Long-term cost of direct Class II molar restorations

The aim was to evaluate the theoretical long-term treatment costs of direct class II molar restorations (amalgam, composite, glass ionomer) using the Median Survival Times (MSTs) derived from longevity studies conducted in the Nordic countries as time for replacement. Theoretical long-term cost calculations were based on fee schedules from all Public Dental Services (PDS) in Sweden, for patients, Social Insurance Offices (SI), and total cost. Costs over 10 years were calculated and sensitivity calculations were conducted in order to demonstrate the effect of different MSTs on the long-term cost development. Glass ionomer molar class II restorations had the lowest and composite restorations had the highest initial total cost. The highest total cost over 10 years was seen for composite restorations. Amalgam restorations had the lowest long-term total cost, except when the costs were based on the shortest MSTs for each material. As there were considerable differences in the long-term costs for class II molar restorations with different materials, the importance of cost-analyses over time cannot be enough emphasised when decisions about resource allocation in the dental health insurance system are considered.     

Finishing occlusion in Class II or Class III molar relation: therapeutic Class II and III

The most frequent extraction regime consists of the removal of upper and lower premolars. Depending on anchorage requirements, camouflage treatment options, surgical intervention, or the absence of teeth in only one arch, it may become necessary to finalize the occlusion with a one-dental-unit discrepancy between the upper and lower dental arches. Guidelines are presented for finishing occlusions in Class II or Class III molar relation.     

A dental Class III malocclusion treated to a full-cusp Class II molar relationship

A case report of a Class III dental malocclusion superimposed on a straight skeletal pattern is presented. The patient was a 14-year-old girl with limited growth potential. This case included congenitally missing maxillary permanent lateral incisors, impacted maxillary permanent canines, and bilateral posterior open bites. The patient's soft-tissue profile was normally convex. In addition to her malocclusion, the patient had a history of difficulty breathing through the nose. The general treatment included palatal expansion, protraction headgear, and comprehensive edgewise orthodontic therapy.     

Reappraisal of Class II molar relationships diagnosed from the lingual side

The buccal and lingual molar relationships in 459 clinically diagnosed Class II cases and the impact of upper first permanent molar rotation on this classification were assessed. Of the 459 Class II cases, 99 (10.78%) sides exhibited unilateral neutral molar relationship assessed from both the buccal and the lingual aspect. None of the molars exhibiting Class I relationship were rotated. The 175 (19.06%) sides with mild Class II molar relationship from the buccal aspect were all judged to be Class I lingually and 85% of these molars were rotated mesially. In the case of a moderate buccal Class II tendency, 55% of the molars were in a Class I relationship when evaluated from the lingual side, whereas 45% belonged to mild (1st degrees ) Class II with molar rotations present in 81% of the cases. When a severe (3rd degrees ) Class II was present from the buccal side, its corresponding lingual Class II tendencies were accordingly elevated (83% 2nd degrees, 17% 3rd degrees ). Among these cases, the molar rotations occurred in 74% of the cases. The results suggested the upper mesiopalatal cusp as a pivotal axis around which the upper first molar rotated. This cusp occluded most frequently in the central fossa, less frequently in the mesio-triangular fossa and rarely anterior to the mesio-triangular fossa. Rotations that correspond to these types of lingual occlusion were 85, 81 and 74%, respectively. The correlation between buccal and lingual molar relationships and their correlation with molar rotation were all significant (p<0.001). Moreover, canine relationship was linearly correlated with the conventional (buccal) molar relationship in Class II cases, expressed by Ycanine relation=1.423+0.47 Xmolar relation (p<0.001). The results indicate that a more differentiated diagnosis of the molar relationship will allow for a more causally directed correction of Class II molar relationship.     

Treatment of Class II molar furcation involvement: meta-analyses of reentry results

Background: Predictable regeneration of lost periodontal tissues in furcations is difficult to achieve. This paper investigates the efficacy of different treatment modalities for Class II molar furcations. Methods: Publications in English were searched using PubMed, Medline, and Cochrane Library databases combined with hand searching from January 1, 1966 to October 1, 2007. The search included randomized controlled human trials in molar Class II furcations with over 6 months of surgical reentry follow‐up. Changes in vertical probing depths, vertical attachment levels, and vertical and horizontal bone levels were compared. Results: The search identified 801 articles of which 34 of 108 randomized clinical trials met the criteria. Thirteen trials had test and control arms allowing three meta‐analyses: 1) five comparing non‐resorbable versus resorbable membranes, 2) five comparing non‐resorbable membranes versus open flap debridement and 3) three comparing resorbable membranes versus open flap debridement. There was significant improvement for resorbable versus non‐resorbable membranes mainly in vertical bone fill (0.77 ± 0.33 mm; [95% CI; 0.13, 1.41]). Non‐resorbable membranes showed significant improvement in vertical probing reduction (0.75 ± 0.31 mm; [95% CI; 0.14, 1.35]), attachment gain (1.41 ± 0.46 mm; [95% CI; 0.50, 2.31]), horizontal bone fill (1.16 ± 0.29 mm; [95% CI; 0.59, 1.73]), and vertical bone fill (0.58 ± 0.11 mm; [95% CI; 0.35, 0.80]) over open flap debridement. Resorbable membranes showed significant improvement in vertical probing reduction (0.73 ± 0.16 mm; [95% CI; 0.42, 1.05]), attachment gain (0.88 ± 0.16 mm; [95% CI; 0.55, 1.20]), horizontal bone fill (0.98 ± 0.12 mm; [95% CI; 0.74, 1.21]) and vertical bone fill (0.78 ± 0.19 mm; [95% CI; 0.42, 1.15]) over open flap debridement. Conclusions: Guided tissue regeneration with the use of resorbable membranes was superior to non‐resorbable membranes in vertical bone fill. Both types of membranes were more effective than open flap debridement in reducing vertical probing depths and gaining vertical attachment levels and in gaining vertical and horizontal bone.     

Long-term stability of miniscrew anchored maxillary molar distalization in Class II treatment

ObjectiveTo investigate treatment stability of miniscrew-anchored maxillary distalization in Class II malocclusion.Materials and MethodsThis retrospective study included a distalization (n = 19) and a control (n = 19) group; a patient group with minor corrections served the control. Lateral cephalograms of 38 adult patients were taken before (T0), immediately after (T1), and 3–4 years after (T2) treatment. Horizontal and vertical movement and tipping of the maxillary first molars (U6) and central incisors (U1) were measured along with skeletal craniofacial parameters at three time points to compare the two groups regarding the achieved treatment effects and their stability.ResultsTotal arch distalization therapy led to 4.2 mm of distal movement of U6 without distal crown tipping (0.6° of axis change) and 3.3° of occlusal plane steepening. Over an average retention period of 42 months, maxillary total arch distalization provided high stability of treatment results, showing the same amount of mesial movement (0.7 mm) as the control group.ConclusionsIn Class II treatment, miniscrew-anchored maxillary total arch distalization can provide stable distal movement of the maxillary first molars and central incisors.     

Individualized clinical evaluation of tooth movement. Treatment of Class II: molar splints and structural effects

The presentation of a synoptic chart allowing a dental arch analysis and Class II correction strategy is presented and followed by a study on 30 patients in mixed dentition and 37 growing patients in permanent dentition. These patients presenting a Class II malocclusion have been treated by Class II mechanics and lower molar individualised splint enhancing the vertical lower face height and skeletal Class II correction. This study shows a good vertical stabilization of the facial planes during the treatment, a significant growth of the lower face but it is noticed a posterior rotation of the occlusal plane in the mixed dentition sample.     

Long-term evaluation of Class II subdivision treatment with unilateral maxillary first molar extraction

Objective:To evaluate the long-term effects of asymmetrical maxillary first molar (M1) extraction in Class II subdivision treatment.Materials and Methods:Records of 20 Class II subdivision whites (7 boys, 13 girls; mean age, 13.0 years; SD, 1.7 years) consecutively treated with the Begg technique and M1 extraction, and 15 untreated asymmetrical Class II adolescents (4 boys, 11 girls; mean age, 12.2 years; SD, 1.3 years) were examined in this study. Cephalometric analysis and PAR assessment were carried out before treatment (T1), after treatment (T2), and on average 2.5 years posttreatment (T3) for the treatment group, and at similar time points and average follow-up of 1.8 years for the controls.Results:The adjusted analysis indicated that the maxillary incisors were 2.3 mm more retracted in relation to A-Pog between T1 and T3 (β  =  2.31; 95% CI; 0.76, 3.87), whereas the mandibular incisors were 1.3 mm more protracted (β  =  1.34; 95% CI; 0.09, 2.59), and 5.9° more proclined to the mandibular plane (β  =  5.92; 95% CI; 1.43, 10.41) compared with controls. The lower lip appeared 1.4 mm more protrusive relative to the subnasale-soft tissue-Pog line throughout the observation period in the treated adolescents (β  =  1.43; 95% CI; 0.18, 2.67). There was a significant PAR score reduction over the entire follow-up period in the molar extraction group (β  =  −6.73; 95% CI; −10.7, −2.7). At T2, 65% of the subjects had maxillary midlines perfectly aligned with the face.Conclusions:Unilateral M1 extraction in asymmetrical Class II cases may lead to favorable occlusal outcomes in the long term without harming the midline esthetics and soft tissue profile.     

Predictive value of molar bite force on Class II functional appliance treatment outcomes

Sagittal intermaxillary changes brought about by functional appliances show large inter-individual variation. One factor that may in part explain these differences is the masticatory musculature and its functional capacity. The aims of this study were to investigate changes in maximal molar bite force during functional appliance treatment and to assess the influence of pre-treatment maximal molar bite force on treatment outcomes with functional appliances used in Class II malocclusion children. Twenty-five children (17 males and 8 females), aged 9-13 years, with a Class II malocclusion and increased overjet were treated with functional appliances for 1-2 years. Dental casts, lateral cephalograms, maximal molar bite force, and finger force measurements were performed before (T1) and after (T2) treatment. These same measurements were also performed 1-2 years before treatment (T0); the intermediate period before starting treatment served as the control. Multiple regression analyses were used to determine possible correlations between initial maximal molar bite force and dental or cephalometric changes during treatment. Maximal molar bite force, which increased pre-treatment (T0-T1), decreased during functional appliance treatment (T1-T2). Children with a weaker T1 maximal molar bite force showed a larger overjet reduction, greater improvement in molar relationship, greater reduction in ANB angle, and greater augmentation in SNB angle from T1 to T2. Treatment of children with Class II malocclusions with functional appliances seems to lead to more favourable treatment outcomes in those with a weaker maximal molar bite force. This was observed both as regards improvements in dental sagittal relationships, namely overjet and molar Class, as well as skeletal changes due to a decrease in ANB and an increase in SNB angles.     

Influence of unilateral maxillary first molar extraction treatment on second and third molar inclination in Class II subdivision patients

Objective:To assess the maxillary second molar (M2) and third molar (M3) inclination following orthodontic treatment of Class II subdivision malocclusion with unilateral maxillary first molar (M1) extraction.Materials and Methods:Panoramic radiographs of 21 Class II subdivision adolescents (eight boys, 13 girls; mean age, 12.8 years; standard deviation, 1.7 years) before treatment, after treatment with extraction of one maxillary first molar and Begg appliances and after at least 1.8 years in retention were retrospectively collected from a private practice. M2 and M3 inclination angles (M2/ITP, M2/IOP, M3/ITP, M3/IOP), constructed by intertuberosity (ITP) and interorbital planes (IOP), were calculated for the extracted and nonextracted segments. Random effects regression analysis was performed to evaluate the effect on the molar angulation of extraction, time, and gender after adjusting for baseline measurements.Results:Time and extraction status were significant predictors for M2 angulation. M2/ITP and M2/IOP decreased by 4.04 (95% confidence interval [CI]: −6.93, 1.16; P  =  .001) and 3.67 (95% CI: −6.76, −0.58; P  =  .020) in the extraction group compared to the nonextraction group after adjusting for time and gender. The adjusted analysis showed that extraction was the only predictor for M3 angulation that reached statistical significance. M3 mesial inclination increased by 7.38° (95% CI: −11.2, −3.54; P < .001) and 7.33° (95% CI: −11.48, −3.19; P  =  .001).Conclusions:M2 and M3 uprighting significantly improved in the extraction side after orthodontic treatment with unilateral maxillary M1 extraction. There was a significant increase in mesial tipping of maxillary second molar crowns over time.