Manish Valiathan

Results of a survey-based study to identify common retention practices in the United States

INTRODUCTION The purpose of this descriptive study was to use a carefully constructed, pilot-tested survey instrument to identify the most common orthodontic retainers and retention protocols prescribed in the United States as reported by active members of the American Association of Orthodontists. METHODS We randomly selected 2000 active members, stratified by region of practice, for the study. Information gathered included, but was not limited to, the types of retainers prescribed in the maxillary and mandibular arches, duration of full-time and part-time wear, use of fixed retainers, appliances fabricated in office vs commercial laboratories, the number of debonds per year, and retention appointment schedules. The survey consisted of 20 questions. Data were gathered on a categorical scale and analyzed. RESULTS We received 658 responses (32.9%) during a 12-week period. Maxillary Hawley retainers (58.2%) and mandibular fixed lingual retainers (40.2%) were the most commonly used. Most orthodontists prescribed less than 9 months of full-time wear of removable retainers and thereafter advised part-time, but lifetime wear. Most orthodontists (75.9%) did not instruct patients to have the fixed lingual retainers removed at a specific time. More orthodontists who prescribed Hawley retainers recommended longer full-time wear compared with clear thermoplastic retainers. The timing of scheduled retention appointments varied among clinicians and depended on the number of years in practice, the volume of patients debonded, and the type of prescribed retainer. The only regional difference associated with retainer design was the Northeast region, where mandibular fixed lingual retainers were used less frequently. Female orthodontists did not use mandibular fixed lingual retainers as often as their male counterparts. CONCLUSIONS Maxillary Hawley and mandibular fixed lingual retainers are most commonly used. This study is the first to describe retention protocols and the scheduling of retention appointments in the United States.

Effects of extraction versus non-extraction treatment on oropharyngeal airway volume.

OBJECTIVE To compare the effects of extraction vs nonextraction orthodontic treatments on oropharyngeal airway volume. MATERIALS AND METHODS An existing patient database was screened for pretreatment (T0) and posttreatment (T1) cone beam computed tomography (CBCT) scans and complete medical histories. Twenty patients treated with removal of four premolars (ExtG) and 20 controls (NExtG), were matched for age, gender, ethnicity, height, weight, body mass index, and oropharyngeal (OP) volumes, among other variables. Constructed lateral cephalograms (three skeletal and four dental variables) and OP volumes were measured at T0 and T1 using Dolphin Imaging 11.0. Independent sample t-tests were used to compare the groups at T0 and the outcome variables at T1. Paired sample t-tests were used to compare the mean changes from T0 to T1. Statistical significance was set at P < or = .05. RESULTS Changes from T0 to T1 were found to be significant in both groups for CoA, CoGn, U1-FH, and IMPA. In the ExtG alone, U1-Na Perp and L1-Na Perp were also significantly different from T0 to T1. Despite the observed differences, no significant differences were found at the end of treatment between the mean OP volumes for either group (12,675.6 +/- 4483.6 for ExtG; 12,002.7 +/- 2857.0 for NExtG, P > .05). Similarly, the mean changes in OP volume (1082.6 mm(3) and 1701.1 mm(3) for ExtG and NExtG, respectively) and increase in mean minimal constricted axial areas (17.4 mm(2) and 1.9 mm(2) for ExtG and NExtG, respectively, P > .05) from T0 to T1 were not significant for the two groups. CONCLUSION Extraction of four premolars with retraction of incisors does not affect OP airway volume.

Changes in hyoid bone position following rapid maxillary expansion in adolescents.

OBJECTIVE To examine changes in hyoid to mandibular plane distance (H-MP) and tongue length (TL) between children who had orthodontic treatment with and without rapid maxillary expansion (RME). MATERIALS AND METHODS Lateral and frontal cephalograms of 138 patients treated with RME and 148 controls treated without RME were used to measure pretreatment (T(1)) and posttreatment (T(2)) intermolar (IM) distance, lateronasal width (LNW), H-MP, and TL. Medical histories were used to collect demographic information, history of mouth breathing, difficulty breathing through the nose, and previous adenotonsillectomy. Groups were group-matched for age and gender. Descriptive statistics were calculated. Group means were compared using t-tests and chi-square statistics. Reliability was estimated using intraclass correlations and kappa statistics. Statistical significance was set at P < .05. RESULTS At T(1), the RME group showed smaller LNW (24.83 ± 1.99 vs 26.18 ± 2.05) and IM (50.17 ± 2.3 vs 51.58 ± 2.83). The distance from H-MP was longer in the RME group (15.69 ± 3.95 vs 13.86 ± 3.4). Mean changes (T(2) - T(1)) in the RME group were increased LNW (+2.48 ± 1.38 vs +0.94 ± 1.11 for the non-RME group) and IM (+3.21 ± 1.72 vs +0.98 ± 1.67). The mean change (T(2) - T(1)) in H-MP for the RME group was -0.68 ± 3.67 compared with +1.1 ± 2.96 for the non-RME group. Mean changes for TL were not statistically significant. No significant differences were noted at T(2) between groups for LNW, H-MP, or TL. CONCLUSIONS In this sample, RME produced significant changes in H-MP, and TL was unaffected.

Retainer wear and compliance in the first 2 years after active orthodontic treatment.

INTRODUCTION The purpose of this descriptive study was to estimate retainer wear and compliance among orthodontic patients in the first 2 years after active orthodontic treatment. METHODS A random sample of 1200 orthodontic patients was selected from 4 offices. Data were collected by a self-administered questionnaire that consisted of 6 items: type of retainer prescribed, age, sex, length of time since debond, and hours per day and nights per week that patients wore their retainers. Responses were solicited by mail or the Internet. Data were gathered on a categorical scale and analyzed. RESULTS The overall response rate was 36% during a 6-week period. In the first 3 months after debond, 60% of patients were wearing their retainers more than 10 hours during a 24-hour cycle, and 69% were wearing the retainers every night. At 19 to 24 months after debond, 19% of the patients were not wearing their retainers, and 81% wore their retainers at least 1 night per week. Compliance rates during the periods of 0 to 3, 4 to 6, 7 to 9, 10 to 12, 13 to 18, and 19 to 24 months were 69%, 76%, 55%, 62%, 45%, and 45%, respectively. Age, sex, and type of retainer did not influence the levels of compliance. CONCLUSIONS Most continued to wear their retainers at least 1 night per week, with compliance rates, as defined, tending to decrease in our sample. It was encouraging that 81% of the patients in this sample largely maintained their orthodontic result.

History of imaging in orthodontics from Broadbent to cone-beam computed tomography

The history of imaging and orthodontics is a story of technology informing biology. Advances in imaging changed our thinking as our understanding of craniofacial growth and the impact of orthodontic treatment deepened. This article traces the history of imaging in orthodontics from the invention of the cephalometer by B. Holly Broadbent in 1930 to the introduction of low-cost, low-radiation-dose cone-beam computed tomography imaging in 2015.

Variation in Timing, Duration, Intensity, and Direction of Adolescent Growth in the Mandible, Maxilla, and Cranial Base: the Fels Longitudinal Study

There is considerable individual variation in the timing, duration, and intensity of growth that occurs in the craniofacial complex during childhood and adolescence. The purpose of this article is to describe the extent of this variation between traits and between individuals within the Fels Longitudinal Study (FLS). Polynomial multilevel models were used to estimate the ages of onset, peak velocity, and cessation of adolescent growth, the time between these ages, the amount of growth between these ages, and peak velocity. This was done at both the group and individual levels for standard cephalometric measurements of the lengths of the mandible, maxilla, and cranial base, the gonial angle, and the saddle angle. Data are from 293 untreated boys and girls age 4–24 years in the FLS. The timing of the adolescent growth spurt was, in general, not significantly different between the mandible and the maxilla, with each having an earlier age of onset, later age of peak velocity, and later age of cessation of growth as compared to the cranial base length. Compared to lengths, angles had in general later ages of onset, peak velocity, and cessation of growth. Accurate characterization of the ontogenetic trajectories of the traits in the craniofacial complex is critical for both clinicians seeking to optimize treatment timing and anatomists interested in examining heterochrony. Anat Rec, 297:1195–1207, 2014.

45 Years of Simultaneous Le Fort III and Le Fort I Osteotomies: A Systematic Literature Review

Objective To review and collectively summarize our knowledge of simultaneous Le Fort III and Le Fort I osteotomies. Design A PubMed search using “Le Fort III,” “simultaneous Le Fort III and Le Fort I,” “combined Le Fort III and Le Fort I,” “dual midface,” and “segmental midface” was performed. Articles with relevant abstracts were obtained for formal review. A new case of simultaneous Le Fort III and Le Fort I is presented to describe and discuss specific operative indications and surgical decisions. Results There were 14 articles that met inclusion criteria with reports of simultaneous Le Fort III and Le Fort I osteotomies. A total of 20 cases were present in the literature. No major complications were reported. We performed combined Le Fort III with Le Fort I osteotomies in a 25-year-old patient with Crouzon syndrome who had undergone a previous Le Fort III at the age of 4 years. The patient tolerated the procedure well, and postoperatively, her exophthalmos and class III malocclusion were corrected. Conclusions Simultaneous Le Fort III and Le Fort I can correct differential upper and lower midface hypoplasia and is a well-tolerated procedure in the mature facial skeleton. This systematic review improves our understanding of the surgical technique and indications for a procedure that can correct complex midfacial deformities.

Innovative Surgical Treatment of Severe Cherubism

Background: Cherubism is an autosomal dominant syndrome characterized by excessive bilateral maxillomandibular bony degeneration and fibrous tissue hyperplasia. Conservative management is the preferred treatment as cherubism has a self-limiting course. Functional or emotional disturbances may, however, demand surgical intervention. We report a patient who underwent surgical intervention. Method/Description: He had significant enlargement of lower cheeks and bilateral lower lid scleral show. On computed tomography of the face, the patient had significant fibrous tissue involving bilateral maxilla and mandible. The mandibular tumor was excised. Given normal inferior border, bilateral sagittal split osteotomy was performed to infracture and inset the outer cortex. During the procedure, patient required blood transfusion intraoperatively, so the maxillary portion of the procedure was delayed until 6 months later. For the maxilla, bilateral transconjunctival approach was used to resect parts of the orbital floors that were concave, resulting in 1 × 2 cm defects bilaterally which were reconstructed using resorbable plates. Then the anterior maxillary tumor was excised. Results: The patient and his parents were satisfied with his appearance after surgery. The patient was noted to have improvement in contour and decreased scleral show. He has most recently followed up 15 months after the initial surgery. There were no long-term complications. Conclusions: Severity of cherubism influences the type of surgical intervention. The present case is innovative because this is the first reported case of recontouring orbital floors with resorbable plates and infracturing of the mandible using sagittal split osteotomies for surgical treatment of cherubism.

Precision and reliability of Dolphin 3-dimensional voxel-based superimposition

Introduction: Superimposition of 2 cone‐beam computed tomography images is possible by using landmarks, surfaces, or density information (voxel‐based). Voxel‐based superimposition is automated and uses the most image content, providing accurate results. Until recently, this superimposition was extremely laborious, but a user‐friendly voxel‐based superimposition has recently been introduced. Our aim was to evaluate the precision and reliability of Dolphin 3‐dimensional voxel‐based superimposition (Dolphin Imaging, Chatsworth, Calif). Methods: This was a retrospective study using existing scans of 31 surgical orthodontic patients with a mean age of 21 ± 8 years (range, 15‐47 years). Each patient had a presurgical and a postsurgical scan taken within 12 months. Surgical patients were used since the reference area for superimposition was not affected by growth or surgical procedures. The volumes were superimposed using voxel‐based methods from Dolphin Imaging and a tested method used previously. This method uses 2 open‐source programs and takes about 3 hours to complete, whereas the Dolphin method takes under 5 minutes. The postsurgical scan was superimposed on the presurgical scan at the cranial base. Postsurgical registrations for both methods were compared with each other using the absolute closest point color map, with emphasis on 7 regions (nasion, A‐point, B‐point, bilateral zygomatic arches, and bilateral gonions). Results: Intraclass correlations showed excellent reliability (0.96). The mean differences between the 2 methods were less than 0.21 mm (voxel size, 0.38). The smallst difference was in the left zygomatic area at 0.09 ± 0.07 mm, and the largest was in the right gonial region at 0.21 ± 0.13 mm. Conclusions: Dolphin 3‐dimensional voxel‐based superimposition, a fast and user‐friendly method, is precise and reliable.

Effects of Case Western Reserve University's transverse analysis on the quality of orthodontic treatment

Introduction The purpose of this study was to evaluate the effect of using the transverse analysis developed at Case Western Reserve University (CWRU) in Cleveland, Ohio. The hypotheses were based on the following: (1) Does following CWRU’s transverse analysis improve the orthodontic results? (2) Does following CWRU’s transverse analysis minimize the active treatment duration? Methods A retrospective cohort research study was conducted on a randomly selected sample of 100 subjects. The sample had CWRU’s analysis performed retrospectively, and the sample was divided according to whether the subjects followed what CWRU’s transverse analysis would have suggested. The American Board of Orthodontics discrepancy index was used to assess the pretreatment records, and quality of the result was evaluated using the American Board of Orthodontics cast/radiograph evaluation. The Mann‐Whitney test was used for the comparison. Results CWRU’s transverse analysis significantly improved the total cast/radiograph evaluation scores (P = 0.041), especially the buccolingual inclination component (P = 0.001). However, it did not significantly affect treatment duration (P = 0.106). Conclusions CWRU’s transverse analysis significantly improves the orthodontic results but does not have significant effects on treatment duration. HighlightsUsing the transverse analysis will result in higher‐quality results.The transverse analysis is reliable.To ignore the transverse dimension may affect the quality of the results.