Orientation of the occlusal plane in a Class I adult population

Abstract

Objective. To primarily evaluate whether Delaire's ideal occlusal plane is present in Class I occlusal relationship adults. Study Design. Pretreatment lateral cephalometric radiographs from 30 orthodontically untreated Caucasian Class I malocclusion adults were obtained. The occlusal, mandibular, and maxillary planes were traced and compared with the ideal occlusal, mandibular, and maxillary planes according to Delaire. Results. The average occlusal plane was 3.5 below the ideal plane. This divergence was more pronounced in males, and in patients presenting with a hypodivergent skeletal pattern. The maxillary plane displayed on average less than 0.5 of divergence to the ideal. The average mandibular plane showed a divergence of 3.3 below the ideal. Conclusions. When aiming to obtain an ideal orientation of the occlusal plane postoperatively, one must keep in mind that in Class I occlusal relationship adults without any dentofacial disharmony, the occlusal plane is rarely coincident with the ideal plane. (Oral Surg Oral Med Oral Pathol Oral Radiol 2013;116:35-40) The orientation of the occlusal plane is often a factor used by maxillofacial surgeons both in predicting optimal functional and esthetic results, and in predicting the stability of a certain operative procedure. [1][2][3] It is thought to be true that if the postoperative occlusal plane is not coincident with the 'ideal' occlusal plane, then the risk for postoperative surgical relapse is increased. For this reason, when performing preoperative surgical planning and perioperative surgical positioning of the jaws, one of the objectives may be to establish the position of the occlusal plane and the jaws in accordance with cephalometric treatment planning. 4,5 This may involve the surgeon performing a rotation of the maxillomandibular complex 6 in order to improve both facial balance and the occlusal plane angle which ultimately is thought to favor occlusal stability.Delaire 7,8 developed a cephalometric analysis, referred to as the architectural and structural craniofacial cephalometric analysis, and discussed its application in the treatment of cranio-maxillo-facial anomalies. This method is often used for orthognathic treatment planning. [9][10][11][12] Delaire proposed that the occlusal plane, stated to pass through the occlusal surfaces of the premolars, in an ideal situation was meant to pass through the inferior part of the skull (a point referred to as the mandibularoccipital point, Om, in the original analysis). Moreover, the occlusal plane, again in an ideal situation, was meant to meet with the maxillary and mandibular planes at this same point (Figure 1). This implies a balance between the maxillary, mandibular, and occlusal planes in relation to the craniospinal articulation and the postero-inferior part of the skull. 8 This proposition by Delaire is, to the best of our knowledge, based on his clinical experience and thus on empirical evidence. There is no clear or available scientific evidence, unless based on unpublished data, which substa...

Relationship Between Occlusal Plane Orientation and Sagittal Malocclusions: Study of an Orthodontic Population

“…), the duration, and observance [27]. Some protocols have been voluntarily excluded, orthopedic and orthognathic treatments [28][29][30][31]. The impact of such protocols on stability of the OP needs to be deeply investigated in the future.…”