Introduction

The human mandible can assume various positions to the maxilla in the horizontal plane aspect (Caldwell & Herbert, 1955). One significant relation among these positions is the centric relation plays a vital role in the dentures (Myers, 1982). The centric relation position acts as a proprioceptive centre to guide the mandibular movements (Yurkstas & Kapur, 2005). It is also a reproducible and stable position which can be repeatedly arrived at. Hence used as a reliable guide to develop centric occlusion in patients (Keshvad & Winstanley, 2001; Yurkstas et al., 2005). There are various methods to record the centric relation, the graphic method resembles gothic arches characterised by high pointed arches (Boucher, 1985; Vijayalakshmi & Ganapathy, 2016). It was introduced by Hess from Germany in 1897 and polarized by Alfred Gysi in 1910. The arrow point tracing is a one dimensional graphic tracing method (Saizar, 1963). It consists of a pen-like pointer (central bearing plate) attached to each rim (Ganapathy, Kannan, & Venugopalan, 2017; Venugopalan, 2014). Pointer and plate together form the central bearing device when the mandible moves (Kunta, Shetty, & Shenoy, 2017).

The characteristic pattern created on a recording plate is called arrow point tracing (Kannan & Venugopalan, 2018). It can be recorded by both intra oral arrow point tracing and the extra oral arrow point tracing (Ajay, 2017; Anehosur, Kumari, Meshramkar, Nadiger, & Lekha, 2016; Basha, Ganapathy, & Venugopalan, 2018). The various forms of arrow tracings were classified as the classical (pointed form) classical, flat form, weak gothic arch tracing, asymmetrical form, miniature form, vertical lines protruding beyond the arrow point.

In typical form, which is the most commonly seen type of intra oral tracing. The TMJ is healthy and there are no condylar interferences (Ashok & Suvitha, 2016; Selvan & Ganapathy, 2016). The mandibular movements are not disturbed (Ashok, 2014; Ganapathy et al., 2017).

In flat form and assymetrical of tracing there is a restriction in the forward movement of the mandible either the left or right condyles is restricted in movement. Miniature Arrow Point occurs if the record bases are not seated or long term habitual position of the condyles. Double arrow tracing point occurs when the patient is not trained properly or when the vertical dimension is altered. Atypical occurs when the patient is a bruxer and the muscle pattern has altered due to the para functional habit.

In the present article we will be assessing the types of arrow points achieved using intra oral tracer in bio functional prosthetic systems.

Materials and Methods

A Retrospective study design was done to assess the types of gothic arch tracing achieved using intraoral tracer in a bio functional prosthetic system. The inclusion criteria were both genders, patients who underwent complete denture, patients who underwent Bio functional prosthetic complete denture. The exclusion criteria were partially edentulous patients, patients with no proper information regarding the treatment, complete denture done without using intra oral tracing method.

The total sample size was assessed based on the inclusion and exclusion criteria and a total of 66 patients who underwent bio functional prosthetic complete denture data was assessed. The patient with no proper information was excluded in the study. One patient's details were excluded in the study. The data collection was from data collection from DIAS ( Dental Hospital Management System). The following details were collected and tabulated : Patient details (Age, Gender), Status of edentulism, Type of tracer used, Types of arrow point achieved.

Results and Discussion

The values of the outcome measures were tabulated and subjected to statistical analysis using SPSS software statistics version 26. Chi square test was done to compare the gender and the type of intraoral tracing given by the patient.

The results of the present study showed that there is no statistically significant difference between the intra oral arrow point tracing and between the genders (Table 1). However, the typical arrow point was seen to be predominant (63%) in males than in females (57.6%) followed by double arrow form Figure 1 tracing was predominantly seen in females (18.2%) than in males (8.3%). Miniature and Atypical forms of intra oral tracing were more seen in males (11.1% and 11.1% respectively) than in females ( 3% and 6.1% respectively). X axis shows the gender and y axis shows the variations in gothic arch.

Asymmetrical type of tracing was seen in females (15.2%) than in males (0%). The non-parametric correlation between the gender arch tracing reveals negligible correlation (Spearman's Rho = -172).

Gothic arch tracing determines the patient centric relation (Duraisamy, 2019; Jyothi, 2017; Selvan et al., 2016; Shin, 2014) and can determine proper vertical dimension. However if the tracing is not done correctly, the occlusion might alter in the patient's mouth. This is a critical step in fabricating a complete denture (Ganapathy, Sathyamoorthy, & Ranganathan, 2016; Selvan et al., 2016). There are many variations in the intra oral tracing (arrow point tracing) (‘Centric Relation Records’, 2020). This will determine the condition of the patient's temporomandibular joint without interferences in the condylar path and can help in proper selection of teeth and set according to the occlusion. The correct gothic arch tracing is obtained only when the tracing point is placed perpendicular to the line from the condyle to point of tracer (Rey, Fernandez, & Weber, 2015). The width and the selection of the teeth can be done based on the arch form and length of the teeth (Ariga, 2018; Jain, 2018). The oral hygiene status after the complete denture fabrication should be evaluated and depends upon the interarch spacing and the tracing achieved (Jyothi, 2017).

According to the study results females show more variations than males. There might be variations in the temporomandibular joints and the surrounding muscles. The para functional habits can also influence arrow tracing (Berrie, 2000). The variations seen in this study are atypical, miniature, asymmetrical, double arrow tracings. The facial forms can also influence the tracing design, longer the face more inclination of the tracing point.

Conclusion

The accurate recording of jaw relation is at most important to construct a complete denture and to restore the form, function, and appearance of the patient. To record a proper centric relation with intra oral tracers is quite challenging and technique sensitive. However minimum time investment will make the gothic arch tracing easier to record jaw relation. Within the limitations of the study, most of the patients have the typical arrow point tracing form and seen in both males and females. Other forms like atypical, double arrow are commonly seen in females and only miniature forms are predominantly seen in males. Clinical rechecking has to be followed throughout the denture construction in order to maintain the maxillomandibular relationship.

Conflict of Interest

The authors declare that they have no conflict of interest for this study.

Funding Support

The authors declare that they have no funding support for this study.