Non-extraction camouflage treatment of skeletal class III malocclusion

@#Class III malocclusion can be defined as a skeletal facial deformity that is characterized by a forward mandibular position with respect to the cranial base and or the maxilla. We present a case of a 15-year-old man with skeletal Class III malocclusion who was treated with non-extraction orthodontic camouflage treatment using an orthodontic conventional technique. A fixed appliance, straight wire appliance (SWA) technique was used with a non-extraction treatment plan. Treatment was accompanied by intermaxillary Class III elastics. The total duration of active treatment was 23 months. There was a significant improvement in his occlusion, smile esthetics, and soft tissue profile pattern. Orthodontic camouflage can be considered an effective therapy for correcting milder cases of skeletal Class III malocclusion.

Implant treatment on anterior cross-bite of a patient who had orthognathic surgery 20 years ago / 대한치과보철학회지

Orthognathic surgery of skeletal Class III malocclusion improves oral function and facial appearance. The greater amount of skeletal discrepancy, the greater amount of teeth movement required for decompensation, and this often causes pathological changes in periodontal tissue especially in lower anterior dentition. We made a Top-Down treatment plan with personalized analysis using Face Hunter, Plane System and ARCUS Digma II, in order to resolve severe mobility and cross-bite of lower anterior teeth for 49-year-old female patient who had undergone orthognathic surgery 20 years ago due to skeletal Class III malocclusion and mandibular prognathism. Lower anterior teeth were extracted and alveoloplasty was done. After healing of the wound, immediate loading was conducted immediately after implant placement. Final restorations were fabricated Zirconia using CAD/CAM, and inserted intraorally screw-retained type. During 6-month follow-up, no abnormal episodes of restorations were observed, and obtained satisfactorily both of functional and esthetic outcomes.

Effect of Developmental Disorders of Maxillary First Molars on Orofacial Morphology / 대한소아치과학회지

This study was aimed to evaluate orofacial morphologies on the cases of developmental disorders of maxillary first molars.Panoramic radiographs, lateral cephalographs, and clinical photos of 2983 children who attended the Pediatric Dental Clinic of Pusan National University Dental Hospital from 2006 to August 2017 were assessed retrospectively. 34 patients were selected whose maxillary first molars were missed or developmentally delayed unilaterally or bilaterally. Demirjian' s method was used for estimating dental age, then which was compared to chronologic age of children. Parameters expressing skeletal and dentoalveolar disharmony were checked and compared with control. Additionally, occlusion relationship was evaluated.Maxillary dental age was significantly delayed compared to chronologic age. Several parameters which show skeletal open-bite tendency and skeletal class III malocclusion with maxillary retrusion were statistically significant. Anterior crossbite and edge-bite were expected in most of these cases, but compensation by occlusion and soft tissue was also verified which might mask skeletal class III tendency.Congenital missed or developmentally delayed maxillary first molars might be related with declined growth of maxilla. If developmental disorders of maxillary first molars were verified during clinical examination, careful monitoring of orofacial growth was necessary during puberty and timed orthopedic and orthodontic intervention were considered.

Morphological changes of skeletal class III malocclusion in mixed dentition with protraction combined activities / Cambios morfológicos en maloclusión de la clase esquelética III en dentición mixta con actividades combinadas de protracción

The objective of the study was to investigate the morphological changes of skeletal class III malocclusion in mixed dentition with light force protraction combined activities. Randomly selected 30 cases of orthodontics in Shanxi Medical University orthodontics patients (ages: 6-10 years) of the lateral cephalograms. Using the oral maxillary casting type of pre-traction device, according to the condition of maxillary dentition to select the corresponding activities of the movable expansion appliance, each side of the force of about 150-200 g, requiring patients to wear 10-12 hours a day, the appliance should be removed after reaching normal occlusion. The correlation cephalometric profile of the cranial lateral radiographs before and after orthodontic treatment was measured. All patients with skeletal class III malocclusion were improved, concave type became direct type, measurements SNA, ANB, A-Ptm, MP-SN, ANS-Me/N-Me increased, maxillary advancement and reconstruction are more obvious; mandible rotates clockwise; the increase of lip inclination of anterior teeth compensatory changes, lower anterior tooth inclination changes smaller; upper lip forward, nasolabial angle decreased, improved appearance significantly. Light force protraction combined activities can make the mixed dentition of skeletal class III malocclusion in patients with significant improvement in profile appearance.

El objetivo de este estudio fue investigar los cambios morfológicos de la maloclusión clase esquelética III, en la dentición mixta, con actividades combinadas de protracción de la fuerza ligera. Se seleccionaron aleatoriamente 30 casos de ortodoncia en pacientes de ortodoncia de la Universidad Médica de Shanxi (edades: 6-10 años) a partir de cefalogramas laterales, utilizando el tipo de dispositivo de pretracción de vaciado maxilar oral, de acuerdo con la condición de la dentición maxilar para seleccionar las actividades correspondientes del dispositivo de expansión móvil, cada lado con fuerza de alrededor de 150-200 g, requiriendo que los pacientes los utilizaran de 10 a 12 horas al día. El dispositivo debía ser retirado después de alcanzar la oclusión normal. Se midió el perfil cefalométrico de correlación de las radiografías laterales craneales, antes y después del tratamiento ortodóncico. Se observó mejoramiento en todos los pacientes con maloclusión de clase esquelética. Las mediciones SNA, ANB, APtm, MP-SN, ANS-Me / N-Me aumentaron, el avance y la reconstrucción maxilar fueron los cambios más significativos; la mandíbula giró en el sentido de las agujas del reloj, se observó un aumento de la inclinación labial de los dientes anteriores. Fue reducida la inclinación anterior del diente inferior, el ángulo nasolabial disminuyó y en general mejoró significativamente la apariencia. Las actividades combinadas de protrusión de la fuerza radiante pueden llevar a una mejora signficativa en el perfil de pacientes con dentición mixta de maloclusión clase III.

Cone-beam computed tomography analysis of transverse dental compensation in patients with skeletal Class III malocclusion and facial asymmetry / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to analyze the transverse dental compensation in reference to the maxillary and mandibular basal bones using cone-beam computed tomography (CBCT) and evaluate the correlations between transverse dental compensation and skeletal asymmetry variables in patients with skeletal Class III malocclusion and facial asymmetry. METHODS: Thirty patients with skeletal Class I (control group; 15 men, 15 women) and 30 patients with skeletal Class III with menton deviation (asymmetry group; 16 men, 14 women) were included. Skeletal and dental measurements were acquired from reconstructed CBCT images using OnDemand3D 1.0 software. All measurements were compared between groups and between the deviated and nondeviated sides of the asymmetry group. Correlation coefficients for the association between skeletal and dental measurements were calculated. RESULTS: Differences in the ramus inclination (p < 0.001), maxillary canine and first molar inclinations (p < 0.001), and distances from the canine and first molar cusp tips to the midmaxillary or midmandibular planes (p < 0.01) between the right and left sides were significantly greater in the asymmetry group than in the control group. In the asymmetry group, the ramus inclination difference (p < 0.05) and mandibular canting (p < 0.05) were correlated with the amount of menton deviation. In addition, dental measurements were positively correlated with the amount of menton deviation (p < 0.05). CONCLUSIONS: Transverse dental compensation was correlated with the maxillary and mandibular asymmetry patterns. These results would be helpful in understanding the pattern of transverse dental compensation and planning surgical procedure for patients with skeletal Class III malocclusion and facial asymmetry.

Study on Airway Size in Class III Malocclusion by the Gender / 체질인류학회지

The purpose of this study was to investigate the difference of airway between skeletal Class III malocclusion according to gender and to analyze the relationship between airway size and oral maxillofacial position. The total of 40 study subjects was sampled by judgment sampling, who were under 1 degree ANB and who wanted orthognathic surgery. They were taken with lateral cephalometric radiograph and the photos were used for final analysis. The variables were calculated using mean and standard deviation, those were analyzed by independent t-test, Pearson's correlation coefficient and multiple regression analysis. It was located forward than the female that was the measurements of frontal bone, maxilla, mandible, and mentum in the male. The laryngeal pharynx size of the hard and soft tissues was also longer than the female. It was not statistically significant that was the correlation between the variables and the oral pharynx size. However, the width of the laryngeal pharynx increased with male and mandibular protrusion, and it was increased with the position of the anterior of frontal bone, maxilla, and mentum. The variables affecting the airway size are the laryngeal pharynx width of the hard and soft tissue.

The long term stability of skeletal class III malocclusion after orthodontic-surgery:A meta-analysis / 实用口腔医学杂志

Objective:To analyze the long term stability of the hard and soft tissues of the skeletal class III malocclusion after ortho-dontic-surgery by Meta-analysis.Methods:The randomized controlled trials(RCT),quasi-randomized controlled trials and clinical case-control trials(CCT)about the long-term stability of skeletal class III malocclusion after orthodontic-surgery was collected from Co-chrane Library,PubMed,Medline,CNKI,VIP and Wanfang databases from inception to December 31,2013 by literature search.Two professionally trained reviewers evaluated the quality of the screened literatures,scored literatures with the NOS evaluation tool,and collectd data and information of the literatures with medium and higher quality.Revman5.2 was used for the Meta-analysis.Results:4 CCTs articles and 178 cases were included.The results of Meta-analysis showed that:1.The stability of the hard tissue:the differ-ence of SNA(WMD =-0.58,95%CI[-1.18,0.02]),SNB (WMD =0.25,95%CI[-0.42,0.91]),ANB(WMD =-0.70, 95%CI[-1.44,0.04])and MP-SN(WMD =0.39,95%CI[-0.25,1.04])at post-operation and 3 years after operation had no statistical significance.Point A remained relatively stable position and point B had some replace 3 years after surgery compared with that at post-operative.2.The stability analysis of soft tissue:the healing effect of the soft tissue was stable,except the LowerlipeNperp had some recurrence 3 years after surgery.Conclusion:In the long term,after orthodontic and surgical treatment for skeletal class III malocclusion the hard and soft tissues kept stabile except a little replapse of the mandibular and the LowerlipeNperp.

THE SKELETAL STABILITY OF LE FORT I MAXILLARY ADVANCEMENT

The differences of STO between before and after presurgical orthodontics in skeletal Class III malocclusions / 대한치과교정학회지

OBJECTIVE: To evaluate the discrepancies between initial STO and final STO in Class III malocclusions and to find which factors are related to the discrepancies. METHODS: Twenty patients were selected for the extraction group and 20 patients for the non-extraction group. They were diagnosed as skeletal Class III and received presurgical orthodontic treatment and mandibular set-back surgery at Pusan National University Hospital. The lateral cephalograms were analyzed for initial STO (T1s) at pretreatment and final STO (T2s) after presurgical orthodontic treatment, and specified the landmarks as coordinates of the X and Y axes. RESULTS: Differences in hard tissue points (T1s-T2s) in the X coordinates of upper central incisor edge, upper first molar mesial end surface, lower central incisor apex, lower first molar mesial end surface and mesio-buccal cusp and Y coordinates of upper central incisor edge, upper central incisor apex, upper first molar mesio-buccal cusp were statistically significant in the extraction group. Differences in hard tissue points (T1s-T2s) in the X coordinates of upper central incisor edge, lower central incisor apex, lower first molar mesial end surface and Y coordinates of lower central incisor apex were statistically significant in the non-extraction group. In the extraction group, the upper arch length discrepancy (UALD) had a statistically significant effect on maxillary incisor and first molar estimation. Lower arch length discrepancy and IMPA had statistically significant effects on mandibular incisor estimation in both groups. CONCLUSIONS: Discrepancies between initial STO and final STO and factors contributing to the accuracy of initial STO must be considered in treatment planning of Class III surgical patients to increase the accuracy of prediction.

Soft tissue change of the midface in skeletal class III orthognathic surgery patients / 대한치과교정학회지

PURPOSE: The first objective of this study was to compare the upper midface morpholgy, focusing on the soft tissues, between skeletal Class III maloccusion patients with midfacial depression and the norm. The second objective was to estimate and analyze the change in the upper midface soft tissues following surgical correction with maxillary advancement by Lefort I osteotomy and mandibular setback by bilateral sagittal split osteotomy (BSSRO). METHODS: The samples consisted of 34 adult patients (15 males and 12 females) with an average age of 21years, who had severe anteroposterior discrepancy with midfacial depression. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Lefort I osteotomy and BSSRO. RESULTS: The correlation coefficient between changes in maxillary advancement and changes in Or' (soft tissue orbitale) was 0.599 (p < 0.05). Change in maxillary plane angle and vertical change of the maxilla were not correlated with the change in Or' (p < 0.05). The ratio of soft tissue change in Or' to maxillary advancement was 43.57 %, and 81.54 % in Sn. Regression equations between maxillary movement and Or' were devised. The r2 value was 0.476. CONCLUSIONS: The majority of measurements in the upper midface in skeletal Class III maloccusions when compared to the norm, showed significant differences. In Class III malocclusion with midfacial depression, maxillary advancement produces soft tissue change in the upper midface.

Interrelationships between occlusal plane angle and vertical skeletal patterns of skeletal Class III malocclusion individuals / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the relationships between the occlusal plane angle and craniofacial skeletal pattern in relation to anterior overbite. METHODS: Lateral cephalograms of 90 adults with skeletal class III malocclusions were traced and measured to analyze skeletal factors and occlusal plane angles. In terms of anterior overbite, all patients were classified into 3 subgroups of positive overbite, edgebite, and negative overbite groups. All measurements were evaluated statistically by ANOVA and Duncan's Post Hoc, and correlation coefficients were evaluated among measurements. RESULTS: In this study, some skeletal measurements (saddle angle, articular angle, Y axis, AFH, SN-FH, SN-Mn, FH-Mn) showed a significant difference among the 3 groups in relation to overbite changes. Correlation coefficient showed that PFH/AFH, SN-Mn, Mx-Mn, and FH-Mn showed a significant difference with FH-Occ, Mx-Occ, and Mn-Occ. Regression analysis showed that Mx-Mn had a determination coefficient of 0.714, 0.560, and 0.677 in relation to FH-Occ, Mx-Occ, and Mn-Occ, respectively. CONCLUSION: This study suggests that consideration of the occlusal plane in relation to the maxillomandibular vertical skeletal state enable the establishment of a more predictable orthognathic surgery result.

Evaluation of nasolabial angle in adult patients with skeletal Class III malocclusion / 대한치과교정학회지

OBJECTIVE: The purposes of this study were to evaluate the nasolabial angle changes between closed lip position at centric occlusion and relaxed lip position at which the bite is open so that the lips do not touch and to elucidate the significance of the relaxed lip position for dentofacial diagnosis. METHODS: The subjects consisted of 60 (35 Males, 25 Females) skeletal Class III malocclusion adult patients (mean age 23.3 years) with anterior crossbite. RESULTS: In Class III malocclusion adult patients, there were significant differences in the nasolabial angle changes between closed lip position and relaxed lip position. Using the cluster analysis, the subjects were divided into three groups according to the pattern of nasolabial angle change: Group 1 (N = 27, 45%, -8 ~ 1), Group 2 (N = 30, 50%, 2degrees ~ 17), and Group 3 (N = 3, 5%, over 18). CONCLUSION: The results showed that the pattern of the nasolabial angle change between closed lip position and relaxed lip position varies in skeletal Class III malocclusion patients. Thus, relaxed lip position should be taken into account when diagnostic records are obtained and analyzed to accurately to evaluate the facial soft tissues and predict facial esthetics after surgical-orthodontic treatment.

Maxillary protraction effects of TTBA (Tandem Traction Bow Appliance) therapy in Korean Class III children / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to investigate the maxillary protraction effects of the Tandem Traction Bow Appliance (TTBA), a new appliance devised several years ago for the treatment of growing skeletal Class III patients. METHODS: Participants were 88 Korean children (42 boys, 46 girls) with skeletal Class III malocclusion treated with TTBA at the orthodontic clinic of Ewha Womans University Mokdong Hospital. Mean age at the start of treatment was 7.5 years +/- 1.5 years. Mean treatment periods were 13 +/- 3 months. Pretreatment and posttreatment lateral cephalograms were traced and superimposed by the same investigator and analyzed by modified McNamara analysis and pitchfork analysis. Changes were evaluated with paired t-tests at a significance level of p < 0.05. RESULTS: The maxilla and maxillary dentition moved forward. The mandible moved backward, although not significantly; and the mandibular dentition moved forward. The net dental changes combined with the apical base change resulted in a favorable total molar relationship correction. Net dental movement was 26% and the apical base change 74% of the total molar relationship correction. CONCLUSION: These results suggest that TTBA has a maxillary protraction effect that can be useful in the treatment of growing skeletal Class III malocclusion with maxillary deficiency.

Analysis of familial tendency in skeletal class III malocclusion

The purpose of this study was to examine the familial tendency of the patients with mandibular prognathism in three generations and to define the relationship between the familial tendency and the skeletal class III morphology. The probands of this study were 103 orthognathic surgery patients with skeletal Class III malocclusions who had undergone (48 men, 55 women) mandibular set-back surgery. A questionnaire was given to patients who sought surgical treatment for excessive mandibular length, and all answers were confirmed in interviews. Lateral cephalograms were analyzed in cranial base parameters, mandibular positional parameters and mandibular skeletal parameters. In the examined families, 58.3% had at least one member other than the proband who had mandibular prognathism. The affected ratio of total relatives was 4.5%, and the value was higher in first-degree (13.4%) than second-degree (5.9%) and third-degree relatives (1.7%). The affected ratio was 51.9% in the offsprings who had at least one affected father or mother. The comparison of the groups according to the familial tendency showed no significant craniofacial skeletal measurments. In conclusion, skeletal class III malocclusion showed high familial tendency, suggesting a significant genetic influence in the etiology. However, the patient's familial tendency did not show the special craniofacial patterns compare to the subjects without familial tendency.

The stability in the adolescent Class III malocclusion treated by fixed appliances / 대한치과교정학회지

The purpose of this study was to investigate the predictors of relapse in orthodontic treatment of skeletal Class III malocclusion in growing patients. A total of 55 patients were studied and all subjects were divided into two groups according to their stability in the post-treatment stage. Of the sample, 33 patients were included in the stable group and the remaining 22 were assigned to the relapse group. Cephalometric data of the pre-treatment stage was taken and compared between the stable and relapse group. The following results were obtained through t-test: 1. This study presented statistical evidence to show that the major skeletal determinant of prognosis in Class III orthodontic treatment was not anteroposterior discrepancy but vertical discrepancy, especially within the AB-maxillo-mandibular triangle. Vertical angular measurements that showed statistically significant differences were AB-MP and ODI(P<0.01) and the vertical ratio measurements were MP-P/AL and PP-P/AL(P<0.05). 2. Relapse tendency increased with the steep occlusal plane, especially the steep lower occlusal plane. As to occlusal plane, there were statistically significant differences in OP(L)-PP, OP-PP, AB-OP(L) and Wits appraisal(P<0.05). This study claimed that anteroposterior discrepancy was not necessarily the proper criteria to predict relapse. Vertical discrepancy had a significant effect on post-treatment stability.

A Comparison of pre and post-surgical characteristics in skeletal Class III malocclusion patients using counterpart analysis / 대한치과교정학회지

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of individuals has been developed. Counterpart analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. In this study we examined surgical changes in skeletal Class III malocclusion patients(male 40, female 40) and compared them with normal occlusion patients using counterpart analysis. The results indicated that : 1. Skeletal anterior-posterior discrepancy was relieved by shortening of the ramus width(B3). 2. The ramus alignment(R3, R4) was displaced posteriorly and the occlusal plane angle(R5) was rotated clockwise. 3. Skeletal Class III pattern was relieved in the post-operative group, but differences in the level of the cranium(R1, R2) was remaining compared to the normal occlusion patients. 4. In the comparison of surgery methods, the two-jaw surgery group presented changes in the maxillary length(A4), ramus alignment(R3,R4) and occlusal plane angle(R5) compared to the one-jaw surgery group, but the differences were not significant. In the past study about Korean skeletal Class III patients, the skeletal characteristics are upward backward rotation of the cranial base, posterior displacement of the maxilla, forward inclination of the ramus and lengthening of the mandibular body, but in this study, skeletal Class III pattern was relieved by shortening of the ramus width and maxillary advancement by orthognathic surgery, because orthognathic surgery is usually performed on limited areas in the maxilla and the mandible.

A study on the preorthodontic prediction values versus the actual postorthodontic values in Class III surgery patients / 대한치과교정학회지

The purpose of this study was to find out and evaluate discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to it in 45 patients(17 male, 28 female) who were diagnosed as skeletal Class III malocclusion and received presurgical orthodontic treatment and orthognathic surgery at Yonsei university dental hospital. Lateral cephalograms were analyzed at pretreatment(T1), orthodontic prediction(T2), immediately before surgery(T3) and designated the landmark as coordinates of X and Y axes. The samples were divided according to ALD, upper and lower incisor inclination(U1 to SN, IMPA), COS, extraction, the position of extracted teeth and the statistical significance was tested to find out the factors contributing to the prediction. The results were as follows : 1. Differences between preorthodontic prediction values and actual postorthodontic values(T2-T3) were statistically significant(p<0.05) in the x coordinates of U6mbc, L1x and in y coordinates of U1i, U1x, U6me, U6mbc, L6mbc 2. The accuracy of prediction is relatively higher in horizontal changes compared to vertical changes. 3. The statistical significance(p<0.05) between prediction and actual values is observed more in the landmarks of the maxilla than the mandible. 4. Differences between prediction and actual values of incisor and first molar were statistically significant(p<0.05) according to extraction vs non-extraction, extraction type, ALD in the maxilla and according to ALD, IMPA in the mandible. Discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to the prediction must be considered in treatment planning of Cl III surgical patients to increase the accuracy of prediction. Furthermore future investigations are needed on the prediction of vertical changes.

Evaluation of craniofacial growth prediction method on Class III malocclusion patients / 대한치과교정학회지

This study was performed to evaluate whether growth prediction method can be used to diagnose and make treatment plan in skeletal Class III malocclusion patients or not. The sample was consisted of 25 patients(13 males, 12 females) who had been diagnosed with skeletal Class III malocclusion at first visit and after that had returned to take orthognathic surgery. Growth prediction performed with Ricketts' growth prediction method from first cephalogram was compared with actual growth of the second cephalogram. The findings of this study were as follows ; 1. There was significant difference between actual growth and growth prediction in Porion Location, Ramus Position, Facial Depth, Facial Axis, Mandibular Plane angle, Maxillary Convexity. So, for these items Ricketts' growth prediction method is not proper to predict growth. 2. Although the growth amount of mandibular body was similar to normal growth amount, mandible was positioned anteriorly because of Porion Location and Ramus Position. 3. In skeletal Class III malocclusion patients, the tendency of mandibular prognathism might be aggreviated because of anterior placement of ramus and anterosuperior rotation of pogonion.

The relationship between posterior dental compensation and skeletal discrepancy in class III malocclusion / 대한치과교정학회지

This study examined the relations between degree of posterior dental compensation and skeletal discrepancy in Class III malocclusion. The pretreatment lateral cephalograms and dental casts of 87 skeletal Class III adults were selected to provide a random sampling of skeletal Class III malocclusion. Skeletal discrepancy was described with ANB angle, Wits appraisal, SN-Mn plane angle, FMA and ratios of basal arch width. Degree of posterior dental compensation was described with maxillary intermolar angle, mandibular intermolar angle and sum of intermoloar angle. The relationships between skeletal discrepancy and degree of posterior dental compensation were analyzed with simple correlation analysis, stepwise multiple regression analysis. The results were as follows : 1. A strong association was found between the variation in the anteroposterior measure, ANB angle and the variation of posterior dental compensation measures, sum of intermolar angle and mandibular intermolar angle in skeletal Class III malocclusion. 2. There was no statistically significant relationship between the variation in the vertical measures and the variation of posterior dental compensation measures in skeletal Class III malocclusion. 3. There was no statistically significant relationship between the variation in the anteroposterior and vertical measures and degree of basal arch width discrepancy.

A Study on the preoperative prediction values versus the postoperative actual values in class III two jaw surgery patients