Correlation between otitis media and craniofacial morphology in adults.

Abstract

We conducted a comparison study to determine if the development of otitis media in adults is correlated with craniofacial morphology. Our study population was made up of 66 adults, aged 18 to 40 years; 32 of these patients had otitis media and 34 did not. All subjects underwent a complete otolaryngologic examination, video-otoscopy, fiberoptic nasal endoscopy, and lateral cephalometry. Statistical analysis of the cephalometric measurements in the otitis media group and the control group revealed significant differences in the angle between the anterior skull base and medial skull base, upper facial height, and anterior facial height. Also, some significant differences were seen between the measurements in the otitis media group and the normal dimensions of the harmonic face as reported in the literature; these differences were seen in the length of the anterior skull base, the angle of cranial deflection, the depth of the maxilla, the angle of the mandibular plane, the angle of facial depth, the angle of the facial cone, and lower facial height. Not all of these significant differences, however, were predictive of the evolution of otitis media. Based on our analysis, we conclude that four cephalometric measurements are predictive of the evolution of otitis media: (1) the length of the anterior skull base, (2) the angle between the anterior skull base and medial skull base, (3) maxillary depth, and (4) upper facial height. No correlations were found between otitis media and nasal blockage or between otitis media and facial type.

Introduction

Facial structure is the product of many variables, including mandibular, maxillary, and orbital configurations. Faces can be round, triangular, or oval. (1) The idea that different facial structures are correlated with different diseases is not new. In The Sixth Book of Epidemics, Hippocrates wrote, "Among those individuals whose heads are long shaped, some have thick necks[,] strong members and bones, others have strongly arched palates; thus teeth are disposed irregularly, crowding one on the other, and they are molested by headaches and otorrhea." (2)

Otitis media is most common during childhood, when tubal dysfunction is more prevalent; its incidence decreases with maturity. (3,4) This decrease has been correlated with the shift in the position of the eustachian tube, which is more vertical in adults. This change occurs as a result of the growth of the craniofacial skeleton. (4,5) As far back as 1862, Politzer suggested that the genesis of otitis media is attributable to poor eustachian tube function. (6)

In 1925, Pautow reported the results of his study of eustachian tube morphology as related to head shape] He found that brachycephalic adults were more likely to have relatively straight tubes. In 1987, Worley et al reached the same conclusion. (8) Moreover, it is well known that children with craniofacial distortions such as cleft palate, Pierre Robin syndrome, Crouzon syndrome, and Down syndrome are prone to middle ear infections. The genesis of these infections can be traced to aberrations in the skull base and its dysmorphic relationship to the eustachian tube. (5)

In the 15th century, Leonardo da Vinci developed a method of measuring the proportions of the human face that involved plotting horizontal and vertical lines. (9) Today, craniofacial measurements are based on cephalometric radiology--specifically, the study of frontally and laterally oriented radiographs. This discipline allows us to study the position of the mandible and maxilla in relation to the position of the basicranium and adjacent structures. (9) Cephalometry is widely used in orthodontic diagnosis and treatment.

Adult otitis media is not uncommon in our practice. In this article, we describe our investigation to determine whether craniofacial morphology and facial type have any effect on the development of otitis media in adults.

Patients and methods

We recruited study subjects from among the patient population at the Department of Otolaryngology at the University of Sao Paulo School of Medicine. Our goal was to identify two suitable groups of patients--one with otitis media and one without. Exclusion criteria included (1) a personal or family history of cleft palate, (2) a personal history of orthodontic treatment or oral, pharyngeal, craniofacial, or nasal surgery, (3) the presence of obstruction of the tympanic ostium of the eustachian tube, and (4) the presence of a cholesteatoma. Ultimately, we enrolled 66 adults, aged 18 to 40 years. Most were white (table 1).

The otitis media group comprised 32 patients--20 men and 12 women (mean age: 26.69 [+ or -] 7.94 yr)--who had chronic bilateral otitis media. Thirteen of these patients reported current or previous nasal blockage diagnosed as one of the following: controlled allergic rhinitis (n = 6), a deviated septum (n = 4), or turbinate hypertrophy (n = 3).

The control group consisted of 34 patients without otitis media--16 men and 18 women (mean age: 27.74 [+ or -] 5.81 yr)--who were being treated for other problems. Fourteen of these subjects reported nasal blockage diagnosed as allergic rhinitis (n = 7), a deviated septum (n = 4), or turbinate hypertrophy (n = 3).

[FIGURE 1 OMITTED]

All subjects provided an otolaryngologic anamnesis and underwent an ENT examination. Otoscopy was performed with a 4-mm Hopkins telescope (Karl Storz; Tuttlingen, Germany) and recorded on videotape. A 3.2-mm flexible video-enabled endoscope (Machida Endoscope Co.; Tokyo) was used to perform the nasal and pharyngeal endoscopic examination, which was also recorded.

Standard lateral cephalograms were obtained for all subjects. Radiographs were taken with each subject's mandibles in centric occlusion and the lips at rest. All radiographs were traced on acetate paper with the aid of a light box. Specific cranial landmarks were identified, and measurements were made of various aspects of the basicranium (figure 1), maxilla (figure 2), and mandible (figure 3), as well as the facial height (figure 4) and the facial axis (figure 5).

Facial type was determined by calculating the VERT index described by Ricketts et al. (10) The VERT index is the arithmetic mean (plus or minus the standard deviation) of the differences between obtained measurements and age-adjusted normal values published in the literature by Ricketts et al (10) and Jarabak and Fizzell (11) (i.e., the harmonic face) divided by 5. These measurements include the angle of the mandibular plane, the angle of the mandibular arch, lower facial height, the angle of facial depth, and the angle of the facial axis.

Mean differences between the otitis media and control groups were assessed by the Student's t test for independent groups; the Student's t test was also used to compare the mean values of the otitis media group with normal values. Correlations between variables were assessed with Pearson's chi-square ([chi square]) test. Based on our measurements and calculations, facial types were designated as either dolichofacial (long face), mesofacial (harmonic), or brachyfacial (short) according to the classification described by Ricketts et al (figure 6). (10)

[FIGURE 2 OMITTED]

Our study protocol was approved by the Ethics in Research Committee of the University of Silo Paulo School of Medicine.

Results

Comparisons of facial measurements between the otitis media group and the controls revealed statistically significant differences in the angle between the anterior skull base and medial skull base, upper facial height, and anterior facial height.

Comparisons of facial measurements in the otitis media group differed significantly from normal measurements reported in the literature with respect to the length of the anterior skull base, the angle of cranial deflection, maxillary depth, the angle of the mandibular plane, the angle of facial depth, the angle of the facial cone, and lower facial height (table 2).

Only four of these significant differences were predictive of the evolution of otitis media. These four measurements were (1) the length of the anterior skull base, (2) the angle between the anterior skull base and medial skull base, (3) maxillary depth, and (4) upper facial height.

No correlation was found between otitis media and nasal blockage ([chi square] = 0.04; p = 0.084).

[FIGURE 4 OMITTED]

More than half the patients in our study had dolichofacial characteristics, which is not unusual in Brazil, (12) but no correlation was found between facial type and otitis media ([chi square] = 9.40; p = 0.094) (table 3).

Discussion

The physical aspect of the ENT examination begins at the face. It is very helpful for an otolaryngologist to have a working knowledge of facial characteristics and craniofacial growth and development. Such knowledge implies a better understanding of the pathophysiology of head and neck diseases.

[FIGURE 5 OMITTED]

Few authors have studied the correlation between craniofacial morphology and otitis media in adults. Because the focus of our study was on otitis media in adults, and given that craniofacial growth is complete at about 17 years of age, (1) we chose to study patients between the ages of 18 and 40 years. It was not our intention to provide sex-specific cephalometric descriptions; measurements were compared irrespective of sex.

We excluded patients with cholesteatoma because the pathophysiology of this disease is not always related to tubal dysfunction. (6)

The cephalometric measurements that we used (basicranial and maxillary measurements) were based on the position of the eustachian tube. Other measurements were used to determine facial types.

The normal values (harmonic face) that we used are based on measurements of white individuals living in the United States. (10,11) Nevertheless, Cerci et al found that there were no differences between those values and values obtained from Brazilian whites. (13)

Basicranial measurements (figure 1). The length of the anterior skull base (N-S) was shorter in the otitis media group than in the control group, but the difference was not statistically significant. (Regarding the abbreviations used for the measurements discussed in this article, a dash [-] represents a line and a period [.] represents an angle.) On the other hand, there was a significant difference in N-S between the otitis media group (again, shorter) and the normal value. This finding strongly suggests a cot relation between otitis media and a shorter anterior skull base, and it corroborates the findings of Mann et al (3) and Kemaloglu et al, (5) who found that the anterior skull base of children with serous otitis media was shorter than that of other children. Our results are also in agreement with those of authors who found a correlation between otitis media and brachycephaly. (8,14)

No significant difference was seen in the length of the medial skull base (S-Ba) in our two groups, and there was no published normal value with which to compare S-Ba. The S-Ba is not related to auditory tube anatomy.

The angle between the anterior skull base and the medial skull base (N-S.Ba) was significantly smaller in the otitis media group than in the control group (no reference value was available). The cartilaginous portion of the eustachian tube is located in the petrosquamous fissure of the temporal bone, which is near the occipital and sphenoid bones. (15) Together, these structures form one of the most important basicranial synchondroses involved in growth and development. (1) Any abnormality in the growth of the petrosquamous fissure can distort the N-S.Ba and lead to aberrations in the cartilaginous portion of the eustachian tube. We conclude that the N-S.Ba is a predictor of the evolution of otitis media. Romero Vidal et al reported that this angle was smaller in patients with abnormal tympanograms. (16)

No significant difference was found between our two groups in terms of the angle of cranial deflection (Ba-N.Po-Or), but the angle in the otitis media group was significantly smaller than the normal Ba-N.Po-Or.

Maxillary measurements (figure 2). No significant difference was found in the length of the palate (ANS-PNS) between the two groups. No reference value for ANS-PNS was found in the literature.

The angle between the palatine and Frankfurt planes (ANS-PNS.Po-Or) was not significantly different in the two groups or different from the normal value. The ANS-PNS.Po-Or correlates with the presence of an anterior open bite and a deep palate, and it has been associated with nasal obstruction during growth. (1) Since we found no correlation between otitis media and nasal obstruction in our study, we did not expect to see any differences in ANS-PNS.Po-Or.

The depth of the maxilla was shorter in the otitis media group than in the control group, but the difference was not statistically significant. However, there was a significant difference between the depth of the maxilla in the otitis media group and the normal value for maxillary depth, and we conclude that this is a factor in the development of otitis media. A shallower maxilla correlates with less downward and forward maxillary movement during craniofacial growth and development.

Mandibular measurements (figure 3). None of the mandibular measurements was significantly different between the two groups. Some significant differences were found, however, between the values in the otitis media group and the reference values; differences were seen in the angle of the mandibular plane, the angle of facial depth, and the angle of the facial cone.

Facial height (figure 4). Upper facial height and anterior facial height were significantly shorter in the otitis media group compared with the controls. This finding was expected because the maxillary depth in the otitis media group was shorter, which indicates arrested development of the maxilla. A shorter vertical dimension of the face may imply poorer eustachian tube function.

Lower facial height in the otitis media group was significantly shorter than the normal height. While this measurement is not relevant to the development of otitis media, it is important in determining facial type.

Facial axis (figure 5). No differences in the angle of the facial axis values were found between the two groups or between the otitis media group and the reference values. The angle of the facial axis represents the direction of craniofacial growth, so this finding suggests that in individuals with otitis media, incomplete growth of the face results in the face maintaining childhood characteristics, including a more horizontal and shorter eustachian tube. (10) It is these eustachian tube anomalies that predispose individuals to otitis media. Maw et al suggested that children with serous otitis media have experienced delayed craniofacial growth. (15)

Nasalobstruction. The lack of correlation between otitis media and nasal obstruction in our study is not surprising. Although it is well known that nasal obstruction and consequent mouth breathing influence craniofacial growth and development, the principal abnormalities affect only the lower part of the face (i.e., enlargement of the lower anterior vertical face, open bite, cross bite, retrognathia, and a larger mandibular angle). (17)

In our study, the primary differences in craniofacial morphology concerned the basicranium and the maxillary complex. Therefore, we can suggest that nasal blockage plays a role in the genesis of tubal dysfunction by contributing to the obstruction of the tympanic ostium. Obstruction of the tympanic ostium is related to conditions such as adenoid hypertrophy and allergies that affect the respiratory mucosa. Nasal obstruction does not appear to be responsible for abnormalities in eustachian tube growth and development.

Type of face. More than half of our study group had a dolichofacial type of face. Atherino studied dry skulls in Brazil and found that dolichofacial features predominated. (12) No correlation was found between facial type and otitis media.

Race. Todd and Bowman studied the prevalence of otitis media in North American Indians and found that they are more prone to otitis media than are North American whites. (18) American Indians are typically brachycephalic.

Blacks have a lower incidence of otitis media than whites. (19) Compared with whites, blacks have a larger angle between the anterior and posterior skull bases (19) and less maxillary depth. (20) Different rates of otitis media among different races have not been found to correlate with environmental or socioeconomic factors. (19)

Anatomic abnormalities. It is well known that otitis media is more common in children with cleft palate. Bishara et al reported that a smaller angle between the anterior and posterior skull bases and a deeper maxilla are correlated with abnormalities in the insertion and course of the eustachian tube and paratubal muscles. (21)

Some of our findings are consistent with characteristics of children with cleft palate. Todd and Bowman found that the rate of cleft uvula, which is a microform of cleft palate, was higher in the Apache Indians they studied than were rates reported for other populations. (18) This might explain the higher incidence of otitis media among the members of that tribe.

In conclusion, tubal dysfunction in childhood can be attributed to the relative position of the eustachian tube and paratubal muscles. (3,4) According to Mann et al (3) and Kemaloglu et al, (5) the development of the eustachian tube is influenced by the way in which the face develops. Our data strongly support the idea that the position of the eustachian tube is associated with craniofacial growth and development. Deviations in this process may affect not only the tendency toward otitis media but also its prognosis.

Acknowledgments

We thank Reinaldo Gianinni, MD, PhD, of the Department of Epidemiology at the University of Sao Paulo School of Medicine for his assistance with the statistical analysis. We are also grateful to Rogrigo Gomes for providing the illustrations.

References

(1.) Enlow DH, Hans MG. Essentials of Facial Growth. Philadelphia: W.B. Saunders: 1996:303.

(2.) Mew JR, Meredith GW. Middle ear effusion: An orthodontic perspective. J Laryngol Otol 1992;106(1):7-13.

(3.) Mann W, Jonas I, Munker G. Growth influence on tubal function. Acta Otolaryngol 1979:87(5-6):451-7.

(4.) Bluestone CD. Klein JO. Otitis media, atelectasis, and eustachian tube dysfunction. In: Bluestone CD, Stool SE, Scheetz MD. eds. Pediatric Otolaryngology. 2nd ed. Philadelphia: W.B. Saunders; 1990:320-486.

(5.) Kemaloglu YK, Goksu N, Koybasioglu A. et al. Prognostic value of craniofacial growth and development in children with secretory otitis media. In: Tos M, Thomsen J, Balle V, eds. Otitis Media Today: Proceedings of the Third Extraordinary Symposium on Recent Advances in Otitis Media: June 1-5, 1997: Copenhagen. The Hague: Kugler Publications: 1999:81-91.

(6.) Bento RF, Marone SA, Miniti A. Tratado de Otologia. Sao Paulo: Editora da Universidade de Silo Paulo: 1998:488.

(7.) Pautow NA. [The various forms of eustachian tube]. Z Hals-NaseOhren 1925:11:467-77.

(8.) Worley G, Frothingham TE, Sturner RA, Green JA. Head shape and middle ear effusion in children. Am J Dis Child 1987;141:375-6.

(9.) Vilella OV. Manual de Cefalometria. Rio de Janeiro: Guanabara Koogan: 1998.

(10.) Ricketts RM, Roth RH, Chaconnas S J, et al. Orthodontic Diagnosis and Planning. Vol. 1. Denver: Rocky Mountain Data Systems; 1982: 53-118.

(11.) Jarabak JR, Fizzell JA. Technique and Treatment with Light-Wire Edgewise Appliances. 2rid ed. St. Louis: Mosby; 1972:1224.

(12.) Atherino CC. Anatomia da parede medial da orbita: Profundidade dos tbrames etmoidais e canal optico e suas relacoes corn as dimensoes cranianas e orbitaria no Brasil [doctoral thesis]. Sao Paulo: Sao Paulo University Medical School: 2000:50.

(13.) Cerci V, Martins JE, Oliveira MA. Cephalometric standards for white Brazilians. Int J Adult Orthodon Orthognath Surg 1993:8(4): 287-92.

(14.) Stolovitzky JP, Todd NW. Head shape and abnormal appearance of tympanic membranes. Ototaryngol Head Neck Surg 1990:102(4): 322-5.

(15.) Maw AR, Smith IM, Lance GN. Lateral cephalometric analysis of children with otitis media with effusion: A comparison with age and sex matched controls. J Laryngol Otol 1991:105(2):71-7.

(16.) Romero Vidal S, Sprekelsen C, Campos Aranda M, Estaca A. [Tubal dysfunction, the angle of the clivus and the base angle: A possible anthropometric relationship]. Acta Otorrinolaringol Esp 1988:39(4):247-9.

(17.) Principato JJ. Upper airway obstruction and craniofacial morphology. Otolaryngol Head Neck Surg 1991 ; 104(6):881-90.

(18.) Todd NW Jr., Bowman CA. Otitis media at Canyon Day, Ariz. A 16-year follow-up inApache Indians.Arch Otolaryngol 1985:111(9): 606-8.

(19.) Griffith TE. Epidemiology of otitis media--an interracial study. Laryngoscope 1979:89(1):22-30.

(20.) Farrow AL, Zarrinnia K, Azizi K. Bimaxillary protrusion in black Americans--an esthetic evaluation and the treatment considerations. Am J Orthod Dentofac Orthop 1993;104(3):240-50.

(21.) Bishara SE, Sierk DL, Huang KS. A longitudinal cephalometric study on unilateral cleft lip and palate subjects. Cleft Palate J 1979: 16(1):59-71.

Renata C. Di Francesco, MD, PhD; Perboyre Lacerda Sampaio, MD, PhD; Ricardo Ferreira Bento, MD, PhD

From the Department of Otolaryngology. University of Silo Paulo School of Medicine. Silo Paulo. Brazil.

Reprint requests: Renata C. Di Francesco, MD, Rua Guarara 529 cj. 121, Cep. 01425-001, Sao Paulo, Brazil. Phone: [phone]: fax: [phone]: e-mail: [e-mail]

The information in this article was originally presented at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery: Sept. 11. 2001: Denver.

Table 1. Racial distribution in the two groups

          OM * group    Controls
Race       (n = 32)     (n = 34)    Total

White         24           28        52
Black         6            4         10
Mulatto       2            2          4

* OM = Otitis media.

Table 2. Cephalometric measurements (in mm or [degrees] as
appropriate)

Measurement *          OM * group              Controls

Basicranium
  N-S             72.75 [+ or -] 3.18     74.35 [+ or -] 5.19
  S-Ba            46.25 [+ or -] 3.56     47.68 [+ or -] 4.73
  N-S.Ba          122.22 [+ or -] 4.95   125.71 [+ or -] 5.99
  Ba-N.Po-Or      23.34 [+ or -] 4.45     22.06 [+ or -] 3.89

Maxilla
  ANS-PNS         54.68 [+ or -] 5.47     55.26 [+ or -] 7.26
  ANS-PNS.Po-Or    2.34 [+ or -] 4.53     3.15 [+ or -] 4.74
  MD              84.47 [+ or -] 4.43     86.09 [+ or -] 5.36

Mandible
  Go-Me           76.03 [+ or -] 14.49    77.23 [+ or -] 6.48
  N-S.Go-Me       35.03 [+ or -] 6.18     36.12 [+ or -] 8.63
  MP              33.09 [+ or -] 6.38     33.18 [+ or -] 7.29
  MA              31.87 [+ or -] 8.24     30.91 [+ or -] 6.06
  FD              84.62 [+ or -] 4.12     84.15 [+ or -] 4.78
  FC              33.28 [+ or -] 6.87     33.91 [+ or -] 7.47

Facial height
  N-ANS           50.09 [+ or -] 4.73     52.65 [+ or -] 4.96
  LFH             43.59 [+ or -] 6.28     45.23 [+ or -] 6.07
  N-Me            124.30 [+ or -] 8.13   130.53 [+ or -] 14.07

Facial axis
  FA              91.19 [+ or -] 4.58     89.32 [+ or -] 6.18

                                                        OM vs. control
Measurement *                   Normal                    t

Basicranium
  N-S                75.5 [+ or -] 3.0 ([dagger])       1.50
  S-Ba                                                  1.38
  N-S.Ba                                                2.57
  Ba-N.Po-Or      27.0 [+ or -] 3.0 ([double dagger])   1.24

Maxilla
  ANS-PNS                                               0.36
  ANS-PNS.Po-Or   1.0 [+ or -] 3.5 ([double dagger])    0.71
  MD              90.0 [+ or -] 3.0 ([double dagger])   1.33

Mandible
  Go-Me                                                 0.44
  N-S.Go-Me                                             0.58
  MP              26.0 [+ or -] 3.0 ([double dagger])   0.05
  MA              30.0 [+ or -] 4.0 ([double dagger])   0.53
  FD              89.5 [+ or -] 3.0 ([double dagger])   0.42
  FC              23.0 [+ or -] 4.0 ([double dagger])   0.36

Facial height
  N-ANS                                                 2.14
  LFH             47.0 [+ or -] 4.0 ([double dagger])   1.08
  N-Me                                                  2.18

Facial axis
  FA              90.0 [+ or -] 3.0 ([double dagger])   1.39

                  OM vs.   OM vs. normal
                 control

Measurement *       p       t       p

Basicranium
  N-S             >0.05   4.89    <0.05
  S-Ba            >0.05
  N-S.Ba          <0.05
  Ba-N.Po-Or      >0.05   4.65    <0.05

Maxilla
  ANS-PNS         >0.05
  ANS-PNS.Po-Or   >0.05   1.67    >0.05
  MD              >0.05   7.06    <0.05

Mandible
  Go-Me           >0.05
  N-S.Go-Me       >0.05
  MP              >0.05   6.29    <0.05
  MA              >0.05   0.84    >0.05
  FD              >0.05   6.70    <0.05
  FC              >0.05   8.46    <0.05

Facial height
  N-ANS           <0.05
  LFH             >0.05   3.07    <0.05
  N-Me            <0.05

Facial axis
  FA              >0.05   1.47    >0.05

* OM = Otitis media. See figures 1 through 5 for an explanation
of the measurement abbreviations.

([dagger]) Normal value according to Jarabak and Fizzell. (11)

[(double dagger]) Normal values according to Ricketts et al (10)

Table 3. The distribution of facial types in the two groups *

                         OM group   Controls
Facial type             (n = 32)   (n = 34)   Total

Dolichofacial, severe      10         16       26

Dolichofacial, mild        4          5         9

Mesofacial                 12         4        16

Brachyfacial               2          5         7

Brachyfacial, severe       4          4         8

* No correlation was found between facial type and otitis media
([chi square] = 9.40; p = 0.094).

Figure 6. Scale depicts the spectrum of facial types according to
the VERT index de-scribed by Ricketts et al. (10)

Facial types

         Dolichofacial             Mesofacial            Brachyfacial

Severe                     Mild                               Severe
  -2.0       -1.0           -0.5       0         +0.5            1.0