Oyku Dalci

Influence of Oral and Craniofacial Dimensions on Mandibular Advancement Splint Treatment Outcome in Patients With Obstructive Sleep Apnea

BACKGROUND Mandibular advancement splints (MASs) can effectively treat obstructive sleep apnea (OSA); however, no validated and reliable prediction method for treatment outcome currently exists. The efficacy of MAS may relate to anatomic factors, including craniofacial size and upper-airway soft-tissue volume and anatomic balance between them. We aimed to assess whether craniofacial and oral measurements are associated with MAS treatment outcome. METHODS Dental impressions and lateral cephalometric radiographs were obtained from patients with OSA prior to commencing MAS treatment. Intertooth distances and palatal depths were measured on dental casts, and standard cephalometric analysis was performed with the addition of cross-sectional area (CSA) of the tongue and bony oral enclosure. Treatment outcome was determined by polysomnography. RESULTS Of 53 patients, 25 were complete responders (posttreatment apnea-hypopnea index [AHI] < 5/h), 17 were partial responders (≥ 50% AHI reduction), and 11 were nonresponders (< 50% AHI reduction). Cephalometric analyses did not reveal any significant differences between responders and nonresponders. Oral cavity measurements or CSA did not differ with treatment outcome; however, there was a trend toward a larger tongue CSA in complete vs partial and nonresponders (39.5 ± 1.3 cm(2) vs 35.5 ± 0.5 cm(2), P = .09). Tongue/oral enclosure CSA ratio, indicating a larger tongue for a given oral cavity size, was greater in complete responders (P = .012, n = 30). CONCLUSIONS Oral dimensions do not appear to differ between patients who respond and those who do not respond to MAS treatment. However, the larger tongue for a given oral cavity size in responders suggests that MAS may help to correct anatomic imbalance. Further research to assess whether the ratio between tongue and bony oral enclosure size may be useful in selecting patients for MAS treatment is warranted.

CPAP pressure for prediction of oral appliance treatment response in obstructive sleep apnea.

STUDY OBJECTIVES Mandibular advancement splints (MAS) are often preferred to CPAP treatment for OSA but are not always equally efficacious. High therapeutic CPAP pressure has been associated with MAS treatment failure in a Japanese population. We sought to assess the relationship between CPAP pressure and MAS treatment response in an Australian population. METHODS Therapeutic CPAP pressure and MAS treatment response were obtained from a one-month crossover trial of both treatments. Predictive utility of CPAP pressure to identify MAS treatment response was assessed. RESULTS Seventy-eight OSA patients were included (age 49.3 ± 11.1 years, BMI 29.1 ± 5.8 kg/m(2)) with predominantly moderate-severe OSA (AHI 30.0 ± 12.7/h). CPAP pressure was lower in MAS responders (MAS AHI < 10/h) 9.7 ± 1.6 vs. 11.7 ± 2.4 cm H O, p < 0.01, with area under ROC curve of 0.74 (95% CI 0.63-0.86), p < 0.01. The best cutoff value of 10.5 cm H O useful for discriminating MAS responders and non-responders in the previous Japanese population, was inadequate for prediction in the current population (0.47 negative predictive value [NPV]). However a cutoff of 13 cm H O identified MAS non-responders (1.0 NPV). Multivariate regression identified CPAP pressure (odds ratio [95% confidence interval] 0.53 [0.33-0.87], age (0.93 [0.87-0.99]) and AHI (0.92 [0.86-0.97]) as predictors of MAS treatment response (model r(2) = 0.54, p < 0.001). CONCLUSIONS In Australian patients, the majority of whom are Caucasian, a higher therapeutic CPAP pressure requirement in conjunction with age and OSA severity characteristics may be useful to indicate likelihood of success with MAS as an alternative therapy.

Growth of the cervical vertebrae in girls from 8 to 17 years. A longitudinal study

An important criterion of orthodontic diagnosis is the determination of the skeletal maturation stage. The cervical vertebral maturation (CVM) method is presented as an alternative to skeletal maturation determination. However, studies published to date concerning CVM have generally been cross-sectional. The aim of this investigation was to longitudinally evaluate growth and development with the CVM method. Lateral cephalometric radiographs of 41 girls, aged 9-16 years, collected between 1978 and 1984 were used to evaluate changes in C2, C3, and C4 dimensions. The mean values, standard deviations, maximum and minimum values of cervical vertebrae growth, and growth rate were calculated for every age and age interval. Cumulative growth increment was determined by summing annual mean values for each parameter. CVM stages were initially evaluated according to the method of Lamparski. The time differences between the following CVM stages were evaluated with a paired t-test. The total length increment was distinct for C2 but similar for C1, C3, and C4. Total length increments reached their maximum between CVM stages 2 and 3, except for C3. The total length increment of C3 reached its peak 1 year earlier. The height increments of the spinose processes of C2, C3, and C4 were similar. The results showed that height increments were greater than length increments, which was due to changes in the anatomical pattern. Vertical growth displayed a decreasing trend from the upper to the lower cervical vertebrae. Determination of skeletal maturation from dimensional measurements and anatomical changes of the cervical vertebrae will facilitate orthodontic evaluation by eliminating the need for hand-wrist films and, therefore, decrease the patients exposure to radiation.

Corticotomies and Orthodontic Tooth Movement: A Systematic Review

PURPOSE A systematic review was conducted to examine the evidence for the effectiveness and safety of corticotomy-facilitated orthodontics. MATERIALS AND METHODS Electronic databases (Ovid Medline, EMBASE, Cochrane, SCOPUS, and Web of Science) were searched for articles that examined the rate of corticotomy-facilitated orthodontic tooth movement and its effects on the periodontium, root resorption, and tooth vitality. Unpublished literature was searched electronically through ClinicalTrials.gov (http://www.clinicaltrials.gov) and the ISRCTN registry (http://www.controlled-trials.com). Relevant orthodontic journals and reference lists also were checked for eligible studies. Randomized clinical trials (RCTs) and controlled clinical trials (CCTs) were considered. Two article reviewers independently assessed the search results, screened the relevant articles, performed data extraction, and evaluated the methodologic quality of the studies. RESULTS Fourteen eligible articles (6 RCTs and 8 CCTs) were included in the review. There was a statistically meaningful increase in the rate of tooth movement compared with controls for all corticotomy techniques assessed. Some studies reported that acceleration in tooth movement was only temporary (lasting a few months). Corticotomy procedures did not seem to produce unwanted adverse effects on the periodontium, root resorption, and tooth vitality. The quality of the body of evidence was regarded as low owing to the presence of multiple methodologic issues, high risks of bias, and heterogeneity in the included articles. CONCLUSION Corticotomy procedures can produce statistically and clinically meaningful temporary increases in the rate of orthodontic tooth movement with minimal side-effects. Additional high-quality randomized clinical trials are needed to allow more definitive conclusions.

The short-term skeleto-dental effects of a new spring for the intrusion of maxillary posterior teeth in open bite patients

BackgroundThe technology surrounding temporary skeletal anchorage devices has improved in leaps and bounds. However, no specific auxiliary exists for the intrusion of molars in conjunction with these devices and currently clinicians are forced to make do with available force delivery materials. A new intrusion auxiliary, the Sydney Intrusion Spring (SIS), was designed to facilitate intrusion without frequent need for reactivation or tissue irritation.MethodsThe subjects consisted of 16 adolescent patients (12 females and 4 males) with an average age of 13.1 years (range 12.2 to 14.3 years). All patients were in the permanent dentition with an anterior open bite of ?2 mm. Four self-drilling miniscrews were placed into the posterior maxillary buccal alveolar bone. The intrusion appliance consisted of a bonded acrylic appliance and the SIS, activated to produce an initial intrusive force of 500 g. Cone beam computed tomograms were taken after miniscrew placement and at the end of active intrusion. Rendered lateral cephalograms were produced and measurements were taken and compared.ResultsAll study objectives were achieved in 4.91 months (range 2.5 to 7.75 months). The mean molar intrusion was 2.9 0.8 mm (P < .001), resulting in over bite increase of 3.0 1.5 mm (P < .001). The intrusion led to a 2.6 1.3 (P < .001) clockwise occlusal plane rotation and a 1.2 1.3 (P < .01) counter-clockwise rotation of the mandible. Dental measurements showed a significant uprighting and elongation of the incisors. There was no significant extrusion of the lower molars.ConclusionThe SIS is an effective appliance for the intrusion of maxillary posterior teeth, in conjunction with miniscrews.

Orthodontic extrusion of a traumatically intruded permanent incisor: a case report with a 5-year follow up.

This report presents a case of intrusive luxation of the immature left maxillary central incisor in an 8-year-old girl. Initially, it was decided to allow the intruded tooth to spontaneous re-erupt because it had open apices. After 12 weeks of monitoring for spontaneous re-eruption, there was no clinical evidence of its occurrence. Therefore, orthodontic extrusion was initiated. The intruded tooth was repositioned with a fixed multibracketed appliance. Twenty weeks after the beginning of orthodontic extrusion, the position of the intruded maxillary central incisor was restored to its original position before its displacement occurred. After 5 years, no clinical or radiographic pathology was detected and obliteration of the pulp canal of the intruded tooth was observed radiographically.

Effect of piezocision on root resorption associated with orthodontic force: A microcomputed tomography study

Introduction The purpose of this study was to investigate the effect of piezocision on orthodontically induced inflammatory root resorption. Methods Fourteen patients were included in this split‐mouth study; 1 side was assigned to piezocision, and the other side served as the control. Vertical corticotomy cuts of 4 to 5 mm in length were performed on either side of each piezocision premolar, and 150‐g buccal tipping forces were applied to the premolars. After 4 weeks, the maxillary first premolars were extracted and scanned with microcomputed tomography. Results There was a significantly greater total amount of root resorption seen on the piezocision sides when compared with the control sides (P = 0.029). The piezocision procedure resulted in a 44% average increase in root resorption. In 5 patients, there was noticeable piezocision‐related iatrogenic root damage. When that was combined with the orthodontic root resorption found on the piezocision‐treated teeth, there was a statistically significant 110% average increase in volumetric root loss when compared with the control side (P = 0.005). Conclusions The piezocision procedure that initiates the regional acceleratory phenomenon may increase the iatrogenic root resorption when used in conjunction with orthodontic forces. Piezocision applied close to the roots may cause iatrogenic damage to the neighboring roots and should be used carefully. HighlightsPiezocision might cause increased root resorption when used with orthodontic forces.Piezocision‐related iatrogenic root damage occurred in 5 of 14 participants.Piezocision should not be used in areas of close root proximity.

Computational and Clinical Investigation on the Role of Mechanical Vibration on Orthodontic Tooth Movement

The aim of this study is to investigate the biomechanics for orthodontic tooth movement (OTM) subjected to concurrent single-tooth vibration (50Hz) with conventional orthodontic force application, via a clinical study and computational simulation. Thirteen patients were recruited in the clinical study, which involved distal retraction of maxillary canines with 1.5N (150g) force for 12weeks. In a split mouth study, vibration and non-vibration sides were randomly assigned to each subject. Vibration of 50Hz, of approximately 0.2N (20g) of magnitude, was applied on the buccal surface of maxillary canine for the vibration group. A mode-based steady-state dynamic finite element analysis (FEA) was conducted based on an anatomically detailed model, complying with the clinical protocol. Both the amounts of space closure and canine distalization of the vibration group were significantly higher than those of the control group, as measured intra-orally or on models (p<0.05). Therefore it is indicated that a 50Hz and 20g single-tooth vibration can accelerate maxillary canine retraction. The volume-average hydrostatic stress (VHS) in the periodontal ligament (PDL) was computationally calculated to be higher with vibration compared with the control group for maxillary teeth and for both linguo-buccal and mesial-distal directions. An increase in vibratory frequency further amplified the PDL response before reaching a local natural frequency. An amplification of PDL response was also shown to be induced by vibration based on computational simulation. The vibration-enhanced OTM can be described by mild, vigorous and diminishing zones among which the mild zone is considered to be clinically beneficial.

Volumetric upper airway changes after rapid maxillary expansion: a systematic review and meta-analysis

Background Although Rapid Maxillary Expansion (RME) has been used for over a century, its effect on upper airways has not yet adequately been assessed in an evidence-based manner. Objective To investigate the volumetric changes in the upper airway spaces following RME in growing subjects by means of acoustic rhinometry, three-dimensional radiography and digital photogrammetry. Search methods Literature search of electronic databases and additional manual searches up to February 2016. Selection criteria Randomized clinical trials, prospective or retrospective controlled clinical trials and cohort clinical studies of at least eight patients, where the RME appliance was left in place for retention, and a maximum follow-up of 8 months post-expansion. Data collection and analysis After duplicate data extraction and assessment of the risk of bias, the mean differences and 95 per cent confidence intervals (CIs) of upper airway volume changes were calculated with random-effects meta-analyses, followed by subgroup analyses, meta-regressions, and sensitivity analyses. Results Twenty studies were eligible for qualitative synthesis, of which 17 (3 controlled clinical studies and 14 cohort studies) were used in quantitative analysis. As far as total airway volume is concerned patients treated with RME showed a significant increase post-expansion (5 studies; increase from baseline: 1218.3mm3; 95 per cent CI: 702.0 to 1734.6mm3), which did not seem to considerably diminish after the retention period (11 studies; increase from baseline: 1143.9mm3; 95 per cent CI: 696.9 to 1590.9mm3). Limitations However, the overall quality of evidence was judged as very low, due to methodological limitations of the included studies, absence of untreated control groups, and inconsistency among studies. Conclusions RME seems to be associated with an increase in the nasal cavity volume in the short and in the long term. However, additional well-conducted prospective controlled clinical studies are needed to confirm the present findings. Registration None. Funding Australian Society of Orthodontics Foundation for Research and Education Inc.

Histomorphological and torque removal comparison of 6 mm orthodontic miniscrews with and without surface treatment in New Zealand rabbits.

AIM The purpose of this study was to assess the difference of removal torque values (RTV) and the bone-to-implant contact (BIC) between the sand-blasted, large grit, and acid-etched (SLA) surface-treated and the machined surface (MA) miniscrews. MATERIAL AND METHODS Miniscrews used in this study were 6mm long with a diameter of 1.5mm. A total of 23 SLA miniscrews and 24 MA miniscrews were placed into the distal femoral condyle of 24 New Zealand rabbits. Removal torque test and the BIC was histologically evaluated at 0 and 8 weeks. RESULTS There was no statistical difference between the RTV in the MA group versus the SLA group at both 0 and 8 weeks. Comparing 0-8 weeks, there was no significant difference in RTV of the SLA group (P = 0.48), however the change in the MA group was statistically significant (P = 0.006). Histological observation showed a significant decrease in BIC comparing 0 and 8 weeks for the MA group. The BIC ratio at 8 weeks was statistically significantly higher in the SLA group compared to the MA group. CONCLUSION SLA surface preparation does not increase the RTV of miniscrews. Further investigations under loading and a large sample size are required.