Dental arch relationships in Turkish patients with complete unilateral cleft lip and palate born between 1976 and 1990: a comparison with eurocleft.

OBJECTIVE: To compare the dental arch relationships of Turkish patients with complete unilateral cleft lip and palate (UCLP) with the results reported for participants in the Eurocleft study. PATIENTS: Study models of 109 patients with complete UCLP from five university clinics in Turkey were evaluated (clinic A = 25 patients, clinic B = 23 patients, clinic C = 20 patients, clinic D = 21 patients, and clinic E = 20 patients). The mean age of the patient cohort was nine years old (range = 8-11 years old), and the cohort was born between 1976 and 1990. METHODS: The examiners rated the three-dimensional (3D) models using the GOSLON Yardstick. The scores were compared with those from the Eurocleft centers: E1(B), E2(E), E3(A), E4(F), E5(C), and E6(D). Intra- and interexaminer agreements were evaluated using weighted kappa statistics. RESULTS: The mean GOSLON scores for the Turkish clinics were as follows: clinic A = 3.16, clinic B = 3.13, clinic C = 3.25, clinic D = 3.67, and clinic E = 3.70. Scores for three of the Turkish clinics (A, B, and C) were significantly worse than the scores for the three best Eurocleft centers, E1(B), E2(E), and E3(A) (P < .001, P < .001, and P < .05, respectively). Scores for two of the Turkish clinics (D and E) were similar to those for Eurocleft center E6(D) but worse than the scores for the other Eurocleft centers (P < .01, P < .001, respectively). CONCLUSIONS: This was the first study in which three-dimensional models were used to derive scores to compare with those of the Eurocleft centers. According to the results of analysis of 109 3D models, 50.4 % of the patients in Turkey were classified as GOSLON score 4 and 5. This may have been attributable to poor surgical procedures, low-volume surgeons, and the decentralized treatment approach in Turkey between 1985 and 2000. Further research is needed to assess the situation in Turkey in more recent years.

The effect of 2 different distraction-compression models on new bone generation.

PURPOSE: To compare the stimulating effect of distraction and 2 different distraction-compression models on maturation of new bone during healing. MATERIALS AND METHODS: Thirty adult Sprague-Dawley rats underwent unilateral mandibular osteotomy. The animals were divided into 3 groups. A unidirectional external distraction device was fixed to the mandible. A total of 4 mm of distraction was planned in all groups. After a latency period of 3 days, 0.2 mm of distraction was performed twice a day for 10 days in the distraction group. In the intermittent distraction-compression group, 0.2 mm of distraction was performed twice a day for 3 days, followed by 0.2 mm of compression twice a day for 1 day. In the overdistraction-compression group, 0.2 mm of distraction was performed twice a day for 14 days, followed by 0.2 mm of compression twice a day for 4 days. After a consolidation period of 6 weeks in all groups, animals were killed for macroscopic, microscopic, and radiologic evaluation. RESULTS: Radiologic evaluation proved that more mature bone generation occurred in the groups in which compression was added to distraction. The number of osteoblasts in the intermittent distraction-compression group was significantly higher than that in the distraction group and overdistraction-compression group (P < .001). The highest number of vessels was found in the intermittent distraction-compression group (17.7 ± 6.4) (P < .001). CONCLUSIONS: The intermittent distraction-compression model was found to generate greater new bone compared with distraction alone. In clinical applications, to increase the quality of the bone and to shorten the consolidation period, compression can be applied during distraction.

The relationship between digital model accuracy and time-dependent deformation of alginate impressions.

OBJECTIVES: To investigate the effects of different storage periods of alginate impressions on digital model accuracy. MATERIALS AND METHODS: A total of 105 impressions were taken from a master model with three different brands of alginates and were poured into stone models in five different storage periods. In all, 21 stone models were poured and immediately were scanned, and 21 digital models were prepared. The remaining 84 impressions were poured after 1, 2, 3, and 4 days, respectively. Five linear measurements were made by three researchers on the master model, the stone models, and the digital models. Time-dependent deformation of alginate impressions at different storage periods and the accuracy of traditional stone models and digital models were evaluated separately. RESULTS: Both the stone models and the digital models were highly correlated with the master model. Significant deformities in the alginate impressions were noted at different storage periods of 1 to 4 days. Alginate impressions of different brands also showed significant differences between each other on the first, third, and fourth days. CONCLUSIONS: Digital orthodontic models are as reliable as traditional stone models and probably will become the standard for orthodontic clinical use. Storing alginate impressions in sealed plastic bags for up to 4 days caused statistically significant deformation of alginate impressions, but the magnitude of these deformations did not appear to be clinically relevant and had no adverse effect on digital modeling.

Upper midline correction in conjunction with rapid maxillary expansion.

INTRODUCTION: The purpose of this study was to investigate a simple method for correcting upper dental midline shift, by physiologic movement of the incisors during the retention period of rapid maxillary expansion. METHODS: Thirty-two patients with upper midline shifts due to constricted maxillae and anterior crowding were selected. All had undergone radiological and clinical examinations to be sure that the midline shift was not functional and was caused only by crowding. The patients were randomly divided into 2 groups. In both groups, acrylic cap splint type expansion appliances were used. In group 1, the acrylic cap covered all the dentition except the incisors and the canine on the shifted side. After expansion, the incisors on the shifted side were allowed to move toward the midline, and the incisors of the other side were held by the acrylic cap. In group 2, the acrylic cap covered only the posterior teeth, from the first premolars on both sides. After expansion, the incisors on the shifted side were allowed to move toward the midline diastema, whereas those on the other side were held in place by ligation of the brackets, which had been placed immediately after expansion. RESULTS: In both groups, the midline shift was corrected by the movement of the shifted incisors toward the midline diastema, without orthodontic force. CONCLUSIONS: Residual or unwanted forces produced during rapid maxillary expansion can be used to correct an upper dental midline shift.

A miniature tooth-borne distractor for the alignment of ankylosed teeth.

The ankylosis of a tooth is one of the most difficult clinical problems that an orthodontist faces. In the literature, the treatment protocols for ankylosed teeth are still insufficient and questionable when considering gingival esthetics and conservation of bone health. The purpose of this report is to evaluate and discuss the effects of a newly designed miniature tooth distractor (MTD), which can be used with infrapositioned ankylosed teeth. Two cases with vertically malpositioned incisors were treated using the MTD, and this device was evaluated and compared with the distraction appliances used before in the literature. In conclusion, it was found to be efficient with its small dimensions, ease of application and removal, ease of activation, buccolingual control, and patient tolerance.

In vivo disintegration of four different luting agents.

The purpose of this study was to evaluate the disintegration of luting agents. An intraoral sample holder was made having four holes of 1.4 mm diameter and 2 mm depth. The holder was soldered onto the buccal surface of an orthodontic band, which was cemented to the first upper molar in 12 patients, average age 26 years. The holes were filled with a zinc phosphate (Phosphate Kulzer), a glass ionomer (Ketac Cem), a resin-modified-glass ionomer (Fuji Plus), and a resin cement (Calibra). Impressions were made at baseline, and 6, 12, and 18 months from which epoxy replicas were made, which were scanned with an optical scanner. Total volume loss was calculated. The rank order of mean volume loss was as follows: Phosphate cement > Ketac Cem = Fuji Plus = Calibra. Cement type and time had statistically significant effects on volume loss of cements (P < 0.001). Under in vivo conditions, zinc phosphate cement disintegrated the most, whereas no significant difference was observed for glass ionomer and resin-based cements. As intraoral conditions are considerably less aggressive than experimental laboratory conditions, the erosion behavior of glass ionomer cement was found to be similar to the resin-based cements in contradiction to previous laboratory results.

Erosion of luting cements exposed to acidic buffer solutions.

The aim of this study was to evaluate acidic erosion of 7 luting cements. Erosion was evaluated via immersion in 0.1 M aqueous sodium lactate/lactic acid buffer (pH = 2.74 and 4.0, respectively). The rank order of cement loss was as follows: Phosphate Cement > Fuji I hand-mixed = Fuji I encapsulated > Ketac Cem > Calibra = Fuji Plus = Variolink Ultra. Cement type, pH, and time had statistically significant effects. Water-based cements exhibited more erosion compared to resin-based cements, and the latter underwent hygroscopic expansion caused by water sorption.

Evaluation of the relationship between the anterior component of occlusal force and postretention crowding.

The aim of this study was to investigate whether a relationship exists between the anterior component of occlusal force (ACF) and postretention crowding in the mandibular incisor area. The study group comprised 32 adults who had undergone fixed orthodontic treatment in the department clinic at Marmara University in Istanbul, Turkey. In 13 subjects, the mandibular arch was treated without extractions; in 19, it was treated with bilateral first premolar extractions. The average postretention period was 3.5 years. The ACF created in the left side of the mandibular dentition was determined by measuring interdental frictional forces at each contact point mesial to the first molar and distal to the canine. Anatomic contact point displacements between the left mandibular anterior teeth (lateral incisor-canine, central incisor-lateral incisor, and central incisor-central incisor) were measured on plaster casts and summed to provide the irregularity index for these teeth. Correlation analysis was used to assess the relationship between the ACF values at each contact and the irregularity index. In the nonextraction group, statistically significant positive correlations were observed between the ACF and the irregularity index at the 3 contact points that were measured. The strongest correlation was found at the canine-first premolar contact (r = 0.65). In the extraction group, a positive correlation was found between the ACF and the irregularity index (r = 0.49, P <.05) at the second premolar-first molar contact, but no correlation was found at the canine-second premolar contact.