Objectives No study has compared pain intensity and pulp vitality of both activation protocols of periodontal distractor (twice and four activations per day) for rapid canine retraction. Since the periodontal distractor may cause some degree of suffering for the patients and may affect pulp vitality, it is important for orthodontists to handle this situation in the best possible way by choosing the most effective and the least painful method of treatment. Therefore the aim of the present study was to evaluate the effect of twice and four activations/day of periodontal distractor on pain intensity and pulp vitality of maxillary canine. Methods The study was carried out on 32 canine of 16 female patients (16–22 years of age) requiring extraction of bilateral maxillary first premolars and maximum anchorage. They were divided into two groups. (Group I): Canine retraction was done by periodontal distractor with twice activations per day. (Group II): Canine retraction was done by periodontal distractor with four activations per day. Periodontal distractor was cemented after bilateral maxillary premolar extraction and inter septal bone corticotomy was done. Pain intensity was evaluated at different times by Visual Analogue scale (1st 48 hour after intervention, during each activation of the distractor, and on the Interval between activation).Pulp vitality was measured by electric pulp tester. Results Comparison of pain intensity between different intervals was performed by using Friedman`s test (non-parametric data) which revealed significant difference in both groups, as 1st 48 hours was significantly the highest (8.8 ± 0.77), (9.2 ± 0.77) followed by During each activation (5.4 ± 0.94), (6.9 ± 1.25), while Interval between activation (1 ± 1.03), (2.7 ± 1.38) regarding group I and II respectively. Comparison between both groups was performed by using Mann Whitney`s test (non-parametric), which revealed that there was significant difference during each activation and intervals between activations as group II was significantly higher than group I (P = 0.0001).None of the teeth reacted negatively to the electrical vitality test that was performed one month after the completion of the distraction procedure. There was no clinical sign of discoloration or pulpal pain in any tooth. Conclusion In this study, Pain intensity was y significantly higher in group II (four activations/ day) than group I (twice activations/ day). The pulp of the retracted canine teeth examined in this study for both groups was vital on both groups.

Objective: This study was designed to evaluate radiographically the effect of passive self-ligating bracket on root surface and bone density in both arches. Patients, materials and methods: The present study was conducted on 20 patients which were divided into two groups; the first group includes 10 adolescent patients aged 13-16 years old and the second group includes 10 adult patients aged 18-21 years old. For each arch of the individuals participating; a quadrant was bonded with passive self-ligating brackets and the other quadrant within the same arch was bonded by conventional brackets. Standardized reproducible digital panoramic radiographs for each patient were evaluated preoperatively (T0), 6 months (T1) and 1 year (T2) after beginning the orthodontic treatment. The four permanent canines were evaluated regarding the root length and bone density. An indirect digital image radiographic system was followed in this study to obtain and evaluate bone density and degree of root resorption. Results: There was no statistical significant difference in bone density and root resorption changes of the maxillary and the mandibular arches between both age groups. Conclusions: Passive self-ligating brackets tend to have the same effect on the bone density and root surface of both the maxilla and the mandible.

Aim: To evaluate the effect of two different activation protocols of periodontal distractor on periodontal health after rabid canine retraction. Objectives: 1) to evaluate the periodontal health of two activations/day of periodontal distractor. 2) To evaluate the periodontal health of four activations/day of periodontal distractor. 3) To compare between two different activation protocols of periodontal distractor on periodontal health. Methods: The study was carried out on 32 canine of 16 female patients (16-22 years of age) requiring extraction of bilateral maxillary first premolars and maximum anchorage. They were divided into two groups. (Group I): Canine retraction was done by periodontal distractor with twice activations per day. (Group II): Canine retraction was done by periodontal distractor with four activations per day. Periodontal distractor was cemented after bilateral maxillary premolar extraction and inter septal bone corticotomy was done. The periodontal health of maxillary canines was evaluated using these parameters before and after retraction: (gingival index, periodontal index and probing depth). All data were explored for normality by using Shapiro Wilk and Kolmogorov Normality test which revealed that all data originated from non-parametric data. Results: for periodontal index and probing depth there was insignificant difference between them in before and after in both groups. For gingival index there was insignificant difference between them in before, while in after group II was significantly higher than group I. Conclusion: In this study, there was increase in all periodontal health parameters including (gingival index, periodontal index and probing depth) after using of periodontal distractor with both protocols of activations denoting gingivitis. The 2 activations/day was better than 4 activations/day for periodontal health during canine retraction by periodontal distractor.