Comparison between Pre and Posttreatment Inclination of Maxillary Incisors in Adults: Association with Facial and Growth Axes.

Objective: The objective of the study is to evaluate the orthodontic treatment effect on maxillary incisors' inclination relative to facial and growth axes in adult subjects. Materials and Methods: Hundred consecutive nongrowing orthodontic patients with an average age of 26.24 ± 9.29 years were selected, and their T1 (initial) and T2 (final) lateral cephalograms were digitized. Cephalometric maxillary incisors' (I) inclination was measured to SN, PP, NA, NBa, and true horizontal (H). Facial and growth axes' inclinations were measured relative to NBa and H. Associations were tested using Chi-square tests for categorical data. Paired sample t-tests and Pearson's correlation were computed for continuous data. Results: Maxillary incisors' inclination, MP/SN, and ANB angle did not show statistically significant differences between T1 and T2, while mandibular incisors' inclination and interincisal angle increased significantly (P = 0.01 and P = 0.02, respectively). Facial and growth axes increased at T2 but changes were not statistically significant among the two groups. At T1, correlations between maxillary incisors' inclination and facial/growth axes were not statistically significant. Similarly, correlations between MP/SN and ANB angles on the one hand and facial/growth axes on the another hand were not statistically significant. At T2, I/PP correlated significantly with facial axis (FA)/NBa (r = 0.308; P = 0.002) and with FA/H (r = 0.268; P = 0.007). Similarly, I/SN and I/NBa correlated significantly with FA/NBa (r = 0.399; P < 0.0001 and r = 0.422; P < 0.0001 correspondingly) and with FA/H (r = 0.305; P = 0.002 and r = 0.325; P = 0.001 correspondingly). Statistically significant negative correlations existed between MP/SN angle and facial/growth axes at T2 (r values ranging -0.704 to -0.409 at P < 0.0001). Conclusions: While there was no correlation between I and facial/growth axes at pretreatment, significant and higher correlations existed at the end of the orthodontic treatment. This association reflects the connection between the corrected posttreatment position of maxillary incisors relative to the corresponding vertical pattern. Therefore, orthodontists should evaluate the position of the maxillary incisors to FA and may consider it in their treatment objectives.

Orthodontic Treatment Effect on Inclination of Maxillary Incisors and Growth Axes in Adult Patients with Various Mandibular Divergent Patterns.

AIM: To evaluate, in an adult population, the effect of orthodontic treatment on the inclination of maxillary incisors, facial, and growth axes in different mandibular divergence pattern. In addition, we aimed to determine if there is an association between the inclination of the maxillary incisors and facial and growth axes and if this association will change after orthodontic treatment. MATERIALS AND METHODS: Two-hundred and thirty-eight consecutive lateral cephalograms (119 at T1 and 119 at T2) of adult patients with an average age of 26.45 ± 9.11 years at T1 and 29.58 ± 9.36 at T2 were selected and digitized. Cephalometric maxillary incisors (I) inclination was measured to cranial base (SN), palatal plane (PP), nasion-A point (NA), nasion-basion (NBa), and true horizontal (H). Facial (FA) and growth (GA) axes' inclinations were measured relative to NBa and H. The sample was stratified in three subgroups based on cephalometric mandibular divergence to anterior SN (MP/SN). A-Hypodivergent = MP/SN ≤27° (n = 28); B-Normodivergent = 27 < MP/SN < 37° (n = 49); C-Hyperdivergent = MP/SN ≥37° (n = 42). Associations were tested using Chi-square tests for categorical data. Paired sample t-tests and Pearson's correlation were computed for continuous data. RESULTS: At T1, there was a tendency to have more proclined I in group A (I/SN = 105.59 ± 10.8°) and more retroclined in group C (I/SN = 99.06 ± 12.04°) with no statistical significance. However, at T2, maxillary incisors were statistically significant different between groups A and C (p = 0.002). Pre-treatment FA and GA were statistically significantly different among the three divergence groups (p <0.0001) with more increased angles in the group A (FA/Nba = 92.77 ± 5.07°) vs group C (FA/Nba = 86.28 ± 5.08°). This angle increases around 2° on average at posttreatment assessment (group A-p = 0.033; group B-p = 0.002). Correlations between I and facial/growth axes were not statistically significant at T1, whereas at T2 those correlations were higher and statistically significant between I/PP to FA/NBa (r = 0.408; p ≤0.0001). CONCLUSION: Correlations between the maxillary incisors' inclination and the facial/growth axes were not statistically significant initially whereas after orthodontic treatment, those correlations were higher and statistically significant. Differences in FA existed between pre- and postorthodontic groups in all divergence groups. CLINICAL SIGNIFICANCE: Orthodontists should assess the inclination of the maxillary incisors, not only to the maxilla and anterior SN but also to FA and take it into consideration in their treatment objectives.

Cephalometric Evaluation of Maxillary Incisors Inclination, Facial, and Growth Axes in Different Vertical and Sagittal Patterns: An Original Study.

AIM: The aim of this study was to evaluate the inclination of the maxillary incisors (I), facial axis (FA), and growth axis (GA) in different vertical and sagittal patterns. MATERIALS AND METHODS: A total of 498 consecutive orthodontic patients, with an average age of 18.87 years (range = 5-63 years), were grouped based on their vertical and sagittal patterns. Maxillary incisors, FA, and GA axes were traced and their corresponding angles to nasion-basion and true horizontal lines were measured. The sample was divided into three groups based on the mandibular divergence (mandibular plane-MP/sella-nasion [SN]): Group 1-hypodivergent pattern (MP/SN ≤ 27; n = 30), Group 2-normodivergent pattern (27 < MP/SN <37; n = 254), and Group 3-hyperdivergent pattern (MP/SN ≥ 37; n = 214); the sample was then divided into three groups based on the sagittal pattern (ANB, angle between points A, Nasion and B): Group I-skeletal CLI (Class I) (0

Malocclusion in elementary school children in beirut: severity and related social/behavioral factors.

Aim. To assess severity of malocclusion in Lebanese elementary school children and the relationship between components of malocclusion and sociodemographic and behavioral factors. Methods. Dental screening was performed on 655 school children aged 6-11 from 2 public (PB) and 5 private (PV) schools in Beirut. A calibrated examiner recorded occlusion, overjet, overbite, posterior crossbite, midline diastema, and crowding. Another examiner determined the DMFT (Decayed/Missing/Filled Teeth) score. A questionnaire filled by the parents provided data on sociodemographic and behavioral factors. Multinomial, binomial, and multiple linear regressions tested the association of these factors with occlusal indices. Results. Malocclusion was more severe in PB students. Age and sucking habit were associated with various components of malocclusion. Crowding was more prevalent among males and significantly associated with the DMFT score. Income and educational level were significantly higher (P < 0.05) in PV pupils and deleterious habits were more frequent in PB children. Conclusions. Children of lower socioeconomic background had more severe malocclusions and poorer general dental health. Compared to Western and WHO norms, the findings prompt health policy suggestions to improve dental care of particularly public school children through regular screenings in schools, prevention methods when applicable, and cost effective practices through public and private enabling agencies.

Comparisons of soft tissue chin thickness in adult patients with various mandibular divergence patterns.

OBJECTIVE: To evaluate the association between soft tissue at the chin (STC) thickness and mandibular divergence. MATERIALS AND METHODS: Nongrowing patients seeking orthodontic treatment (n  =  190; 113 women and 77 men), who had an average age of 26.94 years (range  =  18.10-53.50 years), were stratified in four subgroups based on cephalometric mandibular plane inclination to anterior cranial base (MP/SN): low  =  MP/SN ≤ 27° (n  =  48); medium-low  =  27° < MP/SN ≤ 32° (n  =  60); medium-high  =  32° < MP/SN < 37° (n  =  37); and high  =  MP/SN ≥ 37° (n  =  45). The STC thicknesses were measured at pogonion (Pog), gnathion (Gn), and menton (Me). Group differences were evaluated with two-way analysis of variance and Student's t-test. The Pearson product moment correlation gauged associations between parameters. RESULTS: The STC values were greater in men than women (P < .02) and were smaller in the high group (7.47 ± 2.42 mm) than in all other groups at Gn (mean values  =  9.00 mm < STC < 9.58 mm; P < .001) and at Me (high group  =  6.30 ± 1.89 mm; other groups  =  7.15 mm < STC< 7.57 mm; P  =  .011). CONCLUSION: The STC is thinner at Gn and Me in hyperdivergent facial patterns, apparently in contrast to Pog. This differential thickness warrants focused research as it implies that it is possible (1) to vertically grow hard tissues impinging on the inferior soft tissue envelope in patients with severe hyperdivergence and (2) to plan for genioplasty in such patients when more advancement of the chin might be needed to compensate for the increased vertical height.