MAKING DIAGNOSTIC WAX UP OF MAXILLARY ANTERIOR TEETH IN CROSS BITE CASES

Background: An anterior crossbite is a type of malocclusion in which one or more maxillary anterior teeth are positioned lingually to the mandibular anterior teeth, compromising aesthetics and reducing patient confidence. A thorough understanding of the patient's chief complaint is essential for developing an effective treatment plan. A diagnostic wax-up is recommended to improve predictability and facilitate the modification of maxillary and mandibular relationship ultimately enhancing aesthetic outcome. Purpose: To describe the procedure for creating a diagnostic wax-up of the maxillary anterior teeth in an anterior crossbite case for aesthetic purposes. Case analysis: Maxillary and mandibular working models were received, showing an anterior reverse bite malocclusion, with an overjet of -3 mm and an overbite of 2 mm. The dentist requested a diagnostic wax-up of the maxillary anterior teeth to achieve optimal aesthetic results. Result: The master model was received, marked, occluded, and mounted on an articulator. Wax was then applied and shaped to refine the anatomy of tooth 21, with the point and line angles adjusted toward the center to create a smaller appearance while carefully considering the height and convexity. Wax restorations were made covering 6 anterior teeth from maxillary left canine to maxillary right canines with the occlusal relationships adjusted to approximate a normal appearance. Conclusion: The diagnostic wax-up procedure involves preparing the working models, establishing the median line, mounting the models on an articulator, and sequentially waxing teeth numbers 11 and 21 first, followed by teeth 12 and 22, and finally teeth 13 and 23. The overjet is increased to achieve a more normal maxillomandibular occlusion, followed by careful evaluation.

Introduction

Anterior crossbite is a condition in which one or more maxillary anterior teeth are positioned on the lingual side of the mandibular anterior teeth, resulting in a negative overjet when the jaw is in a centric relationship. Anterior crossbite can affects smile esthetics(Nasir et al., 2021). Anterior crossbite, often observed as a key feature of Class III malocclusion, reflects a developmental anomaly marked by a mesial molar relationship. This condition typically arises from a complex interplay of genetic predisposition and environmental influences during a child’s growth and development(Amudala et al., 2023). The presence of malocclusion also leads to psychological effects on patients(Taibah & Al-Hummayani, 2017).

Anterior crossbites can result from one or a combination of several etiologic factors(Lina et al., 2017). These factors include palatally erupting maxillary anterior teeth, over-retained deciduous tooth or root, presence of supernumerary teeth or any periapical pathology(Kumar et al., 2016). Other etiologies include trauma in anterior primary teeth resulting in displacement of the permanent tooth seeds lingually, premature loss of primary teeth resulting in bone sclerosis or fibrous connective tissue, bad habits, and an inadequate arch length due to eruption of the maxillary permanent teeth lingually. Crossbites can also be caused by ectopic eruption or a displaced tooth position, such as buccal displacement in the mandible or palatal displacement in the maxilla(Truong et al., 2023). The prevalence of anterior crossbite varies significantly among and within populations, with studies reporting rates of 2.14% in Brazil and 6.25% in Saudi Arabia .

The aesthetic success of dental restorations relies on the ability to clearly understand the patient's chief complaint and expectations. Restorations can be an option to significantly improve and enhance aesthetics, especially by affecting the contour, dental arch, and occlusion that was originally less aesthetic. Occlusion is crucial for the long-term success of dental restorations by ensuring stability, durability, and functional harmony. Proper occlusion during the provisional phase minimizes postoperative adjustments and improves long-term results(Aldowish et al., 2024).

The case presented was an anterior cross bite with an overjet of - 3 mm and overbite of 2 mm. Illustrating the results of restoration modification before placing definitive restorations is essential to prevent patient’s disappointment and unnecessary remakes. A diagnostic wax-up is one of the pre-restorative procedures that illustrating the results of restoration modification before placing definitive restorations is essential to prevent patient’s disappointment and unnecessary remakes. In addition, a diagnostic wax-up provides valuable information by estimating the available restoration space, setting occlusion, and defining the dental arch, thereby allowing for thorough evaluation of the proposed restoration. The tooth to be restored is shaped using a wax inlay, while the natural and other teeth act as guides. In addition, a diagnostic wax-up provides valuable information by estimating the available restoration space, setting occlusion, and defining the dental arch, thereby allowing for thorough evaluation of the proposed restoration, waxed-up serve as a valuable tool for analyzing potential treatment outcomes and enable the precise fabrication of mock-ups for restorations within the patient's oral cavity(Ho, 2015). Then, the results of the diagnostic wax-up are used as a communication tool between dental office and dental laboratory and, implicitly, between the dentist and the dental technician(Drafta et al., 2022).

Modification of the natural teeth can be achieved by designing the restoration into a near-normal relationship. In this case, the maxillary and mandibular anterior teeth are positioned edge-to-edge because the distance is too large to allow for a normal occlusion. Through diagnostic wax-up, the dental technician can provide a tentative visual outcome for patient evaluation(Warner, 2017).Therefore, the purpose of this report is to describe the procedure for creating a diagnostic wax-up of maxillary anterior teeth in crossbite cases, serving as a means of communication between dentists, patients, and technicians to achieve optimal functional and aesthetic restorations.

Case study

Based on the study models can be seen inFigure 1and the dental technician's work order letter, a set of type III gypsum casts from a female patient with anterior crossbite was received. The maxillary anterior teeth exhibited excessive lingual inclination relative to the mandibular teeth, with an overjet of -3 mm, an overbite of 2 mm, and a midline deviation of 2 mm to the left. The technician was instructed to perform a diagnostic wax-up of the maxillary anterior region, to simulate ideal tooth relationships thereby improving) function and esthetics. The material used was inlay wax (Renfert, Germany).

Figure 1.Appliance design

Result

The diagnostic wax-up procedure in anterior cross bite cases, begins with carefully reading and interpreting the work order letter to minimize potential errors, during the subsequent work process. In this case, the work order letter specified that the working model presented an anterior crossbite, and the dentist requested a diagnostic wax-up to assist in designing the final restoration. The restoration is intended to correct the crossbite, ensuring that the relationship between the upper and lower anterior teeth appears as normal as possible.

The manufacturing stage, began with the receipt of the master model of the upper and lower jaws. After the median line was drawn, the model was occluded and secured with a stick and sticky wax and then mounted in the articulator. The horizontal pin was positioned at the contact points of the mandibular incisors, and the vertical pin was adjusted to touch the articulator table. Mounting on