Cephalometric investigation of first cervical vertebrae morphology and hyoid position in young adults with different sagittal skeletal patterns.

Seher Gündüz Arslan,Neval Dildeş,Jalen Devecioglu Kama

doi:10.1155/2014/159784

Seher Gündüz Arslan, Neval Dildeş + Show 1 more

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https://doi.org/10.1155/2014/159784

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Abstract

The aim of this retrospective study was to examine hyoid bone position and C1 (atlas) morphology in males and females and analyze these parameters with respect to different sagittal skeletal patterns via cephalometry, with the goal of identifying cephalometric norms. Lateral cephalometric radiographs from 120 individuals (average age: 21.1 ± 2.9 years) were classified according to their ANB angle (Class I, II, or III) and used to assess 14 parameters. Class I and II patients showed significant differences in Hy-NSL, Hy-PD, Hy-CVT, Lum, and a-p measurements. These parameters were consistently larger in males than in females. Intergroup comparisons among males showed significant differences in the SNA, ANB, Hy-CVT, X, and Z measurements. The hyoid was positioned more inferiorly and anteriorly and was more prominent in males than in females in all groups. Among participants exhibiting a Class I skeletal pattern, C1 was also larger in the anterior-posterior direction in males than in females. In the sagittal plane, the hyoid was positioned similarly in males with either Class I or III skeletal patterns but was positioned posteriorly in males with a Class II skeletal pattern. In addition, the vertical position of C1 varied with sagittal skeletal pattern in males.

Highlights

The head and neck have a balanced relationship similar to a lever-and-pivot system, with its fulcrum at the level of the occipital condyle
In the intragroup comparison of Class II participants, significant differences were observed for Hy-NSL (P = 0.006), Hy-NL (P = 0.050), and Hy-CVT (P = 0.001)
Cephalometric radiography, one of the most important tools in orthodontics both clinically and in research, permits the accurate evaluation of the dental, skeletal, and soft tissue relationships of the craniofacial complex before the initiation of treatment and during growth [42,43,44]. In light of this information, the aim of this study was to document the position of the hyoid bone and cervical atlas morphology on the cephalometric radiographs of participants with different sagittal skeletal patterns, with the goal of identifying cephalometric norms

Summary

Introduction

The head and neck have a balanced relationship similar to a lever-and-pivot system, with its fulcrum at the level of the occipital condyle. To maintain an upright position, muscles exert equal but opposing anterior and posterior forces on the occipital condyles [1] such that the head remains balanced over the first cervical vertebra (C1), known as the atlas. Variation in the dimensions of C1, as well as head and neck posture, were associated with differences in craniofacial morphology involving the cranial base [4,5,6,7,8], the upper airway space [9], occlusion [4], and temporomandibular disorders [10, 11]. Treuenfels [12] observed that the inclination of the atlas is associated with sagittal jaw position in that the anterior arch of the atlas shows a more cranial position in progenic compared to orthogenic patients

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