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Dental and occlusal changes during mandibular advancement splint therapy in sleep disordered patients
REVIEWS AND ABSTRACTS
Book reviews and article abstracts Alex Jacobson, DMD, MS, PhD Birmingham, Ala
ARTICLE REVIEWS
Dental and occlusal changes during mandibular advancement splint therapy in sleep disordered patients C. Robertson, P. Herbison, and M. Hurkress European Journal of Orthodontics 2003;25:371-6
The aims of this longitudinal cephalometric study were to determine the extent of dental and occlusal changes after the use of a nonadjustable mandibular advancement splint for treating sleep disorders and to determine these changes over time. The material comprised 114 consecutive adult patients with obstructive sleep apnea, 87 men and 13 women, all referred to an orthodontic practice for a mandibular advancement splint. At the outset, all subjects had 2 lateral cephalometric radiographs taken, one with the teeth in the intercuspal position and the other with the appliance in site. The patients were randomly assigned to be reviewed either 6, 12, 18, 24, or 30 months later, when a third lateral cephalogram was taken with the teeth in the intercuspal position. The findings showed no significant cephalometric differences between the groups or between the sexes. Therefore, all subjects were combined into a single group to determine the extent of the dental and occlusal changes. Total anterior face height, lower face height, and posterior face height increased significantly. Approximately 86% of the increase in total anterior face height occurred in the lower face. Maxillary length increased significantly, and the mandible was displaced significantly downward, but not forward. Both the mandibular first molar and the maxillary first premolar overerupted slightly. Significant retroclination of the maxillary incisors and proclination of the mandibular incisors were accompanied by reductions in maxillary arch length, overbite, and overjet. When the changes over time were examined, there was considerable variation both within and between groups. Only downward displacement of the mandibular symphysis was found at all review periods. Although an increase in face height and a reduction in overbite and overjet were evident at 6 months, overeruption of the maxillary first premolars and mandibular first molars and proclination of the mandibular incisors were not detected until 24 months. Overall, very few of the occlusal changes found in the study were of concern to the patients, with treatment discontinued in only 1 patient because of adverse dental side effects. The preliminary results suggest that overbite changes might be lessened by keeping the bite opening to a minimum. According to the authors, no data on 226
the long-term effects of these appliances on the occlusion have been forthcoming. Alex Jacobson Am J Orthod Dentofacial Orthop 2004;125:226 0889-5406/$30.00 Copyright © 2004 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2003.10.018
Temporomandibular disorders, occlusion and orthodontic treatment T. Hendrikson and M. Nilner Journal of Orthodontics 2003;30:129-37
This prospective investigation was designed to study the symptoms and signs of temporomandibular disorders (TMD) and occlusal changes in girls with Class II malocclusions receiving orthodontic treatment and to compare them with untreated Class II malocclusions and normal occlusions. The sample included 65 girls with Class II malocclusions who received fixed appliance therapy, 58 girls with Class II malocclusions who remained untreated, and 60 girls with normal occlusions. In the treated group, 30 subjects were treated without extractions, and 35 had premolars extracted. Signs and symptoms of TMD, mandibular function, and functional occlusion were registered at each examination by a specialist in stomatognathic physiology. All 3 groups included subjects with more or less pronounced TMD who experienced individual fluctuations during the study. In the normal group, the overall prevalence of signs of TMD was numerically lower than in the other 2 groups at both registrations. The general trend was an increased prevalence of signs of TMD over the 2 years. Exceptions to this trend were found in the orthodontic group, where the prevalence of pain on maximal movements and muscle tenderness to palpation decreased significantly over the 2 years. All 3 groups had an increased prevalence of clicking over the 2 years. Only 2 subjects had reciprocal clicking at both first and second registrations, and no one developed a closed lock during the 2-year period. The authors concluded that orthodontic treatment with or without extractions did not increase the prevalence or worsen pretreatment symptoms and signs of TMD. Individually, TMD fluctuated substantially over time with no predictable pattern. On a group basis, however, the type of occlusion might play a role as a contributory factor for the development of TMD. The large fluctuations of TMD over time led the investigators to suggest a conservative treatment approach when stomatognathic treatment in children and adolescents is considered. Alex Jacobson
American Journal of Orthodontics and Dentofacial Orthopedics /February 2004
Book reviews and article abstracts Alex Jacobson, DMD, MS, PhD Birmingham, Ala
ARTICLE REVIEWS
Dental and occlusal changes during mandibular advancement splint therapy in sleep disordered patients C. Robertson, P. Herbison, and M. Hurkress European Journal of Orthodontics 2003;25:371-6
The aims of this longitudinal cephalometric study were to determine the extent of dental and occlusal changes after the use of a nonadjustable mandibular advancement splint for treating sleep disorders and to determine these changes over time. The material comprised 114 consecutive adult patients with obstructive sleep apnea, 87 men and 13 women, all referred to an orthodontic practice for a mandibular advancement splint. At the outset, all subjects had 2 lateral cephalometric radiographs taken, one with the teeth in the intercuspal position and the other with the appliance in site. The patients were randomly assigned to be reviewed either 6, 12, 18, 24, or 30 months later, when a third lateral cephalogram was taken with the teeth in the intercuspal position. The findings showed no significant cephalometric differences between the groups or between the sexes. Therefore, all subjects were combined into a single group to determine the extent of the dental and occlusal changes. Total anterior face height, lower face height, and posterior face height increased significantly. Approximately 86% of the increase in total anterior face height occurred in the lower face. Maxillary length increased significantly, and the mandible was displaced significantly downward, but not forward. Both the mandibular first molar and the maxillary first premolar overerupted slightly. Significant retroclination of the maxillary incisors and proclination of the mandibular incisors were accompanied by reductions in maxillary arch length, overbite, and overjet. When the changes over time were examined, there was considerable variation both within and between groups. Only downward displacement of the mandibular symphysis was found at all review periods. Although an increase in face height and a reduction in overbite and overjet were evident at 6 months, overeruption of the maxillary first premolars and mandibular first molars and proclination of the mandibular incisors were not detected until 24 months. Overall, very few of the occlusal changes found in the study were of concern to the patients, with treatment discontinued in only 1 patient because of adverse dental side effects. The preliminary results suggest that overbite changes might be lessened by keeping the bite opening to a minimum. According to the authors, no data on 226
the long-term effects of these appliances on the occlusion have been forthcoming. Alex Jacobson Am J Orthod Dentofacial Orthop 2004;125:226 0889-5406/$30.00 Copyright © 2004 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2003.10.018
Temporomandibular disorders, occlusion and orthodontic treatment T. Hendrikson and M. Nilner Journal of Orthodontics 2003;30:129-37
This prospective investigation was designed to study the symptoms and signs of temporomandibular disorders (TMD) and occlusal changes in girls with Class II malocclusions receiving orthodontic treatment and to compare them with untreated Class II malocclusions and normal occlusions. The sample included 65 girls with Class II malocclusions who received fixed appliance therapy, 58 girls with Class II malocclusions who remained untreated, and 60 girls with normal occlusions. In the treated group, 30 subjects were treated without extractions, and 35 had premolars extracted. Signs and symptoms of TMD, mandibular function, and functional occlusion were registered at each examination by a specialist in stomatognathic physiology. All 3 groups included subjects with more or less pronounced TMD who experienced individual fluctuations during the study. In the normal group, the overall prevalence of signs of TMD was numerically lower than in the other 2 groups at both registrations. The general trend was an increased prevalence of signs of TMD over the 2 years. Exceptions to this trend were found in the orthodontic group, where the prevalence of pain on maximal movements and muscle tenderness to palpation decreased significantly over the 2 years. All 3 groups had an increased prevalence of clicking over the 2 years. Only 2 subjects had reciprocal clicking at both first and second registrations, and no one developed a closed lock during the 2-year period. The authors concluded that orthodontic treatment with or without extractions did not increase the prevalence or worsen pretreatment symptoms and signs of TMD. Individually, TMD fluctuated substantially over time with no predictable pattern. On a group basis, however, the type of occlusion might play a role as a contributory factor for the development of TMD. The large fluctuations of TMD over time led the investigators to suggest a conservative treatment approach when stomatognathic treatment in children and adolescents is considered. Alex Jacobson
American Journal of Orthodontics and Dentofacial Orthopedics /February 2004