Cephalometric changes during aging in subjects with normal occlusion.

OBJECTIVE: To assess craniofacial changes from early adulthood to the seventh decade of life in individuals with normal occlusion. METHODOLOGY: The sample comprised lateral cephalograms of 21 subjects with normal occlusion (11 male, 10 female), taken at 17 (T1) and 61 years of age (T2). Anteroposterior and vertical maxillomandibular relationships, and dentoalveolar and soft tissue changes were analyzed. Interphase comparisons were performed using paired t-tests. Differences between sexes, and subgroups with and without tooth loss were evaluated using t-tests (p<0.05). RESULTS: Maxillary and mandibular anterior displacement, and facial and ramus height increased from T1 to T2. Maxillary molars showed significant mesial angulation. Maxillary and mandibular molars, and mandibular incisors developed vertically during the evaluation period. Soft tissue changes included a decrease of the nasolabial angle, upper and lower lip retrusion, decrease of upper lip thickness and increase of the lower lip and soft chin thickness. Maxillary incisor exposure by the upper lip decreased 3.6 mm in 40 years. Males presented counterclockwise rotation of the mandible, whereas females showed mandibular clockwise rotation and backward displacement of the chin. The group with tooth loss showed a greater increase of the posterior facial height and ramus height. CONCLUSION: We observed aging changes in dentoskeletal structures and soft tissue, as well as sexual differences for craniofacial changes during the maturational process. Subjects with multiple tooth losses showed a greater increase in mandibular ramus height.

Pretreatment dentoskeletal comparison between individuals treated with extractions in the 1970s and in the new millennium.

OBJECTIVE: This retrospective study aimed to compare the occlusal and dentoskeletal initial features of patients treated with four first premolar extractions in the 1970s and after 2000. MATERIALS AND METHODS: Group 70' was composed by 30 subjects with Class I malocclusion (mean age of 12.8 years, 10 male, 20 female) treated in the 1970s with four first premolar extractions and comprehensive orthodontic treatment. Group NM comprised 30 subjects with Class I malocclusion (mean age of 13.4 years, 13 male, 17 female) treated in the new millennium, similarly to Group 70'. Initial dental models and lateral cephalograms were digitized and measured using OrthoAnalyzerTM 3D software and Dolphin Imaging 11.0 software, respectively. Initial occlusal and dentoskeletal features were analyzed and compared. Intergroup comparison was performed using t tests (p < 0.05). Holm-Bonferroni correction for multiple comparison was applied. RESULTS: Group NM showed significantly greater maxillary and mandibular effective lengths and greater maxillary and mandibular incisor protrusion in comparison with Group 70'. Group NM presented a significantly greater lower anterior facial height. Group NM also showed significantly smaller nasolabial angle and protruded inferior lip. CONCLUSION: Patients with Class I malocclusion treated with four first premolar extractions in the new millennium present a greater degree of dental and labial protrusion, increased lower anterior facial height, and more acute nasolabial angle compared with patients treated similarly in the 1970s. Greater dental and labial protrusion determines first premolar extractions in the new millennium. CLINICAL RELEVANCE: Despite the decrease of tooth extraction frequency, four first premolar extractions may be justified in cases with severe dental and skeletal protrusions.

Cephalometric changes during aging in subjects with normal occlusion

Abstract Objective To assess craniofacial changes from early adulthood to the seventh decade of life in individuals with normal occlusion. Methodology The sample comprised lateral cephalograms of 21 subjects with normal occlusion (11 male, 10 female), taken at 17 (T1) and 61 years of age (T2). Anteroposterior and vertical maxillomandibular relationships, and dentoalveolar and soft tissue changes were analyzed. Interphase comparisons were performed using paired t-tests. Differences between sexes, and subgroups with and without tooth loss were evaluated using t-tests (p<0.05). Results Maxillary and mandibular anterior displacement, and facial and ramus height increased from T1 to T2. Maxillary molars showed significant mesial angulation. Maxillary and mandibular molars, and mandibular incisors developed vertically during the evaluation period. Soft tissue changes included a decrease of the nasolabial angle, upper and lower lip retrusion, decrease of upper lip thickness and increase of the lower lip and soft chin thickness. Maxillary incisor exposure by the upper lip decreased 3.6 mm in 40 years. Males presented counterclockwise rotation of the mandible, whereas females showed mandibular clockwise rotation and backward displacement of the chin. The group with tooth loss showed a greater increase of the posterior facial height and ramus height. Conclusion We observed aging changes in dentoskeletal structures and soft tissue, as well as sexual differences for craniofacial changes during the maturational process. Subjects with multiple tooth losses showed a greater increase in mandibular ramus height.

Alveolar bone morphology of maxillary central incisors near grafted alveolar clefts after orthodontic treatment.

INTRODUCTION: The aim of this study was to evaluate the thickness and the height of the maxillary central incisors' alveolar bone near the grafted alveolar cleft area, after comprehensive orthodontic treatment. METHODS: The sample comprised 30 patients with unilateral alveolar cleft with a mean age of 20.5 years (range, 17-25.8 years). High-resolution cone-beam computed tomography images of the maxilla were obtained 6 to 24 months after the comprehensive orthodontic treatment. The contralateral maxillary central incisor was used as a comparison group. Axial sections at the level of the central incisor root were used to measure the labial and lingual alveolar bone thicknesses. Cross sections were used to measure the bone crest heights using the cementoenamel junction as the reference. Paired t and Wilcoxon tests were used to compare the cleft and noncleft sides. RESULTS: The labial and lingual bone thicknesses of the maxillary central incisors' alveolar bone were significantly thinner (0.16 and 0.39 mm, respectively), and the labial alveolar crest height distance was significantly greater on the cleft side compared with the noncleft side (-1.2 mm). CONCLUSIONS: In patients with unilateral cleft lip and palate, the maxillary central incisors adjacent to the grafted alveolar cleft had thinner labial and lingual alveolar bones and an apically displaced labial alveolar crest level than the controls.