Determining the occlusal plane using hamular notch incisive papilla plane evaluator: An in vivo study

J Indian Prosthodont Soc. 2020 Jan-Mar;20(1):61-68. doi: 10.4103/jips.jips_167_19. Epub 2020 Jan 27.

Abstract

Aims: Identification and establishment of the occlusal plane in patients with impaired occlusal plane, presents a major hurdle for the execution of natural esthetics, speech, and function. The aim of this study was to minimize such errors while occlusal rehabilitation, and employ hamular notchincisive papilla (H.I.P) plane as landmark and scribe it on the cast using H. I. P evaluator and utilise for occlusal corrections.

Settings and design: HIP plane being parallel to the occlusal plane could ease the operator when it could be scribed on cast to analyze and restore the compromised occlusal plane.

Materials and methods: Dentulous casts of two hundred participants were mounted on the Hanau Wide-Vue articulator. Reference points were marked on the maxillary right central incisor and maxillary molars on casts for attaining different occlusal planes, the incisive papilla and hamular notch region were also marked for HIP plane. A plane parallel HIP was scribed on cast using HIP Evaluator. The casts were then scanned using a three-dimensional coordinate measuring machine attached to perception V5 laser scanner and measurements were made using Geomagic X design software. The most parallel occlusal plane to HIP plane was evaluated, and the reliability of HIP evaluator was verified.

Statistical analysis used: ANOVA test, Post hoc-Bonferroni test, and independent sample "t"-test were carried out for the comparison between occlusal planes, among the genders and for the analysis of the angle of deviation of scribed plane on the cast to HIP plane on the right and left sides.

Results: Occlusal plane III (Mesio-labial incisal edge of upper right central incisor to Mesio-buccal cusp tips of upper second molars) showed least angle of deviation with 1.316° ± 1.158° to HIP plane among tested subjects. There is no significant difference between the genders. The plane scribed on the cast with H. I. P evaluator showed relative parallelism to H. I. P plane with minimum deviation of 0.010° ± 0.363°.

Conclusion: Occlusal plane III is more parallel to H. I. P plane. Scribed plane on the cast using H. I. P evaluator is parallel to H. I. P plane. H. I. P evaluator can be used as an alternative tool to establish the occlusal plane to rehabilitate patient with deficient dentition or disordered occlusal plane.

Keywords: Hamular notch-incisive papilla evaluator; hamular notch; hamular notch-incisive papilla plane; incisive papilla; occlusal plane and perception V5 laser scanner.