Multicentric evaluation of conventional dosimetry vs bio-dosimetry over a period of two years for a three-point contact.

Background: Dental radiology represents the best model for evaluating the effects of low-dose ionizing radiation. Therefore, this study evaluated the awareness on radiation hygiene among dental ancillary personnel through a questionnaire and their absorbed doses by physical and biologic dosimetry. Methods: The multicentric study included two groups. Group I (N = 30) consisted of dental staff involved in dental radiology. An equal number of personnel who were not related to radiology formed the control group. Knowledge (K), attitude (A), and practice (P) of participants were assessed using a KAP questionnaire. Radiation exposure was evaluated by physical dosimetry at 3 time periods: at the beginning of the study (T1), after 10 months (T2), and at the end after 20 months (T3). Similarly, biologic dosimetry was also carried out at 3 time points by dicentric chromosome aberration assay. The data were compared using percentage analysis, analysis of variance (one-way analysis of variance), and Student's t- test. Results: The KAP survey demonstrated enhanced understanding of radiation protection measures and its sound practice by the participants. Physical dosimetry showed a significant increase in absorbed dose at 3 time points: T1, T2, and T3. However, no chromosomal aberrations were observed in blood lymphocytes for any of the participants in the optimized 4-day biodosimetry protocol. Conclusion: Good radiation protection protocols-safe distance from the radiation source and wear of lead aprons and thyroid collars-ensured low absorbed doses. The 4-day protocol is an important step toward developing biodosimetry laboratories in the Armed Forces Medical Services for clinical and national radiation countermeasure strategies.

Comparative Evaluation of Periodontally Accelerated Osteogenic Orthodontics (PAOO) Versus Conventional Orthodontic Tooth Movement in Adult Patients with Bimaxillary Dentoalveolar Protrusion.

The aim of the study was to comparatively evaluate periodontally accelerated osteogenic orthodontics (PAOO) and conventional fixed orthodontic mechanotherapy in the management of bimaxillary dentoalveolar protrusion in adults. The selected patients were grouped into two groups: Group I: PAOO procedure followed by orthodontic fixed mechanotherapy; Group II: orthodontic fixed mechanotherapy alone. The total treatment time, the quantum of root resorption, and the periodontal status of Group I and Group II were compared. Group I had a shorter treatment time and stable overall periodontal health, both of which were statistically significantly different compared to Group II. Within the limitations of this study, significant statistical differences were found in the clinical and radiographic parameters among the patients treated with PAOO along with conventional fixed orthodontic therapy as compared to the patients treated with orthodontic therapy alone.

Skeletal relapse following sagittal split ramus osteotomy advancement.

BACKGROUND: Sagittal split ramus osteotomy (SSRO) is an accepted and standard procedure to address mandibular corpus deficiency. The relapse following the mandibular advancement has a negative impact both on clinician and patient. PURPOSE: To analyse the hard tissue changes and to investigate relapse following SSRO advancement procedure. MATERIALS AND METHODS: A retrospective review of 21 patients treated by bilateral SSRO advancement at our institute was conducted. Lateral cephalograms obtained at pre-treatment (T1), pre-surgery (T2), 2 months (T3) and 2 years post-surgery (T4) were evaluated by an independent investigator. The data T2-T3 revealed immediate postoperative changes, and T3-T4 revealed skeletal relapse following surgery after 2 years. RESULTS: Twelve females and nine males with age ranging from 16 to 24 years underwent mandibular advancement. The mean follow-up period was 2 years 7 months ± 4 months. The mean mandibular advancement at pogonion was 5.1 ± 1.25 mm with significant improvement in SNB, ANB, CoGn, maxillo-mandibular differential and SN:GoPg ratio following surgery. Comparison of the outcomes following surgery revealed that the mean relapse at pogonion was 0.2 ± 0.44 mm. B point, mandibular corpus length, anterior and posterior facial height remained stable with no significant relapse following mandibular advancement. CONCLUSION: Sagittal split ramus osteotomy within the range of mandibular advancement is a stable procedure.

Evaluation of treatment outcome in cleft maxillary hypoplasia treated by rigid external distractor: a cephalometric study.

OBJECTIVE: The aim of the study was to cephalometrically evaluate hard and soft tissue changes in cases of cleft-induced maxillary hypoplasia treated by distraction osteogenesis using rigid external distractor (RED). METHODS: Fifteen cases of cleft-induced maxillary hypoplasia were selected applying the inclusion and exclusion criteria. The cases were operated on under general anesthesia for distraction osteogenesis using RED. Cephalometric evaluation was done at the end of presurgical orthodontics (C1), 1 week after removal of RED (C2), and at the end 12 months postoperatively (C3). The hard tissue parameters considered were Sella Nasion point A angle, Point A-Nasion-point B angle, distance from condylion to point A, anterior nasal spine-menton to Nasion-menton ratio, and upper incisor distance to N vertical. The soft tissue parameters included facial contour angle, nasolabial angle, upper lip to E-line, and lower lip to E-line. RESULT: There were 8 males and 7 females with an average age of 13.07 years. The range of maxillary advancement was 8 to 24.5 mm with an average of 14.46 mm. The cephalometric data were compared using paired t test and 1-way analysis-of-variance test. All the hard tissue changes except SNB were statistically highly significant (P > 0.0001). The percentage of relapse was 13.72% at SNA, 13.3% at ANB, 9.83% for maxillary depth, 8.99% for distance of the upper incisor to N perpendicular and 20.73% for facial contour angle, 2.16% for nasolabial angle, 25.69% for distance of UL to E-line, and 25.12% for distance of LL to E-line. Soft tissue relapse except nasolabial angle after 1 year was more as compared with hard tissue. CONCLUSIONS: All the cephalometric parameters except SNB angle showed significant improvement. However, the significant percentage of relapse should be considered in the preoperative planning.

Evaluation of upper airway dimensional changes and hyoid position following mandibular advancement in patients with skeletal class II malocclusion.

BACKGROUND: Class II skeletal malocclusion due to mandibular deficiency is considered a risk factor for sleep disorders due to oropharyngeal airway deficiencies. In view of the above, a prospective interventional study was undertaken to evaluate upper airway dimensional changes and position of hyoid bone by comparing pretreatment and posttreatment lateral cephalograms. The objective also included the establishment of the ratio of mandibular advancement to increase in airway dimensions. PATIENTS AND METHODS: Pretreatment and posttreatment lateral cephalograms of 20 adults (13 females and 7 males) with skeletal class II malocclusion treated by combined orthodontics and bilateral sagittal split ramus osteotomy was evaluated for changes in posterior airway space (PAS), superior airway space (SAS), minimum airway space (MAS), hyoid bone position (MP-H), effective mandibular length (Co-Gn), mandibular corpus length (Go-Pg), and pogonion position (N perpendicular-Pg). The cephalograms were manually traced by a single operator and the data analyzed using MINITAB 13.2 version software. RESULTS: There was a statistically highly significant (P = 0.0001) increase in PAS, SAS, MP-H, Co-Gn, and Go-Pg. The mean ratio of mandibular advancement to increase PAS, SAS, and MAS was 1:0.35, 1:0.34, and 1:0.24, respectively. Hyoid bone moved superiorly and in an anterior direction by 2.1 ± 2.8 mm and was found to be statistically highly significant (P = 0.0001). CONCLUSIONS: The study showed an overall increase in airway dimension and improvement in hyoid position. Thus, the procedure may be considered beneficial in reducing upper airway collapsibility and preventing sleep disorders due to oropharyngeal airway deficiencies in skeletal class II malocclusion.