Adding Depth to Cephalometric Analysis: Comparing Two- and Three-Dimensional Angular Cephalometric Measurements.

INTRODUCTION: Lateral cephalometric radiographs (LCR) have been the standard tool used for cephalometric analysis in craniofacial surgery. Over the past decade, a three-dimensional (3D) revolution in cephalometric analysis and surgical planning has been underway. To date, research has not validated whether cephalometric measurements taken from two-dimensional (2D) and 3D data sources are equivalent and interchangeable. The authors sought to compare angular cephalometric measurements taken with 2D and 3D modalities. METHODS: Sixty-two head CT scans (36 females, 26 males) with an average age of 63 ±â€Š20 years were studied. Twelve cephalometric angular measurements were taken from 3D reconstructed skulls using the software package Mimics 19.0 (Materialize; Leuven, Belgium). These same facial angles were measured from 2D lateral cephalograms reconstructed from the original CT scans using Dolphin 11.9. Measurements taken with both techniques were compared for agreement using a paired t test. Intra-class correlation coefficient assessment was used to determine inter-rater reliability. Statistical significance was set at P < 0.05. RESULTS: Five of the 12 angular measurements (SNA, SNB, MP-FH, U1-SN, and U1-L1) demonstrated statistically significant differences (P < 0.05) between the 2D and 3D analyses. All of these differences were less than the standard deviations for the respective measure. CONCLUSION: The differences between angular cephalometric values obtained from 2D LCRs and 3D CT reconstructions are small. This supports the practices of using 2D and 3D cephalometric data interchangeably in most applications. Clinicians must be selective in which measures they employ to maximize accuracy and care must be taken when measuring dental inclination with lateral cephalograms.

Clinical Outcomes Utilizing a "Modified Latham" Appliance for Presurgical Infant Orthopedics in Patients With Unilateral Complete Cleft Lip and Palate.

Presurgical infant orthopedic manipulation is utilized prior to cleft lip/nasal repair to facilitate a gingivoperiosteoplasty (GPP) and primary nasolabial repairs. The Latham dentomaxillary advancement appliance uses a screw that must be tightened daily to approximate the cleft segments in unilateral complete clefts. Our cleft center has been utilizing a "modified Latham" appliance since 1987, including an orthodontic elastic power chain to close the gap in a shorter amount of time. We performed a retrospective chart review of all patients undergoing treatment at Johns Hopkins All Children's Hospital (JHACH) with a unilateral complete cleft lip and palate between 1987 and 2017. Patients were identified by the International Classification of Diseases, Ninth Revision code (749.21). The majority of the patients represent the experience of the senior authors (E.R. and R.F.). Two hundred and eighty-one patients with unilateral complete cleft lip/palate were identified. Seventy-five patients were treated with a "modified Latham" appliance prior to their lip repair. The "modified Latham" appliance remained in place on average 20.6 days (range: 4-82), and average hospital stay after placement was 1.18 days. Nearly 96% of patients underwent a successful GPP at the time of nasolabial repair. Modification of the Latham appliance by utilizing an elastic power chain and eliminating the screw allows rapid closure of the alveolar cleft with limited need for adjustments and outpatient visits. Direct approximation of the palatal segments allows successful completion of a GPP in 95.9% of patients with limited dissection.

Bone response to buccal tooth movements-with and without flapless alveolar decortication.

SUMMARY OBJECTIVE: To evaluate the biological response of alveolar bone surrounding maxillary second premolars to flapless alveolar decortication and moderate, continuous forces in a buccal direction. MATERIALS AND METHODS: Using a randomized split-mouth experimental design, unilateral alveolar decortication was performed with a piezosurgery unit around the maxillary second premolars of six female dogs. The contralateral side received a sham surgery. The maxillary second premolars were moved buccally with archwires (initial 163.9 cN expansive force) for 9 weeks, followed by 2 weeks of consolidation. Intraoral, radiographic, and model measurements were performed to evaluate tooth movements; the amount and quality of surrounding bone were quantified using micro-CT; bone formation was evaluated histologically. RESULTS: The experimental premolars were expanded and tipped significantly (P < 0.05) more than the control premolars (1.35 times and 2.05 times as much, respectively). Peak rates of tooth movement occurred around 5 weeks. Dehiscenses were observed on both the experimental and control sides, with no statistically significant side differences in buccal bone height (BBH). Micro-CT analyses showed less mature bone in the apico-buccal and cervico-lingual regions around the experimental teeth. Hematoxylin and eosin sections demonstrated fenestrations on the cervico-buccal bone on both sides. The experimental side showed substantially more new bone formation and modeling of apico-buccal, cervico-lingual, and buccal bone than the control side. CONCLUSIONS: Archwire expansion resulted in reductions in BBH. Piezosurgical flapless alveolar decortication, in combination with archwire expansion, increased tooth movements and tipping and produced less bone, less dense bone, and less mature bone.