained by the CV1 axis and related to the posterior clinoidal process and the floor of the sella. No differences were found regarding linear measurements, except between subjects with different age. These differences in sella shape, that are present in the earlier developmental stages, could be used as a predictor of facial growth, but further studies are needed.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation.

INTRODUCTION: Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. OBJECTIVE: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. METHODOLOGY: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. RESULTS: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. CONCLUSION: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Occlusal traits of 4-5-year-old Estonians. Parents' perception of orthodontic treatment need and satisfaction with dental appearance.

This study aims to evaluate the prevalence of occlusal traits and to assess parents'/caregivers' satisfaction with child's dental appearance and perception of orthodontic treatment need in 4-5-year-old Estonians. Clinical records and plaster casts of 390 children (190 girls and 200 boys, mean age 4.7 years, range 4 - 5 years) were analyzed. Assessed occlusal traits included deciduous canine and second molar sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite, and scissor bite. Parents'/caregivers' opinions regarding their child's teeth were determined with a questionnaire. The most prevalent occlusal traits were symmetrical sagittal relationship in deciduous canines (78.2%) and molars (75.1%), Class I sagittal relationship in deciduous canines (69.7%) and midline diastema (67.7%). Asymmetrical sagittal canine relationship was registered in 21.8% deciduous canines and in 24.9% second deciduous molars. Parents'/caregivers' perceived orthodontic treatment need was related to Class III sagittal relationship in canines, increased overjet and overbite, negative overbite, and crossbite. Prevalence of most occlusal traits in Estonian children were in line with those reported in neighboring countries. Parents/caregivers were well able to observe occlusal traits that deviated from acceptable occlusion.

Comparison of Pharyngeal Airway between Mandibular Setback Surgery Patients (Skeletal Class III) and Nonsurgery Patients (Skeletal Classes I and II).

PURPOSE: We investigated the pharyngeal airway dimensions and their correlations in patients who underwent mandibular setback surgery versus those who did not. MATERIALS AND METHODS: One hundred and sixty cephalometric radiographs (120 patients) were obtained from patients with three skeletal malocclusion classifications: Class I and Class II in the nonsurgery group and Class III in the surgery group (preoperative and postoperative cephalograms). The following dimensions were measured: nasopharyngeal airway (NOP), uvulopharyngeal airway (UOP), shortest distance from the posterior tongue to the pharyngeal wall (TOP), and distance from the epiglottis to the pharyngeal wall (EOP). Paired t test, one-way analysis of variance, and Pearson correlation coefficients were used for statistical analysis. RESULTS: Preoperatively, UOP and TOP of skeletal Class III patients (15.2 mm and 16.6 mm) were significantly larger than those of skeletal Class II (11.5 mm and 12 mm) and Class II (12.3 mm and 12.9 mm) patients, respectively. No differences were observed in EOP between the three skeletal patterns. The hyoid bone of Class III patients was significantly anterior to that of Class I/II patients. Furthermore, UOP had a moderate negative correlation with soft palate length. Postoperatively, no significant difference (UOP, TOP, EOP, soft palate width, and hyoid bone) was found between the skeletal classes. CONCLUSION: Preoperatively, UOP and TOP of skeletal Class III patients were significantly wider than those of skeletal Class I/II patients. Pre- and postoperatively, EOP did not exhibit significant differences among the three skeletal classifications. No differences were found in all postoperative pharyngeal airway dimensions between Class III patients and nonsurgery patients (Class I and Class II).

Changes in cross-sectional measurements of masseter, medial pterygoid muscles, ramus, condyle and occlusal force after bi-maxillary surgery.

PURPOSE: The purpose of this study was to examine changes in masseter and medial pterygoid muscles, ramus, condyle and occlusal force after bi-maxillary surgery in class II and III patients. SUBJECTS AND METHODS: The subjects were 42 patients (84 sides) who underwent sagittal split ramus osteotomy with Le Fort I osteotomy (21 class II cases: mandibular advancement and 21 class III cases: mandibular setback). The cross-sectional measurements of the masseter and medial pterygoid muscles, ramus and condyle were measured in horizontal plane images by computed tomography (CT), before and 1 year after the operation. Occlusal force and contact area were also recorded before and 1 year after the operation. RESULTS: Preoperatively, class II was significantly larger than class III in masseter width (P = 0.0068), masseter area (P < 0.0001) and medial pterygoid length (P < 0.0001). However, class II was significantly smaller than class III in medial pterygoid width (P < 0.0001). After 1 year, class II was significantly smaller than class III in masseter length (P = 0.0017). Class II was still larger than class III in medial pterygoid area after 1 year (P = 0.0343). Class II was significantly larger than class III in condylar angle pre-operatively (P < 0.0001) and after 1 year (P = 0.0006). After 1 year, class II decreased significantly more than class III in condylar thickness (P = 0.0020), condylar width (P < 0.0001) and condylar area (P < 0.0001). CONCLUSION: This study suggested that changes in the cross-sectional measurements of masseter and medial pterygoid muscles and the condyle differed between class II and class III patients, although occlusal force did not significantly change 1 year after surgery in both groups.

Three-dimensional longitudinal evaluation of facial mimicry in orthognathic class III surgery.

The effect of bimaxillary orthognathic surgery on facial mimicry was assessed longitudinally in 15 patients with dentoskeletal class III facial dysmorphism (seven men, eight women, mean age 28 years). The patients were analysed pre-surgery and at 6, 12, and 24 months post-surgery while performing verbal (five vowels) and non-verbal (open and closed mouth smile, lip purse) soft tissue facial movements. The three-dimensional motions of right and left nasogenian, crista philtri, cheilion, and lower lip landmarks were detected by an optoelectronic instrument, and a total mobility index was obtained. Differences between the sides were quantified by the symmetry index. Patient values were compared to those collected previously from healthy volunteers by computing z-scores. On average, no significant differences were found in the mobility of the buccal soft tissues at 24 months after surgery (ANOVA P-value, range 0.075-0.808), with positive median z-scores (pooled mean value close to 0.6). Symmetry indices ranged around the control reference values, showing no stage-related differences (Friedman test P-value, range 0.252-0.937), and exceeding 90% for all movements at 24 months after surgery. Bimaxillary osteotomy does not compromise facial mimicry in either verbal or non-verbal facial movements.

Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation

Abstract Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. Objective: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. Methodology: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2-59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. Results: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. Conclusion: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

Early treatment of pseudo-class III malocclusion with modified swallowing occlusal contact intercept appliance (S.O.C.I.A.).

AIMS: The aim of the present work was to evaluate the dentoskeletal effects of swallowing occlusal contact intercept appliance (SOCIA) III in pseudo Class III malocclusion treatment. MATERIALS AND METHODS: Thirty-six patients (mean age: 9.46 years old) with pseudo-Class III malocclusion and 22 pseudo-Class III untreated controls (mean age: 8.7 years old) were selected and examined. All patients presented with a cervical stage CS2, CS3, or CS4. Patients with CS5 were not enrolled in the study. Cephalometric analysis was performed before phase 1 treatment (T1) and immediately following phase 2 treatment (T2). STATISTICAL ANALYSIS: Paired t-test and independent t-test. RESULTS: SOCIA III had skeletal and dental effects. The main effects of SOCIA III were on the midface with an effective increase of the sagittal growth (cranial base P < 0.001, anterior cranial base (ACB) P < 0.001, and maxilla growth P < 0.001) and vertical growth (anterior facial height P < 0.001). The effects of SOCIA on the mandible were a control of mandibular postrotation (P = 0.82) and the sagittal growth (P < 0.007). At the end of the treatment, a normal overjet was achieved (P < 0.001). CONCLUSIONS: The SOCIA III effects are resumed as follow: (a) an effective maxillary sagittal increase on the sagittal plane; (b) a vertical mandibular control; (c) a resolution of overjet; (d) no increase of overbite; (e) a stimulation of ACB growth.

Effects of Craniofacial Morphology on Nasal Respiratory Function and Upper Airway Morphology.

BACKGROUND: Craniofacial skeletal patterns change after orthognathic surgery. The present study aimed to investigate the effects of different craniofacial patterns on nasal respiratory function and the upper airway. METHODS: Forty-seven healthy subjects were selected and divided into 3 groups according to their mandibular position. Sixteen were in the skeletal Class I group, 15 were in the skeletal Class II group, and 16 were in the skeletal Class III group. Cone beam computed tomography was performed, and nasal airflow and nasal resistance were measured. Differences in nasal respiratory functions and upper airway were compared among the groups. A correlation analysis was conducted for nasal respiratory function, upper airway, and skeletal patterns. RESULTS: There were significant differences among the 3 groups regarding dominant-side nasal inspiratory capacity (P = 0.001), bilateral nasal inspiratory capacity (P = 0.005), nasal partitioning ratio-inspiration (P = 0.007), and velopharyngeal minimum cross-sectional area (P = 0.029). The values were significantly higher for the skeletal Class III group than the skeletal Class I and II groups. A correlation analysis showed that the nasal partitioning ratio and nasal airway resistance were mostly negatively correlated with SNA, but the upper airway volume and cross-sectional area were positively correlated with SNB and negatively correlated with ANB. The dominant-side nasal expiratory capacity was mainly negatively correlated with the mean velopharyngeal cross-sectional area (r = -0.324, P = 0.026), mean glossopharyngeal cross-sectional area (Glosso-A mean) (r = -0.293, P = 0.046), and mean total airway cross-sectional area (Total-A mean) (r = -0.307, P = 0.036). CONCLUSION: Craniofacial skeletal morphology may affect nasal respiratory function and the upper airway.

Effects of bimaxillary orthognathic surgery on pharyngeal airway and respiratory function at sleep in patients with class III skeletal relationship.

PURPOSE: The aim of this study was to examine the effects of bimaxillary orthognathic surgery on pharyngeal airway space (PAS) and respiratory function during sleep. MATERIALS AND METHODS: The subjects were 21 patients with class III skeletal relationship, and all of the patients underwent bimaxillary surgery (Le Fort I advancement and bilateral sagittal split ramus setback osteotomies simultaneously). Pharyngeal volumes of nasopharyngeal (V-NPA), retropalatal (V-RPA), retrolingual (V-RLA), oropharyngeal (V-ORO) and total pharyngeal airways (V-TOT); minimum axial areas of retropalatal (MA-RPA), retrolingual (MA-RLA) and oropharyngeal airways (MA-ORO); and position of the hyoid were studied in order to detect dimensional PAS changes using cone-beam computed tomography (CBCT) with Dolphin 11.8 software immediately before surgery (T1) and during a period of 6-12 months postoperatively (T2) in all of the patients. Apnea-hypopnea index (AHI), respiratory disturbance index (RDI) and apnea in supine position (SupAHI) parameters were measured with a Compumedics E series full polysomnography system. RESULTS: In volumetric measurements, the V-ORO parameter decreased significantly (p < 0,05) while there was no statistically significant change in the rest of the volumetric parameters (p > 0,05). All of the minimum axial area parameters were decreased significantly (p < 0,01). Hyoid bone moved inferiorly (p < 0,05) and posteriorly (p < 0,05). None of the polysomnographic parameters changed significantly (p > 0,05). CONCLUSION: Bimaxillary orthognathic surgery significantly narrowed PAS dimensions but did not cause an increase in AHI, which is a critical determinant parameter for obstructive sleep apnea syndrome.

Three-dimensional mandibular motion in skeletal Class III patients.

OBJECTIVE: The aim of the study was to analyze the characteristics and changes in mandibular condylar motion in patients with skeletal Class III malocclusion. METHODS: Using a 3D motion analyzer, mandibular movements were recorded in 9 patients with skeletal Class III malocclusion and 22 control subjects with Angle Class I jaw relationships. RESULTS: Class III patients had a similar interincisor point displacement but a significantly reduced displacement of both condyles on the sagittal and frontal planes, with smaller translation paths than control subjects (right -9.4 mm; left -4.8 mm). The overall condylar rotation component was larger in Class III patients (right +8.8%; left +7.3%). The largest inter-group significant differences were observed in the first 10% of mouth opening, in which Class III patients had a larger rotating component than control subjects (+20%, p < 0.01). CONCLUSIONS: Condylar motion was reduced in skeletal Class III patients, in particular in the translational path.

Postural Assessment in Class III Patients Before Orthognathic Surgery.

PURPOSE: To determine the postural characteristics of patients with Class III dentofacial deformities before orthognathic surgery by photogrammetry using SAPO postural assessment software. MATERIALS AND METHODS: This was a cross-sectional study. Eligible participants were adult patients who had an indication for orthognathic surgery to correct skeletal Class III dentofacial deformities and were undergoing orthodontic preparation for surgery. Patients were recruited at the outpatient clinic for dentofacial deformities of the authors' institution from March to November 2015. Postural assessment was performed by photogrammetry based on anterior, posterior, and lateral images, which were analyzed using SAPO software. RESULTS: The sample consisted of 40 patients with a mean age of 28.7 years; 55% were men. Postural changes were found in most anatomic structures, and the main changes were anterior displacement of the center of gravity (sagittal plane asymmetry, 43.77%) and a tendency to left lateral deviation (frontal plane asymmetry, -3.89%). The anterior view showed a pattern of head tilt to the left (measured value minus reference value [Δ], -0.22), elevation of the left acromion (Δ, 2.31), elevation of the right anterior superior iliac spine (Δ, -0.56), right knee with genu varum (Δ, 1.25), and left knee with genu valgum (Δ, -1.55). The posterior view displayed scapular asymmetry with abduction of the right scapula (Δ, 7.54) and valgus foot deformity (Δright, 8.35; Δleft, 11.60). The lateral view depicted decreased cervical lordosis (Δright, 22.63; Δleft, 19.98), pelvic anteversion (Δright, -0.56; Δleft, -0.26), and genu flexum at the right (Δ, 6.85) and left (Δ, 4.40) knees. Twenty-seven patients (67.5%) reported temporomandibular joint pain. CONCLUSIONS: Postural assessment by photogrammetry showed that most anatomic structures were outside the normal range in patients with skeletal Class III dentofacial deformities before orthognathic surgery. These results suggest that dentofacial abnormalities can lead to postural disorders in this population.

Effect of orthognathic surgery on masticatory performance and muscle activity in skeletal Class III patients.

OBJECTIVE: To evaluate the effect of double jaw orthognathic surgery (OGS) on masticatory performance and electromyographic activity of the masseter and anterior temporal muscles in skeletal Class III patients. METHODS: Individuals were instructed to chew standardized round tablets of silicone impression material. The cumulative weight percentage was calculated using sieve analysis. The bilateral surface electromyographic activity of the muscles was evaluated. Following the orthodontic treatment, a stabilization splint was fabricated. Patients were instructed to wear it full-time until the surgical procedure occurred. Recordings were performed before the splint application (T0), after the splint application (T1), 1 month after the OGS (T2), and 6-8 months after the OGS (T3). RESULTS: Median particle size of the chewed silicone material did not differ from T0 to T1 with the use of an occlusal splint (p > 0.05). However, it decreased from 9.46 to 6.92 cm from T2 to T3. From T0 to T3, a statistically significant decrease was found, following the surgical intervention (p < 0.01). A significant decrease in masticatory muscle activity was also observed during the relaxation test from T0 to T3, at which time it reached the control group value. DISCUSSION: OGS enhanced masticatory function by improving occlusion in individuals with a dentofacial deformity.

Evaluation of Chewing Movement in Skeletal Class III Patients with Orthognathic Treatment.

The objective of this study was to clarify the influence of improvement in morphology on chewing movement in patients with skeletal reversed occlusion following orthognathic treatment. A total of 10 patients with skeletal class III reversed occlusion undergoing orthognathic treatment were included in the study. A number of parameters, including chewing rhythm, maximum opening and closing velocities, and opening distance during chewing of gum, were measured in a pre- (Pre) and post-treatment (Post) group. The laterality and stability of the measured items were then compared between the two groups and with those in another group of subjects with normal occlusion (Control). Laterality of chewing movement was greater in the Pre group than in the Control group, and significant differences were noted in all parameters, apart from closing Vmax and opening distance. No significant difference was noted in any parameter between the Post and Control groups. The coefficient of variation was significantly higher in the Pre group than in the Control group, apart from for opening phase. All parameters showed a significant decrease in the Post group compared with in the Pre group, yielding a stable chewing movement. Comparison of the Post and Control groups revealed no significant difference in any of the parameters, apart from in the occluding phase. These findings suggest that orthognathic treatment of skeletal class III malocclusion improves chewing movement to levels close to those in subjects with normal occlusion.

Orthodontic-surgical treatment: electromyographic and kinesiographic evaluation in follow up period. Experimental study.

INTRODUCTION: The aim of this study was to investigate muscular function and mandibular kinesiology of patients undergoing orthodontic-surgical treatment by electromyography and kinesiography. Electromyographic evaluation is essential to estimate masticatory forces in patients undergoing combined surgical-orthodontic treatment. MATERIALS AND METHODS: 60 patients referred for orthodontic surgical treatment were included in the study, 43 patients presented a class III while 17 presented a class II. The patients underwent electromyographic and kinesiographic examinations during all the therapeutic orthodontic-surgical phases. RESULTS: The relationship between fundamental electromyographic values and age, weight, asymmetry and activation was weak. A strong and positive relationship was observed between the relaxation percentage after TENS (transcutaneous electrical neuromuscular stimulation), the steepness of the post-surgery rehabilitation curve, the initial POC (percentage overlapping coefficient), and for the values in microvolts of the right and left temporal and masseters at the beginning of treatment. CONCLUSIONS: Patients with dentofacial deformities corrected by surgical treatment, have a significant positive treatment outcome in respect of masticatory activity and performance electromyographic evaluation on, before, during and follow up period of the analized patients permit to underline that this examination can predict long term stability.

A novel method for treatment of Class III malocclusion in growing patients.

BACKGROUND: Management of Class III malocclusion is one of the most challenging treatments in orthodontics, and several methods have been advocated for treatment of this condition. A new treatment protocol involves the use of an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol, in conjunction with full-time Class III elastic wear and coupled with the use of temporary anchorage devices (TADs). The aim of this study was to evaluate the dento-skeletal and profile soft tissue effects of this novel protocol in growing participants with retrognathic maxilla. METHODS: Fourteen growing participants (7 males and 7 females; 12.05 ± 1.09 years), who displayed Class III malocclusions with retrognathic maxilla, were recruited. Pre-treatment records were taken before commencing treatment (T1). All participants had a hybrid mini-implant-supported rapid maxillary expansion (MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. Full-time bone-anchored Class III elastics, delivering 400 g/side, were then used for maxillary protraction. When positive overjet was achieved, protraction was ceased and post-treatment records were taken (T2). Linear and angular cephalometric variables were blindly measured by one investigator and repeated after 1 month. An error measurement (Dahlberg's formula) study was performed to evaluate the intra-examiner reliability. A paired-sample t test (p < 0.05) was used to compare each variable from T1 to T2. RESULTS: Treatment objectives were achieved in all participants within 8.5 weeks of protraction. The maxilla significantly protracted (SNA 1.87°± 1.06°; Vert.T-A 3.29± 1.54 mm p < 0.001), while the mandibular base significantly redirected posteriorly (SNB -2.03° ± 0.85°, Vert.T-B - 3.43± 4.47 mm, p < 0.001 and p < 0.05 respectively), resulting in a significant improvement in the jaw relationship (ANB 3.95°± 0.57°, p < 0.001; Wits 5.15± 1.51 mm, p < 0.001). The Y-axis angle increased significantly (1.95° ± 1.11°, p < 0.001). The upper incisors were significantly proclined (+ 2.98°± 2.71°, p < 0.01), coupled with a significant retroclination of the lower incisors (- 3.2°± 3.4°, p < 0.05). The combined skeletal and dental effects significantly improved the overjet (5.62± 1.36 mm, p < 0.001) and the soft tissue Harmony angle (2.75° ± 1.8°, p < 0.001). CONCLUSIONS: Class III elastics, combined with the Alt-RAMEC activation protocol of the MARPE appliance, is an efficient treatment method for mild/moderate Class III malocclusions. The long-term stability of these changes needs further evaluation.

Change in lip closing force in Classes II and III malocclusion before and after sagittal split ramus osteotomy with Le Fort I osteotomy.

PURPOSE: The purpose of this study was to examine lip closing force in Class II and III patients before and after orthognathic surgery. SUBJECT AND METHODS: The subjects were 45 patients (15 Class II women, 15 Class III men and 15 Class III women) diagnosed with jaw deformity who underwent sagittal split ramus osteotomy with Le Fort I osteotomy and 30 controls with normal skeleton and occlusion (15 men, 15 women). Maximum and minimum lip closing forces were measured using Lip De Cum® before and after surgery, and compared statistically. RESULTS: In the Class II women, maximum and minimum lip closing forces did not change after surgery. However, maximum and minimum lip pressure increased significantly in the Class III men (P = 0.0116, P = 0.0295) and maximum lip closing force increased significantly in the Class III women (P = 0.0082). After 6 months, maximum lip closing force was significantly lower in both Classes II and III women than in the control women (P = 0.0002, P = 0.0045). CONCLUSIONS: This study suggested that maximum postoperative lip pressure did not improve in the Class II women, although maximum lip closing force increased in the Class III men and women after sagittal split ramus osteotomy with Le Fort I osteotomy.

Relationships among nasal resistance, adenoids, tonsils, and tongue posture and maxillofacial form in Class II and Class III children.

INTRODUCTION: The purpose of this study was to clarify the relationships between upper airway factors (nasal resistance, adenoids, tonsils, and tongue posture) and maxillofacial forms in Class II and III children. METHODS: Sixty-four subjects (mean age, 9.3 years) with malocclusion were divided into Class II and Class III groups by ANB angles. Nasal resistance was calculated using computational fluid dynamics from cone-beam computed tomography data. Adenoids, tonsils, and tongue posture were evaluated in the cone-beam computed tomography images. The groups were compared using Mann-Whitney U tests and Student t tests. The Spearman rank correlations test assessed the relationships between the upper airway factors and maxillofacial form. RESULTS: Nasal resistance of the Class II group was significantly larger than that of the Class III group (P = 0.005). Nasal resistance of the Class II group was significantly correlated with inferior tongue posture (P <0.001) and negatively correlated with intermolar width (P = 0.028). Tonsil size of the Class III group was significantly correlated with anterior tongue posture (P <0.001) and mandibular incisor anterior position (P = 0.007). Anterior tongue posture of the Class III group was significantly correlated with mandibular protrusion. CONCLUSIONS: The relationships of upper airway factors differ between Class II and Class III children.

When Do Skeletal Class III Patients Wear Their Reverse Pull Headgears?

Objective. The aim of this study is to evaluate the factors that affect wearing time and patient behavior during reverse pull headgear therapy with a newly designed reverse pull headgear. Methods. In clinical practice, new reverse pull headgears were applied to fifteen patients. The patients were monitored during reverse pull headgear therapy and the data were evaluated. Statistical analysis was made. Results. During the study, patients were monitored successfully and the evaluations showed that patients wear the new reverse pull headgears mostly at night. There are differences between days of week and hours of day. Weekends are more popular than weekdays for wearing reverse pull headgear. Conclusions. This new type of reverse pull headgears can be used successfully in clinical practice and can help the clinician. Study showed that the most important factor that affects the cooperation of reverse pull headgear patient is aesthetic appearance.