Evaluating cranial landmarks for yaw orientation in natural head position: a 3D study.

OBJECTIVES: To assess the symmetry of various cranial anthropometric points used as references for yaw orientation in the natural head position (NHP), relative to the mid-sagittal plane. MATERIALS AND METHODS: A prospective analysis using tomography data from 55 patients was conducted. Radiopaque markers, placed on patients in NHP, facilitated head position recording in three planes, with subsequent digital transfer for orientation analysis. Symmetry of eight points (zygomaxillare, zygion, ectoconchion, frontozygomatic suture, stephanion, porion, mastoidale, condylion laterale) was measured against the mid-sagittal plane. RESULTS: Significant asymmetry was observed in the stephanion, frontozygomatic suture, and ectoconchion points (p < 0.05). No significant differences were found in the symmetry of other points (p > 0.05). CONCLUSIONS: Findings suggest that stephanion, frontozygomatic suture, and ectoconchion are unreliable for yaw orientation in NHP. Other points, combined with clinical measurements, may offer better reliability.

Assessment of nasal respiration and three-dimensional airway volume changes in orthognathic surgery patients.

OBJECTIVES: The aim of this study was to evaluate the effect of maxillary movements in orthognathic surgery on nasal airway volume change and its correlation with airflow and resistance. MATERIALS AND METHODS: This study included 25 patients (8 male, 17 female) with Class II (6 patients) or Class III (19 patients) malocclusion. All patients underwent Le Fort I and bilateral sagittal split ramus osteotomy. Nasal airflow and resistance were measured by using rhinomanometry and acoustic rhinometry pre and six months post-operatively. Nasal volume was measured using computed tomography before surgery and six months after surgery. RESULTS: Nasal volume increased in 10 out of 11 patients with CCW (counterclockwise) rotation and decreased in 1 patient while, nasal volume increased in 5 patients with CW (clockwise) rotation and decreased in 9 patients. Superior nasal airway volume increased significantly, while the effects on nasal flow and resistance were not significant. Additionally, no significant correlation was found between airway volume changes and variations in airflow and resistance. CONCLUSION: CCW rotation in orthognathic surgery patients significantly increased superior nasal airway volume but did not improve nasal airway flow and resistance.

Optimising needle depth in temporomandibular joint arthrocentesis: a magnetic resonance-based study for safety and efficacy.

The aim of this paper was to determine the optimal needle depth for temporomandibular joint (TMJ) arthrocentesis using magnetic resonance imaging (MRI), with the aim of improving procedural safety and efficacy in clinical practice. A retrospective analysis of 264 TMJ MRIs from 132 patients at Istanbul Medipol Mega University Hospital was conducted. T2-weighted MRI sequences were utilised to measure distances from skin to joint capsules at varying needle entry points, applying the double puncture technique. The study adhered to ethical standards with appropriate approvals. The analysis revealed significant gender-related variations in needle depths (females showing shorter distances than males, p < 0.05). No significant gender differences were found in condylar angles. An inverse correlation between age and condylar angle suggested age-related anatomical changes. Crucially, a 20 mm needle depth was identified as safer and more effective than the previously recommended 25 mm. This study underscores the necessity of revising needle depth to 20 mm in TMJ arthrocentesis. These findings hold significant implications for improving procedural safety and catering to demographic variations.

Effect of Horizontal Osteotomy Level on Complication Rates and Neurosensory Deficits After Sagittal Split Ramus Osteotomy.

Horizontal osteotomy is one of the most critical step at sagittal split ramus osteotomy (SSRO) and determination of the ideal height of this horizontal osteotomy is essential to avoid nerve and vessel injury. PURPOSE: The aim of this study was to evaluate the level of the medial horizontal ramus cut as a risk factor for unfavorable outcomes in the SSRO. MATERIALS AND METHODS: Sixty-four patients with dentofacial deformity who applied to Oral & Maxillofacial Surgery Department between August 2018 and August 2019 and undergone orthognathic surgery were evaluated. Out of 64, 49 patients had SSRO with or without maxillary surgery and genioplasty. Twenty-six patient had postoperative computed tomography scan with 6-months follow-up. Finally, 26 patient with 52 SSRO sides were included in this study. Computed tomography scans were evaluated and classification according to osteotomy levels was made. Postoperative neurosensory deficit, bleeding, and intraoperative complications such as bad split, visible damage to inferior alveolar bundle were assessed. Age, gender, neurosensory deficit, bad splits were analyzed and correlated with the level of the osteotomies. RESULTS: Fifteen osteotomies were above lingula, 24 between apex and base of lingula, and 14 below lingula. One bad split occurred, and no visible damage to the inferior alveolar bundle was seen. There was no significant difference between osteotomy groups in terms of visual analogue scale (VAS) scores (P > 0.05) but in all groups; women's VAS scores are statistically significantly higher than men. (P: 0.036). CONCLUSION: There is no correlation between the horizontal osteotomy level and intraoperative or postoperative complications. The low medial horizontal osteotomy can be safely performed in SSRO.