Cranial base measurements in different anteroposterior skeletal relationships using Bjork-Jarabak analysis

Abstract

Objectives To assess the linear and angular cranial base measurements (Bjork polygon) in different anteroposterior (AP) skeletal relationships using Bjork-Jarabak analysis. Materials and Methods Pretreatment lateral cephalograms of 288 (146 women, 142 men, mean ages 21.24 ± 2.72 years and 22.94 ± 3.28 years, respectively) adult patients were divided into Class I, II, and III skeletal relationships according to their ANB angle. Linear and angular measurements of Bjork polygon were measured and compared among different skeletal relationships. Analysis of variance was performed to detect the differences among groups. Independent-sample t-test was used to detect differences between men and women. Results The Class II skeletal relationship has a significantly larger saddle angle than Class III does (P < .05), whereas Class III has a significantly larger gonial angle than Class II does (P < .05). The articular angle and sum of Bjork polygon angles were not significantly different among groups (P > .05). Anterior (N-S) and posterior (S-Ar) cranial base lengths were similar in the different AP skeletal relationships (P > .05). The ramal height and body of the mandible length were significantly larger in Class III compared with Class I and II (P < .05). Women had a significantly larger articular angle than men did (P < .05), although men had significantly larger linear measurements of Bjork polygon than women did (P < .05). Conclusions The Class III skeletal relationship has a smaller saddle angle and larger mandibular length and gonial angle. Men have a larger cranial base and mandibular linear measurements and a smaller articular angle compared with women.

Craniofacial and upper airway morphological characteristics associated with the presence and severity of obstructive sleep apnea in Chinese children

“…The growth of the ramus height is mainly determined by the new bone deposition on the mandibular condyle, which involves highly complicated environmental and genetic factors (34,35). The insufficient growth of the mandibular ramus is usually associated with a reduced posterior facial height, divergent growth pattern, and skeletal class II relationship (36,37), whereas significant condylar and ramus growth could prevent backward rotation of the mandible (38).…”

Novel prediction models for pharyngeal‐airway volume based on the cranial‐base and midsagittal cross‐sectional area of the airway in the pharyngeal region: A cephalometric and magnetic resonance imaging study

“…The cranial base plays a vital role in the development of dentofacial components, particularly through its tight interaction with the maxilla and mandible. 1,2 Notably, several studies have investigated the association between cranial-base components and malocclusion development [3][4][5] ; however, their findings are conflicting. Some authors argue that the cranial base has minimal or no influence on malocclusion development.…”

“…5,6 However, recent findings suggest a potential interaction between malocclusion and cranial-base components. 1,3,4 The Bjork-Jarabak analysis is highly beneficial in investigating craniofacial morphology as it provides adequate clinical data with minimal measurements. Furthermore, it helps elucidate the link between the cranial base and maxillary and mandibular development.…”

Cephalometric analyses of the craniofacial pattern using the Jarabak analysis

“…The mandible is indirectly related towards the posterior portion of the CB via temporomandibular joint, whereas the maxilla is connected directly to the anterior section of the base by development sutures. Consequently, any alteration in the rate and/or angle of CB growth may have either positive or negative consequences lying on the growing mandible as well as maxilla [3].…”

“…Establishing the connection between the development of the maxilla and mandible and the development of the CB may be done with the use of the Bjork-Jarabak assessment [15]. It was hypothesized that the mandible preferred to exhibit a reverse grow spin but the average of the Bjork polygon angles was greater than 400 o , although the mandible inclined to comprise a lateral grow spin if the mean was below 392 o [3]. The role of linear measures and CB angulation inside the formation of AP jaw connections is still up for dispute.…”