Class 2 div 1 by almuzian

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  • 1. Class 2 Division 1 malocclusion Contents Classifications...............................................................................................................................................5 Prevalence ...............................................................................................................................................5 Treatment Need...........................................................................................................................................6 Etiology.........................................................................................................................................................6 ST roles class II D1 in two ways:................................................................................................................7 Type of lips behaviors to achieve anterior oral seal in class II..................................................................7 Features .......................................................................................................................................................8 1.Skeletal: ................................................................................................................................................8 2.Cephalometric values............................................................................................................................9 3.Dental ..................................................................................................................................................9 4.Soft tissues..........................................................................................................................................10 3.Mandibular position............................................................................................................................10 4.Facial growth.......................................................................................................................................10 5.Habits ..................................................................................................................................................10 Assessment and diagnosis .........................................................................................................................10 Treatment modalities ...............................................................................................................................11 Factors influencing treatment options...................................................................................................11 Treatment according to the dental developmental stages.........................................................................12 Favorable features for orthodontics camouflage.......................................................................................14 Orthodontic camouflage appliances.......................................................................................................15 Treatment mechanics in camoflagable treatment in early permanent dentition ..................................16 Crowded Arches .................................................................................................................................17 Growth modification appliance..................................................................................................................18 A functional appliance aims to:..............................................................................................................18
  • 2. The aims of FA after functional is:..........................................................................................................19 Post-functional appliance extract decision depend on...............................................................................19 Effects of functional appliances ............................................................................................................19 Advantages of early growth modification appliance treatment.............................................................20 Disadvantages of growth modification appliance early treatment.........................................................21 Evidences of the results with early growth modification appliance treatment......................................21 Advantages of late growth modification appliance treatment ..............................................................21 Orthognathic surgery..............................................................................................................................22 Summary of treatment modalities in different age group..........................................................................23 Deciduous Dentition ..............................................................................................................................23 Mixed dentition......................................................................................................................................23 Late mixed/early permanent dentition..................................................................................................24 Adult treatment .....................................................................................................................................24 Evidence related to stability of class II D1 malocclusion.............................................................................24 1.Relationship between stability and pattern of extraction.......................................................................25 Post-treatment stability in Class II nonextraction and maxillary premolar extraction protocols, Guilherme. 2012.....................................................................................................................................25 Long-term stability of Class II malocclusion treated with 2- and 4-premolar extraction protocols , Janson , 2009..........................................................................................................................................26 2.Relationship between different treatment mechanics and stability.......................................................26 Long-term stability of Class II, Division 1, nonextraction cervical face-bow therapy: II. Cephalometric analysis. Elms 1996 ................................................................................................................................26 Long-Term Stability of Class II Correction with the Twin Force Bite Corrector Chebber 2010 ...............27 Occlusal stability of adult Class II Division 1 treatment with the Herbst appliance, Bock.......................27 Stability of Class II, Division 1 Treatment with the Headgear-Activator Combination Followed by the Edgewise Appliance Janson, 2004..........................................................................................................28 3.Surgical versus conventional treatment..................................................................................................29 Long-term comparison of treatment outcome and stability of Class II patients treated with functional appliances versus bilateral sagittal split ramus osteotomy.Berger 2005 ..............................................29
  • 3. Long-term follow-up of Class II adults treated with orthodontic camouflage: a comparison with orthognathic surgery outcomes Mihalik 2003........................................................................................30 Stability of skeletal Class II correction with 2 surgical techniques: The sagittal split ramus osteotomy and the total mandibular subapical alveolar osteotomy, Valmy 2001...................................................30 Cause of relapse after treatment of class II D1 malocclusion.....................................................................32 Factors that be considered to control relapse potential............................................................................32 Common Questions related to this topic....................................................................................................36 Literatures..................................................................................................................................................37 Steep and deep ......................................................................................................................................37 High angle class II cases..........................................................................................................................37 Multiple questions..................................................................................................................................38 Is There a Relationship between Malocclusion and Teasing/ Bullying? .................................................38 What Are the Short-Term Effects of Functional Appliances? .................................................................38 How Do These Changes Contrast with the Long-Term Effects? .............................................................38 Dynamax appliance?...............................................................................................................................39 What Factors Influence the Need for Headgear in Association with Functional Appliance Therapy?....40 What Are the Advantages and Disadvantages of Fixed Functional Appliances?.....................................40 What Factors Influence the Choice of a Specific Functional Appliance? ................................................40 What Is Dento-Alveolar Compensation?................................................................................................41 How Long Does Functional Appliance Therapy Take? ...........................................................................41 What Are the Limitations of Headgear? ................................................................................................41 How May Compliance with Headgear Be Improved? ............................................................................42 What Are the Problems Associated with Extracting Premolar Teeth in the Maxillary Arch Only?..........42 What Is the Tip Edge ® Appliance?.........................................................................................................43 What Are the Three Stages of Tip Edge ® Treatment? ...........................................................................43 Is There Any Association between Occlusal Para-Function and Orthodontic Treatment? .....................43 What Are the Risk Factors for Gingival Recession During Orthodontic Treatment? ..............................44 Is Lower Incisor Proclination Likely to Exacerbate Gingival Recession?.................................................44
  • 4. Are There Any Contraindications to a Phase of Fixed Appliance Treatment Following the Successful Use of a Functional Appliance? ....................................................................................................................44 What Are the Options to Conserve Anchorage and Facilitate Overjet Reduction? ................................44
  • 5. Class II D1 malocclusion Classifications • Class II Incisor: Lower incisor occludes distal to the upper incisor cingulum plateau, upper incisors proclined or normally inclined with an increased OJ. • Class II Buccal: MB cusp of the upper first molar mesial to the MB groove of the lower first molar. • Class II Subdivision: one side class I molar relationship and the other is class II MR. • Class II Indefinite: One upper central incisor is proclined one is retroclined (Gravely) • Class II Intermediate: Incisors are of normal inclination but the OJ is 5-7 mm (Williams and Stephens, 1992). Prevalence (Foster and Day 1974) • Class I 44% • Class II D1 27% • Class II D2 17% • Class III 3% • Indefinite 9%
  • 6. Williams & Stephens, 1992 • Class II intermediate 10%, Upper incisor are upright and OJ 5-7mm Treatment Need 1. IOTN • DHC IOTN 5= OJ>9mm • DHC IOTN 4= OJ 6-9mm • DHC IOTN 3= OJ 3-6 incompetent lips • DHC IOTN 2= 3-6 competent lips. 2. Trauma: Todd and Dodd 1988 • 47% >9mm • 27% if it is less than 9mm 3. Aesthetic 4. Oral Health eg. the palate 5. Function Etiology I. Genetic effecting the skeletal growth (see the skeletal features), Harris 1969 II. Environmental
  • 7. 1. Trauma to condyle 2. Habits, Larsson 1987 3. Dental factors due to • Crowding • Pathological teeth migration forward. 4. Soft tissue, it is mainly mediated by the underlying skeletal pattern • Lower lip trapping, hyperactive mentalis, and lip incompetence due to short upper lip. • Decreased muscle tone in cerebral palsy, Hunt et al 5. Airway like mouth breathing. Arnson 1979 ST roles class II D1 in two ways: 1. Etiology and development of class 2 2. Treatment planning, 3. Stability of the result 4. Prognosis 5. Relapse Type of lips behaviors to achieve anterior oral seal in class II 1. Mandibular posture to allow the lips to meet. In these circumstances the soft tissues promote dentoalveolar compensation and reduce the influence of the Class II skeletal pattern. 2. Lower lip to palate: The lower lip functions palatal to the upper incisors in the presence of an increased and complete overbite. This is a more common
  • 8. presentation and is associated with retroclination of the lower incisors and/or proclination of the upper incisors 3. Lower lip to tongue: The tongue is pushed forward to contact the lower lip and the overbite is incomplete. The lower incisors are often proclined and the overbite just incomplete. This forward tongue posture can be described as an adaptive tongue thrust. 4. Hyperactive lower lip musculature will exacerbate an increased overjet, and these patients are described as having a strap-like lower lip. The prognosis for stable overjet reduction in these circumstances is poor. Features 1. Skeletal: Cranial base features: 1. Increased cranial base angle causing retrognathic position of the mandible. (Carter 1987) 2. Increased cranial base length causing maxillary prognathic (Moyers 1982) AP relationship • 75% class II incisor relationship have a class II skeletal pattern (Pancheraz 1997) while the rest distributed between class I and class III. • 25% due to maxilla proganthisim • 75% due to mandible reason (Carter 1987) Vertical relationship Average or increased or decreased FMPA Female>male
  • 9. Transverse relationship Normal or cross bite in thumb sucking habit or might be scissor bite in big maxilla and small mandible 2. Cephalometric values • Increased ANB • Reduced gonial angle • Normal or reduced MMP angle and lower face height • Decreased II angle 3. Dental • Class II incisor relationship • Mostly UI proclined. • Spacing UI • LI proc or retroclined • Crowding L1 • OJ is increased • OB is usually deep and often incomplete • Deep COS • Class II buccal segment • May be X bite secondary to habit
  • 10. 4. Soft tissues • Lip incompetent, competent or potentially competent • Lower lip trapping or normal • Convex profile and may be retrusive ST to E line • Retrogeni or normal • obtuse NLA 3. Mandibular position Sometime the patient can posture forward 4. Facial growth • variable • can expect favorable growth but if patient rotates posteriorly, this will not help buccal segment correction 5. Habits The effect on the incisor relationship may be asymmetrical, and this appearance can help in diagnosis especially if there is a skin callus seen on the digit that is used as part of the habit Assessment and diagnosis 1. the patient’s principal concern 2. growth status 3. The skeletal pattern should be recorded in the anteroposterior, vertical and transverse dimensions.
  • 11. 4. An assessment of facial profile is important, together with a careful examination of the lip position both at rest, and during swallowing and expressive behavior. 5. A detailed occlusal examination will include: 6. Presence/absence of teeth Arch alignment (crowding/spacing and the presence of rotations) 7. Maxillary and mandibular incisor inclinations (normal, proclined or retroclined) 8. Measurement of overjet and overbite 9. Buccal segment relationships. 10.Radiographs like lateral cephalograph Treatment modalities 1. Growth modification 2. Orthodontic camouflage for the dental camouflage, there are essentially two options for this: A.Retraction of the upper labial segment; B.Advancement of the lower labial segment. 3. Orthodontic decompensation and orthognathic surgery Factors influencing treatment options 1. Family history to indicate the underlying hereditary skeletal pattern 2. Age. growth spurt age for female 12-14years and males 13-15 years 3. Growth amount and direction (anterior growth is favorable while posterior growth is not
  • 12. 4. Pt concern and facial appearance (eg a decision either the OJ will be reduced by advancing the mand with functional or distaliztion of the posterior teeth with HG, this depends on the facial appearance) 5. Severity of skeletal problem in 3 plane of space, limitation ANB 9degree (Mitchell 2007) 6. Soft tissue feature (if the lip incompetency is expected at the end of the treatment, then, stability will be an issue in this case) 7. Degree of crowding 8. Clinical condition of the teeth 9. Intra-arch relationship 10.Incisor inclination and the degree of compensation 11.Patient compliance Treatment according to the dental developmental stages A. Primary dentition • No treatment is indicated • Habit encouraged to stop B. Mixed dentition 1. Habit encouraged to stop 2. Functional appliance option in mixed dentition: • If the Upper incisors at risk of damage due to increased overjet, consider early treatment with a removable or functional appliance to reduce overjet. Since reduction of the OJ might reduce the trauma (Burden 1995). If treatment is not
  • 13. undertaken at this stage, a mouthguard should be prescribed for wear during sport. However, the RCT done by Korouluk 2003 contradict these facts (in mixed dentition, 51 pts received no treatment and 42 had functional and 46 had HG treatment. no different in the incisor trauma noticed among the three groups). • Dental appearance promoting teasing (O’Brien 2003). • The disadvantage of this approach is the necessity to then await eruption of the premolar and permanent canine teeth before comprehensive orthodontic treatment can be completed with fixed appliances. Either the functional appliance or a removable retainer will be needed to maintain overjet reduction, and continued compliance with appliance wear can be a problem. There is little evidence to support the benefit of early treatment in terms of final treatment outcome when compared with undertaking definitive treatment in the late mixed/early permanent dentition. (Tulloch 2004, 166 pt in US, half were control gp and half had either modified bionator or HG. 15 months later all pt re-randomized and had their treatment started or finished, no difference in the AP, V, or T between CG and TG) again O’Brien 2009 RCT on 174 half CG and half TG with TB at age of 8-9 years, then at age of 12.5 years the treatment either continued for the earlier TG or just started for the earlier CG, no difference between all except in earlier TG there is high cost and more attendance), Harrison 2008 Cochrane review found treatment in two stage has no advantage over one stage in adolescence C. Late mixed/early permanent dentition 1. Class I skeletal or very mild class II, • FA with or without extraction (using distalizations mechanics).
  • 14. • But if the arch is crowded then functional appliance can be the first phase to reduce the OJ and reduce anchorage requirement then FA with or without extraction. Treatment aims for camoflagable treatment 2. relieve crowding 3. level and align the arches 4. normal OJ 5. normal OB and correct edge - centroid relationship (lower incisor edge should lie anterior to the upper root centroid) HOUSTON 1989 6. Normal II angle Mills 1973 7. Correct the buccal segment relationships Favorable features for orthodontics camouflage Burden et al., 1999 Growth 1. Non-progressive worsening of the Class II. Skeletal 1. Class I or mild class II skeletal base relationship; 2. Small ANB difference 3. Average or reduced lower face height; 4. No transverse problems. Dental
  • 15. 1. OJ less than 9mm 2. Average or slight increased overbite; 3. Mild to moderate crowding 4. No dental compensation (Greater component of OJ being proclination of ULS and retroclination of LLS, this is a good indicator for success Burden 1999.) 5. Molar relationship less than half unit Cl II Soft tissues features 1. favorable soft tissue features, if the ST is retrusive this will end with poor profile if it is camouflaged (Bowman 2000, Proffit et al 1992) 2. Patient not concern about the profile. Habit Cessation of habit (if present) Displacement No mandibular displacement Orthodontic camouflage appliances URA • Simple tipping achieves desired movements • If maxillary incisors are proclined • Canines mesially angulated • HG can be added to get some skeletal changes
  • 16. Fixed appliance 1. if bodily tooth movement is required 2. if Sk problem allows camouflage Treatment mechanics in camoflagable treatment in early permanent dentition Non-crowded Arches 1. If the molar relationship is Class I, the upper incisors are frequently spaced and proclined. Contemporary management will involve the use of a fixed appliance to close space with retraction of the upper incisors using appropriate anchorage reinforcement to prevent forward movement of the molar teeth. 2. Molar relation ½ unit class II can usually be treated with a combination of arch expansion and distal movement of the upper posterior teeth with • Extra oral traction provided by headgear • Single or dual TAD on non-extraction base may be used (BECHTOLD, KIM, 2013) According to the effects of linear force vector(s) from interradicular miniscrews on the distalization pattern of the entire maxillary arch in adult Class II patients:No Significant distal movement of the incisors and molars implies the simultaneous movement of the whole arch was observed in both groups. The dual-screw group displayed significantly greater molar distalization and intrusion and incisor retraction than did the single-screw group. • Molar derotation. This can be done with a transpalatal lingual arch, an auxiliary labial arch, or the inner bow of a facebow. Sometimes upper molars are so mesially rotated that it is difficult or impossible to insert a facebow until the rotation has been partially corrected with a more flexible appliance (such as a
  • 17. heavy labial arch, typically 36 mil steel, inserted into the headgear tubes and tied over an initial alignment archwire). Crowded Arches Remember that extraction in the lower arch is to • Relieve crowding, • Alignment and correct COS • Correct LLS inclination, • Improve OB • Allow constriction of LA if desired • Correct molar relationship • Allowing the use of class II elastic. • Correct ML While the extraction in the upper arch is to • Relieve crowding, • Reduce OJ • Correct ULS inclination, • Increase OB if desired • Allow constriction of UA if desired Anchorage can be reinforced with either • Extraoral devices like headgear
  • 18. • Intraoral devices, TPA, Nance, TAD • Intermaxillary devices like bite corrector appliances or Class II traction. 2. Mild/moderate skeletal discrepancy Functional appliance therapy (if appropriate) maximising effect of any favourable skeletal growth . grater skeletal effect at 10-12 for girl and 11-13 for boys (Bacceti 2000) but Tulloch 1997 found that precise timing is no very effective on long term base. O’Brien 2003 found most of the effect of TB is dental with only 1.9mm skeletal changes Growth modification appliance Functional appliances or HG or combination in high angle class 2 A functional appliance aims to: 1. Reduce OJ 2. Reduce OB 3. Accerlate mandibular growth but on short term base (Tulloch, 1988) 4. Small effect on the maxillary restraint (Kelling 1998 found the maxillary restraint using the bionator is similar to HG appliance effect) 5. Enhance dentoalveolar compensation 6. Achieve normal incisor-lip relationship 7. Reduce the anchorage demand during FA stage 8. Correct transverse problem 9. Mills 1991 found that 60-70% dental and the rest is skeletal
  • 19. The aims of FA after functional is: • Finishing and detailing • Hold the corrected OJ • Correct torque and tip of incisor and molars • Achieve cl1 with the condyle centered in the fossa Post-functional appliance extract decision depend on 1. ST profile condition 2. Degree and location of crowding 3. Incisor proclination 4. Amount of remaining OJ 5. Amount of OB 6. Clinical condition of the teeth 7. Treatment mechanics and appliance used 8. Retention strategy Effects of functional appliances 1. Small amount of restraint of maxillary skeletal growth 2. Small amount of mandibular growth with increase in condylar length and remodelling in the glenoid fossae but not more than genetically determined. 3. Distal translation of the upper teeth 4. Mesial translation of the lower teeth 5. Retroclination of the upper incisors
  • 20. 6. proclination of the lower incisors. 7. UBS expansion 8. Increase facial height due to overeruption of the posterior teeth with subsequent rotation of the occlusal plane in clockwise direction. Advantages of early growth modification appliance treatment 1. Psychosocial advantages if patient is treated early, however, The treatment itself may introduce a new source of bullying, O’Brien et al 2003 2. High trauma with increased overjets (Todd & Dodd 1983) (45% 10 yr olds with OJ more than 9mm have traumatised incisors) however RCT comparing early versus late treatment concluded that All groups experienced trauma, Very early treatment may prevent trauma but not cost effective (Koroluk et al 2003), So that, the provision of a mouthguard is recommended to try to prevent trauma for patients with an increased risk of trauma (contact sports, large OJ). 3. Elimination of gingival/palatal trauma 4. Eliminate growth/local disturbances before they have had time to act fully. 5. Craniofacial tissues more malleable 6. Favorable changes in AP relationship achieved and improved prognosis for adolescent treatment but not significant (O’Brien, 2003) 7. Better co-operation.
  • 21. Disadvantages of growth modification appliance early treatment 1. long treatment 2. cost 3. cooperation 4. Choice of Xtn is difficult whilst young 5. Soft tissues do not mature until 12-14yrs with vertical growth of lips this might affects stability of corrected OJ 6. Arch length not maintained in permanent dentition (Little 1990) Evidences of the results with early growth modification appliance treatment 1. Review of the literature was unable to establish whether early or late treatment provided the most benefit overall: 'we lack definitive cost-benefit information. King et al., 1990 2. Ghafari1998, Baccetti 2000, Tulloch 2004, O’Brien, 2009 all showed that early treatment has no advantages 3. Koroluk 2003, show that no reduction in incisor trauma 4. O’Brien, 2003, show benefit from psychological point of view 5. Recent evidence suggests that early treatment is no more effective than orthodontic treatment in early adolescence Harrison et al., 2007 Advantages of late growth modification appliance treatment 1. Cost 2. One phase treatment 3. Growth still present
  • 22. 4. Exo decision is easy 5. E space can be used 6. Fitness of functional appliance is better 7. No difference from early treatment (Tulloch, O’Brien, Ghafari) 3. Severe skeletal discrepancy • with no concern about facial appearance Fixed appliance therapy with premolar extractions to relieve crowding or distal movement of upper posterior teeth • If there is a concern then Accept then the malocclusion will require a combination of orthodontic treatment and orthognathic surgery at maturity D. Adult treatment 1. Mild/moderate skeletal discrepancy – no concern about facial appearance Camouflage skeletal pattern using fixed appliances – premolar extractions may be required for relief of crowding and to allow upper incisor retraction 2. Severe skeletal discrepancy or a concern about facial appearance Orthognathic surgery required necessitating fixed appliance treatment to align and coordinate arches with correction of incisor inclinations (decompensation) Orthognathic surgery Indication Proffit 1992 1. in non-growing patients 2. patient concern 3. when too severe for orthodontics alone,
  • 23. • OJ 10mm • Pog to N perpendicular 18mm • Mandibular lghth less thn 70 mm • Facial height more than 125mm • ANB > 9° • sever vertical or transverse problem 4. when orthodontic treatment alone might cause determinately affect on the facial and occlusal esthetic as well as PD compromization 5. presence of complete compensation Summary of treatment modalities in different age group Deciduous Dentition • Orthodontic treatment during the deciduous dentition does not prevent the development of a Class II division 1 malocclusion in the permanent dentition, or reduce the complexity of later management. • Digit sucking habits should be discouraged Mixed dentition • increased risk of trauma to the permanent upper incisor teeth. If treatment is not undertaken at this stage, a mouthguard should be prescribed for wear during sport. • Teased by other children and, • Class II females with a significant skeletal discrepancy.
  • 24. • Any digit sucking habits should stop before treatment. • Treatment modalitis are functional appliance, URA+HG Late mixed/early permanent dentition • Mild/moderate skeletal discrepancy Functional appliance therapy (if appropriate) maximising effect of any favourable skeletal growth or Fixed appliance therapy with premolar extractions to relieve crowding or distal movement of upper posterior teeth • Severe skeletal discrepancy or a concern about facial appearance Accept malocclusion will require a combination of orthodontic treatment and orthognathic surgery at maturity Adult treatment • Mild/moderate skeletal discrepancy – no concern about facial appearance Camouflage skeletal pattern using fixed appliances – premolar extractions may be required for relief of crowding and to allow upper incisor retraction • Severe skeletal discrepancy or a concern about facial appearance Orthognathic surgery required necessitating fixed appliance treatment to align and coordinate arches with correction of incisor inclinations (decompensation) Stability and retention in class II division I malocclusion Evidence related to stability of class II D1 malocclusion A.Relationship between stability and pattern of extraction B.Relationship between different treatment mechanics and stability
  • 25. C.Surgical versus conventional treatment 1. Relationship between stability and pattern of extraction Post-treatment stability in Class II nonextraction and maxillary premolar extraction protocols, Guilherme. 2012 • Aim: To cephalometrically compare the overjet, overbite, and molar and canine relationship stability of Class II malocclusion treatment with and without maxillary premolar extractions. • Method: Two groups of 30 patients each with pre- and posttreatment matching characteristics and satisfactory finishing were used. Group 1 consisted of 30 patients treated with nonextraction at a mean pretreatment age of 12.14 years, while group 2 consisted of 30 patients treated with maxillary first premolar extractions at a mean pretreatment age of 12.87 years. Lateral cephalograms obtained before and after treatment and at a mean of 8.2 years after the end of treatment were compared. • Results: long-term stability of the overjet, overbite, and molar and canine relationships were similar in the groups. There were significant but weak correlations between treatment changes in overjet, overbite, and canine relationships with their long-term posttreatment changes. • Conclusion: Non-extraction and maxillary premolar extraction treatment of complete Class II malocclusion have similar long-term post-treatment stability in terms of overjet, overbite, and canine and molar relationships
  • 26. Long-term stability of Class II malocclusion treated with 2- and 4- premolar extraction protocols , Janson , 2009 • Objective of this study was to cephalometrically compare the stability of complete Class II malocclusion treatment with 2 or 4 premolar extractions after a mean period of 9.35 years. • A sample of 57 records from patients with complete Class II malocclusion was selected and divided into 2 groups. Group 1 consisted of 30 patients with an initial mean age of 12.87 years treated with extraction of 2 maxillary premolars. Group 2 consisted of 27 patients with an initial mean age of 13.72 years treated with extraction of 4 premolars. • Group 1 had a statistically greater OJ relapse than group 2. On the other hand, group 2 had a statistically greater molar-relationship relapse toward Class II. There were significant positive correlations between the amounts of treatment and posttreatment dentoalveolar-relationship changes. • Conclusions of complete Class II malocclusions with 2 maxillary premolar extractions or 4 premolar extractions had similar long-term posttreatment stability. 2. Relationship between different treatment mechanics and stability Long-term stability of Class II, Division 1, nonextraction cervical face-bow therapy: II. Cephalometric analysis. Elms 1996 • The long-term stability of Class II, Division 1 nonextraction therapy, using cervical face-bows with full fixed orthodontic appliances was evaluated for 42 randomly selected patients. Each patient was treated by the same practitioner, with the same techniques, and the treatment goals had been attained for all patients. Pretreatment records were taken at a mean age of 11.5 years; the
  • 27. posttreatment and postretention records were taken 3.0 and 11.6 years later, respectively. The ratio of treatment proclination of incisors to posttreatment retroclination is approximately 5:1. Similarly, for every 3 degrees of molar tip back, there was approximately 1 degree of relapse. It is concluded that nonextraction therapy for Class II malocclusion can be largely stable when the orthodontist ensures proper patient selection and compliance and attains treatment objectives. Long-Term Stability of Class II Correction with the Twin Force Bite Corrector Chebber 2010 • Follow-up studies of Class II patients have shown insignificant tendency to return to the original malocclusion after treatment with small increases in overjet and overbite and partial relapse of the molar relationships. Proper interdigitation of the posterior occlusion after bracket removal appears to be an important contributor to the stability of the correction. Occlusal stability of adult Class II Division 1 treatment with the Herbst appliance, Bock • During recent years, some articles have been published on Herbst appliance treatment in adult patients, an approach that has been shown to be most effective in Class II treatment in both early and late adulthood. However, no results on stability have yet been published. Our objective was to analyze the short-term occlusal stability of Herbst therapy in adults with Class II Division 1 malocclusions. • Methods:The subjects comprised 26 adults with Class II Division 1 malocclusions exhibiting a Class II molar relationship>0.5 cusp bilaterally or >1.0 cusp unilaterally and an overjet of >4.0 mm. The average treatment time was 8.8months (Herbst phase) plus 14.7 months (subsequent multi-bracket phase). Study casts from before and after treatment and after an average retention period of 32 months were analyzed.
  • 28. • Results: After retention, molar relationships were stable in 77.6% and canine relationships in 71.2% of the teeth. True relapses were found in • 8.2% (molar relationships) and 1.9% (canine relationships) of the teeth. Overjet was stable in 92.3% and overbite in 96.0% of the patients; true relapse did not occur. • Conclusions: Herbst treatment showed good occlusal stability 2.5 years after treatment in adults with Class II Division 1 malocclusions. Stability of Class II, Division 1 Treatment with the Headgear-Activator Combination Followed by the Edgewise Appliance Janson, 2004 • This study assessed the stability of the headgear-activator combination treatment, followed by edgewise mechanotherapy, 5.75 years after treatment. The experimental group consisted of 23 patients who were evaluated during treatment and after treatment. Two compatible control groups consisting of 15 • Class II, division 1 patients and 24 normal occlusion individuals were used. This enabled us to evaluate the changes during treatment and after treatment, respectively. Results showed that the anteroposterior dentoalveolar changes and the maxillary and the mandibular positions remained stable in the long term. • However, there was a slight relapse of the maxillomandibular relationship probably because the maxilla resumed its normal development and the mandibular growth rate was smaller than in the control group. • The overbite demonstrated a statistically significant relapse that was directly proportional to the amount of its correction. Initial Class II malocclusion severity (ANB and Wits), and initial molar relationship did not present any correlation with molar relationship and overjet relapse. • However, the initial overjet presented a low but statistically significant correlation with molar relationship relapse and overjet relapse.
  • 29. 3. Surgical versus conventional treatment Long-term comparison of treatment outcome and stability of Class II patients treated with functional appliances versus bilateral sagittal split ramus osteotomy.Berger 2005 • The objective of this study was to compare the treatment outcomes and stability of patients with Class II malocclusion treated with either functional appliances or surgical mandibular advancement. • The early-treatment group consisted of 30 patients (15 girls, 15 boys), with a mean age of 10 years 4 months (range, 7 years 5 months to 12 years 5 months), who received either Fränkel II (15 patients) or Herbst appliances (15 patients). The surgical group consisted of 30 patients (23 female, 7 male), with a mean age of 27 years 2 months (range, 13 years 0 months to 53 years 10 months). They were treated with bilateral sagittal split ramus osteotomies with rigid fixation. Lateral cephalograms were taken for the early-treatment group at T1 (initial records), T2 (completion of functional appliance treatment), and Tf (completion of comprehensive treatment). In the surgical group, lateral cephalograms were taken at T1 (initial records), T2 (presurgery), T3 (postsurgery), and Tf (completion of comprehensive treatment). The average times from the completion of functional appliance treatment or surgery to the final cephalograms were 35.8 months and 34.9 months, respectively. • In the functional appliance group, the mandible continued to grow in a favorable direction even after discontinuation of the functional appliance. Both groups had stable results over time. Both groups finished treatment with the same cephalometric measurements. Significant skeletal and soft tissue changes were noted in the treatment groups due to either functional or surgical advancement of the mandible. More vertical relapse was noted in the surgical group than in the functional group.
  • 30. • This study suggests that early correction of Class II dentoskeletal malocclusions with functional appliances yields favorable results without the possible deleterious effects of surgery. Long-term follow-up of Class II adults treated with orthodontic camouflage: a comparison with orthognathic surgery outcomes Mihalik 2003 • Looking at long-term stability of adult Class II treatment it was found that overbite was equally stable in both groups, but overjet relapsed twice as often in surgery patients. Stability of skeletal Class II correction with 2 surgical techniques: The sagittal split ramus osteotomy and the total mandibular subapical alveolar osteotomy, Valmy 2001 • Combined orthodontic and surgical treatment of severe Class II dentoskeletal deformities with the use of the bilateral sagittal split ramus osteotomy is a routine procedure in orthodontic practices. However, an alternative surgical technique, the total mandibular subapical alveolar osteotomy, could be used for the same purpose. The aim of this investigation was to compare the stability of the sagittal split ramus osteotomy with the total mandibular subapical alveolar osteotomy in the correction of dentoskeletal Class II malocclusions. Forty patients that exhibited Class II dentoskeletal relationships were included in the study. Twenty of these patients had mandibular advancement with the sagittal split ramus osteotomy; the remaining 20 patients had advancement of the whole lower alveolar segment with the total mandibular subapical alveolar osteotomy. The cephalograms studied were taken before the surgical procedure (T1 = 4 weeks before operation), immediately after the procedure (T2 = 10 days after surgery), and 1 year later (T3). The results of this study show that both procedures are equally stable when correcting Class II malocclusions. This was proved by the stability of the correction of overjet, B point, and incisor-
  • 31. mandibular plane angle. There were no statistically significant differences between or within the groups in the position of these landmarks over time. There was a statistically significant change in the position of pogonion from T1 to T2 (P < .0028) between the groups, although at T3 this difference was not significant (P < .05). There were no significant changes in face height either within or between the groups over time. The hard/soft tissue interactions for the total mandibular subapical alveolar osteotomy were as follows: The lower lip advanced 60% to the incisor movement; soft tissue B′ point responded with a 130% advancement in relation to the change in its hard tissue counterpart. Soft tissue pogonion advanced 90% in relation to the hard tissue landmark. The data suggest that the total mandibular alveolar osteotomy is the treatment of choice for the correction of severe dentoalveolar retrusive Class II malocclusion for which alteration of the mentolabial sulcus is desirable.
  • 32. Cause of relapse after treatment of class II D1 malocclusion 1. Local factors due to PD changes. 2. Soft tissue factors 3. Differential growth which predisposes to relapse. 4. Continued habits 5. Iatrogenic or Delayed treatment failure specially in surgical treatment. 6. Idiopathic causes eg: ICR 7. Combination Factors that be considered to control relapse potential 1. Regarding AP changes in the lower incisors: In Class II treatment, it is important not to move the lower incisors too far forward, if happen should be permanently retained. 2. Regarding the AP changes in upper incisors: Ensuring that the upper incisors are retracted sufficiently to be in control of the lower lip. 3. Regarding the occlusion: Proper interdigitation of the posterior occlusion after bracket removal appears to be an important contributor to the stability of the correction. Significant amounts of relapse were observed by Pancherz 2009 and Wieslander 2002 in cases treated to unstable occlusal relationships. 4. Regarding anteroposterior change: Overcorrection of the occlusal relationships as a finishing procedure is an important step in controlling tooth movement that would lead to Class II relapse. Even with good retention, 1 to 2 mm of anteroposterior change caused by adjustments in tooth position is likely
  • 33. to occur after treatment, particularly if Class II elastics were employed. This change occurs relatively quickly after active treatment stops. 5. Regarding growing patient: who has a class II skeletal at the start and treated by on camouflaging or comprehensive functional-fixed appliance treatment, further growth (which depend on age and geneder) almost surely will result in some loss of the correction as the original growth pattern persists. This relapse tendency can be controlled in one of two ways. • Continue headgear to the upper molars on a reduced basis (at night, for instance) in conjunction with a retainer to hold the teeth in alignment. • Functional appliance of the activator-bionator type to hold both tooth position and the occlusal relationship. The construction bite for the functional appliance is taken without any mandibular advancement—the idea is to prevent a Class II malocclusion from recurring, not to actively treat one that already exists. The functional appliance will be worn only part time, typically just at night, and daytime retainers of conventional design also will be needed to control tooth position during the first few months. 6. Regarding the treated deep overbite: 1. Good interincisal angle. The interincisal angle must be corrected (average 135°) in addition to the overbite being reduced in order to prevent re-eruption of the incisors after treatment. 2. Correct mandibular incisor edge-centroid relationship. • Possibly the most important factor in overbite stability in all treated cases is correction of the relationship between the mandibular incisor edge and the maxillary incisor root centroid • This is measured as the distance between the perpendicular projections of these two points on the maxillary plane (0–2 mm).
  • 34. • This may be achieved by either retraction of the maxillary incisor root centroid using fixed appliances with palatal root torque, or proclination of the mandibular incisors to advance their edges. • The decision depends on a number of factors including the facial profile, PD support and growth potential. • If a patient has a retrognathic mandible, it is possible to procline the maxillary incisors and to either surgically advance the mandible or in a growing patient to use a functional appliance to help advance the mandibular incisors. • In a patient with good facial profile aesthetics, the treatment may be carried out with fixed appliances alone, so long as the palatal alveolar process is thick enough to allow retraction of the maxillary incisor root centroid. The crowns of the incisor teeth should also be maintained within the zone of soft tissue equilibrium between the musculature of the tongue and the lips. An interesting proposition is that in Class II division 2 malocclusions it may be possible to intrude and torque the maxillary incisor roots palatally, allowing the mandibular incisor crowns to be proclined and hence occupy the position previously occupied by the maxillary incisor crowns, thus maintaining the incisor complex within the zone of soft tissue equilibrium. 3. Proclination of the lower labial segment in Class II cases. This may still be unstable in the long term due to pressure from the lower lip.(Mills 1979) Therefore, long-term retention may be required in such cases and must be discussed with the patient prior to treatment. 4. Avoid change in intermaxillary height in non-growing patients. The extrusion of molars in non-growing patients is unstable, as the muscular forces from the pterygo-masseteric sling will re-intrude the molars if the posterior vertical face height has not accommodated their extrusion.
  • 35. 5. Vertical facial growth. it continues well into the late teenage years. As the pattern of facial growth does not tend to change following treatment it is prudent to place a bite-plane on the maxillary removable retainer after the completion of orthodontic treatment. This may be worn on a part-time basis in order to maintain the corrected overbite until vertical facial growth has subsided. using active removable upper retainer made so that the lower incisors will encounter the baseplate of the retainer if they begin to slip vertically behind the upper incisors. The procedure, in other words, is to build a potential biteplate into the retainer, which the lower incisors will contact if the bite begins to deepen. The retainer does not separate the posterior teeth. Because vertical growth continues into the late teens, a maxillary removable retainer with a bite plane often is needed for several years after fixed appliance orthodontics is completed 7. Regarding the treated anterior open bite: • Continue stopping the habit with tongue spur which is questionable for its effectiveness • a maxillary retainer with bite blocks (or a functional appliance) to impede eruption • high-pull headgear.
  • 36. Common Questions related to this topic Are There Any Circumstances in Which Lower Incisor Proclination Is Likely to Be Stable? 1. Lower incisors retroclined due to:(Mills, 1973) • Pre-existing lip trap • Traped in the palate • Digit habit • Incisors held artificially upright by the occlusion (such as a class II division 2) • Mild class III with reverse OJ that is corrected to normal OJ with positive OB 2. Following orthognathic surgery in class III malocclusion (Artun et al., 1990)
  • 37. Literatures Steep and deep Described by Sandler and DiBiase in 1996. should be 7mm height and 70 degree inclinations in Hawely retainer . Disadvantages • proclination of LLS • theoretically restraining of maxillary growth High angle class II cases 1. if the problem from U posterior vertical overgrowth (No gummy smile) • then HG to molars but this will intrude the U molars and the L molars might be allowed to erupt and causing another problem in developing long face • then functional appliance is used, it is better to use stopper on the terminal molars or use posterior bite block, and increase the bite opening to allow heavy muscle intrusion on posterior teeth when the appliance in the mouth i.e HG effect of the functionl appliances.(Proffit) 2. If the problem from whole maxillary vertical overgrowth (gummy smile) • then HG+buccal or maxillary intrusion splint developed by Orton 1992 but the L molars might be allowed to erupt and causing another problem in developing long face 3. If the problem from whole maxillary vertical overgrowth and returisive mandible (class II gummy smile) • functional+HG+post bite block+torqueing spring on U incisors
  • 38. • intrusion of molars by repelling magnet or Implants; • in adults the Surgical impaction of the maxilla. Multiple questions Is There a Relationship between Malocclusion and Teasing/ Bullying? Teeth have been reported as the fourth most common feature to provoke unfavourable social responses, including bullying. Increased overjet is linked with teasing (Shaw et al., 1980) and reduced self-concept. It is also associated with reduced levels of oral health-related quality of life (Johal et al., 2007; Marques et al., 2009). Some improvement in self-concept has been demonstrated in subjects undergoing early overjet reduction (O’Brien et al., 2003). However, prolonged follow-up has failed to show a sustained effect; self-concept is influenced by an array of features. What Are the Short-Term Effects of Functional Appliances? Short-term effects of functional appliance therapy are both skeletal and dento- alveolar in nature; but dental effects predominate. In particular, retroclination of maxillary incisors and proclination of mandibular incisors contribute to correction of the incisor relationship (O’Brien et al., 2003). Maxillary restraint and acceleration of mandibular growth are also important in the short-term. How Do These Changes Contrast with the Long-Term Effects? Prospective research suggests that prolonged growth modification may not be achievable. These studies have confirmed that skeletal modification is instrumental in producing favourable occlusal change, including overjet reduction and molar correction; however, medium-term follow-up indicates that this growth enhancement may disappear with further maturation (O’Brien et al., 2003; 2009). It appears that mandibular growth potential is largely pre-
  • 39. determined and that our capacity to permanently alter growth of this bone is limited. Nevertheless, occlusal correction tends to be effective and stable. Dynamax appliance? 1. This appliance consists of an upper removable component, which incorporates Adams cribs on the first molars and first premolars, a midline coffin spring and anterior torque spring on the maxillary central incisors. Mandibular posture is achieved using a lower fixed lingual arch, which has shoulders that project horizontally. As the patient closes, two vertical springs, which project from the upper appliance, ensure anterior posturing of the mandible through avoiding interference with the lower lingual arch. The appliance can be reactivated by adjusting the springs on the upper appliance. 2. The reported advantages include: • Simple incremental advancement • Simultaneous use of a lower fixed appliance • Control of incisor inclination • Restriction of vertical facial development. 3. A recent randomized controlled trial has demonstrated that the Twin Block is a more effective functional appliance than the Dynamax when overjet reduction is evaluated, with a significant increase in the incidence of adverse effects seen with the Dynamax (Thiruvenkatachari et al., 2010). But in 2012 another study by Spary found that Dynamax is well tolerated and has almost the similar effect of TB.
  • 40. What Factors Influence the Need for Headgear in Association with Functional Appliance Therapy? • The more severe the class II discrepancy, the more useful headgear support can be. • Cases with maxillary excess, either antero-posterior or vertical will also benefit from the use of headgear with a functional appliance. • Control the inclination of ULS What Are the Advantages and Disadvantages of Fixed Functional Appliances? • Guaranteed wear of the appliance • Improved compliance and completion rate However, these advantages are tempered by: • Greater onus on oral hygiene • Increased cost • Greater chair-side manipulation • Higher breakage rate. What Factors Influence the Choice of a Specific Functional Appliance? • Anticipated compliance • Medical history: Newport used in nickel allergy • Severity of class II • Vertical skeletal pattern :Patients with increased lower anterior face height may benefit from restraint of vertical maxillary growth; the addition of high pull headgear and use of specific functional appliances (Teuscher, van Beek,
  • 41. Dynamax) have been proposed to address this problem. Conversely, with a reduced lower anterior face height, the expression of vertical facial growth and posterior tooth eruption can be more favorable; consequently, specific appliances, including the Medium Opening Activators and Modified Twin Block, are useful. What Is Dento-Alveolar Compensation? 1. A natural alteration in the position of the dentition to limit the occlusal effect of an underlying skeletal discrepancy. 2. It can occur in all three planes of space. 3. It is typically most pronounced in class III malocclusion with retroclination of mandibular incisors and proclination of the maxillary incisors compensating for a skeletal class III discrepancy. How Long Does Functional Appliance Therapy Take? At this stage there is no evidenced-based answer to this question, with treatment time being dictated by operator preferences and the individual response of patients to treatment. However, it usually takes around 6– 12 months. Shorter periods of appliance wear are likely to be less stable than longer courses of treatment. What Are the Limitations of Headgear? 1. Patient compliance. Headgear wear of up to 14 hours per day may be required. The duration of wear is often less than half this time (Brandao et al., 2006). Compliance is particularly poor in adults.
  • 42. 2. Risk of injury. Reports of iatrogenic injury, including blindness, have been attributed to headgear injury, although this is extremely rare (Postlethwaite, 1989). 3. For maximum effect, residual maxillary growth is required. 4. Successful distal molar movement is difficult after maxillary second permanent molars have erupted. How May Compliance with Headgear Be Improved? 1. Encouragement and rewards 2. Headgear charts (Cureton et al., 1993) 3. Headgear timers 4. Patient should be actively growing What Are the Problems Associated with Extracting Premolar Teeth in the Maxillary Arch Only? The main problem originates from the fact that a single maxillary premolar tooth width is often larger than a single tooth ‘unit’. Therefore, with the overjet reduced, the molars in a full unit class II relationship and the canines class I, a small tooth size discrepancy can remain, which can result in a small amount of residual space. This can be completely closed by bringing the molars forward into a ‘super’ class II relationship or rotating the maxillary premolars slightly to increase their relative width.
  • 43. What Is the Tip Edge ® Appliance? Tip Edge ® is a fixed orthodontic appliance modelled on the Begg appliance (Kesling, 1989). The bracket design facilitates tipping of the teeth during the initial stages of treatment, which in combination with the use of rigid round stainless steel wires, anchor bends and class II elastics, allows rapid correction of the overjet and overbite during the first stage of treatment What Are the Three Stages of Tip Edge ® Treatment? Stage 1: Overjet and overbite reduction Stage 2: Space closure Stage 3: Angulation and torque correction Is There Any Association between Occlusal Para-Function and Orthodontic Treatment? This adult patient demonstrated significant occlusal wear. The association between orthodontic treatment, occlusal para-function and temporo-mandibular problems is unclear. A subset of patients experience worsening of their para- function during treatment; others show improvement. This is in keeping with the intermittent nature of para-functional habits. In relation to temporo- mandibular dysfunction, while some cross-sectional and longitudinal studies have noted a trend to improvement in symptoms with treatment, this change is unpredictable. Consequently, orthodontics is considered ‘TMJ neutral’ (Luther, 2007a, b). Nevertheless, it is advisable to carry out a thorough temporo- mandibular joint examination prior to treatment.
  • 44. What Are the Risk Factors for Gingival Recession During Orthodontic Treatment? 1. Thin gingival biotype 2. Pre-existing recession 3. Gingival inflammation 4. Poor oral hygiene (Melsen and Allais, 2005) Is Lower Incisor Proclination Likely to Exacerbate Gingival Recession? Uncontrolled incisor proclination is inadvisable and risks further recession. However, the association between proclination and recession is weak and unpredictable. A retrospective study of 300 adult patients undergoing orthodontic treatment demonstrated an average increase in lower incisor recession of just 0.14 mm with incisor proclination (Allais and Melsen, 2003). Are There Any Contraindications to a Phase of Fixed Appliance Treatment Following the Successful Use of a Functional Appliance? 1. Poor oral hygiene 2. Mixed dentition 3. History of poor compliance 4. Well aligned class I occlusion with no open bites What Are the Options to Conserve Anchorage and Facilitate Overjet Reduction? Anchorage is required to facilitate overjet reduction. Intra-arch auxiliaries that could be considered include headgear, a Nance palatal arch or temporary anchorage devices. Headgear tends to be poorly tolerated in adult patients.
  • 45. Palatal arches can be problematic during orthodontic space closure and overjet reduction, and are traditionally dispensed with prior to this treatment stage. In addition, there is some evidence that palatal arches may be of little real value for antero-posterior anchorage (Stivaros et al., 2010). Consequently, temporary anchorage devices were used to facilitate overjet reduction. Other options that could have been considered include use of differential tooth movement, e.g. Tip Edge ® appliance and inter-arch mechanics, including elastics or fixed class II correctors.