Cephalometric evaluation of adenoids, upper airway, maxilla, velum length, need ratio for determining velopharyngeal incompetency in subjects with unilateral cleft lip and palate.

OBJECTIVES: Children with cleft lip and palate (CLP) are seen to have reduced airway size and large adenoids, which might lead to different characteristics in the upper airway and surrounding tissues from both morphological and functional perspectives. Decrease in adenoid size and increase in need ratio in cleft patients might lead to velopharyngeal incompetency (VPI) and development of nasality in adulthood. No studies have been conducted on the Indian population with variables contributing to VPI. So the aim was to evaluate the size and position of the adenoids, upper airway, maxilla, velum length and need ratio contributing to VPI in subjects with and without unilateral cleft lip and palate (UCLP) during juvenile and adolescent stages. MATERIALS AND METHODS: Cephalograms of 120 subjects with 6-17 years were taken and various linear and angular measurements were measured and data was analyzed using the unpaired t test. RESULTS: Adenoids were significantly larger and the upper airway smaller in the juvenile and adolescent cleft group than in the non-cleft group. In the adolescent cleft group, airway was larger than that in the adolescent non-cleft group. The maxilla was small and retropositioned in juvenile and adolescent subjects as compared to non cleft cases. Length of velum was smaller and need ratio was larger in both juvenile and adolescent groups as compared to the non-cleft group, suggestive of velopharyngeal incompetence. CONCLUSION: Decreased Adenoids, restricted airway, small, retruded maxilla, smaller velum length and larger need ratio larger were seen in the cleft group as compared to the non-cleft group, which was suggestive of VPI.

Effects of low-intensity laser therapy on the rate of orthodontic tooth movement: A clinical trial.

BACKGROUND: Low-intensity laser therapy (LILT) can be utilized for different treatments in the field of orthodontics and dentofacial orthopedics. The aim of the present study was to evaluate the efficacy of LILT on (1) the rate of canine movement during canine retraction phase and (2) evaluate the radiographic changes occurring during LILT around the irradiated area. MATERIALS AND METHODS: A total of 10 patients of both genders were included for this study. One quadrant of the upper arch was considered control group (CG) and received mechanical activation of the canine teeth with 150 g. The opposite quadrant received the same mechanical activation and was also irradiated with a diode emitting light (gallium-arsenide laser) at 904 nm, for 10 s at 12 mW, at 4.2 J/cm(2). Laser application was done on 1(st) day, 3(rd), 7(th), 14(th), 21(th), 28(th), 35(th), 42(nd), 49(th), 56(th) day respectively during the canine retraction phase. Distance was measured on 1(st) day, 35(th) day and 63(rd) day and appliance activation was done on 1(st) and 35(th) day. Results were analyzed using t-test with the significance level set at P < 0.01. RESULTS: Mean value obtained from 1(st) to 63(rd) day was 3.30 ± 2.36 mm for CG and 3.53 ± 2.30 mm for laser group (LG). CONCLUSION: There was no statistically significant difference in the rate of tooth movement during canine retraction between the LG and the CG. There was no evidence of any pathologic changes in the radiograph following LILT.

Effects of first premolar extraction on maxillary and mandibular third molar angulation after orthodontic therapy.

BACKGROUND/AIMS: To compare the change in the angulation of developing mandibular third molar in both first premolar extraction and non-extraction cases and to determine whether premolar extraction results in a more mesial movement of the mandibular buccal segment and causes favorable rotational changes in the mandibular third molar tilt, which can enhance later eruption of the third molars. MATERIALS AND METHODS: Pretreatment (T1) and post treatment (T2) panoramic radiographs were taken of 25 subjects (age 14-19 years) who had been treated by the extraction of all the first premolars and 25 subjects who had been treated with non-extraction. The horizontal reference plane was used to measure and compare the changes in the angles of the developing mandibular third molars. RESULTS: The mean uprighting of the maxillary third molars seen in the extraction group was 4 ± 9° on the left side and -17 ± 13° on the right side following treatment (T2 _ T1). For the non-extraction group the mean difference was -16 ± 12° on the left side and 2 ± 13° on the right side. There was a statistically significant difference between the groups (P _ 0.021 on the right side and P _ 0.041 on the left side). Mandibular 3rd molars in extraction group showed no statistical significant change in the angulation. CONCLUSION: Premolar extractions had a positive influence on the developing maxillary third molar angulations both on right and left. Mandibular 3rd molar have shown change in the angulation but not statistically significant. Non-extraction therapy did not have any adverse effect.

Clinical investigation of periodontal ligament distraction osteogenesis for rapid orthodontic canine retraction.

AIMS: To investigate rapid canine distalisation by periodontal ligament distraction and to determine the effects of periodontal ligament distraction on the canine root and pulpal vitality. METHODS: The sample consisted of 16 upper canines in eight patients who required first premolar extractions. The upper first premolars were extracted and the interseptal bone distal to each canine was thinned and undermined surgically. Custom-built distractors were placed and activated immediately to distract the canines into the extraction spaces. Radiographs were taken before canine distraction and at regular intervals thereafter. The upper canine pulps were tested with an electronic pulp tester before and after the distraction and the canines were examined on the post-distraction radiographs for evidence of apical and lateral root resorption. RESULTS: The canines were retracted to proximal contact with the second premolars in 20.33 +/- 1.87 days. The average amount of retraction was 5.25 mm and the canines tipped distally 15.33 degrees. Although the upper molars did not move mesially, they extruded almost 1 mm. Root resorption was minimal and there was no deterioration in pulp vitality. CONCLUSION: Canines can be rapidly retracted by periodontal ligament distraction without complications. However, the efficacy of the method depends upon the surgical procedure, which is technique sensitive. Resistance offered by the interseptal bone distal to the apex of the canine was thought to be the reason for the canine tipping during distraction.