Does the rhythm and appliance type of rapid maxillary expansion have an effect on root resorption?

OBJECTIVES: To evaluate the volume, amount, and localization of root resorption in the upper first premolars by micro-computed tomography (micro-CT) after three different rapid maxillary expansion appliances and two different activation rhythms. MATERIALS AND METHODS: The patients were divided into three groups; Hyrax, acrylic cap splint (ACS), and full coverage acrylic bonded (FCAB) appliances. Each group was then divided into the following two subgroups: rapid maxillary expansion (RME) and semirapid maxillary expansion (SRME). After expansion was completed, the appliances were stabilized for 12 weeks during the retention period. For each group, 10 premolars (for a total of 60 premolars) were scanned with the micro-CT (SkyScan). The reconstructed 3D images of each root sample were divided into six regions. The resorption craters on these six different root surfaces were analyzed by special CTAn (SkyScan) software for direct volumetric measurements. Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests were used for statistical analysis. RESULTS: The total volume of root resorption was less with FCAB than with ACS and Hyrax (P < .001). In all groups, a greater volume of resorption was found on the buccal surface than on the lingual surface (P < .001). No significant differences were found between the RME and SRME groups (P > .05). CONCLUSIONS: All expansion appliances caused root resorption in the upper first premolar teeth, but FCAB may be safer in terms of root resorption. The resorption craters were generally concentrated on the buccal surface. There was no effect of activation rhythm on root resorption.

The Effects of Maxillary Expansion on Late Alveolar Bone Grafting in Patients With Unilateral Cleft Lip and Palate.

PURPOSE: The purpose of this study was to answer the research question of whether maxillary expansion provides enough postgraft stimulation to decrease the volume loss of alveolar bone grafts in patients with cleft lip and palate (CLP) who missed the appropriate treatment time. MATERIALS AND METHODS: This study was designed as a prospective controlled clinical trial. Thirty patients in the permanent-dentition stage with unilateral CLP were divided into 2 groups: In group I (mean age, 19.33 ± 5.16 years), slow maxillary expansion was performed before secondary alveolar bone grafting (SABG); in group II (mean age, 19.93 ± 3.99 years), slow maxillary expansion was performed 6 weeks after SABG. The iliac crest was preferred as a donor site for autogenous bone graft harvesting. Cone beam computed tomography images were taken 1 week, 6 months, and 12 months postoperatively. The volume and density of the alveolar bone graft were calculated using Mimics software (version 13.1; Materialise, Ann Arbor, MI), and SPSS software (version 19.0; IBM, Armonk, NY) was used for statistical analysis. RESULTS: The bone graft volume loss was significantly higher in group I than in group II after 6 months of healing (P = .003). The increase in bone density was significantly higher in group II than in group I after 6 months of healing (P = .017). Although the mean loss of volume was lower and the mean density of the bone graft was higher in group II, there was no significant difference between the 2 groups in terms of mean graft volume and mean bone density 12 months after the operation. For groups I and II, the mean bone graft volume loss was 46.3% and 34.6%, respectively, and the mean increase in bone density was 16% and 49%, respectively, after 12 months of healing. CONCLUSIONS: Maxillary expansion after late SABG may be taken into consideration as a treatment choice in selected unilateral CLP patients to provide bone graft stimulation.

Evaluation of Skeletal and Dental Effects of Lower Lingual Arches.

OBJECTIVE: A lower lingual arch is usually recommended as a holding device to maintain arch length and to prevent mesial migration of the mandibular first molars. Despite its widespread use, comparatively little is known about the effects of a lower lingual holding arch on preservation of lower arch dimensions and tooth position and the impact of the device on mandibular growth. The aim of this study is to evaluate the skeletal and dental effects of the lower lingual holding arch with regard to arch dimension, positions of mandibular molars and incisors, and usual mandibular growth. STUDY DESIGN: Thirty-four children (18 males and 16 females) who needed space maintainers were included in the present study. The patients were divided into two groups according to whether they were missing second primary molars on one or both sides. Group I comprised 16 children (8 males and 8 females, average age 8.8 ± 0.9 years) with a missing second primary molar on one side; Group II comprised 18 children (10 males and 8 females, average age 8 ± 0.7 years) with extractions on both sides. Lateral cephalograms, dental pantomograms, and study casts of the patients were taken at the beginning and the end of the study period. Average treatment time was 20.4 ± 4 months. RESULTS: Lower incisors moved forward and Incisor Mandibular Plane Angle (IMPA°) increased in both treatment groups. Statistically significant differences between the groups were found when comparing pre-treatment and post-treatment arch dimension and position of mandibular molars. Results were better for lingual arches with extraction on one side than with extraction on both sides Conclusions: A lingual arch seems to be an effective tool for maintaining arch length, and was not found to impair mandibular growth.

Dental anxiety in children with cleft lip and palate: a pilot study.

PURPOSE: To investigate the level of dental fear and anxiety of children who have cleft lip and palate (CLP). MATERIALS AND METHODS: The study was performed at Cukurova University, Faculty of Dentistry. A total of 32 7- to 12-yearold children, 17 of them with CLP (8 girls and 9 boys) and 15 of them without CLP (7 girls and 8 boys) participated in the study. The children were evaluated by using the Facial Image Scale (FIS) and Dental Subscale of Children's Fear Survey Schedule (CFSS-DS) methods. The anxiety state of the children was assessed twice using FIS: first in the dental hospital waiting room (FIS-WR) and after, while sitting in the dental chair (FIS-DC). CFSS-DS was administered to all participants in order to assess the dental anxiety while they were sitting in the dental chair. RESULTS: According to the FIS results, there was no difference between CLP and control group in the waiting room (P = 0.682). However, the CLP group showed lower scores than the control group while they were sitting in the dental chair (P = 0.030). The FIS scores of the CLP group were significantly higher in the waiting room than while sitting in the dental chair (P = 0.007). In the control group, there was no significant difference between FIS-WR and FIS-DC values (P = 0.664). The total CFSS-DS scores of children with CLP were lower than those of the control group, but these differences were not statistically significant (P > 0.05). CONCLUSION: Children with CLP showed more anxiety in the FIS-WR than in the FIS-DC, but they showed lower scores than the control group in the FIS-DC. The positive previous experience of meetings with dentists of the CLP children could explain these results. Positive previous experiences with dentists and a short time in the waiting room could be key elements in the care of CLP children.

Comparison of bovine-derived hydroxyapatite and autogenous bone for secondary alveolar bone grafting in patients with alveolar clefts.

PURPOSE: The aim of this retrospective study was to compare the long-term outcomes of secondary alveolar bone grafting (SABG) using bovine-derived hydroxyapatite versus autogenous bone. PATIENTS AND METHODS: The subjects in this study were 23 patients with unilateral cleft lip and palate (13 male, 10 female) who underwent SABG from 2004 through 2009. The patients were recalled and examined to evaluate the success of the long-term outcomes of SABG. In group 1, there were 12 patients (7 male, 5 female) who underwent grafting with anterior iliac crest bone; in group 2, 11 patients (6 male, 5 female) underwent grafting with bovine-derived hydroxyapatite. RESULTS: The mean ages at grafting were 13 ± 3.76 years in group 1 and 10.82 ± 2.6 years in group 2 (P = .134). The mean lengths of follow-up were 47.33 ± 13.79 months in group 1 and 67.82 ± 10.36 months in group 2 (P = .002). Pocket depth, periodontal index, and gingival index scores were similar and indicated acceptable periodontal status in the 2 groups. The results for patient satisfaction were not statistically different (P > .05). There was no statistically significant difference between the 2 groups when results of the Chelsea scale were analyzed (P > .05). The radiologic results showed an 83.4% success rate in group 1 and a 100% success rate in group 2 (P = .478). When the densitometric values for cleft sites were analyzed, the difference between the 2 groups was not statistically significant (P = .190). CONCLUSIONS: Bovine-derived hydroxyapatite is as successful as the iliac graft for the SABG procedure.

Long-term effects of presurgical infant orthopedics in patients with cleft lip and palate: a systematic review.

OBJECTIVE: This study aimed to assess the scientific evidence on the efficiency of presurgical infant orthopedic appliances in patients with cleft lip and palate to shed light on a specific, contemporary discussion of whether the appliances have long-term advantages with respect to treatment outcomes. DESIGN: A systematic review. METHODS: Two literature surveys from the five electronic databases were performed with a 1-month interval. Randomized controlled trials and controlled clinical trials (controls had no presurgical infant orthopedics) that had follow-up periods of a minimum of 6 years were included in the study. The exceptions to the follow-up limit were studies related to feeding and parent satisfaction. RESULTS: Of the 319 articles retrieved in the literature surveys, 12 were qualified for the final analysis. The level of evidence of these articles ranged from 1b to 4. Eight randomized controlled trials and four controlled clinical trials were available on eight treatment outcomes. The longest follow-up period of the randomized controlled trials was 6 years. No randomized controlled trials were found on active presurgical infant orthopedic appliances and on nasoalveolar molding appliances. CONCLUSIONS: Based on the results, presurgical infant orthopedic appliances have no long-term positive effects on seven of the eight studied treatment outcomes in patients with cleft lip and palate. More randomized controlled trials need to be done to have evidence regarding the effects of presurgical infant orthopedics in different surgical protocols. Also, the encouraging results about the effect of nasolaveolar molding appliances on nasal symmetry have to be supported by future randomized controlled trials.

Two different applications of Class II elastics with nonextraction segmental techniques.

OBJECTIVE: To evaluate the relative effects of Class II elastics applied directly with utility arches (UAs) or with the Reciprocal Mini-Chin Cup (RMCC) appliance. MATERIALS AND METHODS: Thirty patients with Class II division 1 malocclusion were included. Fifteen of them were treated with the RMCC appliance and the other 15 treated with Class II elastics on UAs. Lateral cephalograms of an additional 15 untreated persons having the same characteristics as the treatment groups were used as a control group. RESULTS: The mean control period was 10 months. Class I molar and canine relationships were achieved in a mean treatment time of 4.6 months with the RMCC appliance and in 8.5 months with the elastics on UAs. The amount of overjet reduction was 4.7 mm in the RMCC group (87.87% dental) and 5.2 mm in the UA group (80.76% dental). The molar correction was 4.5 mm in the RMCC group (87.36% dental) and 2.0 mm in the UA group (51.47% dental). The anterior lower facial height increased in both of the treatment groups. CONCLUSIONS: The RMCC appliance is a valuable alternative for Class II elastic use in Class II cases in which the upper molars need to be moved to the distal more than the upper incisors.

Temperature rise during orthodontic bonding with various light-curing units--an in vitro study.

The purpose of this in vitro study was to investigate the temperature changes in the pulp chamber during bracket bonding using three different light sources. Bracket bonding was performed on one lower first premolar and one lower central incisor at two different distances (surface and 10 mm). The measurements were taken with a J-type thermocouple wire, placed in the pulp chamber and connected to a data logger. Analysis of variance revealed that pulp chamber temperature changes were influenced by the light source, the tooth type, and the distance from the tip of the light guide to the bracket surface. Halogen induced significantly higher intrapulpal temperature changes than light-emitting diode and Xenon Plasma Arc (PAC) (P = .000). The temperature increase was significantly higher when the light-guide tip was positioned at the surface of the teeth than at the 10-mm distance with all light-curing units (P = .000). All light-curing units produced higher intrapulpal temperature increase in the mandibular incisor than in the premolar. Power PAC produced significantly higher heat changes in the incisor than in the premolar. Orthodontic bonding with different light-curing units did not exceed the critical 5.5 degrees C value for pulpal health.