Centric relation: A matter of form and substance.

The recent review article by Zonnenberg, Türp and Greene 'Centric relation critically revisited - What are the clinical implications'? opens an important debate by addressing topics of central relevance in Dentistry, namely the relationship between occlusion and the condyle-to-glenoid-fossa position, and the need for diagnostic assessment and therapeutic alteration of the condylar position in orthodontic patients. Zonnenberg, Türp and Greene concluded that the mandibular condyle is correctly situated in most orthodontic patients. Thus, in their view, orthodontists can disregard this aspect during treatment, and rely on the plastic properties of the masticatory supporting structures, while aiming at finishing the cases in a good occlusal relationship. We think that this approach fails to consider that biological variation of the stomatognathic structures can also be pathological and that, as dental occlusion determines condylar relative position within the glenoid fossa, changes in the occlusion are likely to alter the original condylar-to-glenoid-fossa relation. Hence, we claim that whenever the occlusal relationship must be changed, the clinician should carefully monitor the condyle position and the mandibular function to prevent possible iatrogenic effects. To advance the discourse on the topic, we invite Zonnenberg, Türp and Greene to clarify their definition of 'average patient' and their interpretation of 'full-mouth orthodontic and orthognathic treatment', their understanding of 'biologically acceptable condylar relationship', their justification of maximum intercuspation as reference position, the extent to which they think it is safe to rely on the TMJ resilience, and finally their alternative to centric relation in the treatment of patients needing condylar repositioning.

Preventive and Therapeutic Proximal Sealing: A 3.5-Year Randomized Controlled Clinical Trial Follow-Up.

OBJECTIVE: The aim of this split-mouth, randomized controlled clinical trial was to evaluate the efficacy of proximal sealing for avoiding the development of new caries lesions or arresting incipient caries lesions on the mesial surface of first permanent molars (6m) abutting lesions on the distal surface of second primary molars (05d) in children at high caries risk. METHODS: A total of 61 children 8-10 years old were selected based on the caries status of the proximal sites of 05d and 6m. Children with caries on 05d and caries-free 6m were placed in the preventive sealing group and children with caries on both 05d and 6m in the therapeutic group. The children in each group had one 6m surface pair and in each pair one 6m surface was randomly allocated to receive a preventive or therapeutic sealing. Using a split-mouth design, the other 6m surface in the pair served as control. RESULTS: After 3.5 years, standardized follow-up radiographs were obtained for the 45 children who remained. In the preventive sealing group, 4 out of 30 (13.3%) sealed and 16 out of 30 (53.3%) unsealed sound 6m surfaces had developed new caries lesions (p = 0.004, McNemar test). In the therapeutic sealing group, the progression of the carious lesions on 6m was observed in 3 out of 15 sealed (20.0%) and 8 out of 15 (53.3%) unsealed caries control surfaces (p = 0.06). CONCLUSIONS: Preventive sealing on sound 6m surfaces abutting 05d lesions in children at high caries risk efficaciously prevents the development of caries lesions. Therapeutically sealing active non-cavitated caries lesions reduces the progression.

A 5-year clinical follow-up of the efficacy of proximal sealing in high caries risk children.

OBJECTIVE: The aim of the present study was to evaluate, after 5 years, the efficacy of proximal microinvasive sealing of permanent teeth on the risk for caries lesion development. METHODS: Children aged 8 to 10 y at baseline, at high caries risk, were studied. In the preventive (P) group the children had caries lesions on the distal surface of primary second molars (05d) but sound mesial surfaces of the approximating permanent first molars (6m). In the therapeutic (T) group the children had initial caries lesions on 6m that abutted lesions on 05d. Each child in the two groups had one 05d/6m pair. Using a split-mouth design, one 6m surface in each pair was randomly assigned to receive sealing while the other pair served as an unsealed control. RESULTS: Of the 61 children at baseline 42 could be blindly examined clinically and radiographically both at baseline and after 5 years. In the P group, 8 of 28 (28.6%) sealed and 15 of 28 (53.6 %) unsealed sound 6m surfaces had developed caries lesions (p = 0.04). In the T group, the progression of the carious lesions on 6m was observed in 4 of 14 sealed (28.6%) and 8 of 14 (57.1%) unsealed caries control surfaces (p = 0.29). Pooling the data from the two groups, the difference between sealed and non-sealed surfaces was significant (p = 0.013). CONCLUSION: Both preventive and therapeutic sealant to 6m adjacent to a lesion on 05d has effectiveness in caries reduction in high caries risk children CLINICAL SIGNIFICANCE: The beneficial effect of sealing is observed for at least 5 years after a single sealant treatment.

A 2-year clinical evaluation of sealed noncavitated approximal posterior carious lesions in adolescents.

The objective was to evaluate the clinical performance of a therapeutic sealant to arrest the progression of noncavitated approximal posterior carious lesions. The study population comprised 50 adolescents in whom bitewing radiographs had been taken for diagnosis of caries. Approximal noncavitated lesions in premolars and molars (4d-7m) were selected. One group (n=17) had a sealant placed after tooth separation on all enamel lesions. A second group (n=7) received sealant and fluoride varnish in a split-mouth design. A control group (n=26) received a standard fluoride varnish treatment without tooth separation. Follow-up radiographs were taken after 2 years and were analyzed together with the baseline radiographs in a blind study setting. About 93% of the sealed initial carious lesions showed no progression. The corresponding value for the fluoride varnish control group was 88%. In the split-mouth study, 92 and 88% of the surfaces with enamel caries showed no progression after sealant or fluoride varnish treatment, respectively. The difference between the two treatment procedures was not statistically significant. The incidence rate for the transition from enamel caries to dentin caries or fillings was 3.5-3.9 surfaces/100 years in the sealant groups and 5.9-6.1 surfaces/100 years in the fluoride varnish groups. The results show the potential of sealants to act as a noninvasive treatment of early approximal enamel lesions.

La filosofía MEAW y el rol de los terceros molares en el desarrollo y tratamientos de las mordidas abiertas / MEAW philosophy and the riole of third molars in the development and treatment of openbites

Multiloop Edgewise Archwire Technique es una técnica desarrollada en los años 60 por Young H. Kim, la cual ha tenido un fuerte desarrollo en los países de Asia, especialmente Japón y Corea, por el Prof. Sadao Sato de la Universidad de Kanagawa, Japón. En la experiencia de la filosofía MEAW se ha dado particular importancia al tratamiento no quirúrgico de clases III y mordidas abiertas esqueletales. La discrepancia posterior (CP), concepto nuevo para la ortodoncia occidental, es considerada para determinar la remoción temprana de los terceros molares debido a su importancia como factor coadyuvante en la recidiva de los tratamientos de ortodoncia, especialmente el apiñamiento incisivo y en particular en la orientación del Dr. Sato, debido a su importancia en el desarrollo de la DP, que como se ha mencionado, es un factor etiopatogénico en el desarrollo de las maloclusiones esqueletales y mordidas abiertas antes, durante y postratamiento de ortodoncia.

La filosofía MEAW y el rol de los terceros molares en el desarrollo y tratamientos de las mordidas abiertas / MEAW philosophy and the riole of third molars in the development and treatment of openbites

Multiloop Edgewise Archwire Technique es una técnica desarrollada en los años 60 por Young H. Kim, la cual ha tenido un fuerte desarrollo en los países de Asia, especialmente Japón y Corea, por el Prof. Sadao Sato de la Universidad de Kanagawa, Japón. En la experiencia de la filosofía MEAW se ha dado particular importancia al tratamiento no quirúrgico de clases III y mordidas abiertas esqueletales. La discrepancia posterior (CP), concepto nuevo para la ortodoncia occidental, es considerada para determinar la remoción temprana de los terceros molares debido a su importancia como factor coadyuvante en la recidiva de los tratamientos de ortodoncia, especialmente el apiñamiento incisivo y en particular en la orientación del Dr. Sato, debido a su importancia en el desarrollo de la DP, que como se ha mencionado, es un factor etiopatogénico en el desarrollo de las maloclusiones esqueletales y mordidas abiertas antes, durante y postratamiento de ortodoncia.(AU)