Editor’s Summary and Q&A



Editor's Summary and Q&A




American Journal of Orthodontics and Dentofacial Orthopedics, 2010-01-01, Volume 137, Issue 1, Pages 14-15, Copyright © 2010 American Association of Orthodontists


Introduction

The aim of this study was to investigate the prevalence of tooth wear in adolescents with Class II malocclusion, compared with those with normal occlusion.

Methods

The sample consisted of dental casts obtained from 310 subjects, divided into 3 groups: group 1, 110 subjects with normal occlusion (mean age, 13.51 years); group 2, 100 complete Class II Division 1 patients (mean age, 13.44 years); and group 3, 100 half-cusp Class II Division 1 patients (mean age, 13.17 years). Dental wear was assessed by using a modified version of the tooth-wear index. The 3 groups were compared by means of the Kruskal-Wallis and Dunn tests, considering the frequency and the severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%.

Results

The normal occlusion group had statistically greater tooth wear on the palatal surfaces of the maxillary central incisors and the incisal surfaces of the maxillary canines than the corresponding surfaces in both Class II malocclusion groups. The complete and half-cusp Class II Division 1 malocclusion groups had statistically greater tooth wear on the occlusal surfaces of the maxillary second premolar and first molar, the occlusal surfaces of the mandibular premolars, and the buccal surfaces of the mandibular posterior teeth compared with the normal occlusion group. The half-cusp Class II Division 1 malocclusion group had significantly greater tooth wear on the incisal surfaces of the mandibular incisors compared with the complete Class II Division 1 malocclusion group.

Conclusions

Subjects with normal occlusion and complete or half-cusp Class II Division 1 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but, rather, consequent to the different interocclusal tooth arrangement.


You're Reading a Preview

Become a DentistryKey membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here

Was this article helpful?

Editor's Summary and Q&A Guilherme Janson , Paula Vanessa Pedron Oltramari-Navarro , Renata Biella Salles de Oliveira , Camila Leite Quaglio , Sílvia Helena de Carvalho Sales-Peres and Bryan Tompson American Journal of Orthodontics and Dentofacial Orthopedics, 2010-01-01, Volume 137, Issue 1, Pages 14-15, Copyright © 2010 American Association of Orthodontists Introduction The aim of this study was to investigate the prevalence of tooth wear in adolescents with Class II malocclusion, compared with those with normal occlusion. Methods The sample consisted of dental casts obtained from 310 subjects, divided into 3 groups: group 1, 110 subjects with normal occlusion (mean age, 13.51 years); group 2, 100 complete Class II Division 1 patients (mean age, 13.44 years); and group 3, 100 half-cusp Class II Division 1 patients (mean age, 13.17 years). Dental wear was assessed by using a modified version of the tooth-wear index. The 3 groups were compared by means of the Kruskal-Wallis and Dunn tests, considering the frequency and the severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%. Results The normal occlusion group had statistically greater tooth wear on the palatal surfaces of the maxillary central incisors and the incisal surfaces of the maxillary canines than the corresponding surfaces in both Class II malocclusion groups. The complete and half-cusp Class II Division 1 malocclusion groups had statistically greater tooth wear on the occlusal surfaces of the maxillary second premolar and first molar, the occlusal surfaces of the mandibular premolars, and the buccal surfaces of the mandibular posterior teeth compared with the normal occlusion group. The half-cusp Class II Division 1 malocclusion group had significantly greater tooth wear on the incisal surfaces of the mandibular incisors compared with the complete Class II Division 1 malocclusion group. Conclusions Subjects with normal occlusion and complete or half-cusp Class II Division 1 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but, rather, consequent to the different interocclusal tooth arrangement. Editor's summary Tooth wear from erosion, abrasion, and attrition has long been a concern to dentists. Some wear is normal throughout life. Some studies indicate that masticatory forces and malocclusion are the primary etiologic factors for additional wear, but others did not find this correlation. The aims of this study, from universities in São Paulo, Brazil, and Toronto, Ontario, Canada, were to compare patterns of tooth wear in subjects with complete and half-cusp Class II Division 1 malocclusions and normal occlusion. The sample consisted of dental casts from 310 untreated adolescents in 3 groups: 110 with normal occlusion, 100 with complete Class II Division 1 malocclusion, and 100 with half-cusp Class II Division 1 malocclusion. Additional inclusion criteria were no parafunctional habits, no temporomandibular or airway problems, and no open bites. Read this entire article online for details of the techniques used to measure wear facets by a calibrated examiner. Overall, 22,320 dental surfaces were evaluated, and 73.9% showed no dental wear. Interestingly, the normal occlusion group had statistically greater tooth wear on the palatal surfaces of the maxillary central incisors and the incisal edges of the maxillary canines. Although some reports in the literature have suggested an association between increased tooth wear and malocclusion, others did not corroborate this premise. It was concluded that subjects with normal occlusion and complete or half-cusp Class II Division 1 malocclusions have different tooth-wear patterns. Wear in the malocclusion subjects should not be considered pathologic but, rather, a consequence of the different interocclusal arrangement of the teeth. These researchers plan to pursue future studies of older patients; it will be interesting to see the influence of differing interocclusal relationships. Table I Criteria used for tooth-wear evaluation, according to the modified TWI Degree Deciduous teeth Permanent teeth Criterion Description A 0 Normal, no evidence of wear No loss of surface features B 1 Incipient, tooth wear into enamel Loss of enamel giving a smooth, glazed, shiny appearance; dentin is not involved C 2 Moderate, tooth wear into dentin Extensive loss of enamel with dentin involvement; exposure of dentin D 3 Severe, tooth wear into pulp Extensive loss of enamel and dentin with secondary dentin or pulp exposure E 4 Restored, tooth wear leading to restoration Tooth received restorative treatment because of wear — 9 Could not be assessed Extensive caries, large restoration, fractured tooth, or missing tooth Reprinted from Public Health 122, S.H. de Carvalho Sales-Peres et al, Prevalence of dental wear among 12-year-old Brazilian adolescents using a modification of the tooth wear index, 942-8, Copyright 2008, with permission from Elsevier. 22 Table II Intraexaminer analysis (kappa statistics) Tooth wear Percentage of agreement (%) Coefficient value Strength of agreement Dental casts 92.85 0.80 Almost perfect Q & A Turpin: It is fairly obvious why you started with the adolescent age group for this study, but will you have a readily available sample when evaluating older age groups as you plan to do in the future? Janson and Oltramari-Navarro: Yes, we do have a readily available sample of older age groups, especially for the normal occlusion sample. However, for the Class II sample, we have fewer subjects, and we must increase it. Turpin: Do you expect to use this same evaluation technique to study the effects of parafunctional habits on selected groups of patients? Janson and Oltramari-Navarro: Yes, this same evaluation technique can be used in patients with parafunctional habits, but we will have to collect patients with these problems. We had a significant number of patients in this study because it was based on subjects who were continuously collected during many years. To investigate the tooth-wear patterns in patients with parafunctional habits, we need to prospectively collect them. Turpin: Will the availability of 3-dimensional imaging of the dentition make it easier to measure tooth wear than it is now when measuring wear facets on dental casts? Janson and Oltramari-Navarro: Yes, as long as there is high imaging definition and proper hardware and software tools, such as high-definition monitors and digitizing tablets, and measuring, shadow, brightness, and contrast controls. Read the full text online at: www.ajodo.org , pages 14.e1-14.e7

Related Articles

Leave A Comment?