Original Research

Year : 2026 | Volume : 17 | Issue : 3 | Page : 41-52

FEM-Based Comparison of Peri-implant Stress and Stability in Bi-cortical Versus Mono-cortical Mini-implant Anchorage during Bone-borne Maxillary Expansion

Vikashini Dhakshinamoorthy-1, Pavithranand Ammayappan-2, Praveen Kumar-3, Shaick Ashiq-3

1-Postgraduate Resident, 2-Professor and Head, 3-Assistant Professor, Department of Orthodontics and Dentofacial Orthopedics, Sri Balaji Vidyapeeth University, Puducherry, India.

Address for Correspondence:

Dr Pavithranand Ammayappan MDS FDSRCS (England)

Professor and Head,

Department of Orthodontics and Dentofacial Orthopedics,

Sri Balaji Vidyapeeth University, Puducherry, India.

Mobile: +91 9443183590

email: docanandpavi@gmail.com

ABSTRACT

AIM: The aim of this study was to compare the mechanical stability of mono-cortical and bi-cortical mini-implant anchorage in mini-implant assisted rapid palatal expansion (MARPE) in terms of stress and displacement.

METHODS: Using CBCT data of a healthy adolescent, a 3D finite element model of the maxilla, teeth, periodontal ligament and mid-palatal suture was created. Two different MARPE models were simulated: Model A (4 bi-cortical mini-implants) and Model B (anterior mono-cortical and posterior bi-cortical mini-implants). After performing grid-independence testing, all structures were discretized using tetrahedral and hexahedral elements and were assumed to be isotropic, homogeneous and linearly elastic. The 800 g bilateral orthopaedic forces were applied to each mini-implant in identical boundary conditions. To evaluate mechanical stability, von Mises stress and displacement were analyzed around the mini-implants and in the surrounding cortical bone.

RESULTS: Model A had more uniform stress around all the mini-implants, and minimum von Mises stresses in the cervical areas with minimal displacement. Model B exhibited significant stress concentration in the middle and cervical thirds of the anterior mono-cortical mini-implants, and larger mini-implant displacement than bi-cortical mini-implants, suggesting that it has lower mechanical stability compared to bi-cortical mini-implants.

CONCLUSION: This study, because of the limited FEA applied, showed that full bi-cortical mini-implant anchorage in MARPE resulted in lower peri-implant stress and showed less mini-implant displacement than partial mono-cortical anchorage, indicating greater mechanical stability and a reduced risk of mini-implant instability under orthopaedic loading.

KEYWORDS: MARPE; finite element analysis; mono-cortical anchorage; bi-cortical anchorage; mini-implant stability; transverse maxillary deficiency.​

CONFLICT OF INTEREST

Nil

FUNDING

Nil

How to cite this article: Vikashini Dhakshinamoorthy, Pavithranand Ammayappan, Praveen Kumar, Shaick Ashiq. FEM-Based Comparison of Peri-implant Stress and Stability in Bi-cortical Versus Mono-cortical Mini-implant Anchorage during Bone-borne Maxillary Expansion.

Int J OrthodRehabil 2026; 17 (3): 41-52.

Doi: 10.56501/Intjorthodrehabil.172.ijor0103

Original Research

Year : 2026 | Volume : 17 | Issue : 2 | Page : 43-57

Dermatoglyphics, Palatal Rugoscopy, and Cheiloscopy as Markers for Angle’s Class I, II, and III Malocclusions: A Cross-Sectional Study

Sathish Elangovan-1, Pavithranand Ammayappan-2, Sithra P-3, Shaick Ashiq-3, Shivashankar Kengadaran-4

1-Postgraduate Resident, 2-Professor and Head, 3-Senior Lecturer, Department of Orthodontics and Dentofacial Orthopedics, Sri Balaji Vidyapeeth University, Puducherry, India, 4-Associate Professor, Department of Public Health Dentistry, Sri Balaji Vidyapeeth University, Puducherry, India.

Address for Correspondence:

Dr Pavithranand Ammayappan MDS FDSRCS (England)

Professor and Head,

Department of Orthodontics and Dentofacial Orthopedics,

Sri Balaji Vidyapeeth University, Puducherry, India.

Mobile: +91 9443183590

Email: docanandpavi@gmail.com

ABSTRACT

BACKGROUND AND AIM: Early detection of malocclusion is key to providing effective orthodontic treatment. The non-invasive indicators dermatoglyphics, palatal rugoscopy, and cheiloscopy, which have similar embryonic development to the craniofacial structure, could play a role in the early detection of malocclusions. This study examines the correlation between the three indicators and malocclusions such as Angle’s Class I, II, and III in a South Indian population.

MATERIALS AND METHODS: The cross-sectional study was carried out among 120 subjects within the age range of 13 to 25 years, equally divided into three categories of malocclusion (each comprising n = 40 subjects). Impressions of fingerprints were taken by the ink impression method, and the classification was done based on whether the pattern is arch, loop, or whorl. The lip prints were taken using the lipstick-cellophane method, which classified them using the Suzuki-Tsuchihashi classification. The palatal rugae prints were taken using the dental cast, and their classification involved straight, curved, wavy, or circular forms. Statistical analysis included chi-square tests and multinomial logistic regression, with significance set at p<0.05.

RESULTS: Dermatoglyphics analysis showed associations between Class III cases and left thumb (p = 0.019), right index finger (p < 0.001). Patterns of arch had higher incidence among the members of Class III (30% versus 12.5 to 15%). The cheiloscopy pattern was statistically different (p = 0.008), with branched pattern being the most common pattern in Class I (60%), while vertical pattern was more common in Class II and Class III (37.5% each). Multinomial regression showed that lip prints were good predictors. The right rugae 1 and left rugae 4 showed significant differences (p = 0.001 & p < 0.001, respectively). Rugae 5 was not present bilaterally in Class III.

CONCLUSION: Notable correlations were observed between dermatoglyphics, cheiloscopy, and palatal rugoscopy and the classification of Angle’s malocclusions. These findings suggest that these modalities may serve as valuable adjunctive, non-invasive screening tools in orthodontic practice.

KEYWORDS: Dermatoglyphics, cheiloscopy, Palatal rugoscopy, Angle's malocclusion, Orthodontic screening

CONFLICT OF INTEREST AND FUNDING

Nil

How to cite this article: Sathish Elangovan, Pavithranand Ammayappan, Sithra P, Shaick Ashiq, Shivashankar Kengadaran. Dermatoglyphics, Palatal Rugoscopy, and Cheiloscopy as Markers for Angle’s Class I, II, and III Malocclusions: A Cross-Sectional Study. Int J Orthod Rehabil 2026; 17 (2): 43-57.

Doi: 10.56501/Intjorthodrehabil.172.ijor0089