A comparison of the accuracy of two methods used by pre-doctoral students to measure vertical dimension

Correlation of intercondylar distance and occlusal vertical dimension in dentate individuals: A clinical study

STATEMENT OF PROBLEM

Determining the vertical dimension of occlusion for an edentulous patient depends on clinical judgment and the skill and experience of the dentist. Though many methods have been advocated, a universally accepted method of determining the vertical dimension of occlusion in edentulous patients is lacking.

PURPOSE

This clinical study aimed to find a correlation between the intercondylar distance and occlusal vertical dimension in dentate individuals.

MATERIAL AND METHODS

This study was conducted on 258 dentate individuals aged 18 to 30 years. The Denar posterior reference point was used to determine the center of the condyle. The posterior reference point was marked on either side of the face with this scale, and the intercondylar width between these 2 posterior reference points was measured with custom digital vernier calipers. A modified Willis gauge was used to measure the occlusal vertical dimension from the base of the nose to the lower border of the chin when the teeth were in maximum intercuspation. The relationship between the ICD and OVD was analyzed with the Pearson correlation test. Simple regression analysis was used to formulate a regression equation.

RESULTS

The mean intercondylar distance was 133.5 mm, and the mean occlusal vertical dimension was 55.4 mm. A statistically significant correlation (R=0.619) was found between the intercondylar distance and occlusal vertical dimension in the study population (P<.001).

CONCLUSIONS

A significant correlation was found between the intercondylar distance and occlusal vertical dimension of the participants. Occlusal vertical dimension may be predicted from the intercondylar distance by using a regression model.

Tiwari R, Mahajan A, Polavarapu J, Kandregula M, Loganathan J, Varma P. Occlusal vertical dimension and its association with length of thumb: An original research

Introduction:

Establishing an accurate vertical dimension at occlusal (VDO) is a challenge. Hence, we aim to find the association between the VDO and the Thumb Length (TL).

Materials and Methods:

We piloted an observational study by evaluating the VDO and the TL among the Dravidian and Aryan ethnicities with 200 volunteers. The comparisons were made applying the “linear regression analysis” to find the correlation of both.

Results:

We observed that a strong and positive relation was established for the two parameters of VDO and TL for both the ethnicities.

Conclusion:

We can suggest from our study that the thumb length can be used as an aid for the occlusal vertical dimension estimation.

A practical approach to orofacial rehabilitation in a patient after inferior maxillectomy and rhinectomy with mono framework construction supported on a zygomatic implant placed in the glabella: a case report

Background

In the field of craniofacial tumor surgery, an adequately performed excision, despite being a life-saving procedure, is only a first step to successful treatment. During such a procedure, the main goal is to completely remove the lesion, paying less attention to factors contributing to future rehabilitation possibilities. One ty 2of the possibilities for prosthetic rehabilitation of such cases is utilizing one-piece implants with bicortical anchorage.

Case presentation

This case report presents a case of a 48-year-old patient with oral squamous cell carcinoma (OSCC). The treatment protocol consisted of radical surgery to remove the tumor, and intraoral and extraoral rehabilitation with a single framework prosthesis anchored with one-piece implants. Moreover, the intraoral stomatognathic deformity was corrected with a fixed implant-retained prosthesis, and the extraoral defect was covered with a removable epithesis.

Conclusions

The use of one-piece implants with bicortical anchorage may be an additional tool in reconstructing maxillofacial defects. Properly executed treatment may improve the esthetics, speech, masticatory function, muscle support, and the overall quality of life of patients with extensive defects in the maxillofacial region.

Accuracy between Functional Swallowing and Knebelman Craniometric Method to Measure Occlusal Vertical Dimension in Total Denture Wearers: A Quasi-experimental Study

Objective:

The objective was to determine the accuracy between functional swallowing (FS) and the Knebelman craniometric method (KCM) to measure occlusal vertical dimension (OVD) in total denture wearers.

Materials and Methods:

A quasi-experimental, prospective study was conducted considering the KCM diagnostic method as the gold standard compared to FS. All the totally edentulous patients attended at the School of Dentistry of the Universidad Nacional Mayor de San Marcos (n = 32) in 2018–2019 were evaluated. Previous informed consent was obtained from all patients. A Knebelman’s Craniometer was used to obtain longitudinal measurements measured in millimeters. The measurement was made with the Knebelman Craniometer by placing the tip into the external auditory canal inside the right meatus. On the other hand, for the FS method, the patients were seated comfortably with their back supported and their head in a natural position. Both upper and lower rollers were inserted into the mouth and the patient was instructed to swallow saliva for a period of 5min.

Results:

When comparing the measurement of the OVD of KCM versus FS according to sex, men presented an OVD of 68.1 ± 3.9 mm, being 64.1 ± 3.8 mm in women. Accuracy was evaluated with an analysis of concordance between FS and the KCM in the determination of OVD in totally edentulous patients with a value of 0.97 (confidence interval = 0.31–0.99) (P = 0.013).

Conclusions:

There is a good concordance between the FS method and the KCM at the time of determining the OVD of edentulous patients using total prostheses.

An intraoral method of verifying interocclusal distance for completely edentulous patients

This article describes a method of verifying the interocclusal distance of edentulous patients by using acrylic resin wafers of different thicknesses. The wafers are attached to the occlusal surface of the maxillary wax occlusal rim in the first premolar region to facilitate intraoral verification of the proposed interocclusal distance. This method is straightforward and reduces the registration of an incorrect interocclusal distance.

Effects of rehabilitation with complete dentures on bite force and electromyography of jaw and neck muscles and the correlation with occlusal vertical dimension

OBJECTIVES

The purpose of this study was to assess the effects of oral rehabilitation with complete dentures on bite force and electromyography of the suprahyoid and sternocleidomastoid muscles, and their correlation with occlusal vertical dimension (OVD). The research questions were "What are the effects of rehabilitation with complete dentures on bite force and electromyography of suprahyoid and sternocleidomastoid muscles, and how are they correlated with OVD?"

MATERIALS AND METHODS

Patients who are wearers of unsatisfactory removable complete dentures were attended in three sessions (T0, T1, and T2). At T0, while the patients still wore the old dentures, they were submitted to bite force and surface electromyographic exams of the suprahyoid and sternocleidomastoid muscles. These exams were repeated, and the OVD was measured while the patients wore their old and new prostheses, 30 days after insertion of the new prosthesis (T1). The exams were repeated 100 days after the insertion of the new prosthesis (T2). The data were submitted to the Shapiro-Wilk normality test, analysis of variance (ANOVA), and Pearson correlation and linear regression, all with 5% significance.

RESULTS

Fifteen patients participated in the study. No statistically significant difference was observed for bite force or electromyography in T0, T1, or T2. However, the correlation and regression tests showed important interactions between the OVD and maximum voluntary occlusal bite force, as well as the OVD and electromyography during deglutition for the suprahyoid muscles.

CONCLUSION

Rehabilitation did not impact bite force nor the activity of the assessed muscles (electromyography). On the other hand, OVD was shown to be an important factor for bite force, and deglutition of water after rehabilitation.

CLINICAL RELEVANCE

This study shows what are the influences of rehabilitation on oral functions and reinforces the importance of corrected reestablishment of OVD because it has been found to be an important factor for bite force and electromyography during deglutition.

Maxillary denture flange and occlusal discrepancies of Vertex ThermoSens in comparison with conventional heat-cured denture base materials

This study was conducted to investigate the maxillary denture bases and occlusal discrepancies using the Vertex Thermosens in comparison with the conventional polymethyl-methacrylate materials. Twenty maxillary denture bases were prepared from the Vertex ThermoSens and a conventional heat-cured denture base materials. Acrylic maxillary second molars were arranged in their respective positions on the ridge. After curing of both types of denture bases, they were deflasked with their respective master casts. Reference points were prepared for measurements of the antero-posterior and cross-arch dimensions at the denture borders using caliper device. Furthermore, the teeth discrepancies were measured between reference points in the ligual aspect of the second maxillary molars. The recorded data was analyzed using SPSS statistical software version 20. The results showed initial shrinkage of both denture bases in the antero-posterior and cross-arch dimensions immediately after decasting. This contraction was compensated gradually during storage in water up to 2 weeks. Regarding the variable time, there was a significant difference between the tested materials. Moreover, the results revealed occlusal discrepancies and shifting of teeth inward immediately after decasting, followed by outward movement after storage in water for 2 weeks. Regarding the variables time and materials, there were significant differences. Both materials exhibited inward shrinkage in the antero-posterior and cross-arch dimensions immediately after decasting. Both denture bases showed inward shifting of teeth immediately after decasting, followed by outward movement after storage in water up to 2 weeks.

Determination of occlusal vertical dimension for complete dentures patients: an updated review

Determination of the occlusal vertical dimension (OVD) is an integral part of complete dentures fabrication. Due to the lack of teeth, the clinician faces the challenge of how to accurately establish the OVD of the new denture. Therefore, the purpose of this review article was to present, discuss and critique the available methods used in determining the OVD for complete dentures patients. This review identified two main streams to determine the OVD: (i) pre-extraction methods and (ii) post-extraction methods. For the pre-extraction methods, the OVD of the natural dentition is transferred to the new dentures mainly by intra-oral measurements, profile tracing and cephalometric analysis. The post-extraction methods rely on mandibular rest position, facial aesthetic appearance, swallowing pattern, craniofacial landmarks measurements, cephalometric analysis, phonetics and existing dentures. In general, all the available techniques have merits and are helpful for routine clinical use. However, they are empirical in nature, controversial and lack the scientific support. Further, there is no single accurate method for OVD determination. To overcome the limitations of the techniques, the clinician will benefit from applying combination of techniques to approximate the OVD.

A proposed linear skeletal distance to predict occlusal vertical dimension: A cephalometric study

STATEMENT OF PROBLEM

Establishing a correct occlusal vertical dimension is considered one of the most important aspects of facial esthetics for patients in need of oral rehabilitation.

PURPOSE

The purpose of this retrospective study was to evaluate the use of a proposed linear skeletal distance to predict the appropriate occlusal vertical dimension.

MATERIAL AND METHODS

A total of 93 digital cephalometric radiographs were collected in Joint Photographic Experts Group (JPEG) format (51 men, 42 women) from the archive of the orthodontics department at the Faculty of Dentistry, Sana'a University, Yemen. The distance from nasion (Na) to sella (Se) and the distance from anterior nasal spine (ANS) to menton (Me) were measured on the cephalometric radiographs, using ImageJ software. The data were compared statistically using the Pearson correlation coefficient, regression analysis, and paired- and 1-sample t tests (α=.05).

RESULTS

The findings of the study revealed a significant positive correlation (P<.001) between the measured distances in men, with minimum difference between the variables. However, no significant correlation (P=.058) was found for women.

CONCLUSIONS

The distance from Na to Se can be used as an additional aid in estimating the occlusal vertical dimension in men for the study population.

Eye-rima oris distance and its relation to the vertical dimension of occlusion measured by two methods: Anthropometric study in a sample of Yemeni dental students

Objective:

This study was conducted to evaluate the relationship between the distance measured from the distal outer of the eye to the parting line of the lips and the occlusal vertical dimension (OVD) measured by two methods.

Methods:

One hundred and fourteen dental students (76 males and 38 females) were recruited for this study with mean age (22.34 ± 1.83) years. The distance from distal canthus of the eye to rima oris (eye-RO) was compared with two different measurements of the OVD (nasal [N] to gnathion [Gn], and subnasal [Sn] to menton [Me]). All distances were measured using modified digital caliper.

Results:

Pearson correlation coefficient test for correlations and paired samples t-test for differences were used with a significant level of (P < 0.05). There was a positive significant correlation between the eye-RO distance and the two measurements of the OVD. However, this correlation was stronger between eye-RO and the distance from the tip of the nose to the tip of the chin than that between eye-RO and the distance from the septum of the nose to the under of the chin (r = 0.313 with P = 0.0007, r = 0.296 with P = 0.0014), respectively.

Conclusion:

The distance from the outer canthus of the eye to the parting of the lips seems to be a reliable method in predicting the OVD and should relate to the distance from the tip of the nose to the tip of the chin.

Effect of Different Denture Base Materials and Changed Mouth Temperature on Dimensional Stability of Complete Dentures

Background. Type of materials used in fabrication of denture base has an effect on dimension during denture base material processing and other factors related to clinical use. Objective. The study aims were to assess the dimensional stability including thermal changes of three different denture base materials. Methods. Ninety patients were selected to construct complete dentures with different denture base materials. They were randomly divided into three groups: group 1, patients with cobalt chrome metallic base; group 2, patients with heat curing acrylic resin fabricated by injection moulding technique; and group 3, patients with denture bases fabricated by conventional heat curing acrylic resin. The dimensional changes were assessed using digital caliper. Results. After the twelfth month, injection moulding acrylic resin had significantly the highest dimensional change followed by the conventional heat curing acrylic resin. There were no significant differences in the dimensions between the three types of denture base materials at normal mouth temperature, while, after hot tea drinking at 45°C, the dimensional change was significantly the highest in cobalt chrome metallic denture base group. Conclusion. Cobalt chrome metallic denture base has stable dimension compared to denture bases fabricated of acrylic resin but it was more affected by altered mouth temperature. The study was registered in the International Standard Randomized Controlled Trials Number (ISRCTN) registry with study ID (ISRCTN94238244).

An anthropometric study to evaluate the correlation between the occlusal vertical dimension and length of the thumb

BACKGROUND

Establishment of proper occlusal vertical dimension (OVD) is one of the important tasks for successful prosthodontic therapy. An ideal method for determining OVD in terms of cost, time, and instrument requirements has been sought in prosthodontics by various investigators. However, no such single method has been formulated. In the current anthropometric study, the relationship of the length of the thumb to the OVD was tested in two ethnic groups of Nepal, Aryans, and Mongoloids. The result of this study can be useful in determining proper OVD in edentulous patients.

AIMS AND OBJECTIVES

The primary aim of the present study was to evaluate the correlation between the length of the thumb and OVD in Aryan and Mongoloid ethnic groups. The secondary aim was to compare the correlation between OVD and other anatomic measurements (eye-ear distance and pupil-to-rima oris distance) in these ethnicities.

MATERIALS AND METHODS

The OVD, thumb length, eye-ear distance and distance between pupil of eye and rima oris were measured in a total of 500 adult dentulous volunteers. The correlation between OVD and thumb length as well as other anatomic measurements was checked with Pearson's product moment correlation coefficient. Linear regression analysis was performed to determine the relationship of OVD to the length of the thumb.

RESULTS

The thumb length was significantly (P≤0.05) correlated with strong and positive values (Pearson's coefficient =0.874 in the whole population, 0.826 in Aryans, and 0.944 in Mongoloids). Regression analysis showed that thumb length was significantly related to OVD in both ethnic groups.

CONCLUSION

Within the limitations of the present study, the result implies that thumb length can be used as an adjunct for establishing OVD in the edentulous patients.

The relationship between facial morphology and the structure of the alveolar part of the mandible in edentulous complete denture wearers. A preliminary study

OBJECTIVE

Although the effect of involutional processes that occurs in the maxilla and mandible of edentulous subjects is obvious, the problem of factors definitely determining the direction of changes still remains unsolved. This study was aimed at determining the relationship between facial morphology and the structure of the alveolar part and the body of the mandible in edentulous complete denture wearers.

MATERIALS AND METHODS

Twenty-five healthy edentulous Caucasian patients in the 70.5 ± 9 years of age group were examined. All patients underwent tele-X-ray examination with the presence of currently used dentures in the oral cavity. To assess morphological parameters of the facial skeleton, cephalograms were analyzed according to Ricketts and Mc Namara method. To assess the mandible morphology, the films were measured using the method of Tallgren.

RESULTS

The period of edentulism was found to be negatively correlated with the anterior segment of the body of the mandible within its symphysis. The parameter corresponding to the location of the first lower molar showed a directly proportional correlation with G'-Sn', G'-Me', Sn'-Me', N-Ans, N-Me, Ans-Me, Co-Gn and Co-Go. Positive correlations were found between the parameters describing contour of the alveolar part of the body of the mandible and mandibular symphysis and G'-Me', Sn'-Me', N-Me, Ans-Me describing the height of the occlusal vertical dimension.

CONCLUSION

The study showed a directly proportional correlation between the vertical occlusal dimension of the lower face conditioned by prosthetic rehabilitation and the height of the alveolar part in the lateral regions of the mandible.

Avaliação da relação entre disfunção temporomandibular e dimensão vertical de oclusão em crianças de 7 A 12 anos

Objetivo verificar se existe relação entre a presença de disfunção temporomandibular (DTM) relacionada à variabilidade da dimensão vertical de oclusão em crianças e adolescentes na faixa etária de 7 a 12 anos. Métodos foram avaliadas 96 crianças e adolescentes do Instituto Rogacionista em São Paulo. A pesquisa diagnóstica da disfunção temporomandibular foi por meio do Índice de Helkimo e exame clínico posterior. Para a mensuração dos dados referentes à dimensão vertical foram empregadas as distâncias comissura labial - canto externo do olho e base do nariz – mento. A comparação dos valores médios das medidas antropométricas entre os gêneros e os grupos com e sem disfunção temporomandibular foi realizada empregando-se a análise de variância (ANOVA) complementada pelo teste least significance diference. Resultados a dimensão vertical de oclusão demonstrou medidas distintas nas crianças e adolescentes em todas as faixas etárias avaliadas, foram observadas alterações significantes dessa medida nas idades de 10 e 12 anos de ambos os gêneros. Conclusão pode -se concluir que na amostra estudada houve relação direta entre a presença  de DTM e  Dimensão vertical de oclusão (DVO), correlação positiva entre as medidas  comissura labial – canto do olho externo e Násio – Mento no sexo feminino e alterações significantes na dimensão vertical de oclusão nas idades de 10 e 12 anos para ambos os sexos.

Direct restorative treatment of anterior weared teeth after re-establishment of occlusal vertical dimension: a case report

OBJECTIVE

The loss of posterior teeth resulting in a lack of stability may lead to excessive mandibular load on some points of occlusion of the remaining teeth, causing wear. The rehabilitation of these cases must be carefully planned and the treatment requires a period of adaptation with a new vertical dimension.

BACKGROUND

This case report describes the treatment of a patient with a loss of almost all posterior inferior teeth and a consequential loss of occlusal vertical dimension and accentuated wear of anterior elements.

MATERIALS AND METHODS

  Provisional removable partial dentures were manufactured and the patient used them for a period of adaptation prior to restoration of the anterior teeth. After the patient's adaptation with the new occlusal dimension, anterior restorations were made using a mycrohibrid resin composite with different color aspects for an optimal stratification.

RESULTS

The restorations achieved an aesthetic configuration with ideal function as the final result and the occlusion showed a satisfactory stability for a provisional removable partial dentures.

CONCLUSION

This article presents an anterior direct rehabilitation approach not only as an alternative option, but also as viable and less expensive treatment option with an optimally aesthetic and functional result.

An implant-supported, cobalt-chromium milled bar and nonflanged attachment-retained overdenture to rehabilitate the edentulous mandible

Rehabilitation of the edentulous mandible has been revolutionized by the use of osseointegrated endosteal implants. One treatment option for such rehabilitation is an implant-supported bar and overdenture. This article presents a procedure for the fabrication of an implant-supported, cobalt-chromium milled bar and nonflanged attachment-retained overdenture. The prosthesis described meets requirements for masticatory efficiency, natural esthetics, and maintenance of the health of residual tissues. The biological and mechanical considerations of the design, and the advantages, disadvantages, and contraindications of the prosthesis are discussed. (J Prosthet Dent 2009;102:46-51).

Fabrication of a caliper device for interalveolar dimension measurement in the complete denture patient

A method is presented for measuring interalveolar dimension (IAD) of existing dentures using a caliper. Directions for construction of an IAD gauge are included. This device is easy to construct and "zeroes out" in the closed position. The measurement is useful for determining occlusal vertical dimension (OVD) in new dentures and for monitoring changes over time. Its dimension is entered in the patient record for future reference.

Electromyographic evaluation of anterior temporal and suprahyoid muscles using habitual methods to determine clinical rest position

The purpose of this study was to compare the electromyographic (EMG) activity of the anterior temporal and suprahyoid muscles using habitual methods to determine the clinical rest position. The sample included 26 healthy subjects with natural dentition, bilateral molar support, and bilateral molar Angle Class I occlusion. Bipolar surface electrodes were located on the right anterior temporal and suprahyoid muscles for EMG recordings. In each subject EMG activity was recorded while standing while performing the following jaw posture tasks: during light occlusal contact in the intercuspal position; during and after pronouncing the word Mississippi, during and after pronouncing the Spanish terms Sesenta y seis (English translation: sixty six); during and after pronouncing the word, business, during and after swallowing of saliva; and while maintaining their mandible in a relaxed posture. Anterior temporal EMG activity in the intercuspal position was significantly higher than all the other conditions. The same was observed in the suprahyoid muscles excepting after pronouncing the words Mississippi, and business. EMG activity recorded in the clinical rest position by means of phonetic methods, swallowing of saliva and maintaining the mandible in a relaxed posture did not show a significant difference. From an EMG point of view any of these methods could be used to determine clinical rest position.

Complete artificial dentition supported by endosseous implants: a case report of total in-office treatment

This case report demonstrates the construction of a complete restoration of the dentition by the surgical placement of endosseous titanium implants that support a fixed prosthesis in each jaw. The positioning of the implants and teeth in the prostheses are important factors for a successful long-term result. Distribution of the occlusal biting forces over as many implants as possible is important. Off-axial occlusal biting forces should be diverted to the anterior prostheses, where the forces are not as great and the posterior teeth are designed with flat occlusal surfaces that separate during excursionary chewing movements. Medial mandibular flexure caused by the contraction of the medial pterygoid muscle can be addressed by constructing the prosthesis in segments. This is so as not to have a rigid entity encased in flexing bone that may induce stress to the bone, leading to loss of implant integration and failure. Segmenting also insures an appropriate fit of the prosthesis with respect to casting and porcelain firing distortion. Lip support by means of a flange in the prosthesis may be necessary when there has been a large amount of bone loss from edentulous resorption. Cleaning and maintenance of the prostheses every 3 to 6 months is essential.

An Overview of Complete Artificial Fixed Dentition Supported by Endosseous Implants

The construction of a complete restoration of the dentition by the surgical placement of endosseous titanium implants that support a fixed prosthesis in each jaw is possible. The positionings of the implants and teeth in the prostheses are important factors for a successful long-term result. Distribution of the occlusal biting forces over as many implants as possible is important. Off-axial occlusal biting forces should be diverted to the anterior jaws where the forces are not as great. The posterior teeth should be designed with flat occlusal surfaces that separate during excursionary mandibular chewing movements. Medial mandibular flexure caused by the contraction of the medial pterygoid muscle can be addressed by constructing the prosthesis in segments, so as not to have a rigid entity encased in flexing bone that may induce stress in the bone, potentially leading to loss of implant integration and failure. Segmenting also ensures an appropriate fit of the prosthesis with respect to casting and porcelain firing distortion. Lip support by means of a flange in the prosthesis may be necessary when there has been a large amount of bone loss from edentulous resorption. Cleaning and routine maintenance of the prostheses every 3-6 months is essential.