Maxillary Development and Dental Arch Relationships Following Early Two-Stage Palatoplasty: A Comparative Study.

OBJECTIVE: To examine skeletal morphology and dental arch relationships at 8 years of age following early 2-stage palatoplasty, which consists of soft palate plasty at 1 year of age and hard palate closure at 1.5 years of age, and to compare the results with those of conventional pushback palatoplasty. DESIGN: Retrospective. SETTING: Single institutional study. PATIENTS: Eighty-six patients with nonsyndromic complete unilateral cleft lip and palate (UCLP) were selected. INTERVENTION: The subjects were divided into 2 groups according to the palatoplasty protocols, as follows: 45 patients, who underwent early 2-stage palatoplasty (ETS group), and 41 patients, who underwent 1-stage pushback palatoplasty (PB group). MAIN OUTCOME MEASURES: Skeletal morphology was assessed using lateral cephalometric analysis, and dental arch relationships were examined using the GOSLON yardstick. RESULTS: Cephalometric analysis revealed that the anterior-posterior length of the maxilla, measured by PTM-A and PTM-ANS, both projected to the nasal floor (NF) plane, was longer in the ETS group than in the PB group (PTM-A/NF, p = .04; PTM-ANS/NF, p = .03, unpaired t-test), although no significant difference was observed in SNA (p = .09, unpaired t-test). Upper posterior facial height was shorter in the ETS group than in the PB group (p = .02, unpaired t). Assessments with the GOSLON yardstick showed that the ETS group presented better dental arch relationships than the PB group (p = 0.04, Mann-Whitney's U-test). CONCLUSIONS: The present results suggested that the ETS protocol reduced the negative effects of palatal surgery on facial development and dental arch relationships in patients with complete UCLP at 8 years of age.

Occlusion at 5 Years of Age Following Hard Palate Closure With Vestibular Flap.

OBJECTIVE: This study aims to assess occlusal relationships and frequency of oronasal fistula at 5 years of age following 2 hard palate closure techniques and to compare results. DESIGN: Retrospective longitudinal study. SETTING: Institutional study. PATIENTS: Study patients included 57 patients with nonsyndromic complete unilateral cleft lip and palate who were consecutively treated. All patients underwent our early 2-stage protocol for palatoplasty, which consisted of soft palate plasty at 1 year of age and hard palate closure at 1.5 years of age. Twenty-nine patients underwent hard palate closure using vestibular flap (VF group) technique (2009-2011) and 28 patients underwent conventional hard palate closure with local palatal flap (LPF group) technique (2006-2008). MAIN OUTCOME MEASURES: Occlusal relationships were assessed with 5-year-olds' index, and frequency of oronasal fistula was investigated. RESULTS: Average 5-year-olds' index scores for VF and LPF groups were 3.11 and 3.57, respectively (P < .001). Oronasal fistula occurred in approximately 7% of patients in the VF group and in 18% of patients in the LPF group. CONCLUSION: Hard palate closure with VF technique may provide better occlusal relationships at 5 years of age than does conventional local closure with the LPF.

Accuracy and head positioning effects on measurements of anterior tooth length using 3-dimensional and conventional dental panoramic radiography.

INTRODUCTION: The purposes of this study were to examine the accuracy and the head positioning effects on measurements of anterior tooth length using 3-dimensional (3D) and conventional dental panoramic radiography and to investigate whether 3D panoramic radiography is suitable for the evaluation of anterior tooth length. METHODS: A simulated human head was radiographed at 4, 8, and 12 mm displaced positions, and at 5°, 10°, and 15° tilted positions from the standard head position using 3D and conventional panoramic radiography, and also using cone-beam computed tomography. Anterior tooth lengths were measured on the panoramic and cone-beam computed tomography images. The values for the standard head position in the panoramic radiographs were defined as the standard values. Measurement error was defined as the standard value minus the cone-beam computed tomography value on each panoramic radiograph. The head position ratio of the measurement value to the standard value at each head position was calculated. RESULTS: Measurement errors for the 3D panoramic radiographs were significantly smaller than those for the conventional panoramic radiographs. In the 3D panoramic radiographs, the head position ratios at the 4, 8, and 12 mm displaced positions and at the 5° tilted position were within ±5% of the standard value. CONCLUSIONS: Three-dimensional panoramic radiography is suitable for the quantitative evaluation of anterior tooth length with high accuracy.

Cephalometric Outcomes of Maxillary Expansion and Protraction in Patients With Unilateral Cleft Lip and Palate After Two Types of Palatoplasty.

OBJECTIVE: To clarify the differences in the long-term effects of maxillary expansion (ME) and protraction (MP) in patients with complete unilateral cleft lip, alveolus, and palate (UCLP) undergoing two types of palatoplasty. DESIGN: Retrospective longitudinal study. SETTING: Institutional study. PATIENTS AND INTERVENTIONS: Thirty-eight patients with UCLP treated at Osaka University Dental Hospital, Japan, were divided into two groups: 19 patients were treated using Wardill-Kilner push-back palatoplasty (PB), and 19 patients were treated with early two-stage palatoplasty according to the modified Furlow technique (ETS). All patients exhibited a short maxilla at the initial orthodontic visit and were treated with ME using a quad helix appliance and MP with a face mask. Lateral cephalometric data recorded in the initial stage were compared with those obtained at the end of treatment. MAIN OUTCOME MEASUREMENTS: The dentoskeletal features and facial soft tissue profile were evaluated before and after orthodontic treatment. The variation and rate of change during treatment were also calculated. The Mann-Whitney U test was used for the statistical analyses. RESULTS: The ETS group showed significantly greater SNA, SNB, and U1-Pp angles and smaller SN-Mp angles than the PB group after face mask treatment. The variation in the anteroposterior length of the maxilla during treatment was significantly greater in the ETS group than in the PB group. CONCLUSIONS: Maxillary protraction was more efficiently accomplished in the patients with UCLP after early two-stage palatoplasty compared with push-back palatoplasty.

Influence of Different Palatoplasties on the Facial Morphology of Early Mixed Dentition Stage Children With Unilateral Cleft Lip and Palate.

OBJECTIVE: To compare the maxillofacial morphology in the early mixed dentition phase between two patient groups with unilateral cleft lip, alveolus, and palate who underwent different types of palatoplasty. DESIGN: Cross-sectional study. SETTING: An institutional study. PATIENTS AND INTERVENTIONS: Seventy-one patients with unilateral cleft lip and palate (UCLP) treated at Osaka University Dental Hospital, Japan, were divided into two groups: 33 patients were treated by early two-stage palatoplasty by the modified Furlow Technique (ETS), and 38 patients were treated by one-stage Wardill-Kilner push-back palatoplasty (PB). Intergroup comparisons were performed. MAIN OUTCOME MEASURES: The dental, skeletal, and soft-tissue features were evaluated. For intergroup comparisons, Mann-Whitney U test was used for the statistical analyses. RESULTS: No significant differences existed between the ETS and PB groups regarding the skeletal features except for the mandibular ridge height. Meanwhile, the upper central incisor and upper lip of the ETS group showed a more anterior position than those in the PB group. CONCLUSIONS: Early two-stage Furlow palatoplasty leads to more protruded upper lip, providing more anteriorly positioned upper incisors compared with PB, at least at the early mixed dentition stage.

Increased Waist Circumference after One-Year Is Associated with Poor Chewing Status.

BACKGROUND: This study aimed to investigate the relationship between an increase in waist circumference (WC) after 1 year and self-reported chewing status in 10,870 Japanese adults who had received health checkups. Subsequently, 8068 participants were included in the final analysis. METHODS: We defined an increase in WC ≥ 5 cm after 1 year as an unhealthy increase; in total, 613 (7.5%) respondents met this criterion. Chewing status was evaluated using a self-reported questionnaire at baseline; 1080 (13%) respondents were diagnosed with poor chewing status. RESULTS: After adjusting for age, gender, WC, body mass index (BMI), and chewing status, an increase in WC ≥ 5 cm was found to be positively associated with gender (females: odds ratios [ORs]: 1.206; 95% confidence intervals [CIs]: 1.008-1.443), WC (ORs: 0.967; 95% CIs: 0.954-0.981), BMI (≥25 kg/m2; ORs: 2.194; 95% CIs: 1.715-2.808), and chewing status (poor; ORs: 1.356; 95% CIs: 1.084-1.697). CONCLUSIONS: These findings suggest that increased WC after 1 year was associated with self-reported poor chewing status in Japanese adults.

Analysis of pretreatment factors associated with stability in early class III treatment.

BACKGROUND: The purpose of this study was to identify pretreatment factors associated with the stability of early class III treatment, since most orthodontists start the treatment with their uncertain hypotheses and/or predictions. Subjects consisted of 75 patients with a class III skeletal relationship (ANB < 2° and overjet < 0 mm) who had been consecutively treated with rapid maxillary expansion and facemask and followed until their second phase treatment. The patients were divided into two groups according to whether they showed relapse in follow-up. The stable group maintained their positive overjet (n = 55), and the unstable group experienced relapse with a zero or negative overjet (n = 20). Two general, three dental, and 13 cephalometric pretreatment factors were investigated to determine which factors were associated with stability. RESULTS: Sex, pretreatment age, and anteroposterior functional shift, which were hypothesized as associated factors, were not related to the stability of early class III treatment. Significant differences were detected between the two groups in the horizontal distance between the maxillary and mandibular molars in centric relation. Cephalometric variables, such as the mandibular length (Ar-Me), Wits appraisal, SN to ramus plane angle (SN-Rm), gonial angle, incisor mandibular plane angle (IMPA), and Frankfort plane to mandibular incisor angle (FMIA) showed significant differences between the groups. The horizontal distance was the most influential factor by logistic regression analysis. CONCLUSIONS: Hypothesis (related to sex, age, functional shift) were rejected. Several cephalometric factors related to the mandible were associated with stability. The horizontal distance between the maxillary and mandibular molars in centric relation was the best predictor of early class III treatment relapse.

Influence of dental education on eye gaze distribution when observing facial profiles with varying degrees of lip protrusion.

OBJECTIVES: The purpose of the present study was to investigate the influence of dental education on eye gaze distribution when perceiving facial profile images with varying degrees of lip protrusion. METHODS: Fifty-one subjects with dental education (dental-education group) and 47 without dental education (no-dental-education group) were included in this study. The eye gaze distribution of the subjects was recorded for 10 seconds using a non-contact eye tracker when determining whether or not the subjects judged each various facial profile image inappropriate. The facial profile images had varying degrees of upper-lip and lower-lip protrusion. The frequency of eye fixation (lasting >0.06 seconds) was counted. The duration was measured as the total time of eye fixation. The facial images were divided into 4 regions of interest (ROIs): the forehead (ROI-I); the orbit and nose root (ROI-II); the nose tip and upper lip (ROI-III); and the lower lip and chin (ROI-IV). The frequency and duration of eye fixation on each ROI was compared. RESULTS: The frequency of eye fixation on ROI-II was greater in comparison to ROI-I and ROI-IV. The frequency of eye fixation on ROI-III was also greater in comparison to ROI-I and ROI-IV. The duration of eye fixation on ROI-III in the dental-education group was longer in comparison to the no-dental-education group. CONCLUSIONS: Dental education influenced the eye fixation on the nose tip and upper lip when perceiving facial profile images.

Orthodontic treatment of malocclusion improves impaired skillfulness of masticatory jaw movements.

OBJECTIVE: To investigate whether individuals with malocclusion show less skillfulness, as represented by kinematic parameters that characterize masticatory jaw movement, compared with those having normal occlusion and, if so, to examine whether more skilled movements are achieved after completion of orthodontic treatment. MATERIALS AND METHODS: Lower incisor point movement in space during gum chewing was recorded, and the kinematic traits of such movement were compared among four subject groups: a Control Group (36 females with good occlusion), a Malocclusion Group (24 females with dental malocclusions), an Extraction Group (31 females who had received orthodontic treatment with premolar extraction) and a Nonextraction Group (27 females who had been treated orthodontically without tooth extraction). Before treatment, all subjects in the three experimental groups exhibited dental malocclusions and skeletal class I jaw-base relationship. RESULTS: Compared with the Malocclusion Group, the lower normalized jerk-cost, the shorter phase durations, the more symmetric property of the velocity profile, and the smaller variance of lateral jaw-closing trajectories near the tooth intercuspation position were determined in the Extraction Group and the Nonextraction Group as well as in the Control Group. CONCLUSIONS: As measured by kinematic parameters such as normalized jerk-costs, velocity profile, and variance of movement trajectories near the endpoint of movement, dental malocclusions were associated with significantly lower skillfulness of masticatory jaw motion, whereas good occlusion and orthodontically improved occlusion (either with or without premolar extraction) were both associated with more skillful motion.

Improvement in smoothness of the chewing cycle following treatment of anterior crossbite malocclusion: a case report.

This is a report of a case in which improvement in masticatory jaw movement kinematics occurred following orthodontic treatment. A patient who demonstrated a skeletal Class II jaw relationship, with anterior crossbite between the right upper and lower lateral incisors, underwent treatment with an edgewise appliance. The trajectories and smoothness of the patient's jaw-closing movement were compared before and after orthodontic treatment. The correction of the anterior crossbite allowed the patient to consistently close the jaw with wider lateral excursion. Furthermore, after treatment, smoothness of the jaw-closing movements increased significantly, and the velocity profile was characterized as closer to that predicted by the minimum jerk (maximum smoothness) kinematic model. These findings suggest the value of trajectory smoothness (jerk-cost) as an objective indicator of kinematic improvement in gum chewing. In addition, the correction of anterior crossbite is demonstrated to enable the patient to perform smoother jaw-closing movements during chewing.

Demonstration of a sex difference in the predictability of widths of unerupted permanent canines and premolars in a Japanese population.

OBJECTIVES: (1) To identify any differences in the accuracy of the prediction of the summed widths of unerupted permanent canines and premolars for males vs females and, if differences are identified, (2) to examine the sex differences in the best combination of independent variables and (3) to evaluate the practical accuracy using our models for both sexes, respectively. MATERIALS AND METHODS: Records for 200 orthodontic patients (100 males and 100 females) with discernible tooth crowding in the permanent dentition were selected. Mesiodistal tooth crown widths, dental arch widths, and basal arch lengths were measured. Predicted sum widths of permanent canines and premolars in both dental arches were calculated using stepwise regression analysis. RESULTS: Among male subjects, the best combinations of independent variables were the widths of the upper central and lateral incisors (U1, U2) and the first molar (U6) for the maxilla (R(2) = 0.615) and the mandible, lower central and lateral incisors (L1, L2), and the first molar (L6) (R(2) = 0.685), whereas in females, the best combinations for prediction were found to be U1, U2, U6, and the maxillary arch width for the maxilla (R(2) = 0.429) and L1, L2, L6, and the basal arch length for the mandible (R(2) = 0.426). Correlation coefficients between each independent and dependent variable in the female subject group were found to be weaker than those for the male subject group. CONCLUSIONS: We found the sex differences in the accuracy of prediction and the best combination of independent variables for predicting the summed widths of unerupted canines and premolars. These new models should be clinically useful, providing highly accurate prediction.