*Article* **Mask-Transformer-Based Networks for Teeth Segmentation in Panoramic Radiographs**

**Mehreen Kanwal 1,†, Muhammad Mutti Ur Rehman 2,†, Muhammad Umar Farooq <sup>3</sup> and Dong-Kyu Chae 3,\***

<sup>1</sup> DeepChain AI&IT Technologies, Islamabad 45570, Pakistan; mehreen@deepchain.pk

	- umarfarooq@hanyang.ac.kr

**Abstract:** Teeth segmentation plays a pivotal role in dentistry by facilitating accurate diagnoses and aiding the development of effective treatment plans. While traditional methods have primarily focused on teeth segmentation, they often fail to consider the broader oral tissue context. This paper proposes a panoptic-segmentation-based method that combines the results of instance segmentation with semantic segmentation of the background. Particularly, we introduce a novel architecture for instance teeth segmentation that leverages a dual-path transformer-based network, integrated with a panoptic quality (PQ) loss function. The model directly predicts masks and their corresponding classes, with the PQ loss function streamlining the training process. Our proposed architecture features a dual-path transformer block that facilitates bi-directional communication between the pixel path CNN and the memory path. It also contains a stacked decoder block that aggregates multi-scale features across different decoding resolutions. The transformer block integrates pixel-to-memory feedback attention, pixel-to-pixel self-attention, and memory-to-pixel and memory-to-memory selfattention mechanisms. The output heads process features to predict mask classes, while the final mask is obtained by multiplying memory path and pixel path features. When applied to the UFBA-UESC Dental Image dataset, our model exhibits a substantial improvement in segmentation performance, surpassing existing state-of-the-art techniques in terms of performance and robustness. Our research signifies an essential step forward in teeth segmentation and contributes to a deeper understanding of oral structures.

**Keywords:** teeth segmentation; panoramic radiographs; mask-transformer-based networks; panoptic segmentation
