The hard palate, a vital component of the skull, is formed by the fusion of the horizontal plates of the palatine bone, the pre-maxilla, and the palatine processes of the maxilla. This arched structure, characterized by varying depth and breadth, is widest in the molar region and serves to separate the oral cavity from the nasal cavity above [1]. The minor palatine foramina are located posterior to the larger palatine foramen, both of which are situated in the posterior region of the hard palate [2]. Palatal morphology and morphometry are widely recognized as pivotal in forensic dentistry. Due to its protected position within the oral cavity, the hard palate is typically preserved even after trauma, making it a reliable structure for identification in cases of damaged or decomposed skulls [3]. Additionally, skull morphometry plays a significant role in forensic and anthropological studies, aiding in the determination of age, size, and ethnicity [3, 4]. An understanding of the normal anatomical features of the hard palate is essential for procedures such as nasal pharyngoscopy, nasogastric intubation, and the use of related instruments [5]. Furthermore, palatal morphometry is crucial in the planning and execution of treatments for orthodontic disorders, orthognathic surgeries, maxillary dental implants, and cleft palate repair [6]. Accurate morphometric measurements of the hard palate are particularly beneficial in the fabrication of dentures and prosthetic restorations to ensure proper speech and functional rehabilitation [7-9]. Although the hard palate has been extensively studied, the minor palatine foramina and their relationship to surrounding landmarks have not been thoroughly explored in this region [10-14]. The data collected from this study can serve as a baseline for future research in anthropometrics, dentistry, forensic sciences, and anatomy. The present study aimed to measure the morphometric characteristics of the hard palate using dried human skulls, thereby contributing valuable insights into these fields.

The present study was conducted on 50 dried skulls obtained from the Department of Anatomy, Jawahar Lal Nehru Medical College, Bhagalpur, and other medical colleges in Bihar, India. The age and sex of the skulls were not known.

Inclusion Criteria:

• The study included well-preserved, non-pathological adult skulls that were free from any visible abnormalities.
• Only skulls with an intact base, particularly the anterior and middle cranial fossa regions, were considered suitable for detailed morphometric analysis.
• Skulls that were complete in all anatomical aspects, ensuring accurate and reliable measurements of the hard palate, were included in the study.
• Additionally, the selected skulls exhibited no signs of erosion or damage that could compromise the structural integrity of the hard palate.

Exclusion Criteria:

• Skulls that displayed extensive damage, pathological lesions, or significant deformities affecting the hard palate were excluded from the study.
• Fragmented or partially preserved skulls, especially those with missing or altered structures critical for morphometric analysis, were not considered.
• Specimens showing healed fractures, signs of surgical interventions, or any form of postmortem damage that could interfere with accurate observations were also excluded.
• Skulls with erosion or weathering affecting the base of the skull, particularly the anterior and middle cranial fossa regions, were omitted from the analysis.

Figure 1: Hard Palate showing landmarks for measurements.

A digital Vernier caliper with an accuracy of 0.01 mm was used for all measurements. We measured the following morphometry of the hard palate:

1. Length of the hard palate: The distance from the posterior nasal spine posteriorly to the orale anteriorly (From point P to Q as in Figure 1). On the median plane, the orale is the point between the two medial maxillary incisors.
2. Breadth of the hard palate: The distance between the inner edges of the upper second molar sockets (From point R to S as in Figure 1).
3. Height of the hard palate: Height of the palate from the line connecting the endomolaria.
4. Palatine index (PI): The palatine index (PI) was classified using the methods by Hassanali and Mwaniki [15]. PI is the percent ratio of palatine width to palatine length, calculated using this formula:

Palatine index (PI) = Breadth/Length X 100.

Based on the PI measurements the palates were classified as leptostaphyline, mesostaphyline, and brachystaphyline.

Type 1: Leptostaphyline (L): Narrow palate with index ≤79.9%.

Type 2: Mesostaphyline (M): Intermediate palate with index 80-84.9%.

Type 3: Brachystaphyline (B): Wide palate with index ≥85%.

1. Palatine height index (PHI): The following formula was used to calculate the palatal height index:

Palatine height index (PHI) = Palatal height/Breadth X 100.

According to this calculation; the hard palates were classified as follows [15]:

Type 1: Chemostaphyline: Low palate with index ≤27.9 %.

Type 2: Orthostaphyline: Intermediate palate with index 28-39.9%.

Type 3: Hypsistaphyline: High or deep palate with index ≥40 %.

To prevent inter-observer bias, only one observer took all of the measurements. The measurements and data obtained will be useful to clarify the morphometry of the hard palate. Anthropometric research, dental, forensic, and anatomical sciences can use these data.

Statistical Analysis: The Excel 2019 and Statistical Package for Social Sciences (SPSS, version 24.0) were used to evaluate the data that had been gathered. The metric parameters were determined by mean, standard deviation, and range.

The mean palatine length, breadth, and height in the present study were 46.13 ± 2.47 mm, 33.43 ± 1.92 mm, and 11.36 ± 3.45 mm, respectively. The mean values of the palatine index and palatine height index were 72.54 ± 6.56 mm and 35.14 ± 5.83 mm respectively. The most frequent type of hard palate was leptostaphyline (80%), followed by mesostaphyline (16%) according to the palatine index, while brachystaphyline type (4%) was the least commonly reported. While, the most frequent type of hard palate was orthostaphyline (60%), followed by hypsistaphyline (24%) according to the palatine height index, while the chemostaphyline type (16%) was the least commonly reported [Table 1, 2, and 3].

Table 1: Showing different metric parameters and indices of the hard palate

Table 2: Showing the classification of the hard palate according to the palatine index

Table 3: Showing the classification of the hard palate according to the palatine height index

The present study provides valuable insights into the morphometric characteristics of the hard palate, with findings that offer critical implications for clinical, forensic, and anthropological applications. The mean hard palate length in this study (46.13 ± 2.47 mm) aligns closely with previous studies conducted by Kaur A. et al. (46.16 mm) [16], D’Souza AS et al. (49.13 mm) [10], Jotania B. et al. (49.73 mm) [11], and Rao MJ et al. (49.87 mm) [12]. The observed similarities highlight a degree of consistency in palatal length measurements across studies, although slight differences may be attributed to variations in sample size, ethnic diversity, and regional factors. These findings underscore the need for population-specific data to enhance the accuracy of comparative studies and clinical applications. The mean palatal breadth in the current investigation (33.43 ± 1.92 mm) was significantly lower than the values reported by D’Souza AS et al. (40.4 mm) [10], Jotania B. et al. (37.75 mm) [11], Shalaby SA et al. (38 mm) [13], and Sarilita E. et al. (38.68 mm) [14]. However, it closely matched the measurements reported by Kaur A. et al. (33.01 mm) [16] and Rao MJ et al. (34.42 mm) [12]. The observed variations in palatal breadth are likely influenced by genetic, environmental, and dietary factors that affect craniofacial growth and development. These results reinforce the importance of documenting palatal dimensions in different populations to facilitate accurate anthropometric assessments and improve treatment planning for dental and surgical procedures. The mean palatal height recorded in this study (11.36 ± 3.45 mm) closely matched the findings of Sarilita E. et al. (11.8 mm) [14], Kaur A. et al. (11.06 mm) [16], and Shalaby SA et al. (11.5 mm) [13], suggesting that palatal height is relatively consistent across different populations. Palatal height classification in the present study revealed that 60% of skulls were categorized as orthostaphyline, 24% as hypsistaphyline, and 16% as chemostaphyline. This classification differed from studies conducted by Sarilita E. et al. [14] and D’Souza AS et al. [10] but showed greater similarity to the findings of Shalaby SA et al. [13] and Kaur A. et al. [16]. Palatal height classification is particularly significant in clinical practice, as variations in height are associated with syndromic conditions such as Apert syndrome, Turner’s syndrome, and Marfan syndrome, where high and narrow palates are common. Palatal morphology classification revealed that 80% of skulls in this study were leptostaphyline, 16% were mesostaphyline, and 4% were brachystaphyline. These findings were consistent with Kaur A. et al. (83% leptostaphyline) [16] and Sarilita E. et al. (84% leptostaphyline) [14] but varied from the observations of D’Souza AS et al. (37.5% leptostaphyline) [10], Jotania B. et al. (70% leptostaphyline) [11], and Rao MJ et al. (95% leptostaphyline) [12]. The differences in palatal classification likely reflect ethnic and geographic diversity, underscoring the need for further research across broader populations to establish a more comprehensive understanding of palatal variability. Beyond anthropometric implications, the hard palate plays a critical role in forensic dentistry. Its position within the oral cavity shields it from trauma and heat-related stressors, preserving its structural integrity even in cases of significant tissue loss. This makes the hard palate a reliable structure for individual identification and sex estimation in forensic contexts. Shalaby et al. demonstrated that external palate breadth was a particularly reliable parameter, with the ability to classify sex correctly in 66.7% of cases [13]. Similarly, Gangrade et al. emphasized the utility of external palate breadth in forensic investigations [17]. The morphometric characteristics of the palate also hold critical importance in forensic dentistry, as the palatal and dental structures are highly resistant to environmental damage and incineration, making them reliable for forensic identification even in severe scenarios [18, 19].

Knowledge of palatal dimensions is vital in clinical practice for planning and performing procedures such as orthognathic surgeries, maxillary dental implant placement, and cleft palate repair. Palatal measurements also aid in the fabrication of dentures and prosthetic restorations, ensuring optimal functional and aesthetic outcomes. The current study’s data contribute to the growing repository of morphometric information that can enhance the accuracy of clinical and forensic applications. Overall, this study highlights the importance of understanding palatal morphometry in various disciplines.

Limitations of the study: The age and sex of the skull bones were not analyzed due to the unavailability of this information. Additionally, the findings of this study are specific to the population of Bihar. To generalize these results, further research involving diverse ethnicities and geographical regions is necessary. Expanding the scope of future studies will enhance the applicability of palatal morphometry in clinical, forensic, and anthropological contexts, paving the way for more precise and personalized approaches in these fields.

This study provides valuable insights into the fields of anthropometry, dentistry, and medicine. A comprehensive understanding of the anatomy of the hard palate is crucial for various applications, including surgical procedures involving the hard and soft palate, anthropological research, the fabrication of complete maxillary dentures for edentulous patients, and the classification of crania based on ethnic and racial characteristics. Additionally, oral and maxillofacial surgeons can utilize knowledge of the palatal index to enhance surgical outcomes in the repair of cleft palate or lip deformities

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