Evaluation of nsomaxillary growth of adolescent boys in northeastern Iran

Anthropometry, a useful method for evaluating craniofacial soft tissues, makes the quantitative description of the face possible. It also assesses the degree of disharmony and imbalance in the growth and development of the face. The aim of this study was to examine the overall common age-related changes of nasomaxillary complex of adolescent boys in northeast Iran. Three- hundred- twelve 12 to 15 year-old boys voluntarily participated in this study. They were divided into three age groups [12-13, 13-14 and 14-15 yearold groups]. Digital photographs of the subjects' faces were taken in Natural Head Position [NHP] frontal and profile views. After determination of the landmarks, nine anthropometric parameters including nasal length, mouth width, alar width, columella width, philtrum height, nasal width, nasolabial angle, nasal root slope angle and nasal index were measured by the Smile Analyzer software considering the magnification ratio of each image. One way ANOVA and Tukey test were used for statistical analyses. Significant differences between the three groups were detected in the mean alar, mouth and philtrum widths, nose length, nasolabial angle and nasal index [P<0.05]. We did not find any significant differences in the mean nasal-root-slope angle and the mean philtrum height between the groups [P=0.29 and P=0.13, respectively]. Aging of the facial profile is not a gradual process; it occurs in spurts and at different periods of life. During the studied time span, significant growth in nose width and nose length was obvious

Changes in the position of mandibular third molars following extraction and non-extraction orthodontic treatments

Impaction of third molars can be associated with a number of sequelae, each requiring a different type of treatment. The purpose of this study was to assess the changes in the position of lower third molars following extraction and non-extraction orthodontic treatments. Pre- and post-treatment panoramic radiographs of 26 class I malocclusion patients [4 male and 22 female] who were treated on a non-extraction basis were compared with those of 30 class I malocclusion patients [5 male and 25 female] who received orthodontic treatment following the extraction of all first premolars. In each group, the lower third molar angulations and their distance from the lower border of the mandible were assessed. Paired r-tests and independent /-tests detected significant changes in the position of the lower third molars in the extraction group. Both the left and right molars became more upright and their distance from the lower border of the mandible increased. Similar changes were only seen in the position of the right mandibular third molars in the non-extraction group. Tooth extractions can bring about favorable changes in the position of mandibular third molars and possibly reduce their incidence of impaction

[Histologic changes in rabbit temporo mandibular joint following local injection of recombinant-bone morphogenetic protein-2 [RBMP2] during mandibular advancement by bite jumper]

Mandibular deficiency is one of the most common malocclusions that is treated with functional appliances during growth periods. The aim of this study was to evaluate the histologic changes of the single local injection of rBMP2 in combination with bite jumper therapy in a rabbit model TMJ. Eighteen 8-week old Albino New Zealand white male rabbits were divided into three groups: The first group served as control and in the second and third groups rBMP2 and normal saline were injected respectively. The second and third groups had bite jumper appliance. After 8-weeks of bite jumper therapy, in the second group 12.5 microgr rBMP2 powder plus 2.5cc normal saline and in the third group only 2.5 cc normal saline was injected in the TMJs on both sides. After 16-weeks of treatment, the animals were sacrificed and the joints were examined histologically. The rBMP2 group showed greater cartilage cells and maximum condylar cartilage thickness [in the form of cartilage hyperplasia] than control and normal saline groups. The control group had the lowest disc deformity histologically and the rBMP2 group showed lower disc deformity than normal saline group. rBMP2 is able to accelerate condylar cartilage growth in the form of cartilage hyperplasia

Tongue guard appliance in maxillary deficiency treatment - a pilot study

One of the common treatments of Class III patients is maxillary growth modification. In the last three decades in Mashhad dental school, maxillary deficiency has been treated by the Tongue Guard appliance. The purpose of this study was to assess the skeletal and dental effects of the Tongue Guard appliance in patients with maxillary deficiency. Pretreatment and post-treatment lateral cephalograms from 14 Class III patients [9 female and 5 male] with the mean age of 9.7 years were prepared in natural head position [NHP]. These patients were all treated by the Tongue Guard appliance. The mean value and standard deviations of SNA, SNB, A to N-perpendicular, FMA, Ul to FH, Ul to PP, L1 to GoMe,[pns-a.p.max][go-a.p.man] were calculated. SPSS Software and 2- tailed student's t-test with 0.05 significant levels were used for data analysis. Following the treatment, anterior movement of maxilla with significant increase in SNA and A to N- perpendicular were observed [p<0.005]. However, FMA remained unchanged after the treatment. The maxillary incisors were proclined and the mandibular incisors were retroclined, Also, significant increase in maxillary length and maxillary to mandibular length ratio were found.[p<0.05]. The Tongue Guard appliance increases SNA angle, as well as the distance from A to N perpendicular and Maxillary/Mandibular length ratio. But it does not affect facial height

effects of third molars on facial height in adults

To evaluate the effect of third molar eruption on vertical facial dimensions. 60 patients including 38 females and 22 males with the mean age of 19 years and class I malocclusion without any previous orthodontic and surgical treatment were selected. The experimental group [30 patients] had full eruption of all third molars, and control group [30 patients] had missing of the third molars congenitally. Lateral cephalograms were traced and FMA, Gonial Angle, Posterior to Anterior facial height ratio were measured and compared in both groups by Student's t-test. Mean values of FMA were significantly higher and PFH/AFH ratio was significantly lower in experimental group compared to control group. Gonial angle did not differ significantly in two groups. Patients with full eruption of third molars show greater facial height

Lower arch width changes following upper arch expansion by removable appliances

The effect of slow maxillary expansion by removable appliances on mandibular arch width during mixed dentition. This was a clinical trail study containing two groups. The experimental group included 20 patients with posterior cross bite and the mean age of 8.5 and the control group had 10 subjects with the mean age of 8.7 years. Maxillary removable expansion devices were prescribed in the first group but the control group did not receive any kind of expansion treatment. Study models were prepared before and following 8-12 months after treatment. Lower arch widths were measured in three areas [canine, first and second premolar region] in each phase. The arch widths in two phases were compared in each group by paired t-test. In the expansion group, lower arch width increased significantly in the canine and first premolar region [P < 0.001]. In non-expansion group no significant difference in lower arch widths was detected after treatment. Slow maxillary expansion by means of removable appliances significantly increases lower arch width in canine and first premolar region